Bovine blood and milk T-cell subsets in distinct states of activation and differentiation during subclinical Staphylococcus aureus mastitis

Abstract

T-lymphocytes are key mediators of adaptive cellular immunity and knowledge about distinct subsets of these cells in healthy and infected mammary gland secretions remains limited. In this study, we used a multiplex cytometry panel to show that staphylococcal mastitis causes the activation of CD4⁺, CD8⁺ and γδ T-cells found in bovine milk. We also highlight remarkable differences in the proportions of naïve and memory T-cells subsets found in blood and milk. These observations will contribute to a better understanding of cell-mediated immune mechanisms in the udder and to the development of new therapeutic and preventive strategies targeting mastitis.

Keywords: Bovine; Mastitis; Memory T-cells; Staphylococcus aureus; T-lymphocytes.