title: T helper cells in leprosy: An update.
abstract: Leprosy is an ancient disease caused by gram positive, rod shaped bacilli called Mycobacterium leprae. Patients present with varied clinico-pathological disease depending on the host immune response to Mycobacterium leprae. Thus tuberculoid (TT) and lepromatous (LL) patients represent two ends of a spectrum where the former shows limited disease, high T cell mediate immune (CMI) response and low antibody (HI) levels in serum. In contrast the latter has low T cell and high humoral immune response i.e antibody levels. The mechanisms underlying these differences have been investigated intensely; however, there is no consensus on the primary immunological basis. Over three decades, Th1 and Th2 paradigm were thought to underling tuberculoid and lepromatous disease respectively. However many patients were shown to have mixed Th1/Th2 pattern of (IFN-γ/IL-4) cytokines. The present review was undertaken with a view to understand the T cells and cytokine dysregulation in leprosy. In recent years the sub classes of T cells that are Regulatory in nature (Treg) have been implicated in immune diseases where they were shown to suppress T cell functions. Additionally Th17 cells secreting IL-17A, IL17F, were implicated in immune inflammation. Taken together these regulatory cells may play a part in influencing immune responses in leprosy.
authors.affiliation: Department of Biochemistry, All India Institute of Medical sciences, New Delhi 110029, India. Electronic address: chamansaini82@gmail.com.
authors.forename: Chaman
authors.initials: C
authors.lastname: Saini
authors.affiliation: Department of Biochemistry, All India Institute of Medical sciences, New Delhi 110029, India.
authors.forename: Mohd
authors.initials: M
authors.lastname: Tarique
authors.affiliation: Department of Biochemistry, All India Institute of Medical sciences, New Delhi 110029, India.
authors.forename: Reeta
authors.initials: R
authors.lastname: Rai
authors.affiliation: Department of Zoology, Barnagar Science College, Ujjain, M.P, India.
authors.forename: Anisuddin
authors.initials: A
authors.lastname: Siddiqui
authors.affiliation: Department of Dermatology, All India Institute of Medical sciences, New Delhi 110029, India.
authors.forename: Neena
authors.initials: N
authors.lastname: Khanna
authors.affiliation: Department of Biochemistry, All India Institute of Medical sciences, New Delhi 110029, India. Electronic address: dralpanasharma@gmail.com.
authors.forename: Alpana
authors.initials: A
authors.lastname: Sharma
mesh_terms: D000818:Animals; D017635:Clonal Anergy / Q000276:immunology; D016207:Cytokines / Q000378:metabolism; D018450:Disease Progression; D004198:Disease Susceptibility; D054884:Host-Pathogen Interactions / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular; D007918:Leprosy / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D009166:Mycobacterium leprae / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000378:metabolism
chemical_list: D016207:Cytokines
keywords: T helper cells; Th17; Treg and anergy