Chernicky C L, Tan H, Burfeind P, Ilan J, Ilan J
Department of Reproductive Biology, Case Western Reserve University, Cleveland, Ohio, USA.
Mol Reprod Dev. 1996 Feb;43(2):180-6. doi: 10.1002/(SICI)1098-2795(199602)43:2<180::AID-MRD7>3.0.CO;2-N.
There are several cell types within the placenta that produce cytokines which can contribute to the regulatory mechanisms that ensure normal pregnancy. The immunological milieu at the maternofetal interface is considered to be crucial for survival of the fetus. Interleukin-2 (IL-2) is expressed by the syncytiotrophoblast, the cell layer between the mother and the fetus. IL-2 appears to be a key factor in maintenance of pregnancy. Therefore, it was important to determine the sequence of human placental interleukin-2. Direct sequencing of human placental IL-2 cDNA was determined for the coding region. Subclone sequencing was carried out for the 5'- and 3'-untranslated regions (5'-UTR and 3'-UTR). The 5'-UTR for human placental IL-2 cDNA is 294 bp, which is 247 nucleotides longer than that reported for cDNA IL-2 derived from T cells. The sequence of the coding region is identical to that reported for T cell IL-2, while sequence analysis of the polymerase chain reaction (PCR) product showed that the cDNA from the 3' end was the same as that reported for cDNA from T cells. Human placental IL-2 cDNA is 1,028 base pairs (excluding the poly A tail), which is 247 bp longer at the 5' end than that reported for IL-2 T cell cDNA. Therefore, the extended 5'-UTR of the placental IL-2 cDNA may be a consequence of alternative promoter utilization in the placenta.
胎盘中有几种细胞类型可产生细胞因子，这些细胞因子有助于确保正常妊娠的调节机制。母胎界面处的免疫环境被认为对胎儿的存活至关重要。白细胞介素-2（IL-2）由合体滋养层细胞表达，合体滋养层细胞是母亲和胎儿之间的细胞层。IL-2似乎是维持妊娠的关键因素。因此，确定人胎盘白细胞介素-2的序列很重要。对人胎盘IL-2 cDNA的编码区进行了直接测序。对5'-和3'-非翻译区（5'-UTR和3'-UTR）进行了亚克隆测序。人胎盘IL-2 cDNA的5'-UTR为294 bp，比从T细胞衍生的cDNA IL-2报道的长247个核苷酸。编码区的序列与报道的T细胞IL-2相同，而聚合酶链反应（PCR）产物的序列分析表明，3'端的cDNA与报道的T细胞cDNA相同。人胎盘IL-2 cDNA为1028个碱基对（不包括聚腺苷酸尾），5'端比报道的IL-2 T细胞cDNA长247 bp。因此，胎盘IL-2 cDNA延长的5'-UTR可能是胎盘中使用替代启动子的结果。
