Quantificação de mRNA de genes relacionados à resposta imune em bovinos infectados com endoparasitos do gênero Haemonchus spp

Abstract

Brazilian livestock production presents great impact for the national agriculture, possessing the largest bovine commercial herd of the world. However, the productivity is low and gastrintestinal diseases caused by Haemonchus spp are one of the major constraints to the production. It is known that those parasites are responsible for many immunological responses in the host. Cytokine polarization Th1/Th2 has been studied to understand the infections caused by nematodes. However, the studies that try to understand immune response of cattle with Haemonchus spp are still scarce. The goal of this work was to verify differences in the mRNA abundance of genes involved in immune response of calves of Nelore breed (Bos indicus) submitted to the first infection with Haemonchus spp, relating these differences to patterns of cellular infiltrate. Genes were evaluated by real time PCR and relative quantification was made by the software Relative Expression Software Tool. Results showed up-regulation of the interleukins IL-4 (p≤0.05) and IL- 13 (p≤0.05) in the lymph node of challenged animals. No significant differences (p > 0.05) were found in mRNA abundance for the genes analyzed in abomasum. There were no significant differences for mast cells and eosinophil counts in abomasal tissue among analyzed groups. From the results, it can be concluded that for the short infection time, there was increased polarization of Th2 in lymph node, but it was not seen in abomasal tissue.