Segerson E C, Libby D W
Department of Animal Science, North Carolina A&T State University, Greensboro 27411.
Biol Reprod. 1990 Oct;43(4):619-28. doi: 10.1095/biolreprod43.4.619.
Bovine uterine luminal proteins (ULP) collected on Day 17 of pregnancy were tested for inhibition of binding of interleukin-2 (IL-2) to the IL-2 receptor (IL-2R) of bovine (CLC) and human (HLC) T lymphocytes and for binding to IL-2. Additional experiments assessed IL-2 binding to the p55 alpha chain (Tac protein) of the IL-2R of HLC. High- and low-molecular weight (Mr) ULP components (H-ULP greater than 248,000 Mr and L-ULP 21,000 Mr, respectively) inhibited (p less than 0.05 and 0.01, respectively) the binding of 125I-IL-2 to the IL-2R of CLC, whereas only H-ULP inhibited (p less than 0.05) binding to the IL-2R (presumably, the p75 beta chain) of HLC. H-ULP failed (p greater than 0.05) to bind to the p55 alpha chain of the IL-2R of HLC. For IL-2 binding, L-ULP failed (p greater than 0.05) to bind 125I-IL-2 in short (2 h)-term and long (45 h)-term experiments, whereas binding was evident (p less than 0.05) for H-ULP at 2 h of incubation. For H-ULP, mean (+/- SEM) percentages for bound and unbound 125I-IL-2 were 70.1 +/- 11.4 and 29.9 +/- 11.4, respectively. Further purification of H-ULP yielded a component (1.76 x 10(6) Mr) that bound 11.7% of 125I-IL-2 and inhibited (p less than 0.01) thymidine uptake and binding of 125I-IL-2 to the IL-2R of CLC. H-ULP-mediated suppression of lymphocyte proliferation may result from blocking IL-2R recognition of IL-2 as well as binding to IL-2, whereas suppression by L-ULP may predominantly result from blocking IL-2R.
对妊娠第17天收集的牛子宫腔蛋白（ULP）进行检测，以评估其对白细胞介素-2（IL-2）与牛（CLC）和人（HLC）T淋巴细胞的IL-2受体（IL-2R）结合的抑制作用以及与IL-2的结合情况。另外的实验评估了IL-2与HLC的IL-2R的p55α链（Tac蛋白）的结合。高分子量和低分子量（Mr）的ULP成分（分别为Mr大于248,000的H-ULP和Mr为21,000的L-ULP）分别抑制（p分别小于0.05和0.01）125I-IL-2与CLC的IL-2R的结合，而只有H-ULP抑制（p小于0.05）与HLC的IL-2R（推测为p75β链）的结合。H-ULP未能（p大于0.05）与HLC的IL-2R的p55α链结合。对于IL-2结合，在短期（2小时）和长期（45小时）实验中，L-ULP未能（p大于0.05）结合125I-IL-2，而在孵育2小时时，H-ULP的结合明显（p小于0.05）。对于H-ULP，结合和未结合的125I-IL-2的平均（+/-SEM）百分比分别为70.1 +/- 11.4和29.9 +/- 11.4。对H-ULP进一步纯化得到一种成分（1.76 x 10(6) Mr），其结合了11.7%的125I-IL-2，并抑制（p小于0.01）胸苷摄取以及125I-IL-2与CLC的IL-2R的结合。H-ULP介导的淋巴细胞增殖抑制可能是由于阻断IL-2R对IL-2的识别以及与IL-2的结合，而L-ULP的抑制作用可能主要是由于阻断IL-2R。
