SUPPRESSION OF HEMOPOIESIS BY A NOVEL LYMPHOKINE

在一半以上的再生障碍性贫血病例中，病因不明。 然而，免疫调节紊乱的作用是由频繁的 免疫抑制治疗的血液学反应。 抑制基因的一个亚类 在7例患者中，淋巴细胞已被证明介导骨髓抑制 通过可溶性介体（19）。 24名患者中有10名被发现有 循环和骨髓IFN-γ水平增加（22）。 但 IFN-γ水平升高在再生障碍性贫血中的病因学意义 不清楚 集落抑制性淋巴因子（Colony-inhibiting lymphokine，CIL）是一种新的淋巴因子， 未刺激的T淋巴母细胞系，具有强效骨髓抑制 SDS PAGE测得酶活和表观Mr为45，000道尔顿。 易感性 HLA-DR抗原与造血干细胞及肿瘤细胞致CIL相关性研究 表情 它由7个T-淋巴母细胞样细胞系中的7个产生， 在10-13 M范围内抑制造血的能力表明，CIL可能 在造血的下调中起关键作用， 骨髓抑制 本研究的主要目的是：1）确定生物化学 2）克隆CIL的cDNA， 使用合适的载体表达它，3）表征CIL-靶细胞 相互作用，并检查HLA-DR抗原在相互作用中的作用， 4)研究CII在正常和异常造血中的作用。 在蛋白纯化得到证实后，CIL的生物活性将 体外检测，氨基酸序列测定，兔 产生抗血清。 CIL的分子克隆将通过 筛选E.用抗血清和通过 用寡核苷酸探针筛选或检测 转染COS-1细胞的生物活性。 CIL-靶细胞相互作用 将使用125 I-CIL结合试验和HLA-DR的作用进行检查 直接使用抗HLA-DR抗体进行检查。 一个更大的可能性 HLA-DR在CIL-靶相互作用中的间接作用将使用 易感靶标的HLA-DR阴性变体。 CIL对 将在小鼠中研究造血的体内调节。 最后，从有感染风险的病人身上采集血液和骨髓样本， 由于再生障碍性贫血和原因不明的白细胞减少症， CIL水平。 他们的T淋巴细胞和T淋巴细胞亚群， 将测定CIL和CIL mRNA的产生。

In over half the cases of aplastic anemia, the etiology is unknown. However, a role for disordered immunoregulation is suggested by frequent hematologic responses to immunosuppressive therapy. A subset of suppressor lymphocytes have been shown to mediate marrow suppression in 7 patients through a soluble mediator (19). Ten of 24 patients were found to have increased circulating and marrow IFN-gamma levels (22). However, the etiologic significance of elevated IFN-gamma levels in aplastic anemia is unclear. Colony-inhibiting lymphokine (CIL) is a novel lymphokine product of unstimulated T-lymphoblastoic cell lines with potent myelosuppressive activity and apparent Mr of 45,000 dalton by SDS PAGE. Susceptibility of hemopoietic tumor and stem cells to CIL correlates with HLA-DR antigen expression. Its production by 7 of 7 T-lymphoblastoid cell lines and ability to inhibit hemopoiesis in the 10-13 M range suggest that CIL may play a critical role in the down-regulation of hemopoiesis and contribute to myelo-suppression. The aims of the proposed research are: 1) To define the biochemical characteristics of CIL, 2) To molecularly clone the cDNA of CIL, and express it using suitable vectors, 3) To characterize the CIL-target cell interaction and examine the role of HLA-DR antigen in that interaction and 4) To examine the role of CII in normal and disordered hemopoiesis. After protein purification has been confirmed, the bioactivity of CIL will be examined in vitro, the amino acid sequence determined, and rabbit antisera generated. Molecular cloning of CIL will be accomplished through screening of expression libraries in E. coli using antisera and through screening with oligonucleotide probes or testing of supernatants of transfected COS-1 cells for bioactivity. The CIL-target cell interaction will be examined using a 125I-CIL binding assay and the role of HLA-DR examined directly using anti-HLA-DR antibodies. The possibility of a more indirect role of HLA-DR in CIL-target interaction will be examined using HLA-DR negative variants of susceptible targets. The effect of CIL on the in vivo regulation of hemopoiesis will be investigated in the mouse. Finally, blood and bone marrow samples from patients at risk for infection because of aplastic anemia and unexplained leukopenia will be examined for CIL levels. The ability of their T-lymphocytes and T-lymphocyte subsets to produce CIL and CIL mRNA will be determined.