Final answer:
Cytotoxic T cells, also known as killer T cells (Tc cells), are effector cells of the immune system that target and eliminate cells infected with intracellular pathogens. They recognize specific pathogen antigens presented on the surface of infected cells and induce cell death by releasing perforin and granzymes. These cells play a crucial role in protecting against viral infections and halting the progression of intracellular infections.
Step-by-step explanation:
Cytotoxic T cells, also known as killer T cells (Tc cells), are effector cells of the immune system that target and eliminate cells infected with intracellular pathogens. They function through a mechanism similar to natural killer (NK) cells, but with the ability to recognize specific pathogen antigens presented on the surface of infected cells.
Once activated, the T cell receptor (TCR) on cytotoxic T cells binds to the pathogen-specific epitopes displayed on major histocompatibility complex class I (MHC I) molecules of the infected cells. This recognition triggers the release of perforin and granzymes, which destroy the infected cell by creating pores in its membrane and inducing apoptosis.
Cytotoxic T cells play a crucial role in protecting against viral infections, as viruses replicate within host cells and are shielded from extracellular antibodies. Their ability to identify and destroy infected cells before the pathogen can replicate and escape helps halt the progression of intracellular infections.