What is the primary function of CD4 T cells in the immune system?

The primary function of CD4 T cells is to help orchestrate the immune response. These cells, also known as T helper cells, play a critical role in coordinating the immune system's activities. They achieve this by producing cytokines, which are signaling molecules that influence the behavior of other immune cells. CD4 T cells engage with other immune cells, such as B cells and cytotoxic T cells, to enhance antibody production and to facilitate the killing of infected cells, primarily by activating cytotoxic T cells and macrophages.

Their ability to support and regulate the immune response makes them essential for both the adaptive and innate immune systems. Without CD4 T cells, the immune system would be less effective at responding to infections and mounting an appropriate defense, leading to increased susceptibility to various pathogens. Thus, their role in orchestrating the immune response is vital for maintaining immune homeostasis and efficacy against infections.