Dynamic HIV-1 Escape from CCR5 Antagonism in vito

描述（由候选人提供）：gp 120的V3环既是HIV-1的主要中和决定因素，也是病毒细胞嗜性的主要决定因素。在宿主感染过程中，几乎完全早期使用CCR 5进入转变为使用CXCR 4的病毒群体，在感染的前5年内，约50%的患者出现更高的发病率和死亡率。靶向gp 120-CCR 5相互作用的抗逆转录病毒药物的出现，再加上临床试验中观察到辅助受体使用的变化代表了HIV从这些药物逃逸的主要体内途径，再次强调了需要提高我们对序列群体水平辅助受体使用的理解。然而，定量V3和其他基因座的序列多样性的能力受到常规测序的技术和实践限制的限制。 我们假设，跨HIV准种的病毒辅助受体使用比以前认识到的更复杂，并且由大量的共循环CXCR 4和CCR 5使用病毒组成。然后，在辅助受体拮抗剂药物压力下，可以从这种丰富的多样性中选择病毒变体，并导致抗逆转录病毒治疗失败。我们进一步假设，少数使用CXCR 4的变异体比使用CCR 5的变异体更不适合，并将研究通过深度测序鉴定的使用CXCR 4的病毒群体适合性的病毒决定因素。我们建议：1）研究HIV准种中辅助受体使用的多样性，鉴定独特的V3变体，并量化VCV治疗期间其比例的变化，2）表征VCV治疗期间V3环序列的群体动态，3）研究CXCR 4使用微小变体的适应性。 该候选人目前是马萨诸塞州总医院传染病科的讲师，并寻求进一步的实验室和临床研究技能培训，使他能够发展成为独立的临床研究科学家。本计划将在丹尼尔·库里茨克斯博士的指导下实施。 相关性：拟议的研究将阐明CCR 5拮抗剂治疗对病毒辅助受体使用和V3环序列进化的影响，在感染宿主的整个准种。这些研究将有助于更好地理解这些变化在疾病发病机制中可能发挥的作用，并为HIV-1 CCR 5拮抗剂的最佳临床应用提供信息。

DESCRIPTION (provided by candidate): The V3 loop of gp120 is both the principal neutralizing determinant of HIV-1 and the main determinant of the virus' cellular tropism. Over the course of host infection, the almost exclusive early use of CCR5 for entry shifts as CXCR4-using viral populations associated with greater morbidity and mortality emerge in approximately 50% of patients over the first 5 years of infection. The advent of antiretrovirals targeting the gp120-CCR5 interaction, coupled with the observation in clinical trials that changes in coreceptor usage represent the major in vivo pathway of HIV escape from these drugs, have re-emphasized the need to improve our understanding of coreceptor usage at the sequence population level. The ability to quantify sequence diversity at V3 and other loci, however, has been limited by the technical and practical constraints of conventional sequencing. We hypothesize that viral coreceptor usage across the HIV quasispecies is more complex than previously appreciated and consists of a multitude of co-circulating CXCR4- and CCR5- using viruses. Viral variants from this wealth of diversity could then be selected under a coreceptor antagonist drug pressure and contribute to the failure of antiretroviral therapy. We further hypothesize that minority CXCR4-using variants are less fit than their CCR5-using counterparts, and will investigate the viral determinants of fitness of minor CXCR4-using viral populations identified by deep sequencing. We propose to 1) Investigate the diversity of coreceptor usage across the HIV quasispecies, identify unique V3 variants, and quantify shifts in their proportions during VCV treatment, 2) characterize the population dynamics of V3 loop sequences during VCV treatment, and 3) investigate the fitness of CXCR4-using minor variants. The candidate is currently an Instructor in the Division of Infectious Diseases at Massachusetts General Hospital and seeks further training in both bench and clinical research skills that will allow him to develop into and independent clinical research scientist. This plan will be conducted under the mentoring of Dr. Daniel Kuritzkes. RELEVANCE: The proposed studies will illuminate the effects of CCR5 antagonist therapy on viral coreceptor usage and V3 loop sequence evolution across the entire quasispecies within an infected host. These studies will contribute to a better understanding of the role these changes may play in disease pathogenesis and inform the most optimal clinical use of HIV-1 CCR5 antagonists.