title: Mycobacterium leprae reactive T cell clones from lepromatous leprosy patients after prolonged dapsone chemotherapy.
abstract: The proliferative responses of peripheral blood mononuclear cells (PBMC) to Mycobacterium leprae and BCG were studied in two groups of leprosy patients: a group of 8 lepromatous patients who had been on treatment for more than 20 years (TLL) and a group of 8 untreated lepromatous leprosy patients (ULL). The mean response to M. leprae of the TLL group was 6195 cpm with 5 of the 8 patients responding positively. The mean response to M. leprae of the ULL group was 617 cpm, with only 1 patient showing a positive response. The corresponding proliferative responses to BCG were 19,908 cpm in the TLL group and 7908 in the ULL group. Thirteen M. leprae reactive clones were established from 2 TLL patients and 5 M. leprae reactive clones were established from 2 tuberculoid leprosy patients. Seven of these clones, 4 from the TLL patients and 3 from the tuberculoid (TT) patients could be studied further. Three of the TLL clones responded specifically to M. leprae, while one of the clones exhibited a broad cross-reactivity to other mycobacteria. All of these clones were of the CD4+CD8- phenotype. Our findings suggest that responsiveness to M. leprae can be detected in vitro in a proportion of LL patients who have undergone prolonged chemotherapy, and that this response involves M. leprae reactive CD8+CD8- T cells, of which some appear to be specific to M. leprae.
authors.affiliation: Immunology Division, Institute for Medical Research, Kuala Lumpur, Malaysia.
authors.forename: H K
authors.initials: HK
authors.lastname: Gill
authors.forename: D S
authors.initials: DS
authors.lastname: Ridley
authors.forename: J
authors.initials: J
authors.lastname: Ganesan
authors.forename: A S
authors.initials: AS
authors.lastname: Mustafa
authors.forename: R J
authors.initials: RJ
authors.lastname: Rees
authors.forename: T
authors.initials: T
authors.lastname: Godal
mesh_terms: D000942:Antigens, Bacterial / Q000276:immunology; D002999:Clone Cells; D003622:Dapsone / Q000627:therapeutic use*; D006801:Humans; D015440:Leprosy, Lepromatous / Q000188:drug therapy / Q000276:immunology*; D008213:Lymphocyte Activation; D009166:Mycobacterium leprae / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D003622:Dapsone