title: Longitudinal evaluation of CD4+ and CD8+ peripheral blood and mammary gland lymphocytes in cows experimentally inoculated with Staphylococcus aureus.
abstract: Staphylococcus aureus is a major pathogen associated with mastitis, a disease affecting both women and dairy cows. The longitudinal profiles of bovine peripheral blood and mammary gland lymphocyte phenotypes in response to S. aureus-induced mastitis were investigated in dairy cows. Increased percentage of CD4 lymphocytes in the mammary gland between 1 and 8 days post-inoculation, increased milk CD4 protein density per cell between 1-8 days post-inoculation, and a statistically significant negative correlation between post-inoculation bacterial counts in milk and blood lymphocyte CD4 protein density were found. Together with blood and milk leukocyte counts, the milk lymphocyte CD4/CD8 ratio and the milk lymphocyte CD4 protein density were more informative indicators than milk somatic cell counts and bacteriology for identification of early vs. late inflammatory phases. These findings suggest that CD4+ lymphocytes play a protective role in the early stages of S. aureus-induced mastitis.
authors.affiliation: Department of Population Medicine, and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14850, USA. alr4@cornell.edu
authors.forename: A L
authors.initials: AL
authors.lastname: Rivas
authors.forename: F W
authors.initials: FW
authors.lastname: Quimby
authors.forename: O
authors.initials: O
authors.lastname: Coksaygan
authors.forename: L
authors.initials: L
authors.lastname: Olmstead
authors.forename: D H
authors.initials: DH
authors.lastname: Lein
mesh_terms: D000818:Animals; D018791:CD4 Lymphocyte Count / Q000662:veterinary; D016827:CD8 Antigens / Q000032:analysis; D002417:Cattle; D005260:Female; D008137:Longitudinal Studies; D008414:Mastitis, Bovine / Q000276:immunology / Q000382:microbiology*; D008892:Milk / Q000276:immunology / Q000382:microbiology; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000276:immunology*
chemical_list: D016827:CD8 Antigens