Snyder B W, Vitale J, Milos P, Gosselin J, Gillespie F, Ebert K, Hague B F, Kindt T J, Wadsworth S, Leibowitz P
Exemplar Corporation, Bay Colony Corporate Center, Waltham, Massachusetts, USA.
Mol Reprod Dev. 1995 Apr;40(4):419-28. doi: 10.1002/mrd.1080400405.
A major obstacle to understanding AIDS is the lack of a suitable small animal model for studying HIV-1 infection and the subsequent development of AIDS, and for testing diagnostic, therapeutic, and preventive modalities. Our goal is to produce a rabbit model for the study of AIDS. Here we report on the generation of transgenic rabbits that express the human CD4 (hCD4) gene. The transgene, which contains the coding region for hCD4 and approximately 23 kb of sequence upstream of the translation start site, was used previously to direct hcD4 expression on the surface of CD4+ T cells of transgenic mice (Gillespie et al., 1993: Mol Cell Biol 13:2952-2958). The hCD4 transgene was detected in five males and two females derived from the microinjection in five males and two females derived from the microinjection of 271 rabbit embryos. Both hCD4 RNA and protein were expressed in peripheral blood lymphocytes (PBLs) from all five males but neither of the females. Human CD4 was expressed on PBLs from F1 offspring of all founder males. T-cell subset analysis revealed that hCD4 expression was restricted to rabbit CD4 (rCD4) expressing lymphocytes; mature rCD4- rCD8+ lymphocytes did not express hCD4. In preliminary studies, PBLs from hCD4 transgenic rabbits produced greater amounts of HIV-1 p24 core protein following HIV-1 infection in vitro than HIV-1 p24 antigen in nontransgenic rabbit infected cultures. These results extend to rabbits our previous observation that this transgene contains the sequence elements required for high-level expression in the appropriate cells of transgenic mice. Furthermore, these and previous studies demonstrating that expression of hCD4 protein enhances HIV-1 infection of rabbit T cells in vitro, coupled with reports that normal, nontransgenic rabbits are susceptible to HIV-1 infection, suggests that the hCD4 transgenic rabbits described herein will have an increased susceptibility to HIV-1 infection. In vivo HIV-1 infection studies with these rabbits are under way.
理解艾滋病的一个主要障碍是缺乏合适的小动物模型来研究HIV-1感染及后续艾滋病的发展，以及测试诊断、治疗和预防方法。我们的目标是培育出用于艾滋病研究的兔模型。在此，我们报告表达人CD4（hCD4）基因的转基因兔的培育情况。该转基因包含hCD4的编码区及翻译起始位点上游约23 kb的序列，此前曾用于指导转基因小鼠CD4+ T细胞表面的hcD4表达（吉莱斯皮等人，1993年：《分子与细胞生物学》13:2952 - 2958）。在通过显微注射271个兔胚胎获得的5只雄性和2只雌性兔中检测到了hCD4转基因。所有5只雄性兔的外周血淋巴细胞（PBL）中均表达了hCD4 RNA和蛋白质，但2只雌性兔均未表达。所有奠基雄性兔的F1代后代的PBL上均表达了人CD4。T细胞亚群分析显示，hCD4表达仅限于表达兔CD4（rCD4）的淋巴细胞；成熟的rCD4 - rCD8+淋巴细胞不表达hCD4。在初步研究中，hCD4转基因兔的PBL在体外感染HIV-1后产生的HIV-1 p24核心蛋白比未转基因兔感染培养物中的HIV-1 p24抗原更多。这些结果将我们之前的观察扩展到了兔，即该转基因包含在转基因小鼠的合适细胞中进行高水平表达所需的序列元件。此外，这些及之前的研究表明hCD4蛋白的表达增强了兔T细胞在体外对HIV-1的感染，再加上有报道称正常的非转基因兔易受HIV-1感染，这表明本文所述的hCD4转基因兔对HIV-1感染的易感性将会增加。对这些兔进行的体内HIV-1感染研究正在进行中。
