Myeloid differentiation factor 88 is required for resistance to Neospora caninum infection

Autor(es)

Mineo, Tiago W. P. ^{[1, 2]} ; Benevides, Luciana ^[1] ; Silva, Neide M. ^[2] ; Silva, Joao S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Biochem & Immunol, BR-14049 Ribeirao Preto, SP - Brazil

^[2] Univ Fed Uberlandia, Inst Biomed Sci, BR-38400 Uberlandia, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: VETERINARY RESEARCH; v. 40, n. 4, p. 32-32, 2009.
• Citações Web of Science: 20

Resumo

Neospora caninum is an intracellular parasite that causes major economic impact on cattle raising farms, and infects a wide range of warm-blooded hosts worldwide. Innate immune mechanisms that lead to protection against this parasite are still unknown. In order to investigate whether myeloid differentiation factor 88 (MyD88) is required for resistance against N. caninum, genetically deficient mice (MyD88(-/-)) and wild type littermates were infected with live tachyzoites and the resistance to infection was evaluated. We found that sub-lethal tachyzoite doses induced acute mortality of MyD88(-/-) mice, which succumbed to infection due to uncontrolled parasite replication. Higher parasitism in MyD88(-/-) mice was associated with the lack of IL-12 production by dendritic cells, delayed IFN-gamma responses by NKT, CD4(+) and CD8(+) T lymphocytes, and production of high levels of IL-10. MyD88(-/-) mice replenished with IL-12 and IFN-gamma abolished susceptibility as the animals survived throughout the experimental period. We conclude that protective IFN-gamma-mediated immunity to N. caninum is dependent on initial MyD88 signaling, in a mechanism triggered by production of IL-12 by dendritic cells. Further knowledge on Toll-like receptor recognition of N. caninum antigens is encouraged, since it could generate new prophylactic and therapeutic tools to control parasite burden. (AU)

• Processo FAPESP: 06/06803-4 - Avaliação do papel de receptores do tipo Toll na resposta imune ao Neospora caninum
• Beneficiário: Tiago Wilson Patriarca Mineo
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado