What is the primary function of T-lymphocytes?

The primary function of T-lymphocytes, specifically cytotoxic T cells, is to directly kill infected or cancerous cells. These cells play a critical role in the immune response by recognizing specific antigens presented on the surface of infected cells through Major Histocompatibility Complex (MHC) molecules. Upon recognition, cytotoxic T lymphocytes can induce apoptosis, effectively eliminating the infected or abnormal cells from the body.

While T-lymphocytes do have a broader range of functions, including helping to activate other immune cells, the hallmark role that distinguishes them is their ability to directly engage and destroy compromised cells, which is fundamental for controlling infections and maintaining cellular integrity.