ROLE OF VIL-6 IN PRIMARY EFFUSION LYMPHOMAS

人类疱疹病毒8型（Human herpesvirus-8，HHV-8）是一种新近发现的病毒，其序列在所有类型的卡波西肉瘤（Kaposi's sarcoma，AIDS相关的、典型的、地方性的）、AIDS相关的原发性渗出性淋巴瘤（primary effusion lymphoma，PEL）以及多中心Castleman病（multi-centric Castleman's disease，MCD）的病变中都有发现。最近的报告表明，HHV-8也可能与多发性骨髓瘤（MM）有关。 HHV-8直接或间接参与了这些疾病的发生和发展。 具有相关性的发现涉及细胞因子，特别是IL-6，在KS、PEL、MCD和MM的发展中; IL-6促进KS、PEL和骨髓瘤细胞的生长，并且在MCD病变和患者血清中发现水平升高。 在完成病毒基因组测序之前，部分序列分析确定HHV-8是γ-疱疹病毒亚科的成员，并且在已有序列数据的疱疹病毒中，它与松鼠猴疱疹病毒（HVS）关系最密切。 基于HHV-8和HVS的基因组之间的假定的一般遗传共线性，我们鉴定了HHV-8中的γ-疱疹病毒趋异基因组位点，其编码白细胞介素-6（vIL-6）的同源物和三种β-趋化因子同源物（vMIP-1A、vMIP-1B、BCK），其中两种与巨噬细胞炎性蛋白-1密切相关。 我们假设HHV-8可以影响疾病的病理学，该病毒通过vIL-6直接刺激HHV-8感染或周围细胞的有丝分裂，以及通过v-趋化因子的趋化特性募集到感染组织中的淋巴细胞分泌的细胞因子来影响疾病的病理学。 该建议的重点是确定vIL-6对PEL细胞生长和信号转导的作用和机制。 具体目的是（1）确定外源性加入的vIL-6对PEL细胞生长和存活的影响以及IL-6 R对这些活性的影响：（2）鉴定vIL-6在PEL细胞中诱导的VEGF种类和促有丝分裂/抗凋亡功能;（3）鉴定信号转导通路，Jak/STAT和/或MAPK，和MAPK途径中间体，其在PEL细胞中响应vIL-6而被激活，并决定IL-6 R在途径选择中的作用;（4）使用野生型和特异性改变形式的gp 130和IL-6 R进行体外vIL-6-受体结合测定，以表征vIL-6-gp 130/IL-6 R的性质和要求。6 R协会。 这些联合研究将提供确定hIL-6和vIL-6对PEL细胞生长的相对贡献的数据，确定vIL-6在PEL细胞中介导作用的细胞内途径，并确定功能性vIL-6与gp 130和IL-6 R相关的特征。 所产生的数据将为设计潜在的治疗策略提供基础，以特异性地阻断vIL-6对PEL和其他HHV-8相关疾病的促有丝分裂功能。

Human herpesvirus-8 (HHV-8) is a recently discovered virus, sequences of which have been found consistently in Kaposi's sarcoma of all types (AIDS-associated, classical, endemic), in AIDS-associated primary effusion lymphoma (PEL), and at high frequency in lesions of multicentric Castleman's disease (MCD). Recent reports indicate that HHV-8 may also be associated with multiple myeloma (MM). It has been proposed that HHV-8 is directly or indirectly involved in the development and progression of these diseases. Of relevance are findings that implicate cytokines, particularly IL-6, in the development of KS, PEL, MCD and MM; IL-6 promotes the growth of KS, PEL and myeloma cells and is found at elevated levels in MCD lesions and patient sera. Prior to complete sequencing of the viral genome, partial sequence analysis determined that HHV-8 is a member of the gamma- herpesvirus subfamily and that of the herpesviruses for which sequence data are available it is most closely related to herpesvirus saimiri (HVS). On the basis of presumed general genetic collinearity between the genomes of HHV-8 and HVS, we identified a gamma-herpesvirus-divergent genomic locus in HHV-8 that encodes a homologue of interleukin-6 (vIL-6) and three beta- chemokine homologues (vMIP-1A, vMIP-1B, BCK), two of which are closely related to macrophage inflammatory protein-1. We hypothesize that HHV-8 could effect disease pathology with which the virus has been associated by direct mitogenic stimulation of HHV-8 infected or surrounding cells by vIL-6 and by cytokines secreted by lymphocytes recruited into infected tissues through the chemotactic properties of the v-chemokines. The focus of this proposal is to determine the effects and mechanisms of action of vIL-6 on PEL cell growth and signal transduction. The specific aims are (1) to determine the effects of exogenously added vIL-6 on PEL cell growth and survival and the influence of IL-6R on these activities; (2) to identify VEGF species and mitogenic/anti-apoptotic functions induced by vIL-6 in PEL cells; (3) to identify the signal transduction pathways, Jak/STAT and/or MAPK, and MAPK pathway intermediates that are activated in PEL cells in response to vIL-6 and determine the role of IL-6R in pathway selection; (4) to undertake in vitro vIL-6-receptor binding assays using wild-type and specifically altered forms of gp130 and IL-6R to characterize the nature of and requirements for vIL-6-gp130/IL-6R associations. These combined studies will provide data that determine the relative contributions of hIL-6 and vIL-6 to PEL cell growth, identify intracellular pathways through which the effects of vIL-6 are mediated in PEL cells, and determine the characteristics of functional vIL-6 associations with gp130 and IL-6R. The generated data will provide the basis for the design of potentially therapeutic strategies to specifically block vIL-6 mitogenic functions with respect PEL and other HHV-8 associated diseases.