Instituto de Medicina y Biología Experimental de Cuyo, CCT Mendoza, CONICET, Mendoza CP5500, Argentina.
Reproduction. 2013 Jul 31;146(3):233-42. doi: 10.1530/REP-12-0387. Print 2013 Sep.
Mammary stroma is composed of various cell types, including migratory leukocytes. Although mammary antibody-secreting cells have been extensively studied, reports focusing on mammary T cells are scarce. It is thought that the recruitment mechanism of leukocytes to the mammary gland (MG) is controlled by pregnancy- and lactation-specific stimuli. But whether prolactin (PRL) modulates the T-cell population in MG is still unknown. Our aim was to study the relationship between PRL levels and T and B cells during early lactation (L2, day 2 post partum) and mid-lactation (L12, day 12 of lactation). In order to investigate whether PRL is associated with homing events to MG, female Sprague Dawley (SD) and SD-derived desmoglein 4(-/-) hairless (phenotype with lactation deficit, OFA hr/hr) rats were killed during estrus, pregnancy, and post partum, and blood, MG, and corpora lutea were obtained to perform fluorescent-activated cell sorting (FACS), real-time PCR, and histological and RIA studies. Serum PRL levels were lower in OFA hr/hr rats than in SD rats during early lactation. MG of OFA hr/hr rats showed less secretory material compared with SD rats. FACS analysis showed lower percentage of MG CD3+ cells in OFA hr/hr rats compared with SD rats on L2 and L12. OFA hr/hr rats showed higher absolute numbers of circulating CD3+ cells compared with SD rats on L2 but not on L12. These results show that T-cell population in MG is affected in early lactating OFA hr/hr rats and strongly suggest that serum PRL levels may be involved in the homing events to MG, probably helping antibody-secreting cells and protecting the gland during lactation development.
乳腺基质由各种细胞类型组成，包括迁移白细胞。尽管乳腺分泌抗体的细胞已被广泛研究，但关于乳腺 T 细胞的报道却很少。人们认为白细胞募集到乳腺（MG）的机制受妊娠和哺乳期特异性刺激的控制。但是，催乳素（PRL）是否调节 MG 中的 T 细胞群尚不清楚。我们的目的是研究早期哺乳期（L2，产后第 2 天）和中期哺乳期（L12，哺乳期第 12 天）PRL 水平与 T 细胞和 B 细胞之间的关系。为了研究 PRL 是否与向 MG 的归巢事件有关，雌性 Sprague Dawley（SD）和 SD 衍生的桥粒芯糖蛋白 4（-/-）无毛（具有泌乳缺陷的表型，OFA hr/hr）大鼠在发情、妊娠和产后期间被杀死，血液、MG 和黄体被获得以进行荧光激活细胞分选（FACS）、实时 PCR 和组织学和 RIA 研究。在早期哺乳期，OFA hr/hr 大鼠的血清 PRL 水平低于 SD 大鼠。与 SD 大鼠相比，OFA hr/hr 大鼠的 MG 分泌物质较少。FACS 分析显示，在 L2 和 L12 时，OFA hr/hr 大鼠的 MG CD3+细胞百分比低于 SD 大鼠。OFA hr/hr 大鼠在 L2 时的循环 CD3+细胞绝对数量高于 SD 大鼠，但在 L12 时则没有。这些结果表明，MG 中的 T 细胞群在早期哺乳期的 OFA hr/hr 大鼠中受到影响，并强烈表明血清 PRL 水平可能参与 MG 的归巢事件，可能有助于分泌抗体的细胞并在泌乳发育过程中保护腺体。
