RESUMO
In the present study, we examined profiles of the interaction of Mycobacterium leprae and Mycobacterium avium complex (MAC) with murine peritoneal macrophages (M phi s) in terms of up-regulation of M phi expression of proinflammatory and immunosuppressing cytolines (CKs) after infection. First, the reverse transcription polymerase chain reaction (RT-PCR) assay revealed that both MAC and M. leprae infections up-regulated M phi mRNA expression IL-12, TNF-alpha, IL-10, and transformating growth factor-beta (TGF-beta), except that M. leprae-infected M phi s showed no increase in the IL-12 mRNA expression. Second, the RT-PCR assay also showed some differences between M. leprae- and MAC-infected M phi s with respect to the modes of IL-10 and inducible nitric oxide synthase (iNOS) mRNA expression. That is MAC, but not M. leprae, infection caused a prolonged increase in the expression of IL-10 and iNOS mRNAs. Third, a ribonuclease protection assay revealed that M phi s co-infected with MAC and M. leprae showed the Il-12, TNF-alpha and IL-10 mRNA expression in an intermediate mode of those of M phi s infected with either M. leprae or MAC alone. This implies that the CK expression of M. leprae-infected M phi s may be modified by co-infection with MAC. These findings may suggest differential interactions of M. leprae and MAC organisms with murine peritoneal M phi s in terms of the activation of signal transduction pathways for expression of some kinds of immunoregulatory cytokines and immunoprotective enzymes.
Assuntos
RNA , Macrófagos/citologia , Macrófagos/fisiologia , Mycobacterium avium/citologia , Mycobacterium avium/genética , Mycobacterium leprae/citologia , Mycobacterium leprae/genéticaRESUMO
Profiles of intercellular adhesion molecule-1 (ICAM-1) expression on murine peritoneal macrophages (M phi s) infected with Mycobacterium leprae during cultivation were examined with special reference to the regulatory effects of tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta). When M phi s were infected with M. leprae or stimulated with heat-killed M. leprae at day 0, their ICAM-1 expression, measured in terms of the ratio of M phi s positively stained with anti-ICAM-1 antibody (Ab), rapidly increased, peaking during days 1 to 3 and thereafter fell, returning to the normal level by day 7. The addition of TNF-alpha or anti-TGF-beta Ab inhibited the middle phase (day 7) downregulation of M phi ICAM-1 expression, although the late-phase (day 14) downregulation of ICAM-1 was not prevented by them. M. leprae-infected M phi s released small amounts of TNF-alpha and significant amounts of TGF-beta into the culture medium. This may indicate that M. leprae-infected M phi s produced the majority of TNF-alpha in a membrane-bound form. Alternatively, endogenous TNF-alpha might upregulate M phi ICAM-1 expression even at very low concentrations. In any case, these findings indicate the central roles of TNF-alpha and TGF-beta in the early phase upregulation and the middle-to-late phase downregulation, respectively, of ICAM-1 expression by M. leprae-infected M phi s.
Assuntos
Fator de Necrose Tumoral alfa/fisiologia , Fator de Necrose Tumoral alfa/imunologia , Macrófagos/imunologia , Macrófagos/microbiologia , Mycobacterium leprae/fisiologia , Mycobacterium leprae/imunologiaRESUMO
In the present study, we evaluated the in vivo anti-Mycobacterium leprae activities of KRM-1648 (KRM) given at long intervals in combination with ofloxacin (OFLX), clofazimine (CFZ), and dapsone (DDS). We also examined the combined effects of two biological response modifiers (BRMs), gamma interferon (IFN-gamma) and granulocyte-macrophage colony-stimulating factor (GM-CSF), on the therapeutic efficacy of KRM. KRM exhibited potent therapeutic efficacy against M. leprae infection in mice even when given at 4-week intervals. KRM displayed increased efficacy in combination with OFLX, CFZ, and DDS (given three or six times per week) when given to mice in the multidrug combination KRM + OFLX + CFZ + DDS. The therapeutic efficacy of KRM given at 4-week intervals was increased by combined use with IFN-gamma but not by GM-CSF. Adoptive transfer of M. leprae antigen-primed lymphocytes of euthymic mice to recipient athymic nude mice with progressive M. leprae infection markedly enhanced host resistance.
Assuntos
Hanseníase/tratamento farmacológico , Interferon gama/uso terapêutico , Ofloxacino/uso terapêutico , Rifamicinas/uso terapêuticoRESUMO
The susceptibilities of Mycobacterium leprae and M. avium complex (MAC) to the H2-O2-Fe-mediated halogenation system supplemented with antimicrobial agents were evaluated by fluorescein diacetate-ethidium bromide (FDA/EB) staining. In the case of M. leprae, the number of greenstained bacteria (intact cells) was reduced in the presence of the H2O2-Fe-mediated halogenation system supplemented with agents possessing antileprosy activity, such as rifampin, 4,4'-diaminodiphenylsulfone (dapsone), clofazimine, and ofloxacin. In the case of the MAC strain, although viable units of the organisms were reduced by the halogenation system alone, the number of greenstained cells in the FDA/EB stain was not reduced, even when the halogenation system was used in combination with ofloxacin. Because stainability of the cells is related to structural and functional intactness of the membrane, differences between M. leprae and the MAC strain imply possible differences in the rigidity of the cell membrane