title: Induction of lepromin reactivity in cured lepromatous leprosy patients: impaired chemokine response dissociates protective immunity from delayed type hypersensitivity.
abstract: Delayed Type Hypersensitivity (DTH) and protective immunity are thought to be tightly linked. Remarkable similarity exists between their cellular and immune mechanisms. However, their dissociation is also well known. Here we investigate the immunological mechanisms relevant for their dissociation in a group of non-relapsing cured lepromatous leprosy (CLL) patients. In these patients, using lepromin reaction as a model system of DTH we report critical role of tissue chemokine response in synchronous manifestation of these linked phenomena. Results indicate elevation of the threshold of tissue chemokine induction thus dissociating DTH from protective immunity in lepromin -ive CLL patients. We also show that the DTH anergy in these subjects is not an absolute one but depends on the strength of the stimulus. Our data provide insights into the intricate relationship between DTH and immunity and highlight the persistent presence of effector immune mechanisms involving these two pathways in apparently unresponsive lepromatous leprosy patients.
authors.affiliation: Department of Transplant Immunology and Immunogenetics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India. salilmitra1@yahoo.com
authors.forename: Dipendra K
authors.initials: DK
authors.lastname: Mitra
authors.forename: Beenu
authors.initials: B
authors.lastname: Joshi
authors.forename: Amit K
authors.initials: AK
authors.lastname: Dinda
authors.forename: Ambak K
authors.initials: AK
authors.lastname: Rai
authors.forename: B K
authors.initials: BK
authors.lastname: Girdhar
authors.forename: Kiran
authors.initials: K
authors.lastname: Katoch
authors.forename: Maninder S
authors.initials: MS
authors.lastname: Bindra
authors.forename: Utpal
authors.initials: U
authors.lastname: Sengupta
mesh_terms: D018925:Chemokines / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007109:Immunity / Q000276:immunology; D007916:Lepromin / Q000276:immunology*; D015440:Leprosy, Lepromatous / Q000276:immunology* / Q000382:microbiology; D008213:Lymphocyte Activation; D009166:Mycobacterium leprae / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D018925:Chemokines; D007916:Lepromin