B2M mutation

We conclude that in the absence of B2M, activation of CD4+ T cells and NK cells can mediate responses to murine models of PD-1 blockade therapy. Additionally, in human melanoma the intratumoral presence of activated NK cells upon partial B2M loss likely selects against tumor escape through low surface MHC class I expression.

This study comprehensively characterizes PB-DLBCL as a separate entity with distinct clinical and morpho-molecular features. These insights may aid in developing tailored therapeutic strategies and shed light on its pathogenesis.

Here we present genetic profiling of a multi-refractory MM patient who relapsed to PIs, anti-BCMA (Teclistamab), and anti-GPRC5D (Talquetamab) BsAbs. However, the role of B2M alterations in disease progression and drug resistance needs to be elucidated. Predicting the biological impact based on 3D structural models remains speculative, thus, functional confirmation introducing the BCMA and B2M alterations in cell line models by genetic engineering is pending.

Collectively, these results serve to validate H1 and H2 as distinct cHL subtypes, to confirm the characteristic genotypes defining them, and recapitulate their distinctive associations with key clinical and pathological variables including age and EBV status. We further validate the subtypes using orthogonal methods revealing dominant cytokine driven signaling in H1. Conversely, H2 tumors, which largely lack B2M mutations, despite their lower mutational burden, are rather immunogenic triggering T-cell responses.

Conclusion Our multi-dimensional profiling approach enabled us to delineate molecular profiles of HRS cells that are linked to distinct TME patterns. These linkages have implications for current pathogenesis models, molecular subtyping of CHL, and identification of cellular vulnerabilities that might be therapeutically exploitable via targeting of HRS cell phenotypes and/or immune escape mechanisms.

Along with MSI-H and PD-L1+, several biomarkers, including B2M mutation and CD274 amplification, may help predict ICI benefit amongst TMB-H tumors. Co-occurring biomarkers within TMB-H breast cancer warrant evaluation in larger cohorts for response or resistance to ICI to develop composite predictive biomarkers in MBC.

PD-1 mab combined with Rituximab could be a potential treatment option for r/r DLBCL with manageable safety profile.

Treatment for rrPMBCL can include targeted sequential immunotherapy. If a PD1 tumor reduction regimen achieves PR or higher, patients should begin CART as soon as possible. B2M mutation-positive, SOCS1-positive patients can benefit from targeted sequential immunotherapy.

In conclusion, patients carrying MSI-H/dMMR tumors with B2M mutation showed significantly higher TMB. Prescription of ICIs should be thoroughly evaluated for these patients.

To characterize immune response we performed imaging mass cytometry (IMC) with a 18-marker panel on 26 samples from 9 REs and 16 samples from 6 NRs and T-cell receptor sequencing in 18 RE-samples and 9 NR-samples. We observed profound changes in mutation signatures over time, characterized by C>A transitions after exposure to neoadjuvant chemotherapy (FOLFOX), which is consistent with earlier observed oxaliplatin induced mutational signatures... Using a multi-timepoint approach, we integrated genetic analyses with transcriptomic analyses and analyses of the tumor immune microenvironment for a holistic understanding of treatment resistance. This study identifies profound transcriptional changes during treatment with limited evidence that clonal replacement is the cause, suggesting phenotypic plasticity as a mechanism for therapy resistance. The presence of immune escape, a less activated T-cell phenotype and a lack of clonal T-cell expansions in patients with poor clinical treatment response has high pharmacological relevance and could be exploited via combined immune-chemotherapy treatments.

Blastic MZL is associated with a more aggressive clinical course. Even when there is disseminated disease patients while not always cured did not have a fatal course in this series. The light microscopic findings are reproducible. The background of MZL, identification of larger cells in significant numbers without a follicle center phenotype, at times expressing CD5 or CD23 with variable positivity for MUM1, BCL-2 and C-MYC and a high proliferation index define the pathology in most. Certain cytogenetic abnormalities and genetic mutations implicated in large cell transformation into a diffuse large B cell lymphoma are seen in blastic MZL with earlier biopsies prior to transformation potentially harboring at risk genetic mutations.

These results suggest that the mutations of B2M could cause the disruption of the expression and functions of this important subunit of HLA, leading to decreased expression of HLA-I or HLA-II and subsequently to reduce T lymphocyte infiltration in tumor tissues. The consequence of this event lessens the recognition and elimination of EBV+ tumor cells by host immunity and paves the way for the host immune tolerance to EBV+ tumor cells by evading immune recognition and escaping the T lymphocyte killing.

Our results suggest B2M IHC can likely serve as a reliable methodology in detecting B2M loss in CRCs. Our data also reaffirm literature reports that B2M loss characterizes a significant subset of MMR-deficient CRCs (41% in our series). As efforts are ongoing in further defining the clinical and biological relevance of B2M, especially with regard to the response to immunotherapy in MMR-deficient CRCs, B2M IHC may serve as a useful detection method in both clinical and research settings.

Negative selection differs between the two cohorts and is observed in endoplasmic reticulum aminopeptidase genes, ERAP1 and ERAP2 genes, and DNAM-1/TIGIT ligands. Targeting genes or molecular pathways under positive or negative evolutionary selection may permit new treatment options and increase the efficacy of current immunotherapy.

B2M and JAK1/2 loss-of-function mutations occur frequently in microsatellite instability-high CRC. Our study demonstrated that patients with CRC harboring B2M or JAK1/2 mutations should not be excluded from anti-PD-1 therapy.

Our study observed comprehensive CNVs in PLELC patients which is a unique molecular feature compared with other NSCLC subtypes and EBV-positive NPC. Higher TMB level and amplifications of B2M in PLELC patients may be used as potential biomarkers to indicate better treatment responses to ICIs.

Analysis of dynamic blood samples confirmed the utility of ctDNA for the real-time assessment of treatment response and revealed that the increases in ctDNA levels and changes in KMT2D mutation status could be useful predictors of disease progression. Our present results suggest that ctDNA is a promising method for the detection of mutation spectrum and serves as a biomarker for disease monitoring and predicting clinical recurrence.

Eighteen patients received ICB with pembrolizumab and one patient with nivolumab/ipilimumab. Among metastatic MSI GI cancers, B2M-mutant tumors represent a biologically distinct disease with distinct metastatic patterns. To assess ICB response in B2M-mutant MSI cancer patients, future studies need to account for the fact that baseline survival of patients with B2M-mutant MSI cancer may be longer than of patients with B2M-wild type MSI cancer.

We highlight the role of tumor associated effector CD4+ T cells in pre-clinical models and patients with impaired APM. Overall, our findings highlight that the absence of B2M in MMRd cancers, does not prevent clinic response to immune checkpoint blockade.

Our findings thus contribute to an improved understanding of the biological behavior of multiple ENI and provide a clinical rationale for targeting ENI in DLBCL.

For the first time, our data have unveiled the nature of the T cell repertoire in cHL at single cell resolution. Our results reveal a recurrent pattern of clonal expansion within effector CD8+ cells, which may be the HRS antigen-specific T cells that mediate response to PD-1 blockade. This hypothesis requires confirmation through similar analyses of pre- and on-treatment biopsies of cHL patients receiving anti-PD-1 therapy.

Importantly, certain outlier mutations are common in MSI cancers despite being related to frameshift peptides with functionally confirmed immunogenicity, suggesting a possible driver role during MSI tumor evolution. Neoantigens resulting from shared mutations represent promising vaccine candidates for prevention of MSI cancers.

Methylation of the promoter region of the B2M gene was observed in one patient with MSI-H colorectal cancer. Detection of genetic and epigenetic changes in B2M gene could be important in personalized therapy for CRC patients as these changes may be one of the mechanisms of secondary resistance of MSI positive tumors to immunotherapy.

The quantitative and qualitative differences clearly indicate a distinct biology of sporadic and hereditary MSI tumors. Clinically, these findings underline the need for differentiating sporadic and hereditary tumors in basic science studies and clinical trials, including trials evaluating immune checkpoint blockade therapy in MSI tumors.

Next, we investigated mutation landscape in patients with wild-type (WT) TP53 (n = 58) and found that patients harboring MYD88 L265P had significantly inferior TTP than those with WT or non-265P (P = 0.046). This study reveals the mutation spectrum of treatment-naive Chinese DLBCL patients.It also confirms the clinical significance of TP53 mutations and indicates the prognostic value of MYD88 L265P in TP53 WT patients.

(1) Targeting EGFR L858R mutation in patients with HLA-A*33:03 allele appeared to be valuable for the neoantigen-based vaccine designed for Chinese NSCLC patients. (2) The specific immunogenicity of L858R seemed to be little influenced by B2M mutation and HLA-I LOH which were important factors for neoantigen presentation. (3) High pDC and low neutrophils infiltration might contribute to the inhibitive microenvironment associated with L858R mutation.

Here, we describe a patient with BRAF-V600E-positive metastatic melanoma who was sequentially treated with BRAF/MEK inhibitors (dabrafenib/trametinib) and checkpoint inhibitor immunotherapy (nivolumab, followed by pembrolizumab). After the emergence of resistance, whole exome sequencing was performed, implicating MAP2K2 and B2M mutations in loss of response to anti-BRAF/MEK and anti-PD1 therapies, respectively.