title: T follicular helper (Tfh ) cells in normal immune responses and in allergic disorders.
abstract: Follicular helper T cells (Tfh ) are located within germinal centers of lymph nodes. Cognate interaction between Tfh , B cells, and IL-21 drives B cells to proliferate and differentiate into plasma cells thereby leading to antibody production. Tfh cells and IL-21 are involved in infectious and autoimmune diseases, immunodeficiencies, vaccination, and cancer. Human peripheral blood CXCR5(+) CD4(+) T cells comprise different subsets of Tfh -like cells. Despite the importance of the IgE response in the pathogenesis of allergic disorders, little is known about the role of follicular and blood Tfh cells and IL-21 in human and experimental allergic disease. Here, we review recent advances regarding the phenotypic and functional characteristics of both follicular and blood Tfh cells and of the IL-21/IL-21R system in the context of allergic disorders.
authors.affiliation: Immunomodulation and Tolerance Group, Imperial College London, London, UK.|Allergy and Clinical Immunology, Imperial College London, London, UK.
authors.forename: G
authors.initials: G
authors.lastname: Varricchi
authors.affiliation: Inflammation, Repair & Development Section, Faculty of Medicine, National Heart and Lung Institute, Imperial College London, London, UK.|MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK.
authors.forename: J
authors.initials: J
authors.lastname: Harker
authors.affiliation: Department of Translational Medical Sciences and Center for Basic and Clinical Immunology Research (CISI), School of Medicine, University of Naples Federico II, Naples, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Borriello
authors.affiliation: Department of Translational Medical Sciences and Center for Basic and Clinical Immunology Research (CISI), School of Medicine, University of Naples Federico II, Naples, Italy.|CNR Institute of Experimental Endocrinology and Oncology 'G. Salvatore', Naples, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Marone
authors.affiliation: Immunomodulation and Tolerance Group, Imperial College London, London, UK.|Allergy and Clinical Immunology, Imperial College London, London, UK.
authors.forename: S R
authors.initials: SR
authors.lastname: Durham
authors.affiliation: Immunomodulation and Tolerance Group, Imperial College London, London, UK.|Allergy and Clinical Immunology, Imperial College London, London, UK.
authors.forename: M H
authors.initials: MH
authors.lastname: Shamji
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002450:Cell Communication / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D018858:Germinal Center / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology* / Q000378:metabolism*; D055633:Immune System Phenomena; D007109:Immunity; D007378:Interleukins / Q000378:metabolism; D051379:Mice; D023421:Models, Animal; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D000098546:Interleukin-21
chemical_list: D007378:Interleukins; D000098546:Interleukin-21
keywords: Allergen immunotherapy; Allergy; IL-21; IL-4; IgE; T cells; T follicular helper cells