Tissue immune response of Bos taurus and Bos indicus to acute Neospora caninum infection: comparative study

• Grant number: 05/01659-0
• Support Opportunities: Research Grants - Young Investigators Grants
• Start date: January 01, 2006
• End date: April 30, 2008
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Sandra Mayumi Nishi
• Grantee: Sandra Mayumi Nishi
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Rodrigo Martins Soares ; Solange Maria Gennari

Abstract

Neospora caninum infection is an important cause of abortion and natimortality in bovine cattle in several countries worldwide. Since its first description on 1988, advances on biological and epidemiological characterization has been done but there is no known effective control and treatment to date. Under experimental conditions, activation of specific protective mechanisms of the immune system can decrease abortion losses and parasite vertical transmission. However efficacy of vaccination programs under field conditions is still lower than expected. Host response individual variation, effect of gestation on immune system activity and parasite pathogenicity variation are the possible explanations to the transmission persistence. Differences between Bos taurus and Bos indicus resistance to ectoparasites and intestinal helminthes are well documented, but there is no information about variation against N. caninum infection. It is known that ectoparasites and helminthes induce Th2 type response and neosporosis is controlled by Th1 IFN-g mediated cellular immune response. Using IFN-g as a reference cytokine to study resistance to infection, the objective of the present project is to 1) quantitative immune related (IFN-g, TNF-a, IL-4, IL-10, TGF-b and iNOS) gene expression using Real-Time PCR in different tissues and 2) to identify immune cell populations (CD4+, CD8+ T cells and macrophages) by immunohistochemistry technique and that way, to investigate possible differences between Bos taurus and Bos indicus local immune responses against acute N. caninum infection. (AU)