Kaplan Nursing Entrance Exam Practice 2026 – Comprehensive Prep

Killer T cells, also known as cytotoxic T cells, play a crucial role in the immune system by directly attacking and destroying infected cells, as well as cancerous or malignant cells. They possess the capability to recognize specific antigens presented by these compromised cells and use mechanisms such as the release of perforin and granzymes to induce apoptosis, or programmed cell death, in the targeted cells. This function is vital for maintaining the integrity of the body against infections and tumor growth.

Helper T cells serve a different function; they assist in the activation of B cells and other T cells by releasing cytokines, which facilitate a broader immune response. Memory T cells are responsible for remembering past infections and providing a quicker response upon re-exposure to the same pathogen; they do not directly attack cells. Regulatory T cells help maintain immune tolerance and prevent autoimmune reactions, ensuring the immune system does not overreact or attack the body's own tissues. Each type of T cell has a distinct and important role in the immune response, but it is the killer T cells that are specifically responsible for the direct attack on infected or malignant cells.