Littérature scientifique sur le sujet « VPF B-Frames »

ABSTRACT By different approaches, we characterized the birnavirus blotched snakehead virus (BSNV). The sequence of genomic segment A revealed the presence of two open reading frames (ORFs): a large ORF with a 3,207-bp-long nucleotide sequence and a 417-nucleotide-long small ORF located within the N-terminal half of the large ORF, but in a different reading frame. The large ORF was found to encode a polyprotein cotranslationally processed by the viral protease VP4 to generate pVP2 (the VP2 precursor), a 71-amino-acid-long peptide ([X]), VP4, and VP3. The two cleavage sites at the [X]-VP4 and VP4-VP3 junctions were identified by N-terminal sequencing. We showed that the processing of pVP2 generated VP2 and several small peptides (amino acids [aa] 418 to 460, 461 to 467, 468 to 474, and 475 to 486). Two of these peptides (aa 418 to 460 and 475 to 486) were positively identified in the viral particles with 10 additional peptides derived from further processing of the peptide aa 418 to 460. The results suggest that VP4 cleaves multiple Pro-X-Ala↓Ala motifs, with the notable exception of the VP4-VP3 junction. Replacement of the members of the predicted VP4 catalytic dyad (Ser-692 and Lys-729) confirmed their indispensability in the polyprotein processing. The genomic segment B sequence revealed a single large ORF encoding a putative polymerase, VP1. Our results demonstrate that BSNV should be considered a new aquatic birnavirus species, slightly more related to IBDV than to IPNV.

ABSTRACT Rotaviruses are a leading cause of viral acute gastroenteritis in humans and animals. They are grouped according to gene composition and antigenicity of VP6. Whereas group A, B, and C rotaviruses are found in humans and animals, group D rotaviruses have been exclusively detected in birds. Despite their broad distribution among chickens, no nucleotide sequence data exist so far. Here, the first complete genome sequence of a group D rotavirus (strain 05V0049) is presented, which was amplified using sequence-independent amplification strategies and degenerate primers. Open reading frames encoding homologues of rotavirus proteins VP1 to VP4, VP6, VP7, and NSP1 to NSP5 were identified. Amino acid sequence identities between the group D rotavirus and the group A, B, and C rotaviruses varied between 12.3% and 51.7%, 11.0% and 23.1%, and 9.5% and 46.9%, respectively. Segment 10 of the group D rotavirus has an additional open reading frame. Generally, phylogenetic analysis indicated a common evolution of group A, C, and D rotaviruses, separate from that of group B. However, the NSP4 sequence of group C has only very low identities in comparison with cogent sequences of all other groups. The avian group A NSP1 sequences are more closely related to those of group D than those of mammalian group A rotaviruses. Most interestingly, the nucleotide sequences at the termini of the 11 genome segments are identical between group D and group A rotaviruses. Further investigations should clarify whether these conserved structures allow an exchange of genome segments between group A and group D rotaviruses.

Coxsackie B (CVB) viruses have been associated with type 1 diabetes. We have recently observed that CVB1 was linked to the initiation of the autoimmune process leading to type 1 diabetes in Finnish children. Viral persistency in the pancreas is currently considered as one possible mechanism. In the current study persistent infection was established in pancreatic ductal and beta cell lines (PANC-1 and 1.1B4) using four different CVB1 strains, including the prototype strain and three clinical isolates. We sequenced 5′ untranslated region (UTR) and regions coding for structural and non-structural proteins and the second single open reading frame (ORF) protein of all persisting CVB1 strains using next generation sequencing to identify mutations that are common for all of these strains. One mutation, K257R in VP1, was found from all persisting CVB1 strains. The mutations were mainly accumulated in viral structural proteins, especially at BC, DE, EF loops and C-terminus of viral capsid protein 1 (VP1), the puff region of VP2, the knob region of VP3 and infection-enhancing epitope of VP4. This showed that the capsid region of the viruses sustains various changes during persistency some of which could be hallmark(s) of persistency.

ABSTRACTHuman noroviruses are a leading cause of gastroenteritis across the globe, but the pathogenic mechanisms responsible for disease are not well established. The availability of a murine norovirus model system provides the opportunity to elucidate viral and host determinants of virulence in a natural host. For example, previous studies have revealed that the protruding domain of the murine norovirus capsid protein VP1, specifically residue 296 of VP1, regulates virulent infection. We identified a panel of nonsynonymous mutations in the open reading frame 2 (ORF2) gene encoding VP1 that arose in persistently infected mice and tested whether these mutations conferred phenotypic changes to viral replication and virulence. Consistent with previous studies, we demonstrate that a glutamic acid at position 296 results in attenuation. For the first time, we also demonstrate that a lysine at this position is sufficient to confer virulence on an otherwise attenuated murine norovirus strain. Moreover, our studies reveal a direct correlation between the efficiency of viral replication in B cells and virulence. These data are especially striking because mutations causing reduced B cell replication and attenuation had minimal effects on the ability of the virus to replicate in macrophages. Thus, norovirus infection of B cells may directly contribute to disease outcome.IMPORTANCEHuman noroviruses are a major global cause of disease, yet we know very little about their pathogenic mechanisms. The availability of a murine norovirus model system facilitates investigation of noroviruses in a natural host organism and the identification of viral and host determinants of pathogenesis. We have identified a panel of mutations arising in the viral capsid protein VP1 during persistent infection of mice. Our data reveal that the protruding domain of VP1 regulates the ability of the virus to replicate in B cells, and this directly correlates with virulence. Importantly, mutations impairing B cell infection had minimal effects on macrophage infection, revealing a potentially critical role for B cell infection in norovirus pathogenesis.

The major inner capsid protein (VP6) gene of the bovine group B rotavirus (GBR) Nemuro strain is 1269 nt in length and contains one open reading frame encoding 391 aa. Nucleotide and amino acid sequence identities of the Nemuro VP6 gene compared with the published corresponding human and rodent GBR genes were respectively 66–67 and 70–72 %, which are notably lower than those between human and rodent viruses (72–73 and 83–84 %, respectively). Overall identities of VP6 genes among GBRs were substantially lower than those among both group A rotaviruses (GARs) and group C rotaviruses (GCRs) derived from different species of mammals. These results demonstrate that bovine GBR is remarkably distinct from other GBRs and that GBRs from different species may have had a longer period of divergence than GARs and GCRs. Recombinant VP6 was generated with a baculovirus expression system and used for an ELISA to detect GBR antibodies. All 13 paired sera from adult cows with GBR-induced diarrhoea in the field showed antibody responses in the ELISA. In serological surveys of GBR infection using the ELISA, 47 % of cattle sera were positive for GBR antibodies, with a higher antibody prevalence in adults than in young cattle. In pigs, a high prevalence of GBR antibodies (97 %) was detected in sera from sows. These results suggest that GBR infection is common in cattle and pigs, notwithstanding the scarcity of reports of GBR detection in these species to date.

Phylogenetic analysis within the VP1 region now enables molecular typing of enteroviruses consistent with neutralization results. Three untypable isolates, 2776/82, 57/99 and 22/00, from Korea, North India and Bangladesh, respectively, showed within this region 98·0–99·0% amino acid identities. These were less than 77% to the previous enterovirus prototypes, but 91·5–92·5% to CA55-1988, the recently identified enterovirus 73 (EV73) prototype from California. All three strains were, however, most similar to CA64-4454, an EV73 prime strain, to which they shared 96·5–98·5% identity. Seven compared EV73 strains formed two clusters in the VP1 dendrogram, one cluster with strains from South and East Asia and CA64-4454, and the other with strains from Oman and California including the prototype. When sequencing the complete open reading frame of 2776/82, its non-structural region was found to be divergent from all human enterovirus B (HEV-B) strains, including CA55-1988, indicating that one or other strain was recombinant. Boot scanning of the genomes showed a recombination point within the P2 region. Therefore, part of this was sequenced for 57/99 and 22/00 and was found similar to 2776/82, while CA55-1988 was similar to coxsackievirus B3, demonstrating that CA55-1988 was the recombinant. Since all strains of EV73 isolated so far outside California originate from Asia, where it has a broad geographical distribution, it seems that EV73 may have been introduced to California from Asia. Further analysis of EV73 strains will reveal if the recombination occurred in the USA or in Asia and will help to elucidate the origin of this virus.

Abstract Myeloproliferative neoplasms (MPNs) are clonal malignant disorders characterized by the increased production of mature myeloid cells in blood. The classical MPNs include Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF). Those pathologies are due to the acquisition of gain-of-function mutations leading to the constitutive activation of the cytokine receptor / JAK2 signaling pathway: JAK2V617F in 70% of cases and mutations in the thrombopoietin receptor (MPL) gene in 5% of cases. More recently, around fifty different mutations in the calreticulin (CALR) gene have been described in 30% of ET and PMF with two more frequent mutations called del52 (type 1) and ins5 (type 2). All the CALR mutations induce a frameshiflt to an alternative reading frame in the exon 9 leading to a new C-term tail of the protein with hydrophobic features, and the loss of the KDEL sequence, which is involved in its endoplasmic reticulum retention. The goal of this work was to understand the role of CALR mutants (del52, del46, del34, ins5, del19, del13) in human hematopoiesis. By studying the variant allele frequency (VAF) in 20 patients, we have shown that the CALR mutations are present in all blood mature cells not only in granulocytes and monocytes (CD14+) with a VAF >30% but also in B cells (CD19+), NK cells (CD56+) and in some cases in T cells (CD3+). Moreover, we have observed that CALR mutations are present in all hematopoietic progenitors including CD34+CD38-CD90+ (HSC), CD34+CD38-CD90- (immature progenitors) and CD34+CD38+ (committed progenitors) cell fractions after investigating the clonal architecture of the progenitors. CALR mutation was detectable in more than 40% of progenitor cells except in 2 patients (15 patients studied) and with, in some cases, no detectable wild type CALR progenitors. Homozygous CALR mutations were rare except in one case associated with disease progression. Whatever the VAF, there was no significant differences among the different progenitor types and granulocytes. Finally, we observed that all the associated mutations studied (TET2, PHF6, SYNE1, SCARA5, PIK3CD, SETD1B) in 6 patients postdated CALR mutations. We could also show in 15 patients samples that CALR mutants give a specific megakaryocytic progenitor (CFU-MK) spontaneous growth mediated both by MPL and JAK2 activation using specific inhibitors and short hairpin RNAs. The CFU-MK spontaneous growth correlated with a constitutive activation of JAK2/STAT3/5 pathway in megakaryocytes derived from in vitro cultures of CD34+ progenitors. In aggregate, these results show that all CALR mutants studied are present in all human hematopoietic cells including myeloid and lymphoid cells, give an early clonal advantage at the level of the HSC compartment and a specific increased growth of the megakaryocytic lineage via MPL/JAK2 activation. Disclosures No relevant conflicts of interest to declare.

Abstract The persistence of leukemic mutation(s) in AML patients who have achieved a morphologic complete remission (CR) after intensive induction chemotherapy is a strong predictor of early relapse and reduced overall survival (OS) (Klco JAMA, 2015; Morita, J Clin Oncol 2018; Jongen-Lavrencic, NEJM, 2018). There is no clinical consensus as to the optimal consolidation therapy for the ~50% of patients with intermediate-risk AML. The median relapse-free survival (RFS) for patients ≤60 years with ELN intermediate-risk disease is 0.8 years to 1.2 years, with a median OS of 1.2-2.1 years (Mrozek, J Clin Oncol, 2012). We have shown that intermediate-risk patients who clear all leukemia-associated mutations (LAMs) to a variant allele fraction (VAF) of <2.5% in first morphologic CR have a median event-free survival of 25.6 months, vs 8.8 months if they do not (HR 3.32). Median overall survival is 46.8 months if all LAMs are cleared, vs 19.3 months if they are not (HR 2.88). We hypothesized that improved post-remission risk stratification using LAM clearance can further refine risk assessment and optimize alloHCT decisions by identifying patients at lower risk of relapse, who might be expected to do well with standard chemotherapy. Here, we report the development of a pipeline to prospectively determine the persistence of LAMs after remission-induction, and return results in a clinically actionable time-frame. We perform enhanced exome sequencing (EES) of paired skin or buccal swab (normal tissue) and bone marrow DNA to comprehensively identify all LAMs at diagnosis (Day 0) and to assess their clearance post-induction (~Day 30). EES data are generated using a CLIA-compliant assay in the CLIA-licensed environment (CLE) lab at the McDonnell Genome Institute, and results are returned to the treating physician. Intermediate risk patients ≤60 years with clearance of all LAMs (VAFs <2.5%) are assigned to receive consolidation with high-dose cytarabine (HiDAC) (Cohort A). Patients with persistence of any mutation at a VAF ≥ 2.5% are assigned to the investigator's choice arm, and are treated with HiDAC and/or alloHCT at the discretion of the treating physician (Cohort B). This stratification is part of an ongoing clinical protocol (NCT02756962) whose primary objective is to determine whether the RFS of patients who have cleared all LAM(s) post-induction (VAFs <2.5%) and are treated with HiDAC alone (Cohort A) is significantly higher than expected from a historical intermediate risk group. Measurable residual disease testing by "difference from normal" flow cytometry (lower level of detection of 0.02%, Hematologics, Seattle WA) post-induction will be correlated with clearance or persistence of mutations and clinical outcomes. For the 23 patients sequenced to date, the mean turnaround time to issue sequencing results to the treating physician was 24 days from the time of the remission biopsy. All 23 patients had detectable LAMs at presentation (mean 28 per patient, range, 6 to 43) that could be used to track persistent disease in the day 30 remission sample. Eleven patients (48%) cleared all LAMs and received HiDAC only (Cohort A). There was no flow cytometric evidence of residual AML in Cohort A. Twelve patients (52%) had persistent LAMs (Cohort B, investigator's choice). The number of persistent leukemia-associated variants present in Cohort B ranged between 1 and 14. Surprisingly, 9 of the 12 patients with persistent LAMs by sequencing had no flow cytometric evidence of residual leukemia. Seven of 12 patients on the investigator's choice arm have received an alloHCT, and none have relapsed to date. The median follow-up for all subjects is 378 days (range, 59-683). Neither the median RFS (Fig. 1A) nor the median OS (Fig. 1B) has been reached for either cohort. While preliminary, these results suggest that patients who clear all LAMs to a VAF of <2.5% may have durable responses with HiDAC alone. The encouraging RFS seen in the investigator's choice arm (Cohort B) may reflect the decision to recommend transplant "upfront" in CR1 for patients who have molecular persistent disease. In summary, identifying persistent LAMs after induction chemotherapy is feasible in an actionable time-frame. Early data suggest that using LAM clearance post-induction may improve current risk-stratification for intermediate-risk AML. Accrual of patients and continued follow-up are ongoing. Disclosures Jacoby: NovoNordisk: Consultancy; Celgene: Speakers Bureau. Loken:Hematologics, Inc: Employment, Equity Ownership. Schroeder:Amgen Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees. Uy:GlycoMimetics: Consultancy; Curis: Consultancy. Vij:Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Jansson: Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Kahl:Gilead: Consultancy; AstraZeneca: Consultancy; Genentech: Consultancy; CTI: Consultancy; ADC Therapeutics: Consultancy; Abbvie: Consultancy; Seattle Genetics: Consultancy; Acerta: Consultancy; Juno: Consultancy; Celgene: Consultancy.

Abstract *Contributed equally as first authors. **Contributed equally as senior authors. Recurrent mutations within EGR2, a versatile transcription factor involved in differentiation of hematopoietic cells, were recently reported in 8% of advanced-stage chronic lymphocytic leukemia (CLL) patients, where they appear to be associated with a worse outcome. EGR2 is activated through ERK phosphorylation upon B-cell receptor (BcR) stimulation, and we have previously shown that EGR2 -mutated CLL patients display altered expression of EGR2 down-stream target genes compared to wildtype (wt) patients, thereby pointing to a pathogenic role for EGR2 mutations in dysregulating BcR signaling. To gain further insight into the incidence and prognostic impact of EGR2 mutations in CLL, we screened samples from a well-characterized series of 1430 patients, either by Sanger sequencing (n=1019) or targeted deep-sequencing (n=370), both covering the recently reported EGR2 hotspot in exon 2. In addition, whole-exome data was available for an additional 43 patients. Different cohorts were included in our analysis ranging from 'general practice' CLL (33% IGHV-unmutated (U-CLL), 6% TP53 -aberrant (TP53abn), n=693), to adverse-prognostic CLL (89% U-CLL, 26% TP53abn, n=325), patients belonging to clinically aggressive stereotyped subsets #1-3 & #5-8 (n=342), patients relapsing after FCR therapy (n=41) and Richter transformed cases (n=31), thus reflecting the heterogeneous nature of CLL. Nineteen EGR2 mutations were detected by Sanger sequencing, while 22 additional mutations were identified with deep-sequencing using a 5% variant allele frequency (VAF) cutoff (median 39%, range 5.6-63.9%, median coverage 43,000X). With the exception of one in-frame deletion, all mutations were missense alterations located within the three zinc-finger domains. Significant enrichment of EGR2 mutations was observed in adverse-prognostic (18/325, 5.5%) and FCR-relapsing (4/41, 9.8%) CLL compared to the 'general practice' cohort (18/693, 2.6%, Figure 1A). A surprisingly low frequency was observed among clinically aggressive stereotyped subsets (5/342, 1.5%), although the cause for this observation is currently unknown. Finally, 2/31 (6.5%) cases with Richter transformation carried an EGR2 mutation. Of the 4 FCR-relapsing, EGR2 -mutated cases with available overtime samples, all demonstrated a significant expansion of the EGR2 -mutated clone at relapse (VAF-increase between 15-41%). In addition, subclonal levels of EGR2 hotspot mutations (VAF 0.5-5%) were detected in an additional 13/370 (3.5%) cases by deep-sequencing. The majority of EGR2 -mutated CLL patients (32/39, 82%) concerned U-CLL and the following aberrations co-occurred: 11q-deletions (n=10), TP53abn (n=6), NOTCH1 (n=3)or SF3B1 (n=3) mutations. EGR2 -mutated patients displayed a significantly worse overall survival compared to wt patients (median survival 59 vs. 141 months, p=0.003, using a conservative 10% VAF cutoff), and a poor outcome similar to cases with TP53abn (Figure 1B). In multivariate analysis (n=583), EGR2 status remained an independent factor (p=0.038), along with stage (p=0.048) and IGHV status (p<0.0001), while TP53abn and del(11q) showed borderline significant values (p=0.069 and p=0.059, respectively). To investigate the impact of EGR2 mutations in a homogeneously treated patient cohort, EGR2 mutation analysis of the UK CLL4 trial is underway. To date, 8/247 patients have been identified as EGR2 -mutated by deep-sequencing and they show a decrease of their median overall survival (42 vs. 77 months) compared to wt patients; however, this did not reach statistical significance, probably due to the low number of EGR2 -mutated cases. Final results of the UK CLL4 trial will be presented at the ASH meeting. In summary, EGR2 -mutant cases appear to constitute a novel poor-prognostic subgroup of CLL, with mutations occurring either as disease-initiating aberrations, i.e. in cases where mutations were found in the entire clone, or as subclonal driver events linked to progressive disease. The latter is reflected by the enrichment of EGR2 mutations in aggressive CLL and the association of EGR2 mutations with an overall dismal prognosis. Considering the potential role of mutated EGR2 in altering BcR signaling, it will be particularly relevant to study the efficacy of BcR inhibitors in this patient group. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Langerak: Roche: Other: Lab services in the field of MRD diagnostics provided by Dept of Immunology, Erasmus MC (Rotterdam); InVivoScribe: Patents & Royalties: Licensing of IP and Patent on BIOMED-2-based methods for PCR-based Clonality Diagnostics.; DAKO: Patents & Royalties: Licensing of IP and Patent on Split-Signal FISH. Royalties for Dept. of Immunology, Erasmus MC, Rotterdam, NL. Schuh:Acerta Pharma BV: Research Funding. Strefford:Roche: Research Funding.

Abstract Background: Follicular lymphoma (FL) is the most common indolent NHL (iNHL), exhibits a variable clinical course, and remains largely incurable. The pathogenesis of FL is complex and involves over expression of Bcl2 via t(14;18) translocation, as well as copy number alterations, recurrent somatic mutations, and changes in the tumor microenvironment. In line with recent publications, we hypothesized that recurrent somatic genomic mutations in FL will be present and may impact FL development, progression, transformation, and clinical outcomes. Methods: To address this, we performed exome sequencing (NimbleGen SeqCap EZ V2.0) of tumor and normal frozen tissue pairs from 24 patients in a discovery cohort with untreated FL (12), relapsed FL (6), or transformed FL/iNHL (6). We developed a custom capture assay (NimbleGen) that targets 7.05 MB corresponding to the coding, 5' and 3' UTR regions of 1717 genes. The custom capture genes included somatic mutations identified in our exome discovery cohort (898 genes) or somatic mutations previously published to be recurrently mutated in B cell NHL (819 genes). Instrument data from the discovery cohort exome and re-sequenced custom capture were combined and analyzed using the McDonnell Genome Institute (MGI) somatic caller pipeline (5 SNV callers, 3 indel callers), filtered (minimum 20X coverage, minimum 2.5% VAF, maximum 10% normal VAF) and manually reviewed. Additionally, the 1717 custom capture strategy was used to sequence an extension cohort consisting of FFPE tumor samples from 80 patients with FL, achieving >20x coverage for >75% of the targeted region. All discovery and extension samples have clinical annotations that include FLIPI prognostic score, treatment, and clinical outcomes. Results: Combined analysis of exome and custom capture data for the discovery cohort yielded a robust data set with good sequence coverage of >78% of the targeted regions with at least 20x depth in all samples and a mean depth of 89x. Based upon somatic mutations identified and manually reviewed using this approach, we conservatively estimate 0.98 mutations per MB in FL. 23 genes were recurrently mutated in 3 or more cases, and an additional 75 genes recurrently mutated in 2 cases in the discovery cohort. Consistent with recent publications (Li H et. al., Blood, 2014; Green MR, PNAS, 2015; Yildiz M et al, Blood, 2015) we confirmed a number of genes that were highly recurrently mutated in FL [TNFRSF14 (50%), Bcl2 (25%), IRF8 (13%), TP53 (13%)] including chromatin modifying genes consisting of histone methyl transferases [KMT2D/MLL2 (58%), EZH2 (13%)], histone acetyltransferases [CREBBP (42%), EP300 (17%)], histone linkers [HIST1H1C (13%), HIST1H1E (8%), HIST1H2BO (8%), HIST1H3G (8%), HIST2H2AC (8%); collectively 42%]. We also confirmed (ATP6V1B2, 13%) and found unreported (ATP6AP2, 8%; ATP6V0A1, 4%; ATP6V1F, 4%) mutations in vacuolar ATPase proton pump genes and P5 or Ca++ ATPase genes (ATP13A2, 4%; ATP13A4, 4%, ATP2B4, 4%;). We confirmed (CD79B, 13%; BCL10, 8%) and found unreported (CD22, 13%) mutations in components of the B cell receptor signaling pathway. The previously unreported recurrent mutations in CD22 were consistent with loss-of function (2 missense, 1 nonsense, 1 frame shift deletion). As a negative regulator of BCR signaling, mutation of CD22 may represent a strategy of to enhance BCR signals in malignant germinal center B cells. We also identified members of the SWI/SNF complex mutated in 33% of this FL cohort: ARID1B (8%), BCL11A (4%), SMARCB1 (4%) in addition to previously reported members BCL7A (12%), SMARCA4 (8%), ARID1A (4%). Somatic mutations were also identified in the Notch pathway: DTX1 (29%), Notch2 (4%), Notch3 (4%), Notch4 (4%). We identified several genes that have not been reported as highly recurrent in FL CXCR4 (42%, mutation calls primarily in RNA), DMD (13%), DNAH9 (13%), FLG (13%), GON4L (13%), PCDH7 (13%), RLTPR (13%), SCN7A (13%), ST6GAL1 (13%). Conclusions: FL genomes harbor a large number of recurrent mutations, consistent with a role in the development and progression of this malignancy. Analysis of the extension cohort and association of recurrently mutated genes and pathways with clinical outcomes is ongoing and will be presented. Disclosures Bartlett: Gilead: Consultancy, Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding; Pfizer: Research Funding; Novartis: Research Funding; Millennium: Research Funding; Colgene: Research Funding; Medimmune: Research Funding; Kite: Research Funding; Insight: Research Funding; Seattle Genetics: Consultancy, Research Funding; MERC: Research Funding; Dynavax: Research Funding; Idera: Research Funding; Portola: Research Funding; Bristol Meyers Squibb: Research Funding; Infinity: Research Funding; LAM Theapeutics: Research Funding.

The escalation of multimedia contents exchange, especially of videos belonging to mobile devices, and the availability of a great amount of editing software has raised grave doubts on their digital life-cycle. In this thesis, we firstly introduce a new dataset for multimedia forensics and then develop forensic tools that analyse the video-container and the video-signal in order to evaluate possible tampering that have been introduced in the life-cycle of a video content. The first contribution consists on the release of a new Dataset of videos and images captured from to 35 modern smartphones/tablets belonging to 11 different brands: Apple, Asus, Huawei, Lenovo, LG electronics, Microsoft, Oneplus, Samsung, Sony, Wiko and Xiaomi. Overall, we collected 11732 native images; 7565 of them were shared through Facebook, in both high and low quality, and through WhatsApp, resulting in a total of 34427 images. Furthermore we acquired 648 native videos, 622 of which were shared through YouTube at the maximum available resolution, and 644 through WhatsApp, resulting in a total of 1914 videos. The uniqueness of the VISION dataset was tested on well known forensic tool, i.e., the detection of the Sensor Pattern Noise (SPN) left by the acquisition device for the source identification of native/social media contents. The second contribution is based on the analysis of the container structure of videos acquired by means of mobile devices. We argue that the atoms belonging to the container, in terms of order and value, are fragile and that it is more difficult to hide their modifications than the regular metadata. This characteristic can be exploited to perform Source Identification and Integrity Verification of videos taken from devices belonging to well known operating systems and manufactures. In the third contribution we focus on the video-signal and on its encoding process. We used codecs that perform a hybrid video coding scheme, and developed a classification technique able to perform group of picture length estimation and double compression detection. The proposed technique is one of the fastest approaches that use videos encoded with B-frames, with both constant bit rate and variable bit rate.