STUDY OF B CELL GROWTH BY EPSTEIN BARR VIRUS

EB病毒(EBV)感染人B细胞并诱导其表达 永垂不朽。EB病毒永生的分子基础主要是 未知。最近，人们观察到，当EBV永生化细胞 在极低密度下无血清培养，增殖停止 然后细胞就会死亡。然而，添加无细胞上清液 从指数级增长的EBV永生化细胞系可以拯救这些 使细胞免于死亡，并促进其增殖。最近，我们有 确认IL-6是一种自分泌生长因子 然而，EBV永生化的B细胞(Tosato，G.等，J.Virol，1990)仅 大约25%的自分泌生长因子活性可归因于 IL-6，而剩余的自分泌生长因子活性处于较低水平 分子量组分。本研究的目标是确定 分子负责这种低分子质量的一个或多个分子 自分泌生长因子。到目前为止，我们已经收集了大量 但目前还没有确定这一低点的结构 分子量增长@因子活性。我们已经确定它的 相对分子质量大于200小于500。我们有 也确定了它不是一种肽，因为治疗旨在 破坏多肽键不能降低其生物活性。 低分子量自分泌生长因子的纯化 正在进行中，并已确定了一些步骤，包括规模 分级、阴离子交换层析和逆流 电泳仪。未来的努力将集中在进一步净化 从污染物中提取分子并确定其结构。

Epstein-Barr virus (EBV) infects human B cells and induces their immortalization. The molecular basis for EBV immortalization is largely unknown. Recently, it was observed that when EBV immortalized cells are cultured without serum at critically low densities, proliferation ceases and the cells die. However, addition of cell-free supernatants from-exponentially growing EBV-immortalized cell lines can rescue these cells from death and promote their proliferation. Recently, we have identified IL-6 as being one of the autocrine growth factors for EBV-immortalized B cells (Tosato, G. et al, J. Virol., 1990) However, only approximately 25% of autocrine growth factor activity is attributable to IL-6 while the remaining autocrine growth factor activity resides in a low molecular weight component. The goal of the present study is to identify the molecule or molecules responsible for this low molecular weight autocrine growth factor. So far, we have gathered a great deal of information but have not as yet identified the structure of this low molecular weight growth@factor activity. We have determined that its relative molecular weight is greater than 200 and smaller than 500. We have also determined that it is not a peptide because treatments designed to destroy the peptide bond fail to reduce its biological activity. Purification of the low molecular weight autocrine growth factor is underway and a number of steps have been identified, including size fractionation, anion exchange chromatography and counter current electrophores. Future efforts will concentrate on further purifying the molecule from contaminants and determining its structure.