IMMUNOBIOLOGY OF EQUINE INFECTIOUS ANEMIA VIRUS, A RETROVIRUS MODEL FOR AIDS

马传染性贫血病毒（EIAV）在形态上， 与人类免疫缺陷有遗传和血清学相关性 病毒（HIV），从而为研究提供了一个有用的模型 慢病毒引起的疾病中病毒与宿主的相互作用。 马传染性贫血（EIA）的特点是发作性的 与外观相关的临床疾病的性质 新的病毒变种。 该项目涉及 阐明产生和选择的重要因素 这些病毒变体以及理解变异的作用 慢病毒持久性和发病机制。 我们之前的工作 表明在病程早期，EIAV 变异可能 通过非免疫机制在体内进行选择。 我们有 因此启动了体外宿主细胞向性的研究 EIAV 的各种毒株及其与病毒的可能相关性 致病性。 分离出的病毒，经选择用于体外 在连续细胞系中的复制显示出 1,000-10,000- 原代马单核细胞病毒复制减少倍数 培养物（HMC）与连续细胞系中的复制相比。 此外，这显着减少了马体内的病毒复制 单核细胞，被认为是 EIAV 复制的靶细胞 体内，与病毒毒力的丧失有关。 这建议 体外 HMC 中的病毒复制水平可能与 体内致病性。 因此，我们加大了力度 分离出具有复制能力的 EIAV 分子克隆 作为理解病毒结构特征的基础 对于病毒的致病性具有重要意义。

Equine infectious anemia virus (EIAV) is morphologically, genetically, and serologically related to human immunodeficiency virus (HIV) and thus provides a useful model for the study of virus-host interactions in lentivirus-induced disease. Characteristic of equine infectious anemia (EIA) is the episodic nature of clinical disease which is associated with the appearance of novel viral variants. This project is concerned with elucidating the factors important in the generation and selection of these viral variants and in understanding the role of variation in lentivirus persistence and pathogenesis. Our previous work suggested that early in the course of disease, EIAV variants may be selected in vivo by non-immunological mechanisms. We have therefore initiated studies on the in vitro host cell tropism of various strains of EIAV and its possible correlation with viral pathogenicity. Virus isolated which were selected for in vitro replication in continuous cell lines demonstrated a 1,000-10,000- fold reduction in viral replication in primary horse monocyte cultures (HMC) as compared to replication in continuous cell lines. Moreover, this marked reduction of viral replication in horse monocytes, believed to be the target cell for EIAV replication in vivo, was associated with a loss of viral virulence. This suggest that levels of viral replication in in vitro HMC may be a correlate of in vivo pathogenicity. Thus, we have increased our efforts to isolate a replication-competent molecular clone of EIAV which could serve as a basis for understanding structural viral features important in viral pathogenicity.