title: Interleukin-12 restores interferon-gamma production and cytotoxic responses in visceral leishmaniasis.
abstract: American visceral leishmaniasis (AVL) is associated with the absence of lymphocyte proliferative responses and interleukin (IL)-2 and interferon-gamma (IFN-gamma) production upon stimulation with Leishmania antigen. In contrast, cure of AVL is associated with restoration of these T cell functions. In the present study, the ability of IL-12, a cytokine that acts on NK and T cells to restore cellular immune responses in AVL, was evaluated. Participants of the study included 12 patients with AVL and 7 subjects cured of AVL. The [3H]thymidine uptake and IFN-gamma production in cultures of peripheral blood mononuclear cells (from AVL patients) stimulated with Leishmania chagasi antigen were 882 +/- 1393 cpm and zero, respectively. Addition of IL-12 enhanced the proliferative response to 5097 +/- 6429 cpm (P < .001) and IFN-gamma production to 305 +/- 325 pg/mL (P < .01). IL-12 also restored cytotoxic activity against the K562 cell line. These results indicate that IL-12 has an important role in the regulation of the cellular immune response in human leishmaniasis.
authors.affiliation: Immunology Service of Hospital Universitário Professor Edgard Santos, Federal University of Bahia, Brazil.
authors.forename: O
authors.initials: O
authors.lastname: Bacellar
authors.forename: C
authors.initials: C
authors.lastname: Brodskyn
authors.forename: J
authors.initials: J
authors.lastname: Guerreiro
authors.forename: M
authors.initials: M
authors.lastname: Barral-Netto
authors.forename: C H
authors.initials: CH
authors.lastname: Costa
authors.forename: R L
authors.initials: RL
authors.lastname: Coffman
authors.forename: W D
authors.initials: WD
authors.lastname: Johnson
authors.forename: E M
authors.initials: EM
authors.lastname: Carvalho
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D004247:DNA / Q000096:biosynthesis; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D016753:Interleukin-10 / Q000276:immunology; D018664:Interleukin-12 / Q000494:pharmacology*; D018314:Leishmania infantum / Q000276:immunology; D007898:Leishmaniasis, Visceral / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D011994:Recombinant Proteins / Q000494:pharmacology
chemical_list: D000953:Antigens, Protozoan; D011994:Recombinant Proteins; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma; D004247:DNA