Expansion of CD4+ cytotoxic T lymphocytes with specific gene expression patterns may contribute to suppression of tumor immunity in oral squamous cell carcinoma: single-cell analysis and in vitro experiments

• Published in: Frontiers in immunology Vol. 14; p. 1305783
• Main Authors: Chen, Hu, Sameshima, Junsei, Yokomizo, Shiho, Sueyoshi, Tomoki, Nagano, Haruki, Miyahara, Yuka, Sakamoto, Taiki, Fujii, Shinsuke, Kiyoshima, Tamotsu, Guy, Thomas, Nakamura, Seiji, Moriyama, Masafumi, Kaneko, Naoki, Kawano, Shintaro
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 2023
• Subjects: CD4+ cytotoxic T lymphocytes; CTLA-4; CXCL13; double negative B cells; oral squamous cell carcinoma; T cell dysfunction; double negative B cells; CD4+ cytotoxic T lymphocytes; CTLA-4; oral squamous cell carcinoma; CXCL13; T cell dysfunction
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2023.1305783

Cancer immunotherapy targeting CD8
T cells has made remarkable progress, even for oral squamous cell carcinoma (OSCC), a heterogeneous epithelial tumor without a substantial increase in the overall survival rate over the past decade. However, the therapeutic effects remain limited due to therapy resistance. Thus, a more comprehensive understanding of the roles of CD4
T cells and B cells is crucial for more robust development of cancer immunotherapy.
In this study, we examined immune responses and effector functions of CD4
T cells, CD8
T cells and B cells infiltrating in OSCC lesions using single-cell RNA sequencing analysis, T cell receptor (TCR) and B cell receptor (BCR) repertoire sequencing analysis, and multi-color immunofluorescence staining. Finally, two Kaplan-Meier curves and several Cox proportional hazards models were constructed for the survival analysis.
We observed expansion of CD4
cytotoxic T lymphocytes (CTLs) expressing granzymes, which are reported to induce cell apoptosis, with a unique gene expression patterns. CD4
CTLs also expressed CXCL13, which is a B cell chemoattractant. Cell-cell communication analysis and multi-color immunofluorescence staining demonstrated potential interactions between CD4
CTLs and B cells, particularly IgD
CD27
double negative (DN) B cells. Expansion of CD4
CTLs, DN B cells, and their contacts has been reported in T and B cell-activated diseases, including IgG4-related disease and COVID-19. Notably, we observed upregulation of several inhibitory receptor genes including CTLA-4 in CD4
CTLs, which possibly dampened T and B cell activity. We next demonstrated comprehensive delineation of the potential for CD8
T cell differentiation towards dysfunctional states. Furthermore, prognostic analysis revealed unfavorable outcomes of patients with a high proportion of CD4
CTLs in OSCC lesions.
Our study provides a dynamic landscape of lymphocytes and demonstrates a systemic investigation of CD4
CTL effects infiltrating into OSCC lesions, which may share some pathogenesis reported in severe T and B cell-activated diseases such as autoimmune and infectious diseases.