title: Immunisation with a major Trypanosoma cruzi antigen promotes pro-inflammatory cytokines, nitric oxide production and increases TLR2 expression.
abstract: Innate and adaptive immunity collaborate in the protection of intracellular pathogens including Trypanosoma cruzi infection. However, the parasite molecules that regulate the host immune response have not been fully identified. We previously demonstrated that the immunisation of C57BL/6 mice with cruzipain, an immunogenic T. cruzi glycoprotein, induced a strong specific T-cell response. In this study, we demonstrated that active immunisation with cruzipain was able to stimulate nitric oxide (NO) production by splenocytes. Immune cells also showed increased inducible nitric oxide synthase protein and mRNA expression. Spleen adherent cells secreted high levels of IFN-gamma and IL-12. Microbicidal activity in vitro was mainly mediated by reactive nitrogen intermediaries and IFN-gamma, as demonstrated by the inhibitory effects of NO synthase inhibitor or by IFN-gamma neutralisation. Specific T-cells were essential for NO, IFN-gamma and TNF-alpha production. Furthermore, we reported that cruzipain enhanced CD80 and major histocompatibility complex-II molecule surface expression on F4/80+ spleen cells. Interestingly, we also showed that cruzipain up-regulated toll like receptor-2 expression, not only in F4/80+ but also in total spleen cells which may be involved in the effector immune response. Our findings suggest that a single parasite antigen such as cruzipain, through adaptive immune cells and cytokines, can modulate the macrophage response not only as antigen presenting cells, but also as effector cells displaying enhanced microbicidal activity with reactive nitrogen intermediary participation. This may represent a mechanism that contributes to the immunoregulatory process during Chagas disease.
authors.affiliation: CIBICI-CONICET, Inmunología, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Haya de la Torre y Medina Allende S/N, (5000) Córdoba, Argentina.
authors.forename: Natalia
authors.initials: N
authors.lastname: Guiñazú
authors.forename: Andrea
authors.initials: A
authors.lastname: Pellegrini
authors.forename: Eugenio Antonio
authors.initials: EA
authors.lastname: Carrera-Silva
authors.forename: Maria Pilar
authors.initials: MP
authors.lastname: Aoki
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Cabanillas
authors.forename: Nuria
authors.initials: N
authors.lastname: Gìronés
authors.forename: Manuel
authors.initials: M
authors.lastname: Fresno
authors.forename: Roxana
authors.initials: R
authors.lastname: Cano
authors.forename: Susana
authors.initials: S
authors.lastname: Gea
mesh_terms: D000818:Animals; D018122:B7-1 Antigen / Q000276:immunology; D015415:Biomarkers / Q000032:analysis; D014355:Chagas Disease / Q000276:immunology / Q000517:prevention & control*; D003546:Cysteine Endopeptidases / Q000008:administration & dosage*; D016207:Cytokines / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000032:analysis; D015800:Protozoan Proteins; D016052:Protozoan Vaccines / Q000008:administration & dosage*; D013154:Spleen / Q000276:immunology*; D051195:Toll-Like Receptor 2 / Q000032:analysis; D051197:Toll-Like Receptor 4 / Q000032:analysis; D014349:Trypanosoma cruzi / Q000276:immunology*
chemical_list: D018122:B7-1 Antigen; D015415:Biomarkers; D016207:Cytokines; D000949:Histocompatibility Antigens Class II; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D018664:Interleukin-12; D009569:Nitric Oxide; D007371:Interferon-gamma; D052247:Nitric Oxide Synthase Type II; D003546:Cysteine Endopeptidases; C063214:cruzipain