Tumor antigen-specific CD4+ T-lymphocyte (CD4+ TST)

Tumor antigen-specific CD4+ T-lymphocytes are a specialized subset of helper T cells that recognize specific antigens, including neoantigens and tumor-associated antigens, presented by major histocompatibility complex (MHC) class II molecules [3, 10]. These cells play a critical role in the antitumor immune response by secreting pro-inflammatory cytokines such as interferon-gamma (IFN-γ) and interleukin-2 (IL-2), which facilitate the recruitment and activation of cytotoxic CD8+ T cells and natural killer (NK) cells [4, 9]. Beyond their helper functions, certain subsets of these CD4+ T cells can exert direct cytotoxic effects on tumor cells through granzyme and perforin pathways [4, 10]. In clinical practice, they are the primary effectors modulated by immune checkpoint inhibitors like pembrolizumab and nivolumab, which block inhibitory receptors such as PD-1 and CTLA-4 to restore their activity [6, 13]. Furthermore, they are a key component of adoptive cell therapies (ACT), such as tumor-infiltrating lymphocyte (TIL) therapy, where they are isolated from tumors, expanded ex vivo, and re-infused to provide a potent, personalized immune attack against cancer [2, 6].

Other names

Tumor-reactive CD4+ T cellsNeoantigen-specific CD4+ T cellsCD4+ Tumor-infiltrating lymphocytes (TILs)CD4+ TSTsHelper T cells (tumor-specific subset)

Immune checkpoint inhibition, Adoptive cell transfer, Antigen-specific activation