Comparison of immune parameters in cows with normal and prolonged involution time of uterus

Abstract

Indices of cellular immunity in postpartum Holsteincows with the normal (n = 9) and prolonged (n = 4) uterine involution time were evaluated. Peripheral white blood cells were isolated by lysis from postpartum animals. An indirect immunofluorescence method for staining and flow cytometric analysis was employed to determine the cell subpopulation of lymphocytes. The function assays were also used to examine the activity of lymphocytes and phagocytes. A significant decrease in the lymphocyte absolute number, and subpopulation of T (CD2+, CD4+, CD8+), and B (IgM+) cells in dams with postparturient complications and prolonged uterine involution time was observed. The quantitative changes of immune cells were accompanied by a significant decline of phagocyte functional activity in an iodo-nitro-tetrazolium reductase test and polyclonal lymphocyte activation to phytohemagglutinin in a leukocyte migration-inhibition assay. In conclusion, a significant decrease in the lymphocyte absolute number and subpopulation of T (CD2+, CD4+, CD8+), and B (IgM+) cells was observed and the host defense role of phagocytes and lymphocytes was impaired in cows with prolonged uterine involution, which can increase their susceptibility to infections.

Keywords

• dairy cows
• periparturient period
• phagocytes
• lymphocytes
• cell-mediated immune functions
• immu-nosuppression
• flow cytometry