Theta-defensins: Novel HIV-1 Uptake Inhibitors

我们的主要目标是：确定先天免疫在预防HIV感染和疾病进展中的作用；探索灵长类Theta-Defensins的抗病毒特性并确定其活性机制，并为未来的治疗开发寻找有前景的0-Defensin多肽。Theta-Defensins是环状十八肽。它们在体内是由两个非编码肽在翻译后拼接而成的，每一个都来自一个截短的、由DIFT基因编码的类似阿尔法防御素的前肽。大约750万到1000万年前，智人祖先的灵巧基因在外显子2获得了一个过早的终止密码子，该密码子编码了信号序列。因此，尽管人类细胞仍然表达theta-Defensin mRNA，但它们不再产生theta-Defensin多肽。我们合成了三种theta-防御素多肽(逆周期蛋白-1、-2和-3)，如果人类细胞的灵巧基因没有被沉默，它们可能会产生。逆转录周期蛋白-2在保护CD4阳性细胞免受T型和M型HIV-1毒株的感染方面非常有效。其广泛的保护范围包括在我国引起大多数感染的B类菌株和在南部非洲和印度占主导地位的C类菌株。我们的初步数据表明，逆转录细胞色素是一种凝集素，它们与GP 120、CD4和半乳糖神经酰胺有很高的亲和力。这项建议的具体目标是：a)。合成新的theta-防御素，包括基于非人类灵长类灵长类动物Dft基因序列的多肽，b)。测试theta-防御素和选定的α-防御素(包括人类HN1-3)，以对抗实验室适应的HIV-1、HIV-2和SIV野生型毒株；c)鉴定灵长类theta和α-防御素识别的糖和低聚糖，并将其与其抗逆转录病毒特性相关联；以及d)确定哪些人淋巴细胞表达0-防御素mRNA，以及精氨酸糖苷是否使人类细胞能够产生0-防御素多肽。与健康相关：0-防御素构成了一类新型的艾滋病毒吸收抑制剂，具有良好的未来治疗开发潜力。这项拟议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中心和疾控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.