What is the primary function of cytotoxic T cells in the immune response?

The primary function of cytotoxic T cells, also known as CD8+ T cells, is to induce apoptosis in abnormal cells, such as those that are infected with viruses or are cancerous. These cells are equipped with specific receptors that recognize antigens presented on the surface of infected or abnormal cells. Once a cytotoxic T cell identifies a target cell, it can directly trigger a series of events leading to the programmed cell death (apoptosis) of the infected or dysfunctional cell.

This action is critical in maintaining the integrity of the body's defenses, as it helps to eliminate cells that could otherwise proliferate and cause disease. By selectively removing these harmful cells, cytotoxic T cells play a vital role in controlling infections and preventing the development of tumors, thereby contributing to the overall effectiveness of the immune response.

Other options such as antibody production and the enhancement of T helper cell activity relate to the roles of different components of the immune system but do not describe the unique function of cytotoxic T cells. Presenting antigens to naive T cells is a role fulfilled primarily by antigen-presenting cells, such as dendritic cells and macrophages, and is separate from the direct cytotoxic function of CD8+ T cells.