CD4+ T cell recognizing MHC class II-presented tumor peptide (CD4+ tumor-reactive T cell)

CD4+ T cells recognizing MHC class II-presented tumor peptides are specialized lymphocytes that play a central role in orchestrating the anti-tumor immune response (PubMed: 30104441). These cells identify specific tumor antigens, such as neoantigens or overexpressed self-antigens, when they are processed and displayed by Major Histocompatibility Complex (MHC) class II molecules (NIH: PMC6103412). While MHC II is primarily expressed on professional antigen-presenting cells like dendritic cells, its expression can also be induced on tumor cells themselves, allowing for direct recognition (PubMed: 28945246). Upon activation, these CD4+ T cells secrete pro-inflammatory cytokines, such as interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), which enhance the activity of CD8+ cytotoxic T cells and innate immune effectors (PubMed: 29973717). In some contexts, CD4+ T cells can also exert direct cytotoxic activity against MHC II-positive tumor cells (Nature: 547, 217–221). Therapeutic interventions, including checkpoint inhibitors and personalized cancer vaccines, aim to expand or reactivate these populations to overcome tumor-induced immunosuppression (PubMed: 31048552). Consequently, they are a major focus of research in developing more effective and durable cancer immunotherapies.

Other names

MHC II-restricted tumor-infiltrating lymphocyteCD4+ tumor-infiltrating lymphocyte (TIL)Helper T cell recognizing tumor neoantigenMHC II-restricted CD4+ T cellTumor-reactive CD4+ T cell

Activation and expansion of MHC class II-restricted CD4+ T cells to enhance anti-tumor immunity through cytokine secretion and direct cytotoxicity.