Theta-defensins: Novel HIV-1 Uptake Inhibitors

我们的主要目标是：确定先天免疫在预防艾滋病毒感染和疾病进展中的作用；探索灵长类动物防御素的抗病毒特性，确定其活性机制，并为未来的治疗开发寻找有前途的0-防御素肽。防御素是环状的八肽。它们在体内由两个非肽的翻译后剪接形成，每个非肽都来自由DEFT基因编码的截断的α -防御素样前肽。大约750万到1000万年前，智人的原始人祖先的DEFT基因在外显子2上获得了一个过早的停止密码子，该密码子编码信号序列。因此，尽管人类细胞仍然表达-防御素mRNA，但它们不再产生-防御素肽。我们合成了三种防御肽（逆转录细胞周期蛋白- 1，-2和-3），如果人类细胞的DEFT基因没有被沉默，它们可能会产生。逆转录细胞周期素-2在保护cd4阳性细胞免受T和Mtropic株HIV-1的感染方面非常有效。其广泛的保护谱包括在我国引起大多数感染的B支分离株和在南部非洲和印度占主导地位的C支分离株。我们的初步数据显示，逆转录细胞素是一种凝集素，它们与gp 120、CD4和半乳糖神经酰胺具有高亲和力。本建议的具体目的是：a)。合成新的防御素，包括基于非人灵长类动物DEFT基因序列的肽，b)。测试β -防御素和选定的α -防御素（包括人类hn1 -3）对实验室适应型和野生型HIV-1、HIV-2和SIV毒株的抗性；c)鉴定灵长类动物α -防御素和α -防御素识别的糖和寡糖，并将其与它们的抗逆转录病毒特性联系起来；d)确定哪些人类淋巴细胞表达0-防御素mRNA，以及是否氨基酸糖苷能使人类细胞产生0-防御素肽。健康相关性：0-防御素是一种新型的hiv摄取抑制剂，在未来的治疗发展中具有良好的潜力。拟议中的研究将允许加州大学洛杉矶分校、埃默里大学耶克斯灵长类动物中心和疾病预防控制中心的经验丰富的研究人员为这一发展奠定必要的基础。

Our broad objectives are: to ascertain the role of innate immunity in protecting against HIV-infection and disease progression; to explore the antiviral properties of primate theta-defensins and determine their mechanism of activity, and identify promising 0-defensin peptides for future therapeutic development. Theta-defensins are circular octadecapeptides. They are formed in vivo by the post-translational splicing of two nonapeptides, each derived from a truncated, alpha-defensin-like propeptide that is encoded by a DEFT gene. Some 7.5 to 10 million years ago, the DEFT genes of a hominid ancestor of Homo sapiens acquired a premature stop codon in Exon 2, which encodes the signal sequence. Consequently, although human cells still express theta-defensin mRNA, they no longer produce theta-defensin peptides. We synthesized three theta-defensin peptides (retrocyclins- 1, -2 and-3) that human ceils could have produced if their DEFT genes had not been silenced. Retrocyclin-2 was remarkably effective in protecting CD4-positive cells from infection by both T and Mtropic strains of HIV-1. Its wide protective spectrum encompassed the clade B isolates that cause most infections in our country and the Clade C isolates that predominate in southern Africa and India. Our preliminary data revealed that retrocyelins are lectins, and that they bind gp 120, CD4 and galactosylceramide with high affinity. The specific aims of this proposal are: a). To synthesize novel theta-defensins, including peptides based on DEFT gene sequences in non-human primates, b). To test theta-defensins and selected alpha- defensins (including human HN 1-3), against laboratory-adapted and wild-type strains of HIV-1, HIV-2, and SIV; c) To identify the sugars and oligosaccharides recognized by primate theta- and alpha-defensins and correlate this with their antiretroviral properties, and d) To determine which human lymphocytes express 0-defensin mRNA, and if arninoglycosides enable human cells to produce 0-defensin peptides. Health relatedness: 0- defensins constitute a novel class of HIV-uptake inhibitors with excellent potential for future therapeutic development. The proposed research will allow experienced investigators based at UCLA, The Yerkes Primate Center at Emory University and the CDC to build the required foundation for this development.