PubMed:8409434 JSONTXT

{"project":"AIMed","denotations":[{"id":"T1","span":{"begin":48,"end":61},"obj":"protein"},{"id":"T2","span":{"begin":106,"end":110},"obj":"protein"},{"id":"T3","span":{"begin":210,"end":215},"obj":"protein"},{"id":"T4","span":{"begin":349,"end":354},"obj":"protein"},{"id":"T5","span":{"begin":525,"end":530},"obj":"protein"},{"id":"T6","span":{"begin":597,"end":601},"obj":"protein"},{"id":"T7","span":{"begin":664,"end":667},"obj":"protein"},{"id":"T8","span":{"begin":672,"end":675},"obj":"protein"},{"id":"T9","span":{"begin":762,"end":766},"obj":"protein"},{"id":"T10","span":{"begin":789,"end":794},"obj":"protein"},{"id":"T11","span":{"begin":943,"end":947},"obj":"protein"},{"id":"T12","span":{"begin":982,"end":985},"obj":"protein"},{"id":"T13","span":{"begin":986,"end":991},"obj":"protein"},{"id":"T14","span":{"begin":1024,"end":1027},"obj":"protein"},{"id":"T15","span":{"begin":1028,"end":1033},"obj":"protein"},{"id":"T16","span":{"begin":1035,"end":1039},"obj":"protein"},{"id":"T17","span":{"begin":1091,"end":1096},"obj":"protein"},{"id":"T18","span":{"begin":1158,"end":1161},"obj":"protein"},{"id":"T19","span":{"begin":1162,"end":1167},"obj":"protein"},{"id":"T20","span":{"begin":1173,"end":1176},"obj":"protein"},{"id":"T21","span":{"begin":1177,"end":1182},"obj":"protein"},{"id":"T22","span":{"begin":1189,"end":1193},"obj":"protein"},{"id":"T23","span":{"begin":1290,"end":1293},"obj":"protein"},{"id":"T24","span":{"begin":1298,"end":1301},"obj":"protein"},{"id":"T25","span":{"begin":1302,"end":1307},"obj":"protein"},{"id":"T26","span":{"begin":1422,"end":1427},"obj":"protein"},{"id":"T27","span":{"begin":1491,"end":1494},"obj":"protein"},{"id":"T28","span":{"begin":1495,"end":1500},"obj":"protein"},{"id":"T29","span":{"begin":1554,"end":1557},"obj":"protein"},{"id":"T30","span":{"begin":1558,"end":1563},"obj":"protein"},{"id":"T31","span":{"begin":1617,"end":1622},"obj":"protein"},{"id":"T32","span":{"begin":1748,"end":1753},"obj":"protein"},{"id":"T33","span":{"begin":1784,"end":1787},"obj":"protein"},{"id":"T34","span":{"begin":1873,"end":1878},"obj":"protein"},{"id":"T35","span":{"begin":1923,"end":1926},"obj":"protein"},{"id":"T36","span":{"begin":1927,"end":1932},"obj":"protein"},{"id":"T37","span":{"begin":1990,"end":1995},"obj":"protein"},{"id":"T38","span":{"begin":2029,"end":2032},"obj":"protein"},{"id":"T39","span":{"begin":2033,"end":2038},"obj":"protein"},{"id":"T40","span":{"begin":2077,"end":2082},"obj":"protein"},{"id":"T41","span":{"begin":2103,"end":2106},"obj":"protein"},{"id":"T42","span":{"begin":2111,"end":2114},"obj":"protein"},{"id":"T43","span":{"begin":2115,"end":2120},"obj":"protein"},{"id":"T44","span":{"begin":2243,"end":2248},"obj":"protein"},{"id":"T45","span":{"begin":2275,"end":2279},"obj":"protein"}],"text":"Characterization of a novel high affinity human IL-7 receptor. Expression on T cells and association with IL-7 driven proliferation.\nAlthough both unstimulated and activated human T cells express high affinity IL-7R, only activated T cells can proliferate to IL-7. This responsiveness may occur as a direct result of changes in the structure of the IL-7R during T-cell activation. We have previously demonstrated such changes by affinity cross-linking studies, and have shown that unstimulated human T cells express a single IL-7R of 90 kDa, whereas activated T cells express an additional 76-kDa IL-7 binding protein. In this study the origin and function of the p90 and p76 molecules have been investigated. To determine the role of each of these receptors in IL-7 driven proliferation, IL-7R expression and proliferative capacity were monitored during mitogenic stimulation. These analyses showed that the ability of PBMC to proliferate to IL-7 correlated with expression of the p76 IL-7R, and not with expression of the p90 IL-7R. IL-7-driven proliferation is mediated via high affinity IL-7R, and accordingly, Scatchard analysis revealed that, like the p90 IL-7R, the p76 IL-7R bound IL-7 with dual (high; Kd 38 pM and low; Kd 360 pM) affinity. Deglycosylation studies showed that the p90 and p76 IL-7R are not simply differently glycosylated isoforms of a single receptor. In agreement, mAb to the previously cloned IL-7R were found to stain unstimulated T cells that express only the p90 IL-7R but not T-cell clones that express predominantly the p76 IL-7R. These antibodies also immunoprecipitated the cloned IL-7R as a 90-kDa species from both 125-I-surface-labeled resting and activated T cells, but were unable to precipitate the 76-kDa IL-7R. In addition, PCR analysis of p76-expressing cells could not detect splicing of the extracellular domain of the cloned IL-7R, thereby excluding the possibility that the p76 IL-7R is a previously undescribed splice variant of the cloned IL-7R. These data demonstrate that the p90 IL-7R is the T-cell homologue of the cloned IL-7R, and imply that the p90 and p76 IL-7R have different extracellular domains. Taken together these data suggest that the 76-kDa receptor is a novel high affinity IL-7R that may be necessary for IL-7 driven proliferation in human T cells."}