POU2F2⁺ B cells enhance antitumor immunity and predict better survival in non small cell lung cancer

Immune checkpoint inhibitors are an effective adjuvant therapy for non-small cell lung cancer (NSCLC). Recent studies have highlighted the critical role of tumor-infiltrating B cells in tumor immunity. However, research specifically focusing on B cells in NSCLC is limited. This study aims to elucidate the role of POU2F2⁺ B cells in patient survival and immune cell infiltration in NSCLC. Pseudotime analysis was performed to identify B cell pseudotime-related gene sets from two single-cell RNA sequencing (scRNA-seq) datasets of NSCLC. Differentially expressed genes (DEGs) were identified from two NSCLC immunotherapy-related bulk RNA sequencing datasets. A Venn diagram was used to determine core genes shared between these datasets. Kaplan-Meier survival curves were utilized to analyze overall survival (OS). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed based on the differential genes between POU2F2⁺ and POU2F2^- B cells. CIBERSORT analysis was conducted to compare the proportions of immune cell subpopulations between groups. Multiplex immunohistochemistry (mIHC) was used to localize POU2F2⁺ cells and measure distances between different immune cells. Three hallmark genes, POU2F2, CD2, and CST7, were identified as being associated with B cell maturation and immunotherapy efficacy in NSCLC. High expression of POU2F2 was associated with poorer OS in both LUAD and LUSC. However, the POU2F2⁺ B cell score specifically correlated with the OS of LUAD but not with LUSC. Further analysis using scRNA-seq and mIHC methods revealed that POU2F2 is predominantly expressed in B cells. In LUAD tumor tissues, POU2F2⁺ CD20⁺ B cells were spatially further from PD-1⁺ CD8⁺ T cells and CD206⁺ CD68⁺ macrophages compared to POU2F2^- CD20⁺ B cells. In LUSC tumor tissues, POU2F2⁺ CD20⁺ B cells were spatially further from CD206⁺ CD68⁺ macrophages but showed no significant spatial difference from PD-1⁺ CD8⁺ T cells compared to POU2F2^- CD20⁺ B cells. In patients with high POU2F2⁺ B cell scores, LUAD tissues showed an increased proportion of CD8⁺ T cells and M1 macrophages, and a decreased proportion of M2 macrophages. In contrast, in LUSC tissues, a high POU2F2⁺ B cell score was associated only with an increased proportion of M1 macrophages, with no significant differences in the proportions of CD8⁺ T cells or M2 macrophages between groups. This study elucidates the significant role of POU2F2⁺ B cells in influencing survival and immune cell infiltration in NSCLC. Our findings highlight POU2F2 as a novel target for NSCLC immunotherapy. Targeting POU2F2 may modulate the tumor immune microenvironment, enhance the infiltration and activity of critical immune cells, and ultimately improve patient survival.