Submitted to: Conference Research Workers Disease Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/12/2001
Publication Date: N/A
Technical Abstract: Leukocyte infiltration following infection of the mammary gland is necessary for clearance of pathogens, but excess infiltration results in inflammation and tissue damage. Regulation of leukocyte trafficking in the mammary gland may be key to the control of mastitis, and prevention of tissue damage. A first step to understanding this regulation is to characterize the adhesion receptors on leukocytes in the mammary gland. Using fluorescent antibody cell labeling and analysis of cells by flow cytometry, we examined expression of L-selectin, LFA-1, LPAM-1 and CD44 on CD4+, CD8+, gamma/delta+ T cells and granulocytes from milk and blood of periparturient cows. L-Selectin was expressed on 90-100% of T cell subsets in milk and 60-80% in blood from 0 to 21 days after parturition. All granulocytes in blood expressed L-selectin compared with 70-80% in milk. LFA-1 was found on 10-30% of T cells in blood, and 40-80% in milk. All granulocytes in blood expressed LFA-1 compared with 70-80% in milk. LPAM-1 was expressed on 80-90% of T cells in milk and 20% in blood. Sixty percent of granulocytes in milk expressed LPAM-1, and 20% in blood. CD44 was expressed on 80-100% of T cells from both milk and blood. All granulocytes in blood expressed CD44 compared with 50% in milk. Differences in the percents of leukocytes expressing adhesion molecules in milk compared to blood suggest that these cells are selectively recruited to mammary gland from the circulation.