Molecular and virological analysis of simian and human cell-tropic HIV-1

HIV-I具有严格限制的物种嗜性，并且仅对人类具有致病性。因此，无法进行对研究高致病性病毒（如HIV-1）至关重要的动物实验。我们最近在世界上首次成功地构建了一个嗜猴的HIV-I。该病毒在Gag-CA和Vif中具有HIV-1 CypA结合区的SIV同源物。在本研究项目中，我们的目标是：1。确定负责猴细胞向性的基因组区域，2.阐明猴细胞向性的机制，3.适于在猴细胞中良好生长的病毒克隆的产生和表征，4.猴细胞嗜性R5病毒的产生，5.辅助基因突变体的产生和表征。一种嗜猴的HIV-1（X4）原型被发现感染猪尾猴和食蟹猴并诱导免疫反应。然而，它在猴细胞和动物中的生长比致病性标准SIVmac差。通过改变Gag-CA中的一个区域以提高其在猴细胞中的生长能力，成功地修复了该病毒关于TRIM 5 α限制的生长缺陷。我们还获得了具有与SIVmac相似的复制潜力的细胞适应病毒克隆（X4和R5）。我们最终产生了携带上述所有突变的前病毒分子克隆，以及从它们衍生的辅助基因的突变体。我们现在准备进行各种HIV-1/AIDS基础（病毒复制和致病性的潜在机制;辅助蛋白的体内作用）和临床问题研究的动物实验。

HIV-I possesses a tightly restricted species tropism, and is pathogenic only for humans. It has been, therefore, impossible to perform the animal experiments critical for studies on highly pathogenic viruses such as HIV-1. We recently have successfully constructed a monkey-tropic HIV-I for the first time in the world. This virus has the SIV homologues of HIV-1 CypA-binding region in Gag-CA and Vif. In this research project, we aimed at : 1. determination of genomic regions responsible for monkey cell tropism, 2. elucidation of the mechanism for monkey cell tropism, 3. generation and characterization of virus clones that are adapted to grow well in monkey cells, 4. generation of monkey cell-tropic R5 viruses, 5. generation and characterization of mutants of accessory genes. A prototype monkey-tropic HIV-1 (X4) was found to infect pig-tailed and cynomolgus monkeys and to induce immunological reactions. However, it grew more poorly than the pathogenic standard SIVmac in monkey cells and in animals. A growth-defect of this virus concerning TRIM5α-restriction was successfully repaired considerably by altering a region in Gag-CA to improve its growth ability in monkey cells. We also have obtained cell-adapted virus clones (X4 and R5) with replication potentials similar to that of SIVmac. We finally generated proviral molecular clones which carry all the mutations described above, and mutants of accessory genes derived from them. We are now ready to perform animal experiments for various HIV-1/AIDS studies on basic (underlying mechanisms for viral replication and pathogenicity ; in vivo roles of accessory proteins) and clinical issues.