Follicular helper T lymphocytes (TFH) in health and disease

Abstract

A correct antibody response requires the participationof both B and T lymphocytes and antigen presentingcells. In this review we address the role of follicularhelper T lymphocytes (TFH) in this reaction. We shall focuson the regulation of their development and functionin health and disease. TFH can be characterized on thebasis of their phenotype and the pattern of secretionof cytokines. This fact is useful to study their participationin the generation of antibody deficiency in primaryimmunodeficiency diseases such as common variableimmunodeficiency, X-linked hyper IgM syndrome orX-linked lymphoproliferative disease. Increased numbersof TFH have been demonstrated in several autoimmunediseases and are thought to play a role in thedevelopment of autoantibodies. In chronic viral infectionscaused by the human immunodeficiency virus,hepatitis B or C virus, increased circulating TFH havebeen observed, but their role in the protective immuneresponse to these agents is under discussion. Likewise,an important role of TFH in the control of some experimentalprotozoan infections has been proposed, and itwill be important to assess their relevance in order todesign effective vaccination strategies.