Effect Of Early Pregnancy On Expression Of Th1 And Th2 Cytokines In Bovine Peripheral Blood Mononuclear Cells

Peripheral blood mononuclear cells contains lymphocytes and monocytes which are originated form bone marrow hematopoietic stem cells, involved in systemic immune as a whole through blood circulation or lymphatic circulation to reach tissue or organ in the body. In order to study the regular pattern of expression of Th1 and Th2 cytokines in bovine peripheral blood mononuclear cells, 12 healthy Holsteins were used to investigate peripheral blood mononuclear cells by density gradient centrifugation in this study. The change of expression of Th1 and Th2 cytokines in bovine peripheral blood mononuclear cells was analyzed using real-time fluorescence quantitative PCR, Western blot, immunocytochemistry during early pregnancy. The results were as the follows:1. Peripheral blood mononuclear cells were obtained successfully from bovine peripheral blood by density gradient centrifugation. The result of the separation showed that there was an obviously cell stratification, and the plasma, mononuclear cells, granulocytes, and red blood cells were from the upper to the lower in order. It was easy to obtain the cloudy mononuclear cells by this method.2. The results of real-time quantitative PCR detection showed that expression of IFN-γ, as a Th1-type cytokine, decreased in bovine peripheral blood mononuclear cells during early pregnancy, but TNF-α and IL-2 expression gradually increased. However, expressions of Th2-type cytokines, including IL-4, IL-5, IL-6, IL-10 and IL-13, were gradually increased in bovine peripheral blood mononuclear cells at the 30 days of gestation. In short, the expressions of Th2 cytokines increased in bovine peripheral blood mononuclear cells during early pregnancy, which was essential for successful pregnancy in cattle.3. Effect of early pregnancy on expression of IFN-γ in bovine peripheral blood mononuclear cells was analyzed by Western blot detection. The results indicated that the expression of IFN-γ in non-pregnant bovine peripheral blood mononuclear cells is higher than that in pregnant cows. It was found that the decreasing expression of IFN-γ protein is critical during early pregnancy in the bovine.4. The result of immunocytochemistry also confirmed that the levels of IFN-γ expression in non-pregnant 18 cows were higher than that in 18 and 30 days of pregnant cows in peripheral blood mononuclear cells, and there was a strong immune staining for IFN-γ in the cytoplasm of peripheral blood mononuclear cells, with stronger immune staining for IFN-γ in mononuclear cells than in lymphocytes.