Regulatory T cell-mediated cytolysis of effector T cells (Treg-mediated cytolysis)

Regulatory T cell-mediated cytolysis of effector T cells is a biological mechanism of immune regulation where Regulatory T cells (Tregs) directly eliminate effector T cells (Teffs) or other immune cells to maintain peripheral tolerance (Grossman et al., 2004). This process is primarily executed through the 'cytolytic machinery' consisting of the pore-forming protein Perforin and the serine protease Granzyme B (GZMB) (Gondek et al., 2005). Upon activation, Tregs release these molecules into the immunological synapse; Perforin creates pores in the target cell membrane, allowing Granzyme B to enter and trigger apoptosis via caspase-dependent and independent pathways (Cao et al., 2007). This mechanism is vital for preventing autoimmunity and chronic inflammation by controlling the expansion of effector populations. In the context of cancer, tumors often exploit this machinery by recruiting Tregs that kill anti-tumor effector T cells and Natural Killer (NK) cells, thereby facilitating immune evasion (Vignali et al., 2008). Therapeutic strategies targeting this pathway include the use of Granzyme B inhibitors to enhance anti-tumor immunity or Treg-modulating agents like low-dose IL-2 or checkpoint inhibitors to restore immune balance in various disease states (Zhuo et al., 2023).

Other names

Treg cytolytic machineryGranzyme B-dependent Treg suppressionPerforin-dependent Treg suppressionTreg-mediated killing of effector T cellsEffector T cell suppression via Treg cytolysis

Modulation of the frequency or activity of Regulatory T cells to alter their ability to secrete cytolytic granules (Granzyme B and Perforin) and induce apoptosis in effector T cells.