Helper T cells

What are helper T cells?

Helper T cells are one of the main types of immune cells. They detect infections and activate other immune cells to fight the infection.

Your thymus develops helper T cells. The thymus is a small gland in the front of your chest. The other types of T cells include:

• Cytotoxic T cells, which fight infections.
• Regulatory T cells, which regulate or suppress other immune cells when needed.
• NKT cells, which can enhance immunity in general.

What is the role of helper T cells in adaptive immune response?

Helper T cells are one of the most important parts of your adaptive immunity. They’re involved in almost all adaptive immune responses. They activate two types of cells:

• B cells, which produce antibodies, the chemicals designed to fight specific foreign substances.
• Cytotoxic T cells, another type of T cell that kills infections.

What are the subtypes of helper T cells?

When helper T cells detect an infection, they form into one of two subtypes:

• TH1 helper cells release a molecule that activates a type of cell called a macrophage. Macrophages are specialized cells that help eliminate foreign substances from your body. TH1 cells also activate cytotoxic T cells.
• TH2 helper cells release molecules that activate B cells. B cells create antibodies. They also release cells that cause coughing, sneezing or diarrhea to help your body get rid of foreign substances. This group of T cells helps generate allergy antibodies.

What is the function of helper T cells?

Helper T cells activate other immune cells that attack and destroy foreign substances.

How are helper T cells activated?

Helper T cells have a receptor on their surface called a CD4 receptor. The CD4 receptor interacts with major histocompatibility complex (MHC) class II molecules. MHC class II molecules sense when there’s an infection or foreign substance in your body.

The CD4 receptor and MHC class II molecules activate the helper T cells. The helper T cells release molecules called cytokines. Cytokines send messages to other immune cells to start an immune response.

How do helper T cells work with cytotoxic T cells?

The cytokines released by helper T cells help activate cytotoxic T cells. Cytotoxic T cells send out molecules to fight the infection. Cytotoxic T Cells can also recognize cells that are infected and directly kill them to prevent further infection.

Where are helper T cells located?

T cells start in your bone marrow, the spongey substance that fills some of your bones. They move to your thymus while they’re developing. Your thymus helps your T cells mature, and then circulates them throughout your body. Your thymus also teaches your T cells how to know the difference between your body and the pathogen that’s infecting it.

You have numerous T cells throughout your lymphatic system. You have high concentrations of helper T cells in your:

• Bone marrow.
• Intestines.
• Lungs.
• Lymph nodes.
• Spleen.
• Tonsils.

What are the common conditions and disorders that affect helper T cells?

Several types of autoimmune diseases affect your T cells. Other conditions that affect your T cells include:

• Acute lymphocytic leukemia, a type of cancer that starts in your blood and bone marrow.
• Adult Hodgkin lymphoma, a disease in which cancer cells start in your lymph system.
• HIV, a virus that attacks your white blood cells and potentially leads to AIDS.
• Job syndrome, a rare immune system disorder that causes repeat infections.
• Thymic aplasia, a condition in which you’re born with an underdeveloped thymus.

What simple lifestyle changes keep my immune system healthy?

Some lifestyle changes can keep your immune system healthy. You may:

• Avoid alcohol or consume it in moderation only.
• Eat a diet filled with fruits, vegetables, whole grains, lean proteins and healthy fats.
• Exercise consistently, incorporating strengthening, flexibility and aerobic activities.
• Sleep at least seven to eight hours nightly.
• Quit smoking or don’t start.
• Wash your hands frequently with soap and water to avoid germs.

A note from Cleveland Clinic

Helper T cells are a type of immune cell. When they sense an infection, they activate other immune cells to fight it. They may activate cytotoxic T cells or they may activate B cells, which produce antibodies. Your helper T cells are one the most important types of cells involved in your adaptive immune response.