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Lactation Stage‐Dependent Changes of Lymphocyte Subpopulations in Mammary Secretions: Inversion of CD4 + /CD8 + T Cell Ratios at Parturition
Author(s) -
Yang T.J.,
Ayoub Ihsan A.,
Rewinski Michael J.
Publication year - 1997
Publication title -
american journal of reproductive immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.071
H-Index - 97
eISSN - 1600-0897
pISSN - 1046-7408
DOI - 10.1111/j.1600-0897.1997.tb00247.x
Subject(s) - lactation , colostrum , biology , mammary gland , medicine , endocrinology , cd8 , lymphocyte , t lymphocyte , antigen , andrology , antibody , immunology , pregnancy , genetics , cancer , breast cancer
PROBLEM: Determination of lactation stage‐dependent changes in levels of lymphocyte subpopulations in milk. METHOD: Flow cytometric assay was used to identify and assay lymphocyte subpopulations in bovine milk at different stages of lactation. RESULTS: Lymphocyte subpopulations in mammary secretions of dairy cows change during the lactation cycle. In involuting glands (dry gland), ∼ 80–90% of lymphocytes were CD2 + T cells. The proportion of CD2 + T cells, however, decreased to ∼ 50% at the colostral stage and fluctuated between 50 to 60% in normal (mature) milk. Throughout the lactation stages, less than 5% were B cells as identified by the monoclonal antibodies against CD21 and MHC class II antigens. Subset analysis showed, however, that the proportion of CD5 + T cells decreased from 90% in involuting gland secretions to 75% in colostrum (peripartum stage), and to ∼ 40–50% in the normal (mature) milk. CD4 + T cells constituted between 45 to 55% of lymphocytes in the dry gland secretion but decreased drastically at parturition and maintained at the level below 20% throughout normal lactation. In contrast, the proportion of CD8 + T cells in the dry gland secretion was low, between 30 to 40%, but increased steadily, in an inversely‐related manner with that of CD4 + T cells, to ∼ 40–50% at parturition and maintained at ∼ 30–40% during the normal lactation stage thereafter. Two‐color immunofluorescence study revealed further that practically all of the CD8 + cells in dry gland secretions were CD2 + , and approximately 40% of them were CD5 — . Throughout the lactation cycle, WC1 + γδ T cells comprised only 2 to 5% of lymphocytes in mammary secretions. CONCLUSIONS: T lymphocyte subpopulations change dynamically during stages of the lactation cycle. The selective migration of T lymphocyte subpopulations to and from the mammary gland, and their functional roles in the immune competence and regulation of the dam and sucklings remain to be elucidated.