Cytotoxic T lymphocyte-mediated tumor cell lysis (CTL-mediated lysis)

The process termed “cytotoxic T lymphocyte (CTL)-mediated tumor cell lysis” describes the destruction of cells expressing tumor-associated antigens by CD8+ T lymphocytes. CTLs recognize antigenic peptides presented by major histocompatibility complex (MHC) class I molecules on target (e.g., tumor) cells. Upon engagement, CTLs undergo activation through T cell receptor (TCR) signaling, followed by a tightly regulated process that includes cytoskeletal rearrangement, granule polarization, and release of cytotoxic molecules (perforin, granzymes) at the immunological synapse[1][2][3]. Additional pathways include Fas-FasL interactions leading to apoptotic signaling in the target cell[3][5]. This process is central to immune surveillance against malignancy and forms the mechanistic basis for modern cancer immunotherapies that either enhance endogenous CTL responses or introduce engineered T cells into patients[3][4][6].

Other names

Cytotoxic T cell-mediated tumor cell killingCD8+ T cell cytotoxic responseCTL antitumor activity

Drugs and biologics may enhance CTL activity by: - Blocking inhibitory checkpoints (e.g., PD-1/PD-L1, CTLA-4), thus sustaining CTL activation against tumor cells - Providing costimulatory signals (via agonist antibodies) - Supply of cytokines (e.g., IL-2) to promote expansion and activation of CTLs - Engineering T cells (CAR-T, TCR-T cells) to recognize tumor antigens, enabling more robust tumor cell killing