Study on the Regulation of Thymic Hormone Secretion by Neural and Endocrine System-Using Primary Culture System of the Thymic Hormone-Secreting (Thymus Epthelial) Cells-

(1)胸腺上皮细胞(TEC)培养上清中生物活性多肽的分离。分子量为2.5kD的多肽组分具有诱导大鼠胸腺淋巴细胞(TLS)对刀豆蛋白A和植物血凝素的反应性。通过反相柱的进一步分离，前者存在于疏水部分，其靶细胞富含较轻的TLS，而后者存在于亲水部分，其靶点为较重的TLS。约80%的TAT TL与豚鼠红细胞和玫瑰花结(RFC)结合，而其他TL(非RFC)则不结合。3kD组分具有使非RFC具有重排形成活性的能力。此外，通过反相柱分离得到的两个不同组分中还发现了诱导玫瑰花结的活性。通过上述相同的方法，…淋巴细胞占优势的胸腺瘤TAD3的培养上清液中，10kD组分具有较强的刺激TLS增殖的活性。假设10kD片段的靶细胞具有CD4-8表型，在最不成熟的TL中观察到，胸腺中的贴壁细胞也在增殖系统中发挥作用。(2)神经递质和激素对胸腺上皮细胞功能的影响。结果表明，胆碱能激动剂刺激TEC在融合前状态下增殖。另一方面，在融合状态下，激动剂刺激TEC合成蛋白质。这些活性可能是通过TEC表面的烟碱型乙酰胆碱受体信号诱导的。此外，还观察了生长激素对TEC的影响。提示该激素可提高融合前TAD3细胞的分裂指数，促进融合时IT-45R1细胞的蛋白质合成。此外，利用我们制备的抗合成胸腺素α1抗体，检测到生长激素促进融合状态的IT-45R1细胞胸腺素α1的合成。较少

(1) Separation of biologically active polypeptides (BAPs) from the culture supernatant of thymus epithelial cells (TEC).We tried to separate BAPs from the culture supernatant of TEC line, IT-45R1. The polypeptide fraction with 2.5kD in molecular weisht possessed the capacity to induce the responsiveness of rat thymic lymphocytes (TLs) against concanavalin A and phytohemagglutinin. By further separation using reversed-phase column, the former was found in the hydrophobic fraction and its target cells were enriched in lighter TLs, while the latter was detected in the hydrophilic fraction and its target was heavier TLs. About 80% of tat TLs bind to guinea pig erythrocytes and from rosettes (RFC), whereas other TLs (non-RFC) do not. The 3kD fraction possessed the capacity to endow non-RFC with resette forming activity. Furthermore, rosette formation-inducing activity was found in the two different fractions separated by reversed-phase column method. By the same methods described above, the … More activity to induce proliferation of TLs was recognized in 10kD fraction from the culture supernatant of TAD3, derived from lymphocyte dominant thymoma. It is assumed that the target cells for 10kD fraction bear CD4-8- phenotype, observed in the most immature TLs and that the adherent cells in thymus take, also, an role in the proliferation system.(2) Effects of neurotransmitter and hormone on the function of thymus epithelial cells.The effect of cholinergic agonists on TEC was examined by using TAD3. It is revealed that cholinergic agonists stimulate TEC to proliferate at preconfluent state. On the other hand, at confluent state, the agonists stimulate TEC to synthesize proteins. These activities were possibly induced by the signal through nicotinic acetylcholine receptor on TEC surface. Furthermore, the effect of growth hormone on TEC was examined. It is suggested that the hormone enhances the mitotic index of the TAD3 cells at preconfluent state and enhances the protein synthesis of IT-45R1 cells at confluent. Furthermore, growth hormone is detected to increase thymosin alpha 1 aynthesis of IT-45R1 cells at confluent state by using anti-synthetic thymosin alpha 1 antibody, prepared by us. Less