Page 412 - Veterinary Immunology, 10th Edition

VetBooks.ir Helper T Cell Subpopulations

+
CD4 T cells are very diverse. As naïve T cells develop and
differentiate, four major subpopulations emerge. They are called

helper 1 (Th1), helper 2 (Th2), helper 17 (Th17), and regulatory
(Treg) cells, and each is distinguished by the mixture of cytokines
that they secrete (Fig. 14.13). As always, many of the details of their
function have been investigated in mice and humans, and it must
not be assumed that they function in a completely identical manner

in other mammals.

FIG. 14.13 The major populations of helper T cells. Note that their
differentiation is induced by different mixtures of polarizing
cytokines. These induce specific transcription factors in each
population. Once polarized, the T cells synthesize and secrete
different mixtures of effector cytokines.

412