CD58 alterations govern antitumor immune responses by inducing PD-L1 and IDO in diffuse large B-cell lymphoma.

Recurrent abnormalities in immune surveillance-related genes affect the progression of diffuse large B-cell lymphoma (DLBCL) and modulate the response to therapeutic interventions. CD58 interacts with the CD2 receptor on T cells and natural killer (NK) cells and is recurrently mutated and deleted in DLBCL, suggesting it may play a role in regulating antitumor immunity. Herein, we comprehensively analyzed the genomic characteristics of CD58 through targeted next-generation sequencing, RNA-sequencing, whole-exome sequencing, and single-cell RNA-sequencing in patients with newly diagnosed DLBCL. The CD58 mutation rate was 9.1%, and the copy number loss rate was 44.7% among all enrolled DLBCL patients. Notably, CD58 genetic alterations, along with low CD58 expression, significantly correlated with reduced rates of response to R-CHOP therapy and inferior progression-free and overall survival. Single-cell RNA sequencing revealed that CD58 expression in tumor cells was negatively correlated with CD8+ T cell exhaustion/dysfunction status. Insufficient T-cell activation resulting from CD58 alterations could not be attributed solely to CD2 signaling. CD58 inhibited the activity of the JAK2/STAT1 pathway by activating the Lyn/CD22/SHP1 axis, thereby limiting PD-L1 and IDO expression. Elevated PD-L1 and IDO expression in CD58 deficient DLBCL cells led to immune evasion and tumor-intrinsic resistance to CAR T-cell therapy. Direct activation of CD58-CD2 costimulatory signaling in combination with anti-PD-L1 blockade or IDO inhibitor sensitized CD58-deficient DLBCL to CAR T-cell therapy. Collectively, this work identified the multiple roles of CD58 in regulating antitumor immune responses in DLBCL.

OX40 shapes an inflamed tumor immune microenvironment and predicts response to immunochemotherapy in diffuse large B-cell lymphoma.

OX40 enhances the T-cell activation via costimulatory signaling. However, its molecular characteristics and value in predicting response to immunochemotherapy in DLBCL remain largely unexplored. Here, we performed an integrative analysis of sequencing and multiplex immunofluorescence staining, and discovered abnormally higher expression of OX40 in DLBCL patients. Elevated OX40 could activate T cells leading to a higher immune score for tumor immune microenvironment (TiME). OX40 upregulation simultaneously happened with immune-related genes including PD-1, CTLA4 and TIGIT et,al. Patients with high OX40 expression exhibited a lower Ann Arbor stage and IPI score and more easily achieved a complete response/partial response. The analysis of infiltrated T-cell subset revealed that patients with a greater number of CD4+/OX40+ or CD8+/OX40+ T cells had a longer OS. Our findings indicated that OX40 shapes an inflamed tumor immune microenvironment and predicts response to immunochemotherapy, providing insights for the application of OX40 agonist in DLBCL patients.

A novel prognostic signature based on immune-related genes of diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) presents a great clinical challenge and has a poor prognosis, with immune-related genes playing a crucial role. We aimed to develop an immune-related prognostic signature for improving prognosis prediction in DLBCL. Samples from the GSE31312 dataset were randomly allocated to discovery and internal validation cohorts. Univariate Cox, random forest, LASSO regression and multivariate Cox analyses were utilized to develop a prognostic signature, which was verified in the internal validation cohort, entire validation cohort and external validation cohort (GSE10846). The tumor microenvironment was investigated using the CIBERSORT and ESTIMATE tools. Gene set enrichment analysis (GSEA) was further applied to analyze the entire GSE31312 cohort. We identified four immune-related genes (CD48, IL1RL, PSDM3, RXFP3) significantly associated with overall survival. Based on discovery and validation cohort analyses, this four-gene signature could classify patients into high- and low-risk groups, with significantly different prognoses. Activated memory CD4 T cells and activated dendritic cells were significantly decreased in the high-risk group, and these patients had lower immune scores. GSEA revealed enrichment of signaling pathways, such as T cell receptor, antigen receptor-mediated, antigen processing and presentation of peptide antigen via MHC class I, in the low-risk group. In conclusion, a robust signature based on four immune-related genes was successfully constructed for predicting prognosis in DLBCL patients.

Reduced radiotherapy clinical benefit for primary Waldeyer's ring diffuse large B-cell lymphoma in the rituximab era.

This study aimed to identify the prognostic factors in patients with Waldeyer's ring diffuse large B-cell lymphoma (WR-DLBCL), comparing the efficacy of radiotherapy (RT) for the WR-DLBCL patients in the pre-rituximab and rituximab eras. We conducted a retrospective analysis of 134 patients diagnosed with WR-DLBCL. Univariate and multivariate analyses were performed to identify the prognostic factors for WR-DLBCL. Then, we divided these patients into the rituximab plus chemotherapy group (R-chemotherapy) (n = 88) and chemotherapy group (n = 46), and the Kaplan-Meier and Cox regression model analyses were applied to investigate the treatment value of RT in both the groups. Multivariate analysis revealed international prognostic index (IPI) ≥ 3 and chemotherapy without rituximab as significant risk factors for the progression-free survival (PFS, IPI ≥ 3: p = 0.001; chemotherapy without rituximab: p = 0.002) and overall survival (OS, IPI ≥ 3, p < 0.001; chemotherapy without rituximab, p = 0.024). Rituximab combined with chemotherapy significantly improved PFS (p = 0.002) and OS (p = 0.006) in these patients. RT did not significantly contribute to the survival in the overall cohort analysis, whereas in the subgroup analysis, RT significantly improved the PFS (p = 0.025) and OS (p = 0.029) for the patients in the chemotherapy group, but not in the R-chemotherapy group. In conclusion, the WR-DLBCL patients could benefit from RT in the pre-rituximab era, whereas the addition of rituximab to chemotherapy significantly improved the survival of WR-DLBCL patients, and the clinical benefit of RT was reduced.