Asai K, Kai K, Rikiishi H, Sugawara S, Maruyama Y, Yamaguchi T, Ohta M, Kumagai K
T-Cell Research Institute, Sendai, Japan.
Vet Immunol Immunopathol. 1998 Sep 16;65(1):51-61. doi: 10.1016/s0165-2427(98)00176-7.
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.
利用单克隆抗体通过免疫荧光细胞术研究了奶牛不同泌乳阶段的乳腺分泌物（MGS）中的T淋巴细胞亚群。在泌乳早期和晚期，MGS中CD4⁺/CD8⁺ T淋巴细胞的平均比例分别为0.5和0.8。很大一部分CD8⁺细胞共表达激活分子ACT2。这些结果表明，CD8⁺ ACT2⁺细胞在整个泌乳期构成了T淋巴细胞的主要表型。然而，在诱导干奶的奶牛乳腺中，CD8⁺ ACT2⁺细胞的比例下降，导致MGS中CD4⁺/CD8⁺比例增加。在非泌乳后期，该比例达到2.5 - 4.0的最高水平，与外周血中的水平相似或更高。CD4⁺/CD8⁺细胞比例的这种选择性增加与MGS中总细胞浓度的增加相关。干奶期这种高CD4⁺/CD8⁺细胞比例在分娩前迅速下降，与MGS中总细胞浓度的下降相关，在泌乳早期达到最低水平。在非泌乳期分离的细胞产生细胞因子IL - 2和IL - 4的水平远高于在泌乳期分离的细胞，且增加与CD4⁺ T淋巴细胞比例相关。
