What Is the Function of Helper T-Cells in the Body?

T-Cells in the Immune System

• Helper T-cells are part of the larger group of T-cells that are a vital component of the overall immune response. T-cells form what is called cell-mediated immunity, which is the type of immunity that does not produce antibodies and instead activates other whole cells, and they are formed in the bone marrow before going to the thymus to mature. Other T-cells include killer T-cells and suppressor T-cells. In addition to the T-cells, the immune system also includes plenty of other types of cells. B-cells, which produce antibodies, are another type of lymphocyte, the larger group that all of the T-cell types belong to as well. Lymphocytes are the major group of white blood cells that help fight infection throughout the body.

General Function

• The general function of helper T-cells, like all of the T-cells, is to fight against invading organisms. T-cells operate against viruses, bacteria, fungi and protozoans that cause disease. T-cells also help protect the body against cancer by recognizing and destroying cancer cells. Helper T-cells do not directly kill invaders themselves. Instead, they recognize antigens and then communicate with other cells of the immune system by producing small chemical messengers called cytokines. These cytokines activate other immune cells, such as causing B-cells to produce more antibodies and directing phagocytes to the area to kill the infectious organism.

Types

• Helper T-cells separate into different subtypes, with each type having a slightly different function and ability. These include the subtypes Th1, Th2, Th9, Th17 and Tfh cells. The different types can maneuver into different tissues to look for antigens in different places. In addition, they can send out chemical messages to other immune cells to guarantee that the cells that respond are the appropriate ones to handle the specific antigen.

Concerns

• HIV, the virus that causes acquired immune deficiency syndrome, or AIDS, specifically infects helper T-cells. It kills these cells and dampens the immune system, making the infected individual more prone to other diseases. As the helper T-cells die off, the ability to call in other immune cells to kill off invaders decreases and the B cells don't get the message to make antibodies. Many people with AIDS die not of the disease itself but of opportunistic infections that take hold as the immune system fails.