title: In vitro initial immune response against Leishmania amazonensis infection is characterized by an increased production of IL-10 and IL-13.
abstract: The initial encounter of Leishmania with its host's immune system is important in the outcome of infection. Previous studies have shown that PBMCs from healthy volunteers (HV) exposed to Leishmania differ in IFN-γ production. We have expanded such observations evaluating the profile and kinetics of cytokines (IFN-γ, IL-12p70, IL-10, IL-13), chemokines (CCL5, CCL3, CCL4, CXCL10), and chemokine receptors (CCR1,CCR5, CXCR3, CCR4) in vitro L. amazonensis-stimulated of HV's PBMCs. HVs were divided in groups of high (HR) or low (LR) IFN-γ responders. In both groups, HR and LR, after L. amazonensis infection there was a predominance of IL-10 and IL-13 over IFN-γ production, while IL-12 was produced in similar amount. Regarding chemokines, a more striking difference was observed for CCL3 expression that was lower at 12 hours and 48 hours post infection in LR than in HR. Interestingly, a downregulation of CCR5 and a greater expression of CCR4 were found in low IFN-γ responders. These data suggest that early after L. amazonensis infection there is a cytokine milieu dominated by IL-13 and IL-10, and despite of this environment, IFN-γ is produced, supporting the complexity of the response. It is noteworthy that the pattern of immune response is mounted in first hours after Leishmania stimulation, with the definition of the differentiation of Th1 versus Th2 cells. It remains to be determined if such an in vitro difference has an in vivo counterpart in terms of susceptibility to infection.
authors.affiliation: Medical School of Universidade Federal do Ceará, Rua Alexandre Baraúna, Fortaleza, Brazil.
authors.forename: Zirlane Castelo B
authors.initials: ZC
authors.lastname: Coêlho
authors.forename: Maria Jania
authors.initials: MJ
authors.lastname: Teixeira
authors.forename: Erika Freitas
authors.initials: EF
authors.lastname: Mota
authors.forename: Mércia Sindeaux
authors.initials: MS
authors.lastname: Frutuoso
authors.forename: João Santana da
authors.initials: JS
authors.lastname: Silva
authors.forename: Aldina
authors.initials: A
authors.lastname: Barral
authors.forename: Manoel
authors.initials: M
authors.lastname: Barral-Netto
authors.forename: Margarida Maria L
authors.initials: MM
authors.lastname: Pompeu
mesh_terms: D016207:Cytokines / Q000096:biosynthesis; D016054:DNA, Protozoan / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D006790:Host-Parasite Interactions / Q000276:immunology*; D006801:Humans; D056724:Immunity, Humoral / Q000276:immunology*; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000276:immunology; D018793:Interleukin-13 / Q000096:biosynthesis* / Q000276:immunology; D007894:Leishmania mexicana / Q000276:immunology* / Q000502:physiology; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000469:parasitology*; D016053:RNA, Protozoan / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D016207:Cytokines; D016054:DNA, Protozoan; D018793:Interleukin-13; D016053:RNA, Protozoan; D016753:Interleukin-10