title: Distinct courses of infection with Leishmania (L.) amazonensis are observed in BALB/c, BALB/c nude and C57BL/6 mice.
abstract: Leishmania (L.) amazonensis [L. (L.) amazonensis] is widely distributed in Brazil and its symptomatic infections usually lead to few localized lesions and sometimes to diffuse cutaneous form, with nodules throughout the body, anergy to parasite antigens and poor therapeutic response. The variability of these manifestations draws attention to the need for studies on the pathophysiology of infection by this species. In this study, we analysed the course and immunological aspects of L. (L.) amazonensis infection in BALB/c and C57BL/6 strains, both susceptible, but displaying different clinical courses, and athymic BALB/c nude, to illustrate the role of T cell dependent responses. We analysed footpad thickness and parasite burden by in vivo imaging. Furthermore, we evaluated the cellular profile and cytokine production in lymph nodes and the inflammatory infiltrates of lesions. Nude mice showed delayed lesion development and less inflammatory cells in lesions, but higher parasite burden than BALB/c and C57BL/6. BALB/c and C57BL/6 mice had similar parasite burdens, lesion sizes and infiltrates until 6 weeks after infection, and after that C57BL/6 mice controlled the infection. Small differences in parasite numbers were observed in C57BL/6 macrophages in vitro, indicating that in vivo milieu accounts for most differences in infection. We believe our results shed light on the role of host immune system in the course of L. (L.) amazonensis infection by comparing three mouse strains that differ in parasitaemia and inflammatory cells.
authors.affiliation: Department of Parasitology,Institute of Biomedical Sciences,University of São Paulo,São Paulo,Brazil.
authors.forename: Leonardo G
authors.initials: LG
authors.lastname: Velasquez
authors.affiliation: Department of Parasitology,Institute of Biomedical Sciences,University of São Paulo,São Paulo,Brazil.
authors.forename: Mariana K
authors.initials: MK
authors.lastname: Galuppo
authors.affiliation: Department of Parasitology,Institute of Biomedical Sciences,University of São Paulo,São Paulo,Brazil.
authors.forename: Eloiza
authors.initials: E
authors.lastname: DE Rezende
authors.affiliation: Department of Immunology,Institute of Biomedical Sciences,University of São Paulo,São Paulo,Brazil.
authors.forename: Wesley N
authors.initials: WN
authors.lastname: Brandão
authors.affiliation: Department of Immunology,Institute of Biomedical Sciences,University of São Paulo,São Paulo,Brazil.
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Peron
authors.affiliation: Department of Parasitology,Institute of Biomedical Sciences,University of São Paulo,São Paulo,Brazil.
authors.forename: Silvia R B
authors.initials: SR
authors.lastname: Uliana
authors.affiliation: Department of Pathology,University of São Paulo School of Medicine,São Paulo,Brazil.
authors.forename: Maria Irma
authors.initials: MI
authors.lastname: Duarte
authors.affiliation: Department of Parasitology,Institute of Biomedical Sciences,University of São Paulo,São Paulo,Brazil.
authors.forename: Beatriz S
authors.initials: BS
authors.lastname: Stolf
mesh_terms: D000818:Animals; D016207:Cytokines / Q000276:immunology; D006790:Host-Parasite Interactions / Q000276:immunology*; D007891:Leishmania / Q000276:immunology; D016773:Leishmaniasis, Cutaneous / Q000276:immunology*; D008198:Lymph Nodes / Q000166:cytology; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D059208:Parasite Load; D013045:Species Specificity
chemical_list: D016207:Cytokines
keywords: Leishmania (L.) amazonensis; immune response; in vivo imaging; infection course; inflammation; mouse strains; nude mice; parasite burden