Yu Z, Croy B A, Chapeau C, King G J
Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
J Reprod Immunol. 1993 Jul;24(2):153-64. doi: 10.1016/0165-0378(93)90017-c.
This study investigated an extended time course of endometrial NK cell activity during gestation and the mechanisms underlying changes in uterine NK cell activity in pigs. Endometrial tissues were collected from cyclic, pseudopregnant and pregnant nulliparous pigs on various days post-estrus, and from pigs 10 days after insemination with seminal plasma or killed spermatozoa. NK effector cells were isolated from each endometrial sample, size fractionated and tested for cytolytic activity against NK target cells (K562) using chromium release assays and immunocytochemically for the frequency of perforin-positive cells. Various cell fractions showed different levels of NK activity and had different proportions of cells expressing perforin. Morphologically, cells in the fraction with maximal NK activity almost all showed typical lymphocyte size and shape. Substantially elevated NK cell activity was recorded in pregnant pigs on days 10 and 20 of gestation. By day 30, the cytolytic activity declined dramatically to an almost undetectable level. Very little activity was found in uterine cells isolated from cyclic, pseudopregnant, and seminal plasma or killed spermatozoa inseminated animals, and no differences were detected either between follicular and luteal phases of the estrous cycle or between different days of pseudopregnancy. These results indicate that elevated NK cell activity during early porcine pregnancy cannot be attributed to contributions from either the maternal systemic endocrine status or from components of boar semen. The changes in NK cell activity observed in porcine endometrial tissues during early pregnancy must therefore be associated with the actual presence of conceptuses.
本研究调查了妊娠期间猪子宫内膜自然杀伤（NK）细胞活性的延长时间进程以及子宫NK细胞活性变化的潜在机制。在发情后的不同天数，从处于发情周期、假孕和未孕的未产母猪中采集子宫内膜组织，并在输精（用精浆或灭活精子）10天后从母猪中采集子宫内膜组织。从每个子宫内膜样本中分离出NK效应细胞，进行大小分级，并使用铬释放试验检测其对NK靶细胞（K562）的细胞溶解活性，同时通过免疫细胞化学方法检测穿孔素阳性细胞的频率。不同的细胞分级显示出不同水平的NK活性，并且表达穿孔素的细胞比例也不同。从形态学上看，具有最大NK活性的分级中的细胞几乎都呈现典型的淋巴细胞大小和形状。在妊娠第10天和第20天的怀孕母猪中记录到NK细胞活性显著升高。到第30天，细胞溶解活性急剧下降至几乎检测不到的水平。从处于发情周期、假孕以及输精（用精浆或灭活精子）的动物中分离出的子宫细胞中几乎没有活性，并且在发情周期的卵泡期和黄体期之间或假孕的不同天数之间均未检测到差异。这些结果表明，猪妊娠早期NK细胞活性的升高不能归因于母体全身内分泌状态或公猪精液成分的作用。因此，在猪妊娠早期子宫内膜组织中观察到的NK细胞活性变化必定与实际存在的孕体有关。
