Tumor antigen-specific CD4+ and CD8+ T cells (CD4+/CD8+ T cells)

Tumor antigen-specific CD4+ and CD8+ T cells are specialized lymphocytes of the adaptive immune system that recognize and respond to specific proteins (antigens) expressed by malignant cells (Waldman et al., 2020, Nature Reviews Immunology). CD8+ T cells, also known as cytotoxic T lymphocytes (CTLs), are responsible for the direct lysis of tumor cells through the release of perforin and granzymes upon recognition of antigen-MHC class I complexes (Borst et al., 2018, Nature Reviews Immunology). CD4+ T cells, or helper T cells, recognize antigens presented on MHC class II molecules and provide essential support by secreting cytokines like interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), which promote the expansion and persistence of CD8+ T cells and modulate the tumor microenvironment (Tay et al., 2021, Cancer Cell). In many cancers, these cells enter a state of exhaustion characterized by the high expression of inhibitory receptors such as PD-1 and CTLA-4, which limits their anti-tumor efficacy (Wherry & Kurachi, 2015, Nature Reviews Immunology). Therapeutic interventions like immune checkpoint inhibitors aim to block these inhibitory pathways to restore T-cell function, while adoptive cell transfer (ACT) therapies, such as tumor-infiltrating lymphocyte (TIL) therapy, involve the isolation, expansion, and re-infusion of these cells to treat advanced malignancies (Rosenberg & Restifo, 2015, Science).

Other names

Tumor-infiltrating lymphocytesTILsAntigen-specific T cellsCytotoxic T lymphocytes and Helper T cellsNeoantigen-specific T cellsTumor-reactive T cells

Enhancement of T-cell activation, proliferation, and effector function through checkpoint blockade (e.g., PD-1/CTLA-4 inhibition), cytokine stimulation, or adoptive transfer of ex vivo expanded populations.