Helper T cells

T helper cell (TH cells) assist other white blood cells in immunologic processes, including maturation of B cells into plasma cells and B memory cells, and activation of cytotoxic T cells and macrophages, among other functions. These cells are also known as CD4+ T cells because they express the CD4 protein on their surface. Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules that are expressed on the surface of Antigen Presenting Cells (APCs). Once activated, they divide rapidly and secrete small proteins called cytokines that regulate or assist in the active immune response. These cells can differentiate into one of several subtypes, including TH1, TH2, TH3, TH17, or TFH, which secrete different cytokines to facilitate a different type of immune response. The mechanism by which T cells are directed into a particular subtype is poorly understood, though signalling patterns from the APC are thought to play an important role.

http://en.wikipedia.org/wiki/T_cell#Helper

http://en.wikipedia.org/wiki/T_helper_cell

TH17

Associates with "autoimmune" conditions. http://en.wikipedia.org/wiki/T_helper_17_cell

Compound Effectively Halts Progression of Multiple Sclerosis in Animal Model http://www.sciencedaily.com/releases/2011/04/110418093846.htm