T cells are primarily involved in the cell-mediated immune response, which is a crucial component of the adaptive immune system. This response is characterized by the direct action of T cells against infected cells, cancer cells, and foreign cells.
There are different types of T cells, such as cytotoxic T cells and helper T cells, that play essential roles in this response. Cytotoxic T cells recognize and kill infected or cancerous cells by recognizing specific antigens presented by major histocompatibility complex (MHC) molecules on these cells. Helper T cells, on the other hand, support the immune response by releasing cytokines that enhance the activity of other immune cells, including B cells and macrophages.
In contrast, the humoral response primarily involves B cells, which produce antibodies that bind to pathogens or toxins, marking them for destruction or neutralizing their activity. The innate defense refers to the body’s first line of defense against pathogens, which includes physical barriers, such as skin, and immune cells like neutrophils and macrophages that act quickly and non-specifically. Complement fixation is part of the humoral immune response that involves a series of proteins that enhance the ability of antibodies to clear pathogens, but it is not a direct function of T