title: Development of T follicular helper cells and their role in disease and immune system.
abstract: The T follicular helper cells (TFH) are a subset of CD4+ T cells specialized to regulate antibody responses. The production of these cells is associated with the dendritic cells (DCs) and B cells. TFH cells help B cells form germinal centers (GC) differentiate into memory and plasma cells (antibody-secreting cells) as humoral responses. In addition, there is strong evidence that TFH cells play a pivotal role in the development of long-lived humoral immunity. Molecular factors such as transcription factors, surface receptors, cytokine and micro RNAs are involved in the formation of TFH cells. Such TFH cells are diagnosed by transcription factor (BCL-6), surface marker expression (including CXCR5, PD-1, ICOS and CD40L) and a unique cytokine production pattern (such as IL-21 and IL-6). Memory TFH cells, accompanied by memory B cells, are known to be formed during antibody responses. It is now clear that the precise control of TFH cells is critically important for both inducing the optimal affinity maturation of antibody responses and preventing self-reactivity. Exclusive controls of TFH cell function and production are essential for human health. However, it is important to note that excessive activities may lead to autoimmune diseases, while reduced activity often results in immunodeficiency. It has also been shown that TFH cells are associated with cancers such as angioimmunoblastic T-cell lymphoma (AITL), follicular T-cell lymphoma (FTCL) and nonspecific Peripheral T-cell lymphomas (PTCLs). The biology of TFH cells, including their differentiation and transcriptional regulation will be described in the present review. Some of The developments of these cells in immunodeficiency diseases, autoimmunity and cancer will also be taken into account.
authors.affiliation: Department of Anatomy, Faculty of Medicine. Iran University Medical Sciences, Tehran, Iran.
authors.forename: Sadegh
authors.initials: S
authors.lastname: Eivazi
authors.affiliation: Department of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Hybridoma Lab., Immunology Dept., Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Salman
authors.initials: S
authors.lastname: Bagheri
authors.affiliation: Applied Virology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Sadegh
authors.initials: MS
authors.lastname: Hashemzadeh
authors.affiliation: Applied Virology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Majdedin
authors.initials: M
authors.lastname: Ghalavand
authors.affiliation: Department of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Hybridoma Lab., Immunology Dept., Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Elmira Safaie
authors.initials: ES
authors.lastname: Qamsari
authors.affiliation: Applied Virology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran. Electronic address: R.dorost@yahoo.com.
authors.forename: Ruhollah
authors.initials: R
authors.lastname: Dorostkar
authors.affiliation: Microbial biotechnology, Islamic azad University Damghan branch, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Yasemi
mesh_terms: D000818:Animals; D004194:Disease; D006801:Humans; D007107:Immune System / Q000276:immunology*; D007109:Immunity; D007156:Immunologic Memory; D008954:Models, Biological; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
keywords: Autoimmune diseases; Cancer; Cytokine; Immunodeficiency; T cell; TFH cell