SUPPRESSION OF HEMOPOIESIS BY A NOVEL LYMPHOKINE

在超过一半的再生障碍性贫血病例中，病因不明。 然而，频繁的研究表明免疫调节紊乱的原因之一。 血液学对免疫抑制治疗的反应。抑制子的一个子集 在7例患者中，淋巴细胞被证明是介导骨髓抑制的因素。 通过可溶的中介体(19)。24名患者中有10名被发现患有 循环和骨髓中的干扰素-γ水平升高(22例)。然而， 再生障碍性贫血患者干扰素-γ水平升高的病因学意义 不清楚。 集落抑制淋巴因子(CIL)是一种新的淋巴因子产物 具有强大骨髓抑制作用的未刺激T淋巴母细胞系 用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法测定45,000道尔顿的活性和表观MR。易感性 造血肿瘤和干细胞对CIL的作用与人类白细胞抗原DR的相关性 表情。7个T淋巴母细胞系和7个T淋巴母细胞系 在10-13M范围内抑制造血的能力表明CIL可能 在下调造血方面发挥关键作用，并做出贡献 为了骨髓抑制。 这项研究的目的是：1)定义生物化学 CIL的特性：2)分子克隆CIL的基因，以及 用合适的载体表达，3)鉴定CIL-靶细胞 并研究人类白细胞抗原-DR抗原在这种相互作用中的作用以及 4)探讨CII在正常和无序造血中的作用。 在蛋白质纯化得到确认后，CIL的生物活性将 在体外被检测，氨基酸序列测定，和兔 产生了抗血清。CIL的分子克隆将通过以下途径完成 用抗血清和穿透技术筛选大肠杆菌表达文库 用寡核苷酸探针筛选或检测猪瘟病毒上清液 转染COS-1细胞进行生物活性检测。CIL与靶细胞的相互作用 将使用125I-CIL结合试验和人类白细胞抗原-DR的作用进行检测 用抗人类白细胞抗原-DR抗体直接检测。可能会有更多 人类白细胞抗原-DR在CIL-靶相互作用中的间接作用将被用 易感靶点的HLA-DR阴性变异体。慢性白细胞介素性肺炎对人的影响 体内的造血调节将在小鼠身上进行研究。 最后，来自有感染风险的患者的血液和骨髓样本 因为再生障碍性贫血和不明原因的白细胞减少症将被检查 CIL水平。他们的T淋巴细胞和T淋巴细胞亚群 产生CIL和CIL mRNA将被测定。

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.