Neurohypophysial Receptor Gene Expression by Thymic T Cell Subsets and Thymic T Cell Lymphoma Cell Lines

摘要

AbstractNeurohypophysial oxytocin (OT) and vasopressin (VP) genes aretranscribed in thymic epithelium, while immature T lymphocytes express functional neurohypophysial receptors. Neurohypophysial receptors belong to the G protein-linked seven-transmembrane receptor superfamily and are encoded by four distinct genes,OTR,V1R,V2RandV3R. The objective of this study was to identify the nature of neurohypophysial receptor in thymic T cell subsets purified by immunomagnetic selection, as well as in murine thymic lymphoma cell lines RL12-NP and BW5147.OTRis transcribed in all thymic T cell subsets and T cell lines, whileV3Rtranscription is restricted to CD4+CD8+and CD8+thymic cells. NeitherV1RnorV2Rtranscripts are detected in any kind of T cells. The OTR protein was identified by immunocytochemistry on thymocytes freshly isolated from C57BL/6 mice. In murine fetal thymic organ cultures, a specific OTR antagonist does not modify the percentage of T cell subsets, but increases late T cell apoptosis further evidencing the involvement of OT/OTR signaling in the control of T cell proliferation and survival. According to these data,OTRandV3Rare differentially expressed during T cell ontogeny. Moreover, the restriction ofOTRtranscription to T cell lines derived from thymic lymphomas may be important in the context of T cell leukemia pathogenesis and treatment.