Identification and Regulation of TCRαβ+CD8αα+ Intraepithelial Lymphocytes in Murine Oral Mucosa

Establishment and validation of a tumor-infiltrating γδT cell related prognostic gene signature in head and neck squamous cell carcinoma

γδT cells are unconventional T cells only accounting for 1-5 % of circulating T lymphocytes. Their potent anti-tumor capability has been evidenced by accumulating studies. However, the prognostic value of γδT cells remains not well documented in head and neck squamous cell carcinoma (HNSCC). In this study, we utilized the TCGA HNSCC database to evaluate the infiltration of γδT cells and the association between γδT cells and clinicopathological factors by related gene signature, which were then validated by a total of 100 collected tumor samples from HNSCC patient cohort. Heterogeneity and functional characteristics of distinct infiltrating γδT cell profiles in HNSCC were then investigated based on the scRNA-seq data from the GEO database. We found higher γδT cell gene signature score was significantly associated with longer survival. Cox regression models showed that γδT cell gene signature could serve as an independent prognostic indicator for HNSCC patients. A high level of γδT cell-related gene signature was positively correlated with the infiltration of tumor-infiltrating lymphocytes and immune score. Through scRNA-seq analysis, we identified that γδ+ Trm cells and γδ+ CTL cells possessed anti-tumor and immunoregulatory properties. Notably, we found a significant association between the presence of these cells and improved survival outcomes. In our cell-cell communication analyses, we identified that γδT cells have the potential to eliminate tumor cells through the secretion of interferon-gamma and granzyme. Collectively, the infiltration of γδT cells may serve as a promising prognostic tool, prompting the consideration of treatment options for patients with HNSCC.

IFN-γ and TGF-β, Crucial Players in Immune Responses: A Tribute to Howard Young

Interferon gamma (IFN-γ) and transforming growth factor beta (TGF-β), both pleiotropic cytokines, have been long studied and described as critical mediators of the immune response, notably in T cells. One of the investigators who made seminal and critical discoveries in the field of IFN-γ biology is Dr. Howard Young. In this review, we provide an overview of the biology of IFN-γ as well as its role in cancer and autoimmunity with an emphasis on Dr. Young's critical work in the field. We also describe how Dr. Young's work influenced our own research studying the role of TGF-β in the modulation of immune responses.

Effector T cell responses unleashed by regulatory T cell ablation exacerbate oral squamous cell carcinoma

Immune suppression by CD4+FOXP3+ regulatory T (Treg) cells and tumor infiltration by CD8+ effector T cells represent two major factors impacting response to cancer immunotherapy. Using deconvolution-based transcriptional profiling of human papilloma virus (HPV)-negative oral squamous cell carcinomas (OSCCs) and other solid cancers, we demonstrate that the density of Treg cells does not correlate with that of CD8+ T cells in many tumors, revealing polarized clusters enriched for either CD8+ T cells or CD4+ Treg and conventional T cells. In a mouse model of carcinogen-induced OSCC characterized by CD4+ T cell enrichment, late-stage Treg cell ablation triggers increased densities of both CD4+ and CD8+ effector T cells within oral lesions. Notably, this intervention does not induce tumor regression but instead induces rapid emergence of invasive OSCCs via an effector T cell-dependent process. Thus, induction of a T cell-inflamed phenotype via therapeutic manipulation of Treg cells may trigger unexpected tumor-promoting effects in OSCC.