title: Analysis of the cytokine profile in spleen cells from dogs naturally infected by Leishmania chagasi.
abstract: Recent studies suggest that asymptomatic dogs infected with canine visceral leishmaniasis (CVL) develop a Th1 immunological profile whilst oligosymptomatic and symptomatic CVL-infected animals present a Th2 profile. In the present study, an RT-PCR method has been standardised and employed to evaluate the frequency and the semi-quantitative level of expression of the cytokines IL-4, IL-10, IL-12, INF-gamma and TNF-alpha in splenocytes of 30 dogs naturally infected with Leishmania chagasi and of 7 non-infected dogs (NID). An increase in the level of expression of IL-12 (p=0.059) was detected in all CVL-infected dogs compared with NID. In dogs exhibiting high parasitism, the frequency of expression of IL-10 was higher (p=0.011) than in animals presenting low parasitism or medium parasitism (MP) and in NID animals, whilst the level of expression of IL-10 was higher (p=0.0094) than in animals exhibiting MP and in the NID group. Positive correlations between the levels of expression of IL-10 with respect to the progression of the disease (IL-10: r=0.3510; p=0.0337) and the levels of expression of IL-10 and INF-gamma increase in parasitism (IL-10: r=0.3428; p=0.0438 and INF-gamma: r=0.4690; p=0.0045) were observed. Such data suggest that CVL is marked by a balanced production of Th1 and Th2 cytokines, with a predominant accumulation of IL-10 as a consequence of an increase in parasitic load and progression of the disease, and INF-gamma was related with the increase in parasitic load.
authors.affiliation: Laboratório de Imunologia Celular e Molecular, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: R S
authors.initials: RS
authors.lastname: Lage
authors.forename: G C
authors.initials: GC
authors.lastname: Oliveira
authors.forename: S U
authors.initials: SU
authors.lastname: Busek
authors.forename: L L
authors.initials: LL
authors.lastname: Guerra
authors.forename: R C
authors.initials: RC
authors.lastname: Giunchetti
authors.forename: R
authors.initials: R
authors.lastname: Corrêa-Oliveira
authors.forename: A B
authors.initials: AB
authors.lastname: Reis
mesh_terms: D000818:Animals; D016207:Cytokines / Q000235:genetics*; D004283:Dog Diseases / Q000276:immunology*; D004285:Dogs; D018314:Leishmania infantum; D007898:Leishmaniasis, Visceral / Q000276:immunology / Q000662:veterinary*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000276:immunology*
chemical_list: D016207:Cytokines; D012333:RNA, Messenger