What do T cells produce that instruct phagocytes?

T cells produce cytokine proteins that play a crucial role in the immune response, particularly by instructing and coordinating the actions of phagocytes. When T cells recognize infected or abnormal cells, they release various cytokines, such as interleukins and tumor necrosis factor (TNF), which serve as signaling molecules to other immune cells. These cytokines can enhance the phagocytic activity of cells such as macrophages and neutrophils, leading to more effective elimination of pathogens.

Cytokines also help regulate the intensity and duration of immune responses, influencing the behavior of many different types of immune cells. This communication is essential not just for promoting phagocytosis, but also for orchestrating a well-rounded immune response to various challenges.

In contrast, histamines are associated primarily with allergic reactions and do not have the same instructive role for phagocytes as cytokines. Antibodies are produced by B cells and function to neutralize pathogens rather than instruct phagocytes directly. Antigens are molecules that can trigger an immune response, but they are not produced by T cells; instead, they are typically found on the surfaces of pathogens or infected cells.