Liu Peng, Zuo Jinjiao, Lu Hui, Zhang Bin, Wu Caihong
Jiangsu Agri-Animal Husbandry Vocational College, Jiangsu, 225300, PR China.
Jiangsu Agri-Animal Husbandry Vocational College, Jiangsu, 225300, PR China.
Poult Sci. 2025 May 20;104(8):105322. doi: 10.1016/j.psj.2025.105322.
The colostrum of sows contains a large number of lymphocytes originating from breast tissue. However, the mechanism of lymphocyte migration across the mammary epithelium remains unclear. Hormonal fluctuations during pregnancy are known to influence lymphocyte homing to the breast. In this study, we established a mammary epithelial cells (MECs)/T lymphocytes co-culture system to investigate the effects of colostral hormones on lymphocyte migration. Electron microscope and fluorescence-activated cell sorting results showed that the proportion of T lymphocytes in colostrum was about 9 %. Subsequently, the hormone concentration and number of T lymphocytes in colostrum were tested. The results revealed that there is a high content of prolactin and estrogen in colostrum, and the content of prolactin and estrogen is positively correlated with the number of T lymphocytes in colostrum. Furthermore, T lymphocytes were added to the upper ventricle in Transwell insert, and the estrogen and prolactin were added to the lower ventricle. The results showed that prolactin significantly promoted the T lymphocyte migration across the mammary epithelium, while estrogen had no effect. Finally, our study found that prolactin can promote the mammary epithelial cell to secrete CCL2 by Real-time quantitative PCR (RT-qPCR) and Enzyme-linked immunosorbent assay (ELISA). In order to further explore the transepithelial migration, a neutralizing antibody was applied to block CCL2. Results revealed that the migration of T lymphocytes across the breast epithelium was significantly inhibited after blocking CCL2. The above results showed that prolactin can promote the secretion of CCL2 by breast epithelial cells, and regulate the lymphocyte migration across the mammary epithelium into colostrum, and thereby may further improve lactogenic immunity in sows.
母猪的初乳中含有大量源自乳腺组织的淋巴细胞。然而，淋巴细胞穿越乳腺上皮的机制仍不清楚。已知孕期的激素波动会影响淋巴细胞归巢至乳腺。在本研究中，我们建立了乳腺上皮细胞（MECs）/T淋巴细胞共培养系统，以研究初乳激素对淋巴细胞迁移的影响。电子显微镜和荧光激活细胞分选结果显示，初乳中T淋巴细胞的比例约为9%。随后，检测了初乳中的激素浓度和T淋巴细胞数量。结果显示，初乳中催乳素和雌激素含量较高，且催乳素和雌激素的含量与初乳中T淋巴细胞的数量呈正相关。此外，将T淋巴细胞添加到Transwell小室的上腔，将雌激素和催乳素添加到下腔。结果显示，催乳素显著促进T淋巴细胞穿越乳腺上皮的迁移，而雌激素则无此作用。最后，我们的研究通过实时定量PCR（RT-qPCR）和酶联免疫吸附测定（ELISA）发现，催乳素可促进乳腺上皮细胞分泌CCL2。为了进一步探究跨上皮迁移，应用中和抗体阻断CCL2。结果显示，阻断CCL2后，T淋巴细胞穿越乳腺上皮的迁移受到显著抑制。上述结果表明，催乳素可促进乳腺上皮细胞分泌CCL2，调节淋巴细胞穿越乳腺上皮进入初乳的迁移，从而可能进一步提高母猪的泌乳免疫。
