Articoli di riviste: "T cells Identification"

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Aerts, Nicolaas E., Evelyne J. Dombrecht, Didier G. Ebo, Chris H. Bridts, Wim J. Stevens e Luc S. De Clerck. "Activated T cells complicate the identification of regulatory T cells in rheumatoid arthritis". Cellular Immunology 251, n. 2 (2008): 109–15. http://dx.doi.org/10.1016/j.cellimm.2008.04.008.

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Graca, Luis, Stephen P. Cobbold e Herman Waldmann. "Identification of Regulatory T Cells in Tolerated Allografts". Journal of Experimental Medicine 195, n. 12 (10 giugno 2002): 1641–46. http://dx.doi.org/10.1084/jem.20012097.

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Induction of transplantation tolerance with certain therapeutic nondepleting monoclonal antibodies can lead to a robust state of peripheral “dominant” tolerance. Regulatory CD4+ T cells, which mediate this form of “dominant” tolerance, can be isolated from spleens of tolerant animals. To determine whether there were any extra-lymphoid sites that might harbor regulatory T cells we sought their presence in tolerated skin allografts and in normal skin. When tolerated skin grafts are retransplanted onto T cell–depleted hosts, graft-infiltrating T cells exit the graft and recolonize the new host. These colonizing T cells can be shown to contain members with regulatory function, as they can prevent nontolerant lymphocytes from rejecting fresh skin allografts, without hindrance of rejection of third party skin. Our results suggest that T cell suppression of graft rejection is an active process that operates beyond secondary lymphoid tissue, and involves the persistent presence of regulatory T cells at the site of the tolerated transplant.

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Souter, M. N., C. V. Nguyen-Robertson, F. J. Ross, S. J. J. Reddiex, J. Waddington, I. Van Rhijn, S. B. G. Eckle et al. "Identification and characterization of CD1-restricted T cells". Journal of Immunology 196, n. 1_Supplement (1 maggio 2016): 206.6. http://dx.doi.org/10.4049/jimmunol.196.supp.206.6.

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Abstract Most studies of T cells have focused on those that respond to foreign peptides. However, other specialized populations of T cells exist that recognize lipid antigens and make up a substantial component of the human immune system. These lipid reactive T cells recognize antigens presented by antigen presentation molecules from the CD1 family. Four CD1 molecules exist (CD1a, CD1b, CD1c and CD1d), and each is capable of presenting a unique repertoire of lipids antigens to T cells. Much of what we have learned about lipid reactive T cells stems from studies of CD1d restricted NKT cells as these are present is both mice and humans and can be detected using CD1d/α-GalCer tetramers. In contrast, our understanding of the biology of CD1a, CD1b, CD1c restricted T cells is relatively limited. However, the recent generation of CD1a, CD1b and CD1c tetramers is helping with the identification and characterisation of these CD1-restricted T cells. We have produced CD1 tetramers loaded with mammalian self-lipids or lipid antigens from Mycobacterium tuberculosis. In conjunction, with a tetramer-based enrichment method, we have successfully identified both autoreactive and microbial lipid antigen specific T cells from healthy human blood. We reveal the phenotypic characteristics of these CD1-restricted T cells and used CD1 mutagenesis to provide new insight into TCR recognition of CD1-lipid antigen complexes. Collectively, these studies will serve as a basis for future studies of lipid reactive T cells in health and disease.

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Illes, Z., T. Kondo, K. Yokoyama, T. Ohashi, T. Tabira e T. Yamamura. "Identification of autoimmune T-cells among in vivo expanded CD25+ T-cells in multiple sclerosis". Journal of Neuroimmunology 90, n. 1 (settembre 1998): 73. http://dx.doi.org/10.1016/s0165-5728(98)91617-4.

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Illés, Zsolt, Takayuki Kondo, Kazumasa Yokoyama, Takashi Ohashi, Takeshi Tabira e Takashi Yamamura. "Identification of Autoimmune T Cells Among In Vivo Expanded CD25+ T Cells in Multiple Sclerosis". Journal of Immunology 162, n. 3 (1 febbraio 1999): 1811–17. http://dx.doi.org/10.4049/jimmunol.162.3.1811.

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Abstract Although clonal expansion of autoimmune T cells has been reported in multiple sclerosis (MS), very limited information is available on specificities, clonal size, or activation state of the expanded clones. Here we address the issue of clonal expansion by using a novel technique demonstrating clonotypes defined by single-strand conformation polymorphism of TCR β-chain cDNAs. Examination of activated T cells (CD3+CD25+) isolated from the peripheral blood of MS revealed limited numbers (20∼82) of expanded clones defined by single-strand conformation polymorphism clonotype. To estimate the Ag specificities of dominant clonotypes in the activated T cells, these samples were examined in parallel with Th1 T cell clones specific for myelin basic protein or proteolipid protein (PLP) derived from the same patients. Analysis of two patients demonstrated that the dominant clonotypes would contain those specific for myelin basic protein or PLP. Although the majority of the clonotypes could be detected only transiently, a PLP95–116-specific clonotype was found to persist for over 1 yr. Thus, single-strand conformation polymorphism clonotype analysis allows us to monitor the kinetics of given T cell clones in vivo and could provide useful information for designing clonotype (Id)-specific manipulation of human diseases such as MS.

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Baseggio, L., F. Berger, D. Morel, M.-h. Delfau-Larue, G. Goedert, G. Salles, J.-p. Magaud e P. Felman. "Identification of circulating CD10 positive T cells in angioimmunoblastic T-cell lymphoma". Leukemia 20, n. 2 (8 dicembre 2005): 296–303. http://dx.doi.org/10.1038/sj.leu.2404013.

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Azimi, Maryam, Saeed Aslani, Sahar Mortezagholi, Amir Salek, Mohammad Reza Javan, Alireza Rezaiemanesh, Mojgan Ghaedi, Mehrdad Gholamzad e Eisa Salehi. "Identification, Isolation, and Functional Assay of Regulatory T Cells". Immunological Investigations 45, n. 7 (15 luglio 2016): 584–602. http://dx.doi.org/10.1080/08820139.2016.1193869.

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Kobayashi, Hiroya, e Esteban Celis. "Peptide epitope identification for tumor-reactive CD4 T cells". Current Opinion in Immunology 20, n. 2 (aprile 2008): 221–27. http://dx.doi.org/10.1016/j.coi.2008.04.011.

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Gerli, Roberto, Giuseppe Nocentini, Alessia Alunno, Elena Bartoloni Bocci, Rodolfo Bianchini, Onelia Bistoni e Carlo Riccardi. "Identification of regulatory T cells in systemic lupus erythematosus". Autoimmunity Reviews 8, n. 5 (marzo 2009): 426–30. http://dx.doi.org/10.1016/j.autrev.2009.01.004.

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Cardarelli, P. M., e M. D. Pierschbacher. "Identification of fibronectin receptors on T lymphocytes." Journal of Cell Biology 105, n. 1 (1 luglio 1987): 499–506. http://dx.doi.org/10.1083/jcb.105.1.499.

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We report the identification of fibronectin receptors on thymocytes and T lymphoma cells. Affinity chromatography of extracts of the T cell lymphoma, WR16.1, on a fibronectin-Sepharose column combined with specific elution using a synthetic peptide containing the cell attachment-promoting sequence, arginine-glycine-aspartic acid, yielded two polypeptide components having apparent molecular masses of approximately 160 kD reduced and 175 and 150 kD nonreduced. Immunoprecipitations from surface-iodinated WR16.1 cells or fibronectin-adherent thymocytes using a rabbit antiserum raised against the fibronectin receptor that is present on human fibroblasts revealed, in each case, the same two radiolabeled components. In contrast, immunoprecipitation from fibronectin-nonadherent T lymphoma cells, designated WR2.3, revealed the presence of only the smaller subunit. Although the lymphocyte receptor and the fibronectin receptor identified on fibroblasts share immunologic determinants, they differ in that the molecular mass of the lymphocyte protein is larger. Moreover, trypsinization of either thymocytes or the WR16.1 T lymphoma cells resulted in a subsequent loss of their ability to adhere to fibronectin-coated substrates and a reduction in the electrophoretic mobility of each of the polypeptide chains of the fibronectin receptor present on their surfaces. These changes, however, were not observed with normal rat kidney fibroblasts or mouse 3T3 fibroblasts in response to trypsinization. The data establish the existence on normal lymphocytes of fibronectin receptors that are quite similar to those found on fibroblasts. The possible function of this molecule on thymocytes is discussed.

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Kasheta, Melissa, Corrie A. Painter, Finola E. Moore, Riadh Lobbardi, Alysia Bryll, Eli Freiman, David Stachura et al. "Identification and characterization of T reg–like cells in zebrafish". Journal of Experimental Medicine 214, n. 12 (24 ottobre 2017): 3519–30. http://dx.doi.org/10.1084/jem.20162084.

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Regulatory T (T reg) cells are a specialized sublineage of T lymphocytes that suppress autoreactive T cells. Functional studies of T reg cells in vitro have defined multiple suppression mechanisms, and studies of T reg–deficient humans and mice have made clear the important role that these cells play in preventing autoimmunity. However, many questions remain about how T reg cells act in vivo. Specifically, it is not clear which suppression mechanisms are most important, where T reg cells act, and how they get there. To begin to address these issues, we sought to identify T reg cells in zebrafish, a model system that provides unparalleled advantages in live-cell imaging and high-throughput genetic analyses. Using a FOXP3 orthologue as a marker, we identified CD4-enriched, mature T lymphocytes with properties of T reg cells. Zebrafish mutant for foxp3a displayed excess T lymphocytes, splenomegaly, and a profound inflammatory phenotype that was suppressed by genetic ablation of lymphocytes. This study identifies T reg–like cells in zebrafish, providing both a model to study the normal functions of these cells in vivo and mutants to explore the consequences of their loss.

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Tretter, Theresa, Ram KC Venigalla, Volker Eckstein e Hanns-Martin Lorenz. "Identification of human B cells with immunoregulatory properties (92.12)". Journal of Immunology 178, n. 1_Supplement (1 aprile 2007): S165. http://dx.doi.org/10.4049/jimmunol.178.supp.92.12.

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Abstract Regulation of immune responses and tolerance is mediated by a variety of mechanisms and cells. So far the role of B cells in this process is not well known, yet. Methods: Highly purified CD19+B and CD4+T cells were separated from human PBMC by MACS. B cells were prestimulated with SAC, αIgM/IgG or αCD40, washed and set up in cocultures with freshly isolated autologous CD4+T cells under addition of αCD3+IL-2 or αCD28. CD4+ T cell proliferation was determined after 3–6d by 3H Thymidine incorporation and PKH-26; apoptosis by AnnexinV. Results: under optimal stimulatory conditions T cell proliferation was inhibited more than 50% in presence of SAC-activated B cells and to a lesser extent by αIgM/IgG stimulated B cells. Enrichment of SAC-activated large CD25+ B cells by FACSsorting enhanced suppression further up to 68%, while the small CD25− population had no significant effect. Separation of B and T cells by cell culture inserts abolished inhibition, suggesting a requirement for direct cell-contact. In addition to growth inhibition, T cell specific cytokine production (IFNγ, IL-10) was downregulated, and a significant proportion of T cells (37% vs 17%) went into apoptosis. Conclusions: B cells are able to inhibit T cell mediated responses depending on their mode of activation. Further experiments are dealing with the mechanisms of B cell mediated suppression and their pathophysiological impact also in autoimmune diseases.

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Schwarz, Benjamin A., e Avinash Bhandoola. "Identification of Thymus Settling Progenitors." Blood 104, n. 11 (16 novembre 2004): 2677. http://dx.doi.org/10.1182/blood.v104.11.2677.2677.

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Abstract T cells develop in the thymus, but are ultimately derived from hematopoietic stem cells (HSCs) that reside in the bone marrow. In order to produce T cells throughout adult life, the thymus must be periodically seeded by bone marrow progenitors via the blood. The identity of progenitors that seed the adult thymus is unknown. To determine which bone marrow progenitors that have access to they thymus, we analyzed the blood of adult mice (Schwarz & Bhandoola, Nature Immunology 2004). We found that the only progenitors in blood with T lineage potential were lineage negative cells with high expression of Sca-1 and c-Kit (LSK). Such LSK cells in blood were potent T lineage progenitors, with the capacity to expand over a million fold in the thymus. Like the corresponding population in the bone marrow, the blood LSK population was heterogeneous, containing HSCs and downstream multipotent progenitors (MPPs) including RAG-expressing early lymphoid progenitors (ELPs) and CD62L+ cells. In order to determine which of these LSK subsets can settle in the thymus, we developed a quantitative assay for thymic seeding in normal adult mice. We find that the fraction of LSK cells that settle in the thymus from the blood is extremely small. Of the estimated 3,000 to 4,000 LSK cells that pass through the thymic circulation each day, less than 10 cells are able to settle in the thymus. Our data suggest that any decrease in thymic seeding, as may occur in aging, would lead to a decrease in total thymic output.

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Greaves, Sarah A., Michael Falta, Radleigh Santos, Clemencia Pinilla, Johan Grunewald e Andrew Fontenot. "Identification of T cell epitopes in sarcoidosis". Journal of Immunology 204, n. 1_Supplement (1 maggio 2020): 224.26. http://dx.doi.org/10.4049/jimmunol.204.supp.224.26.

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Abstract Sarcoidosis is an inflammatory granulomatous disease that primarily affects the lung. It has a worldwide distribution and affects individuals of all ages. Despite the prevalence of the disease, the cause of sarcoidosis remains unknown. Evidence suggests that CD4+ T cells in the bronchoalveolar lavage (BAL) of sarcoidosis patients are instrumental in disease progression. Löfgren’s syndrome (LS) is an acute form of sarcoidosis with a specific set of inflammatory symptoms. In patients with LS, disease susceptibility has been associated with expression of HLA-DR3 and an expansion of BAL CD4+ T cells expressing T cell receptor (TCR) α-chain variable region (TRAV) 12-1 and TCR β-chain variable region (TRBV) 2. These oligoclonal T cell populations accumulate within the lung and disappear with disease resolution. We hypothesize that in these HLA-DR3+ LS patients, TRAV12-1/TRBV2 CD4+ T cell clones accumulate and expand in the lung in response to unknown etiologic antigens. We have identified a set of expanded and related TRAV12-1/TRBV2 αβTCRs derived from the BAL CD4+ T cells of DR3+ LS patients. We screened T cell hybridomas expressing these disease-relevant TCRs with decapeptide positional scanning libraries and identified stimulatory mimotopes for this set of TCRs. We identified several naturally occurring peptides derived from relevant fungal and bacterial species that stimulate the LS TCRs. Validation of these peptides as pathogenic T cell epitopes in LS is currently underway. Peptides that stimulate LS-associated TCRs have not been discovered until now, making this a major novel achievement in the field. Identification of an etiologic antigen in LS will narrow our search of the stimuli driving sarcoidosis in the US.

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Garcia-Guerrero, Estefania, Luis I. Sanchez-Abarca, Esther Domingo, Teresa Ramos, Jose Antonio Bejarano-García, Jose A. Gonzalez-Campos, Teresa Caballero-Velázquez e José A. Pérez-Simón. "Identification and Isolation of Tumor-Specific Cytotoxic T Lymphocytes in Acute Myeloid Leukemia Patients through the Identification of T-Cells Capable to Establish Stable Interactions with Leukemic Cells". Blood 132, Supplement 1 (29 novembre 2018): 3336. http://dx.doi.org/10.1182/blood-2018-99-118118.

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Abstract Introduction Autologous adoptive T cell therapies, based on the use of tumor infiltrating lymphocytes (TILs), have made great progress in recent years for the treatment of solid tumors, especially melanoma. However, further work is needed to isolate tumor-reactive T cells among patients diagnosed with hematologic malignancies. The dynamics of the interaction between T cells and antigen presenting cells (APC) dictate the quality of the immune responses. While stable joints between target cells and T lymphocytes lead to the induction of T cell activation and immune response, brief contacts contribute to the induction of immune-tolerance. Taking advantage of the strong interaction between target cell and activated T-cells, we show the feasibility to identify and isolate tumor-specific cytotoxic T lymphocytes (CTLs) from acute myeloid leukemia (AML) patients. Using this approach, CTLs stably bound through T cell receptor to tumor cells (doublet forming T-cells) can be identified in peripheral blood and bone marrow and subsequently selected and isolated by FACS-based cell sorting. Methods Co-cultures between PBMC from AML patients in complete remission and AML tumor cells (PKH-stained) from the same patient were performed to study the percentage of doublet-forming T cells (CD3+PKH+) (T cell bound to a tumor cell). After 15 hours of co-culture, cells were stained and sorted. Secondary co-cultures with autologous tumor cells (used in primary co-culture) were performed to study the cytotoxic activity and cytokine production of T-cells capable or not to form stable joints with the leukemic cells (doublet population vs non-doublet population). Results Doublet-forming T cells from AML patients were identified in a range of 2% to 6% (mean=3.83%, n=5). Immunophenotyping analysis showed differences between doublet-forming T cells (CD3+PKH+) and those T cells which did not form stable and strong interactions with target cells (CD3+PKH-). Doublet T cells displayed a higher percentage of CD8+ T cells and higher percentage of effector CD4+ and CD8+ T cells compared to non-doublet T cells. Next, we explored, among effector CD4+ and CD8+ cells, those with cytotoxic phenotype. As expected, a high percentage of effector CD8+ doublet T cells showed Granzyme B and perforin expression, thus corresponding with a cytotoxic immune-phenotype (n=3, mean 65.51%). Within effector CD4+ doublet T cells, a mean of 9.053 % showed expression of both Granzyme B and perforin corresponding with CD4+ CTL (n=3). Regarding CD57 and CD16 markers, a mean of 18.62% of effector CD4+ doublet T cells were positive for both markers, compared to 65.84% of effector CD8+ doublet T cells (n=3). Further, we performed secondary co-cultures to analyze the CD69 activation marker after 24h of co-culture. A high percentage of CD69+ cells was observed in co-cultures with doublet-forming T cells against target cells as compared to non-doublet T cells (n=3, p=0.0053). Finally, analysis of supernatants of co-culture of doublet T cells and non-doublet T cells with target cells revealed specific secretion of IFNγ and IL-2 (n=3, p=0.0001; p=0.0005, respectively). The cytolytic activity was evaluated comparing the viability of tumor cells cultured alone or with doublet-forming T cells or non-doublet T cells from the same patient. A significant increase of the specific lysis of AML cells was observed when doublet T cells were co-cultured as compared to non-doublet T cells (p=0.0424, n=5). This encouraged us to examine whether we were able to identify doublet-forming T cells from bone marrow of AML patients at diagnosis. Analyses of bone marrow by flow cytometry reveled a small percentage of CD3+CD34+ population corresponding with bone marrow-doublet-forming T cells (n=3, mean=2.9%). Interestingly, bone marrow-doublet-forming T cells show a higher percentage of CD4+ T cells, whereas bone marrow-non-doublet T cells show a higher percentage of CD8+ T cells. Conclusions Our data demonstrate that when T cells from AML patients are co-cultured with tumor cells, a "doublet T cell" population appears. This population consists of T cells capable to bind tumor cells. These CTLs display higher percentage of effector cells and a marked cytotoxic activity against AML blasts. In conclusion, we have developed a new procedure to identify and select specific cytotoxic T cells in both bone marrow and peripheral blood from patients diagnosed with acute myeloid leukemia. Figure. Figure. Disclosures Sanchez-Abarca: Virgen del Rocio University Hospital: Patents & Royalties. Ramos:Takeda Oncology: Research Funding.

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LESESVE. "CAR-T cells microscopic and phenotypic identification in the peripheral blood". Mediterranean Journal of Hematology and Infectious Diseases 14, n. 1 (27 febbraio 2022): e2022024. http://dx.doi.org/10.4084/mjhid.2022.024.

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CAR-T cells are a new possibility for care poor prognostic conditions. CAR-T cells injection lead to T chimeric cells circulation into the blood. Here is reported the cytomorphologic and immunophenotypic features of CAR-T cells in the peripheral blood.

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Pietschmann, P., J. J. Cush, P. E. Lipsky e N. Oppenheimer-Marks. "Identification of subsets of human T cells capable of enhanced transendothelial migration." Journal of Immunology 149, n. 4 (15 agosto 1992): 1170–78. http://dx.doi.org/10.4049/jimmunol.149.4.1170.

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Abstract A critical step in immunologically mediated inflammation is the migration of T cells between endothelial cells of postcapillary venules and into the tissues. To determine whether specific cells are capable of transendothelial migration, T cells that had migrated through endothelial monolayers were retrieved and analyzed. To accomplish this, human umbilical vein endothelial cells (EC) were cultured to confluence on collagen gels and incubated with human T cells. T cells that were nonadherent to the EC, those that bound to the endothelium, and cells that had migrated through the endothelial monolayer and into the collagen were individually harvested and characterized. After a 4-h incubation with EC, T cells distributed themselves such that 77 +/- 2% were nonadherent, 13 +/- 2% were bound to EC, and 10 +/- 1% had migrated into the collagen. The CD4+ T cells that had migrated into the collagen were predominantly CD29bright/CD45RObright and CD45RA-. CD8+ T cells demonstrated a greater transendothelial migratory capacity than the CD4+ T cells. The migrated CD8+ T cells were mainly CD29bright but CD45RA+. Additional phenotypic analysis of the migrating cells indicated that they contained fewer cells that expressed L-selectin. Moreover the surface expression of CD7 was less dense in the T cells that had migrated than in the nonadherent T cells. Finally the T cells that migrated were not enriched for CD45RBdim T cells. Prolonging the incubation with EC to 36 h increased the number of T cells that migrated but did not alter the predominance of CD29bright T cells in the migrated population. Stimulation of EC with IL-1 or IFN-gamma also increased the number of adherent and migrating T cells, respectively, but did not alter the phenotype of the migrating cells. These results indicate that the capacity for transendothelial migration is an intrinsic ability of certain subpopulations of T cells and is related to their stage of differentiation as identified by their surface phenotype.

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Kabelitz, D., e P. Conradt. "Identification of CD2-/CD3+ T cells in fetal human tissue." Journal of Experimental Medicine 168, n. 5 (1 novembre 1988): 1941–46. http://dx.doi.org/10.1084/jem.168.5.1941.

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From 1 to 23% of fetal human spleen or thymus cells (from the 20th to 24th week of gestation) were found to display a previously unrecognized CD2-/CD3+ phenotype. IL-2-dependent, long-term clones of CD2-/3+ T cells did not react with a panel of anti-CD2 mAbs and did not form rosettes with sheep erythrocytes. These results show that (a) significant numbers of CD2-/3+ T cells are present in fetal human spleen and/or thymus; and (b) in contrast to the widely accepted view, expression of CD2 is not a prerequisite for the expression of the CD3 molecular complex on human T cells.

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Nelson, Michelle H., Hannah M. Knochelmann, Stefanie R. Bailey, Logan W. Huff, Jacob S. Bowers, Kinga Majchrzak-Kuligowska, Megan M. Wyatt et al. "Identification of human CD4+ T cell populations with distinct antitumor activity". Science Advances 6, n. 27 (luglio 2020): eaba7443. http://dx.doi.org/10.1126/sciadv.aba7443.

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How naturally arising human CD4+ T helper subsets affect cancer immunotherapy is unclear. We reported that human CD4+CD26high T cells elicit potent immunity against solid tumors. As CD26high T cells are often categorized as TH17 cells for their IL-17 production and high CD26 expression, we posited these populations would have similar molecular properties. Here, we reveal that CD26high T cells are epigenetically and transcriptionally distinct from TH17 cells. Of clinical importance, CD26high and TH17 cells engineered with a chimeric antigen receptor (CAR) regressed large human tumors to a greater extent than enriched TH1 or TH2 cells. Only human CD26high T cells mediated curative responses, even when redirected with a suboptimal CAR and without aid by CD8+ CAR T cells. CD26high T cells cosecreted effector cytokines, produced cytotoxic molecules, and persisted long term. Collectively, our work underscores the promise of CD4+ T cell populations to improve durability of solid tumor therapies.

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Mustafa, Abu Salim, e Fredrik Oftung. "Identification of Mycobacterial Recombinant Antigens Recognized by Human T Cells". Medical Principles and Practice 6, n. 2 (1997): 57–65. http://dx.doi.org/10.1159/000157428.

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Allison, James P., e Lewis L. Lanier. "Identification of antigen receptor-associated structures on murine T cells". Nature 314, n. 6006 (marzo 1985): 107–9. http://dx.doi.org/10.1038/314107a0.

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Rodrigues, Olivia Roos, Cláudia Marques, Marta Soares-Clemente, Maria Helena Ferronha e Gabriela Maria Santos-Gomes. "Identification of regulatory T cells during experimental Leishmania infantum infection". Immunobiology 214, n. 2 (febbraio 2009): 101–11. http://dx.doi.org/10.1016/j.imbio.2008.07.001.

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Goh, Shan, Daniel Ngugi, Regina Lizundia, Isabel Hostettler, Kerry Woods, Keith Ballingall, Niall D. MacHugh et al. "Identification of Theileria lestoquardi Antigens Recognized by CD8+ T Cells". PLOS ONE 11, n. 9 (9 settembre 2016): e0162571. http://dx.doi.org/10.1371/journal.pone.0162571.

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Zimring, James C., e Judith A. Kapp. "Identification and Characterization of CD8⁺ Suppressor T Cells". Immunologic Research 29, n. 1-3 (2004): 303–12. http://dx.doi.org/10.1385/ir:29:1-3:303.

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GEISLER, C., J. K. LARSEN e T. PLESNER. "Identification of alphabeta and gammadelta T Cell Receptor-Positive Cells". Scandinavian Journal of Immunology 28, n. 6 (dicembre 1988): 741–45. http://dx.doi.org/10.1111/j.1365-3083.1988.tb01508.x.

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MILLER, G. G., e W. J. STRITTMATTER. "Identification of Human T Cells that Require Zinc for Growth". Scandinavian Journal of Immunology 36, n. 2 (agosto 1992): 269–77. http://dx.doi.org/10.1111/j.1365-3083.1992.tb03099.x.

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Auberson, Yves P., Emmanuelle Briard, Bettina Rudolph, Klemens Kaupmann, Paul Smith e Berndt Oberhauser. "PET Imaging of T Cells: Target Identification and Feasibility Assessment". ChemMedChem 13, n. 15 (2 luglio 2018): 1566–79. http://dx.doi.org/10.1002/cmdc.201800241.

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Buchwalow, Igor, Dmitri Atiakshin, Vera Samoilova, Werner Boecker e Markus Tiemann. "Identification of autofluorescent cells in human angioimmunoblastic T-cell lymphoma". Histochemistry and Cell Biology 149, n. 2 (2 dicembre 2017): 169–77. http://dx.doi.org/10.1007/s00418-017-1624-y.

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Michalek, Jaroslav, Darina Ocadlikova, Lenka Zahradova, Lucie Kovarova, Miroslav Penka e Roman Hajek. "Identification and Expansion of Myeloma-Specific Cytotoxic T Cells In Vitro." Blood 106, n. 11 (16 novembre 2005): 5138. http://dx.doi.org/10.1182/blood.v106.11.5138.5138.

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Abstract Multiple myeloma (MM) has been considered as low immunogenic incurable disease. The attempts has been made to invert the immune status to recognize myeloma cells by T cells or other cells of the immune system. Here we studied biology of myeloma-specific T cells in vitro. Irradiated myeloma cell line ARH 77 has been used as tumor antigen to stimulate peripheral blood mononuclear cells (PBMC) of 8 healthy volunteers. Dendritic Cells loaded by irradiated autologous MM cells has been used to stimulate PBMC of 10 MM patients. Activated responder T cells have been immunomagnetically separated based on surface expression of interferon gamma (Miltenyi Biotech) and expanded in 5 cases by phytohemaglutinin and repeated high-doses of interleukin 2. Cytotoxicity against the original myeloma cells has been tested after the expansion using propidium iodide or 7-amino actinomycin D. Responder T cells were labeled by CFSE to distinguish them from myeloma cells. Third-party PBMC and interferon gamma negative fraction of T cells served as controls. The percentage of interferon gamma positive cells in healthy donors has been enriched from 2.8±0.9 and 2.6±0.8 to 48.6±23.4 and 73.2±25.9 of CD3+CD4+ and CD3+CD8+ T cells, respectively, by immunomagnetic separation. Interferon gamma positive T cells have been further expanded in vitro from 0.54x106 ± 0.05x106 to 214.00x106 ± 103.46x106 within 4 weeks. A specific cytotoxicity has been tested after expansion. The killing of myeloma cells by expanded IFN g+ T cells reached 68.1±14.2%, while interferon gamma negative fraction killed only 0.8±0.3% of myeloma cells. As another control, killing of third-party PBMC by expanded interferon gamma positive T cells was 6.9±2.5%. Similar observations were made in MM patients and will be presented at the meeting. These data demonstrate a specific cytotoxic effect of expanded interferon gamma positive T cells against myeloma cell line ARH 77 and open the possibility for clinical use of tumor-specific T cells in MM.

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30

Zhu, Yuwen, Alessandro Paniccia, Alexander C. Schulick, Wei Chen, Michelle R. Koenig, Joshua T. Byers, Sheng Yao, Shaun Bevers e Barish H. Edil. "Identification of CD112R as a novel checkpoint for human T cells". Journal of Experimental Medicine 213, n. 2 (11 gennaio 2016): 167–76. http://dx.doi.org/10.1084/jem.20150785.

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Abstract (sommario):

T cell immunoglobulin and ITIM domain (TIGIT) and CD226 emerge as a novel T cell cosignaling pathway in which CD226 and TIGIT serve as costimulatory and coinhibitory receptors, respectively, for the ligands CD155 and CD112. In this study, we describe CD112R, a member of poliovirus receptor–like proteins, as a new coinhibitory receptor for human T cells. CD112R is preferentially expressed on T cells and inhibits T cell receptor–mediated signals. We further identify that CD112, widely expressed on antigen-presenting cells and tumor cells, is the ligand for CD112R with high affinity. CD112R competes with CD226 to bind to CD112. Disrupting the CD112R–CD112 interaction enhances human T cell response. Our experiments identify CD112R as a novel checkpoint for human T cells via interaction with CD112.

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31

Surh, Charles D. "Homeostasis of Mature T Cells." Blood 112, n. 11 (16 novembre 2008): sci—24—sci—24. http://dx.doi.org/10.1182/blood.v112.11.sci-24.sci-24.

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Abstract (sommario):

Abstract The overall size and composition of the mature T cell pool is regulated by homeostatic mechanisms. A hallmark of homeostatic regulation is the ability of the T cells to undergo spontaneous “homeostatic” proliferation in response to severe lymphopenia. By defining the factors that drive such homeostatic proliferation, we have determined that homeostasis of naïve and memory T cells is controlled by signals from contact with self-MHC/peptide ligands and/or two cytokines, namely IL-7 and IL-15. In addition, we have recently described a simple and highly effective way to administer IL-2, IL-7, IL-15, and other cytokines to strongly expand selective populations of T cell under normal physiological conditions. This new approach overcomes the current limitations that prevent therapeutic use of these essential T cell regulators in their native form. Identification of these homeostatic factors has already proven to be highly clinically relevant in devising novel therapeutic modalities for treatment of cancer and restoration of the immune deficiency from lympho-depleting regiments and advanced aging. The new method of delivering exogenous cytokines should further expand the clinical applicability of homeostatic cytokines.

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32

Morawski, Peter A., Thomas Duhen, Maria M. Klicznik, Barbara Hoellbacher, Samantha Motley, Daniel J. Campbell e Iris K. Gratz. "Identification of functionally unique CD4 T cells that are the circulating counterparts of epidermal resident memory T cells". Journal of Immunology 200, n. 1_Supplement (1 maggio 2018): 173.1. http://dx.doi.org/10.4049/jimmunol.200.supp.173.1.

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Abstract As a barrier organ, the skin contains specialized T cell populations that combat infection and also help maintain tissue homeostasis and promote wound repair. Circulating skin-tropic T cells can also be identified in the blood based on their expression of the cutaneous lymphocyte antigen (CLA), but the developmental and functional relationships between these circulating CLA+ T cells and tissue-resident T cells in the skin are not fully understood. Using 33-parameter Cytometry by time-of-flight (CyTOF) analysis we identified a novel population of skin-tropic CD4+ T cells in human blood that expresses the CD103 integrin and phenotypically and functionally resembles epidermal resident memory T cells (TRM) in the skin. RNA sequencing identified a set of signature genes shared by circulating CD103+CLAhi T cells in the blood and epidermal TRM cells in the skin, and suggested that CD103+CLAhiT cells contribute to normal skin function and response to tissue damage. Finally, using humanized NSG mice carrying full-thickness human skin grafts we demonstrated that, despite their identification as TRM, CD103+CLAhi T cells in the skin are capable of exiting the tissue and re-entering circulation. Thus, CD103+CLAhi T cells in the blood represent a circulating T cell population of cutaneous TRM, and this provides novel opportunities for the study and therapeutic manipulation of TRM cells in the contexts of cutaneous infection, inflammation, and tissue-repair.

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33

Ogura, Hideki, Paula Preston-Hurlburt, Ana Luisa Perdigoto, Matthew Amodio, Smita Krishnaswamy, Pamela Clark, Hua Yu et al. "Identification and Analysis of Islet Antigen–Specific CD8+ T Cells with T Cell Libraries". Journal of Immunology 201, n. 6 (6 agosto 2018): 1662–70. http://dx.doi.org/10.4049/jimmunol.1800267.

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34

Hoog, Anna, Sonia Villanueva-Hernández, Mahsa Adib Razavi, Katinka van Dongen, Thomas Eder, Lauriane Piney, Ludivine Chapat et al. "Identification of CD4+ T cells with T follicular helper cell characteristics in the pig". Developmental & Comparative Immunology 134 (settembre 2022): 104462. http://dx.doi.org/10.1016/j.dci.2022.104462.

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35

Stein, H., M. Sperling, D. Dienemann, M. Zeitz e E. O. Riecken. "IDENTIFICATION OF A T CELL LYMPHOMA CATEGORY DERIVED FROM INTESTINAL-MUCOSA-ASSOCIATED T CELLS". Lancet 332, n. 8619 (novembre 1988): 1053–54. http://dx.doi.org/10.1016/s0140-6736(88)90068-2.

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36

Au, Sam H. "10,368 first dates: Microfluidic T cell matchmaking". Science Translational Medicine 10, n. 468 (21 novembre 2018): eaav9144. http://dx.doi.org/10.1126/scitranslmed.aav9144.

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37

Frentsch, Marco, Regina Stark, Joanna Listopad, Sarah Meier, Axel Schulz, Sibel Durlanik, Thomas Blankenstein e Andreas Thiel. "Identification and characterization of CD8+ T helper cells based on CD40L expression (155.1)". Journal of Immunology 186, n. 1_Supplement (1 aprile 2011): 155.1. http://dx.doi.org/10.4049/jimmunol.186.supp.155.1.

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Abstract (sommario):

Abstract CD8+ T cells are primarily regarded as cytotoxic cells. We have identified a substantial subset of CD40L expressing non-cytotoxic T-cells among primary human CD8+ T cells. CD40L+ CD8+ T cells exert diverse characteristic Th-cell functions such as activation of B cells, induction of DC maturation and secretion of cytokines such as IL-2, IFNγ, TNFα or IL-4. Up to 25% of total human central and effector memory CD8+ T cells express CD40L including cells specific for pathogens such as influenza, CMV and EBV, as well as yellow fever virus specific cells after primary vaccination. At next we assessed the functional relevance of CD40L expression on CD8+ T cells during a anti-tumor response. We challenged Rag1-/- mice with SV40 Tag expressing tumor cells and injected in parallel wt or CD40L-/- CD8+ T cells. Only application of CD40L competent wt CD8+ T cells prevented the establishment of tumors, whereas injection of CD40L-/- CD8+ T cells resulted in non-controlled tumor progression similar to non-treated tumors, although tumor-specific T cells were primed in these mice. Our results disclose an essential functional relevance of CD40L expressed by CD8+ T cells. Especially, in situations of reduced CD4+ T-cell help and MHC-II antigen presentation and/or limited danger signals CD40L+ CD8+ T cells may exert essential helper responsibilities for immunity and thus are potent candidate T cells to execute or support effective anti-tumor or anti-pathogen immune therapies.

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38

Ranes-Goldberg, M. G., T. Hori, S. Mohan-Peterson e H. Spits. "Identification of human pre-T/NK cell-associated genes." Journal of Immunology 151, n. 10 (15 novembre 1993): 5810–21. http://dx.doi.org/10.4049/jimmunol.151.10.5810.

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Abstract (sommario):

Abstract We have used a combination of subtractive cloning and differential screening techniques to identify genes preferentially expressed in early stages of human T/NK cell development compared with mature T and NK cells. A fetal liver-derived cytoplasmic (c) CD3+ membrane (m) CD3- clone, FL508, which expresses markers characteristic of pre-T and pre-NK cells served as a cell source for our cloning experiments. A cDNA library enriched for genes expressed in FL508 was constructed by removal of cDNA that hybridized to mRNA from a B cell line, JY. One-tenth of the resulting library of 5000 clones was screened by differential hybridization with cDNA probes from JY and a mature CD4+ T cell clone, B21. The relative expression levels of six selected clones were analyzed in 17 different cell/tissue types by semiquantitative polymerase chain reaction. Four of these clones are expressed at higher levels in thymocytes than in mature T or NK cells, and three clones are expressed at higher levels in fetal liver cells than in either mature T or NK cells. Partial and complete DNA sequence information suggests that these six cDNA correspond to previously unidentified genes. Genes identified in this study may be useful not only as markers for early stages of T/NK cell ontogeny, but also as tools for understanding novel developmental events.

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39

Bohana-Kashtan, Osnat, Hyam Levitsky e Curt I. Civin. "Identification of New Alloantigen-Reactive CD8+ Cytotoxic and Suppressor T Cell Subpopulations." Blood 110, n. 11 (16 novembre 2007): 3229. http://dx.doi.org/10.1182/blood.v110.11.3229.3229.

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Abstract (sommario):

We sought to develop a better understanding of the T cells involved in the human allogeneic immune response, in order to eventually engineer a donor graft with reduced GVHD-mediating potential, without ablating general immune competence. Prior studies reported that all the activated CD4+ T cells responding to a specific antigen challenge reside within the CD4high population expressing high levels of membrane CD4. We identified a new population of activated CD8+ T cells that developed during an in vitro allogeneic immune response, along with the allo-activated CD4high T cell population. Analogous to activated CD4+ T cells, this new T cell population was distinguished by up-regulated CD8 (and CD38) expression (CD8highCD38+). In accordance with Martins et al. (Blood 2004, 104:3429), we found that the depletion of the CD4highCD38+ population resulted in reduced 2o response to the original 2nd party stimulators. In contrast, depletion of the CD8highCD38+ population resulted in an increased 2o response to 2nd party cells, with no change in the response to 3rd party or CMV antigens. Elevated numbers of CD8highCD38+ T cells potently reduced the 1o and 2o responses to 2nd party, but not to 3rd party cells or CMV antigens. The complementary, non-activated CD8normalCD38− T cell population had no inhibitory effect. Importantly, we found that CD8highCD38+ T cells mediated both a specific cytotoxic response (that could be inhibited by the pan-caspase inhibitor, Z-VAD), and a specific suppressive response toward the original 2nd party stimulators (that was not affected by Z-VAD), and within this CD8highCD38+ population, there was a subpopulation of cytotoxic T cells (perforin+LAMP1+CD56+CD11b+CD11c+) and a subpopulation of non-cytotoxic T cells. Furthermore, we found that although CD8highCD38+ T cells differentially expressed CD28, both CD8highCD38+CD28− and CD8highCD38+CD28− T cells mediated a cytotoxic as well as a suppressor T cell response toward the original 2nd party cells (different from the published suppressive function of CD8+CD28− T cells observed by Liu et al, Int Immunol 1998, 10:775). Upon separation of cytotoxic CD8highCD38+ T cells from suppressor CD8highCD38+ T cells, we will explore the GVHD potential of these 2 novel activated CD8high T cell subpopulations, in a sensitive in vivo xenograft model for GVHD using NOD/SCID/IL2Rγnull immunodeficient mice.

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40

Kass, L. "Identification of lymphocyte subpopulations with a polymethine dye." Journal of Histochemistry & Cytochemistry 36, n. 7 (luglio 1988): 711–15. http://dx.doi.org/10.1177/36.7.2454984.

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Abstract (sommario):

Using the polymethine dye p-ethoxyphenyl-p-aminostyryl-1,3,3-trimethyl-3H-indolium chloride as an aqueous stain applied to specimens of peripheral blood or buffy coat fixed in FAA fixative, differential coloration of leukocytes was achieved using darkfield illumination. Neutrophils stained dark maroon and contained green granules, eosinophils contained bright blue granules, basophils revealed yellow and pink granules, and monocytes stained green with green and yellow vacuoles. In studies of purified lymphocyte subpopulations obtained in a cell sorter, T-helper cells stained red, T-suppressor cells were yellow orange, B-cells appeared yellow and often contained yellow annular structures in the cytoplasm, and natural killer (NK) cells stained green and contained large green granules. As a rapid screening technique for identification of T-helper and T-suppressor cells and their ratios in health and disease, the new polymethine stain may complement the more complex monoclonal antibody techniques for identification of these cells.

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41

Tiemann, Markus, Dmitri Atiakshin, Vera Samoilova e Igor Buchwalow. "Identification of CTLA-4-Positive Cells in the Human Tonsil". Cells 10, n. 5 (27 aprile 2021): 1027. http://dx.doi.org/10.3390/cells10051027.

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Abstract (sommario):

CTLA-4 (cytotoxic T-lymphocyte-associated protein 4) was originally defined as a T-lymphocyte antigen and was used as a target in cancer immunotherapy. Unfortunately, the existence of CTLA-4 in cells other than T-lymphocytes is often overlooked. The goal of the present study was to analyze the distribution pattern of CTLA-4 in the human tonsils using a panel of anti–CTLA-4 antibodies of different clones. We found that CTLA-4 was expressed in T-lymphocyte cells of various geneses, including hematopoietic cells and their derivatives (monocytes, macrophages, dendritic, plasma cells, mast cells, and neutrophils), as well as stromal cells of mesodermal (mesenchymal) origin and reticular epithelial cells of ectodermal origin. The expression of CTLA-4 in cells of different origins supports the proposition that CTLA-4 is not restricted to the lymphoid cell lineage and can provide broader effects of CTLA-4 on immune regulation.

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42

Chen, C. L., L. L. Ager, G. L. Gartland e M. D. Cooper. "Identification of a T3/T cell receptor complex in chickens." Journal of Experimental Medicine 164, n. 1 (1 luglio 1986): 375–80. http://dx.doi.org/10.1084/jem.164.1.375.

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Abstract (sommario):

A mouse mAb, CT-3, recognizes on chicken T cells a complex of three polypeptides, Mr 20,000, 19,000, and 17,000, two of which are N-glycosylated. The CT-3 antibody is mitogenic for chicken T cells, and it coprecipitates two additional polypeptides of Mr 49,000 and 38,000 in lysates of T cell membranes. Ontogeny studies revealed that 5-6 d after thymic influx of hemopoietic stem cells, their thymocyte progeny begin to express the T3/TCR complex. After hatching 1 wk later, the CT-3+ cells begin splenic migration in large numbers.

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43

Zuckerman, L. A., A. J. Sant e J. Miller. "Identification of a unique costimulatory activity for murine T helper 1 T cell clones." Journal of Immunology 154, n. 9 (1 maggio 1995): 4503–12. http://dx.doi.org/10.4049/jimmunol.154.9.4503.

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Abstract (sommario):

Abstract We have examined the ability of several class II-positive tumor cell transfectants to stimulate murine Th1 clones. Most of the transfectants failed to activate the Th1 clones and, in fact, induced Ag-specific anergy. However, we found that one tumor, a UV-induced fibrosarcoma (6130-VAR1), was capable of stimulating both cytokine production and proliferation in Th1 clones. We believe that 6130-VAR1 cells possess a unique costimulatory activity for the following reasons. First, these cells fail to express known costimulatory molecules including B7-1 and B7-2. Second, 6130-VAR1-mediated stimulation of Th1 clones was not blocked by anti-CD28 Fab or by CTLA4Ig, which suggests that members of the B7 family were not up-regulated during the course of stimulation and that activation does not occur via a CD28-dependent pathway. Third, 6130-VAR1 could provide costimulation when presented on a different surface than the class II/peptide ligand for the TCR. This last finding suggested that the activity on these cells was not simply an adhesion molecule that facilitated increased efficiency of T cell:MHC interactions. Finally, like B7-1 transfectants, stimulation by class II-positive 6130-VAR1 cells prevented the induction of anergy in the Th1 clones. Taken together, these results strongly suggest that 6130-VAR1 expresses a unique costimulatory activity (VAM-1) that, like B7-1, can promote T cell activation and prevent anergy induction.

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44

Lightstone, Liz, e Jacqueline Marvel. "CD45RA+ T Cells: Not Simple Virgins". Clinical Science 85, n. 5 (1 novembre 1993): 515–19. http://dx.doi.org/10.1042/cs0850515.

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Abstract (sommario):

1. The T cells which mediate immunological memory remain elusive. Identification of such cells would open the door to increasingly specific immunotherapy in areas such as transplantation and autoimmunity. 2. Over the last few years attempts have been made to identify phenotypic markers which can distinguish naive or virgin T cells from primed or memory ones. In humans, great hopes were raised when it was shown that the level of expression of the higher-molecular-mass isoforms (CD45RA) of the tyrosine phosphatase, CD45, correlated with previous exposure to antigen. 4. However, our studies in the mouse and more recent studies in rat and human suggest that expression of CD45RA more closely correlates with the state of responsiveness of the T cell. 5. Thus, with time, activated/memory T cells return to a state of quiescence or hypo-responsiveness and express high levels of CD45RA. Hence, not all CD45RA+ T cells are virgins.

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45

Kang, Chung Hyo, Yeongrin Kim, Heung Kyoung Lee, So Myoung Lee, Hye Gwang Jeong, Sang Un Choi e Chi Hoon Park. "Identification of Potent CD19 scFv for CAR T Cells through scFv Screening with NK/T-Cell Line". International Journal of Molecular Sciences 21, n. 23 (1 dicembre 2020): 9163. http://dx.doi.org/10.3390/ijms21239163.

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Abstract (sommario):

CD19 is the most promising target for developing chimeric-antigen receptor (CAR) T cells against B-cell leukemic cancer. Currently, two CAR-T-cell products, Kymriah and Yescarta, are approved for leukemia patients, and various anti-CD19 CAR T cells are undergoing clinical trial. Most of these anti-CD19 CAR T cells use FMC63 single-chain variable fragments (scFvs) for binding CD19 expressed on the cancer cell surface. In this study, we screened several known CD19 scFvs for developing anti-CD19 CAR T cells. We used the KHYG-1 NK/T-cell line for screening of CD19 scFvs because it has advantages in terms of cell culture and gene transduction compared to primary T cells. Using our CAR construct backbone, we made anti-CD19 CAR constructs which each had CD19 scFvs including FMC63, B43, 25C1, BLY3, 4G7, HD37, HB12a, and HB12b, then made each anti-CD19 CAR KHYG-1 cells. Interestingly, only FMC63 CAR KHYG-1 and 4G7 CAR KHYG-1 efficiently lysed CD19-positive cell lines. In addition, in Jurkat cell line, only these two CAR Jurkat cell lines secreted IL-2 when co-cultured with CD19-positive cell line, NALM-6. Based on these results, we made FMC63 CAR T cells and 4G7 CAR T cells from PBMC. In in vitro lysis assay, 4G7 CAR T cells lysed CD19-positive cell line as well as FMC63 CAR T cells. In in vivo assay with NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice, 4G7 CAR T cells eradicated NALM-6 as potently as FMC63 CAR T cells. Therefore, we anticipate that 4G7 CAR T cells will show as good a result as FMC63 CAR T cells for B-cell leukemia patients.

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Chavarria, Melina, Jessica Vazquez e Aleksandar Stanic-Kostic. "Identification of MAIT Cells in Human Term Decidua". Journal of Immunology 198, n. 1_Supplement (1 maggio 2017): 149.4. http://dx.doi.org/10.4049/jimmunol.198.supp.149.4.

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Abstract (sommario):

Abstract Mucosal-associated invariant T (MAIT) cells are a CD161+Vα7+ MR1-restricted T-cell subset, that has a complex relationship in regulating the microbiome and defense from invasive bacteria. Recent discovery of a placental microbiome, and genital mucosa MAIT cells, raises the possibility that MAIT are present at the maternal fetal interface and perform regulatory functions in this setting. As a first step, we analyzed human term decidua to detect MAIT cells and analyze their transcriptional programming. Decidua was dissected from human term placentas and mononuclear cells (MCs) were isolated by mechanical (GentleMACS) and enzymatic (Collagenase V, DNAse I) disruption. MCs labeled by flurochrome-conjugated antibodies against CD3, 4, 8, 19, 27, 45RO, 161, and TCR Vα7.2 and intracellular Eomes, RORγt, and T-bet. Data was acquired on a 5 laser (355, 405, 488, 562, 633nm), 18-color BD Fortessa cytometer and analyzed with FlowJo 10.1r7. Data revealed MAIT (CD3+CD161+Vα7.2+) cells in human term decidua, particularly of a memory CD8+ phenotype (CD27+CD45R0+), while fewer of CD4-CD8- and scant CD4+ cells were seen. Transcription factor expression analysis demonstrated uniform expression of PLZF, RORγt, and EOMES in phenotypic MAIT cells, confirming MAIT programming. MAIT cells are present in human term decidua and add a new dimension to the immunological complex regulating the maternal-fetal interface. Mucosal immune dysregulation is implicated in pregnancy pathology, and our findings open a novel area to mechanistic investigation.

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47

Bedke, Tanja, Sarah Lurati, Claudia Stuehler, Nina Khanna, Hermann Einsele e Max S. Topp. "Identification and Characterization of Human Aspergillus Fumigatus-Specific Tr1-(Like) Cells". Blood 118, n. 21 (18 novembre 2011): 181. http://dx.doi.org/10.1182/blood.v118.21.181.181.

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Abstract (sommario):

Abstract Abstract 181 Introduction: The ubiquitous mold Aspergillus fumigatus (A. fumigatus) induces two forms of pathogenesis: invasive aspergillosis in neutropenic patients and allergic aspergillosis in patients with chronic obstructive lung disease as well as in immunosuppressed patients. Mouse models of aspergillosis suggest that not only effector T cells (Teff) but also regulatory T cells (Treg) play a crucial role for the regulation of a protective T cell-mediated immunity to A. fumigatus. However, it is little-known about the involvement of Treg during A. fumigatus infection in humans. In order to develop new therapeutical strategies for the treatment of aspergillosis this project aims to understand the influence of regulatory T cells on A. fumigatus infection in humans. Material/Methods: A. fumigatus-specific CD4+ T cell clones were established from PBMC of healthy donors. Based on this clone pool Treg clones were identified due to their inability to proliferate in the absence of costimulation assessed by 3[H]-TdR incorporation as well as their Ag-specific cytokine production and phenotype determined by flow cytometry. Treg function was analyzed by their ability to suppress proliferation of autologous CD4+ T cells using CFSE dilution. Results: We identified A. fumigatus-specific T cell clones that exhibited marginal detectable proliferation after restimulation with immobilized anti-CD3 mAb in the absence of costimulation. However, these T cell clones vigorously proliferated in response to restimulation with their cognate antigen. A more detailed characterization showed that these suppressor T cell clones produced high amounts of IL-10 and moderate levels of IFN-gamma upon Ag-specific restimulation and expressed low amounts of Foxp3 but not Helios, a transcription factor that had recently been linked to natural occurring Treg. Most importantly, these T cell clones suppressed Ag-specific expansion of CD4+ Teff. This effect was contact-independent since suppression of Ag-specific CD4+ T cell expansion detected in transwell experiments was comparable to cocultures that enabled cellular-contact. Furthermore, anti-CD3/CD28-induced proliferation of naïve CD4+ T cells was not reduced in the presence of culture supernatants obtained from suppressor T cell clones after their antigen-specific restimulation in the absence of DCs. Conclusions: We identified for the first time A. fumigatus-specific CD4+ T cell clones with a Tr1(-like) IL-10+IFN-gamma+Foxp3lowHelios− phenotype. These cells suppressed expansion of A. fumigatus-specific Teff in an Ag-specific manner mediated by soluble factors released from Tr1(-like) cell clones. Since these factors did not affect CD4+ T cell proliferation in the absence of DCs our data suggest, that Tr1(-like) cell clones rather negatively regulate the stimulatory capacity of DCs leading to a reduced expansion of Ag-specific CD4+ T cells. Therefore these Tr1(-like) cells might play a protective role during A. fumigatus infection in humans. Thus, adoptive transfer of A. fumigatus-specific Treg could be useful to enhance protective immunity in patients with chronic A. fumigatus infection. Disclosures: Topp: Micromet: Consultancy, Honoraria.

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48

Fujiki, Tsukasa, Ryosuke Shinozaki, Miyako Udono e Yoshinori Katakura. "Identification and Functional Evaluation of Polyphenols That Induce Regulatory T Cells". Nutrients 14, n. 14 (13 luglio 2022): 2862. http://dx.doi.org/10.3390/nu14142862.

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Abstract (sommario):

Regulatory T cells (Tregs) and CD4+/CD25+ T cells play an important role in the suppression of excessive immune responses, homeostasis of immune function, and oral tolerance. In this study, we screened for food-derived polyphenols that induce Tregs in response to retinaldehyde dehydrogenase (RALDH2) activation using macrophage-like THP-1 cells. THP-1 cells were transfected with an EGFP reporter vector whose expression is regulated under the control of mouse Raldh2 promoter and named THP-1 (Raldh2p-EGFP) cells. The THP-1 (Raldh2p-EGFP) cells were treated with 33 polyphenols after inducing their differentiation into macrophage-like cells using phorbol 12-myristate 13-acetate. Of the 33 polyphenols, five (kaempferol, quercetin, morin, luteolin and fisetin) activated Raldh2 promoter activity, and both quercetin and luteolin activated the endogenous Raldh2 mRNA expression and enzymatic activity. Furthermore, these two polyphenols increased transforming growth factor beta 1 and forkhead box P3 mRNA expression, suggesting that they have Treg-inducing ability. Finally, we verified that these polyphenols could induce Tregs in vivo and consequently induce IgA production. Oral administration of quercetin and luteolin increased IgA production in feces of mice. Therefore, quercetin and luteolin can induce Tregs via RALDH2 activation and consequently increase IgA production, suggesting that they can enhance intestinal barrier function.

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49

Dahl, C. A., R. P. Schall, H. L. He e J. S. Cairns. "Identification of a novel gene expressed in activated natural killer cells and T cells." Journal of Immunology 148, n. 2 (15 gennaio 1992): 597–603. http://dx.doi.org/10.4049/jimmunol.148.2.597.

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Abstract (sommario):

Abstract We have isolated a cDNA clone from a human activated NK cell-derived cDNA library that identifies a transcript (NK4) that is selectively expressed in lymphocytes. The expression of this transcript is increased after activation of T cells by mitogens or activation of NK cells by IL-2 (lymphokine-activated killer cells). The transcript levels demonstrated by Northern blot analysis increase by 12 h after activation, remain high for at least 48 h, and require protein synthesis for expression. Southern blot analysis of B lymphoblastoid lines derived from 18 unrelated individuals reveal variable banding patterns suggestive of polymorphism within the NK4 gene. No homology was found between the sequence of the coding region of this transcript and any sequences in the GenBank data base. Sequence homology to the U1 small nuclear RNA was found within the 3' untranslated region immediately upstream of the site of polyadenylation, suggesting a possible role for U1 in the polyadenylation process. Sequence analysis indicates the transcript would encode a protein having a mass of 27 kDa. The presence of a signal sequence and lack of a transmembrane region suggests that the protein is secreted. In addition, the protein contains an RGD sequence that may be involved in cellular adhesion. This transcript appears to encode a novel product common to the activation pathways of both NK cells and T cells.

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50

Tilden, A. B., K. Itoh e C. M. Balch. "Human lymphokine-activated killer (LAK) cells: identification of two types of effector cells." Journal of Immunology 138, n. 4 (15 febbraio 1987): 1068–73. http://dx.doi.org/10.4049/jimmunol.138.4.1068.

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Abstract (sommario):

Abstract We analyzed the antigenic phenotype of lymphokine-activated killer (LAK) effector cells. Human blood lymphocytes were cultured for 3 days with 100 U/ml recombinant interleukin 2 (rIL 2), subpopulations isolated with monoclonal antibodies and a fluorescence-activated cell sorter (FACS) and assayed for cytotoxic activity against 51chromium labeled noncultured melanoma tumor cells. Initial experiments compared the LAK effector function of CD5+ T lymphocytes vs CD5- cells (predominantly CD16+ NK cells). The mean percent specific release at a 10:1 effector:target (E:T) ratio was 25% +/- 16 for CD5- cells, 10% +/- 6 for CD5+ cells, and 22% +/- 9 for unsorted cells. In contrast, when lymphocyte subpopulations were isolated before rIL 2 culture (LAK precursors), CD5- cells but not CD5+ cells developed LAK activity (28% +/- 12 vs 1% +/- 1, mean percent specific release, 10:1 E:T ratio), confirming our previous results showing that only CD16+ cells were LAK precursors. The discrepancy between LAK effector and precursor phenotypes suggested that LAK precursors acquired CD5 determinants during rIL 2 culture; however, double label immunofluorescence of rIL 2 cultured CD16+ cells showed that this was not the case. The data suggested that in the presence of other cell types, some T lymphocytes may develop LAK activity, but purified blood T lymphocytes do not develop LAK function when cultured with rIL 2 alone. We also analyzed LAK effector function in lymphocyte subpopulations defined by CD4 and CD8 antigens. The data showed that lymphocytes with a low density expression of CD8 and no expression of CD4 were enriched for LAK effector cells, whereas CD4+ and CD8- had less activity than unsorted cells. Lymphocytes with a high density expression of CD8 had activity similar to unsorted cells. We also assessed the contribution of Leu-7 (HNK-1) granular lymphocytes to LAK effector function. After culture with IL 2, lymphocytes were depleted of Leu-7+ cells by antibody and complement treatment and then were sorted into CD5+ and CD5- fractions. The cytotoxic activity of Leu-7-CD5+ cells was a mean 5% +/- 5 vs a mean 14% +/- 8 for the total CD5+ population (20:1 E:T ratio). The activity of Leu-7- CD5- was slightly less than the total CD5- fraction (21% +/- 9 vs 28% +/- 14, 10:1 E:T ratio). In conclusion, LAK effector function was highest in non-T cell (CD5- CD16+) populations and some activity was also present in T cell populations (CD5+ and predominantly Leu-7+).

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