title: Variation in CD4+ T and CD8+ T lymphocyte subpopulations in bovine mammary gland secretions during lactating and non-lactating periods.
abstract: Mammary gland secretions (MGS) of dairy cows at different stages of lactation were studied by immunofluorescence cytometry for T lymphocyte subpopulations using monoclonal antibodies. During early and late lactation, the mean ratio of CD4+/CD8+ T lymphocytes in the MGS was 0.5 and 0.8, respectively. A large proportion of the CD8+ cells coexpressed the activation molecule, ACT2. These results indicate that CD8+ ACT2+ cells constituted the major phenotype in the T lymphocytes throughout lactation. In the mammary gland of cows in which drying off was induced, however, the proportion of CD8+ ACT2+ cells decreased, resulting in the increase of the CD4+/ CD8+ ratio in the MGS. At the late non-lactation stage, the ratio reached a maximal level of 2.5-4.0, which was similar to or higher than that found in the peripheral blood. This selective increase of CD4+/CD8+ cell ratio correlated with an increase in the concentrations of total cells in the MGS. This high CD4+/CD8+ cell ratio during the drying off stage rapidly decreased just before parturition, correlating with the decrease in concentrations of total cells in the MGS, reaching the lowest level at early lactation. The cells isolated at the non-lactation stage produced the cytokines IL-2 and IL-4 at a level much higher than those of cells isolated at lactation stages, and the increases were correlated with the CD4+ T lymphocyte proportions.
authors.affiliation: T-Cell Research Institute, Sendai, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Asai
authors.forename: K
authors.initials: K
authors.lastname: Kai
authors.forename: H
authors.initials: H
authors.lastname: Rikiishi
authors.forename: S
authors.initials: S
authors.lastname: Sugawara
authors.forename: Y
authors.initials: Y
authors.lastname: Maruyama
authors.forename: T
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: M
authors.initials: M
authors.lastname: Ohta
authors.forename: K
authors.initials: K
authors.lastname: Kumagai
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D016516:CD4-CD8 Ratio / Q000662:veterinary; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology* / Q000502:physiology; D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology* / Q000502:physiology; D002417:Cattle / Q000276:immunology*; D054407:Chemokine CCL4; D002642:Chick Embryo; D018076:DNA, Complementary / Q000737:chemistry; D005260:Female; D005434:Flow Cytometry / Q000662:veterinary; D007376:Interleukin-2 / Q000032:analysis / Q000378:metabolism; D015847:Interleukin-4 / Q000032:analysis / Q000378:metabolism; D007774:Lactation / Q000276:immunology*; D019402:Macrophage Inflammatory Proteins / Q000737:chemistry / Q000276:immunology / Q000502:physiology; D008321:Mammary Glands, Animal / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D008892:Milk / Q000276:immunology; D011247:Pregnancy; D012333:RNA, Messenger / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary
chemical_list: D000911:Antibodies, Monoclonal; D054407:Chemokine CCL4; D018076:DNA, Complementary; D007376:Interleukin-2; D019402:Macrophage Inflammatory Proteins; D012333:RNA, Messenger; D015847:Interleukin-4