Definition: Helper T cells have the function to help other immune cells through the production and secretion of cytokines. These T cells can be divided into different subsets. The subsets are based on the expression of particular surface markers and on the cytokine production of the helper T cell.
Types of Helper T Cells:
-> CD 4-expressing T Helper Cells: They help B cells and to assist them in the process of differentiation into plasma cells. Helper T cells are able to do that by producing and secreting cytokines like IL-4. In addition, in order to help the particular B cell, the T cell has to be in direct contact with it.
-> TH1 Helper Cells: These helper cells secrete TNF and interferon gamma. "TNF" stands for tumor necrosis factor. Interferon gamma helps with the activation of macrophages and stimulation of an inflammatory response. In addition, TH1 helper cells produce antibodies, such as IgG1 and IgG3. <u</u>
-> TH2 Helper Cells: These helper cells secrete IL-10 and IL-4. IL-4 aids B cell class switching to the IgE and IgG1 isotypes.
-> TH17 Helper Cells: These helper cells secrete IL-17.