title: Immunotherapy with live BCG plus heat killed Leishmania induces a T helper 1-like response in American cutaneous leishmaniasis patients.
abstract: Previous work has shown that American cutaneous leishmaniasis (ACL) patients treated with viable BCG plus heat killed promastigotes of Leishmania amazonensis show the same rate of cure as patients receiving conventional chemotherapy. The treatment is safe and economical, but the immunological correlates of cure have not been examined. In the present study, T cell responses have been analysed in 43 ACL patients, including patient groups sampled before and after therapy, and in 10 endemic controls. Lymphocyte proliferation, interferon (IFN)-gamma and interleukin (IL)-5 responses to crude antigen (L. amazonensis, MEL; Mycobacterium tuberculosis PPD; M. bovis BCG) stimulation, and serum IL-5 levels, were analysed. In endemic volunteers, proliferative responses to BCG were high and IFN-gamma responses low. In contrast, localized cutaneous (LCL) and mucocutaneous (MCL) patients showed low proliferative and high IFN-gamma responses to BCG. Treatment enhanced the IFN-gamma response and further decreased the proliferative response to BCG, especially in MCL patients. LCL and MCL patients showed an increase in proliferative and IFN-gamma responses to MEL with treatment, but the response was not exaggerated in MCL patients, either before or after treatment, compared to LCL patients. IL-5 production was low in T cell assays, and > 62% of untreated patients had very low serum IL-5 levels. There were no significant changes in serum IL-5 with treatment. Overall results show enhanced antigen-specific IFN-gamma responses to the two components of the immunotherapy, live M. bovis BCG and heat killed L. amazonensis, which is consistent with a shift in balance of T cell response towards a T helper 1 response and clinical cure mediated by IFN-gamma.
authors.affiliation: Instituto de Biomedicina, Facultad de Medicina, Universidad Central de Venezuela, Apdo 4043 (Carmelitas), Caracas 1010-A Venezuela.
authors.forename: M
authors.initials: M
authors.lastname: Cabrera
authors.forename: J M
authors.initials: JM
authors.lastname: Blackwell
authors.forename: M
authors.initials: M
authors.lastname: Castes
authors.forename: D
authors.initials: D
authors.lastname: Trujillo
authors.forename: J
authors.initials: J
authors.lastname: Convit
authors.forename: M A
authors.initials: MA
authors.lastname: Shaw
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000981:Antiprotozoal Agents / Q000627:therapeutic use; D001500:BCG Vaccine / Q000627:therapeutic use*; D002455:Cell Division; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000097:blood; D015848:Interleukin-5 / Q000097:blood; D007891:Leishmania / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000097:blood / Q000276:immunology* / Q000628:therapy; D007897:Leishmaniasis, Mucocutaneous / Q000097:blood / Q000276:immunology / Q000628:therapy; D008213:Lymphocyte Activation; D008297:Male; D008536:Meglumine / Q000627:therapeutic use; D000077485:Meglumine Antimoniate; D008875:Middle Aged; D009163:Mycobacterium bovis / Q000276:immunology; D009942:Organometallic Compounds / Q000627:therapeutic use; D016052:Protozoan Vaccines / Q000494:pharmacology / Q000627:therapeutic use*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D014373:Tuberculin / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000981:Antiprotozoal Agents; D001500:BCG Vaccine; D015848:Interleukin-5; D009942:Organometallic Compounds; D016052:Protozoan Vaccines; D014373:Tuberculin; D008536:Meglumine; D000077485:Meglumine Antimoniate; D007371:Interferon-gamma