Characterization of HIV excape mutants and T cell responses in elite suppressors

精英抑制者是HIV-1感染患者，他们的病毒载量为50拷贝/毫升，没有抗逆转录病毒药物 心理治疗。我们最近首次表明，可复制的病毒可以从一些 这表明对具有复制能力的HIV-1进行免疫控制是可能的。 有趣的是，我们还首次表明，在这些患者的血浆中存在低水平的病毒。 个人。我们证明了血浆中的GAG序列与静息状态之间存在显著的不一致。 CD4+T细胞。在从血浆中扩增的所有克隆中都发现了T细胞表位的替换，但 从静止的CD4+T细胞中扩增出的克隆很少见。免疫学分析证实，这些 替换是一种逃逸突变，它是对 HIV-1特异性CD8+T细胞。尽管有这些逃逸突变，但病毒的复制速度不够快 病毒载量超过50拷贝/毫升的水平。 这项建议的目的是确定免疫控制这种复制的机制 达到了有能力的病毒。完整的HIV-1蛋白质组将被分析T细胞表位和 将对血浆和静止的CD4T细胞中这些表位的序列进行分析，以帮助确定 一些关键的表位仍然没有突变。这可能解释了为什么实现了免疫控制。 即使在某些表位发生逃逸突变。另一种假设是病毒适合性是 由于逃逸突变的存在而大大减少。这将通过构建重组的 HIV-1包含从血浆中获得的分离物的序列。这些分离株的复制能力 将与野生型病毒进行比较。最后，我们将比较代表野生动物的多肽的能力 类型表位和逃逸突变体诱导T细胞激活的几个方面，包括细胞因子的分泌， 增殖和基因转录。这有助于确定HIV-1保护的免疫相关性。 疾病。 这项工作对于开发可用于改善HIV特异性的疫苗将是重要的 HIV-1感染者的免疫反应。这可能允许一些患者在没有病毒的情况下控制病毒 长时间的抗逆转录病毒治疗。

Elite suppresors are HIV-1 infected patients who mantain viral loads of <50 copies/ml without antiretroviral therapy. We have recently shown for the first time that replication competent virus can be isolated from some of these individuals suggesting that immunologic control of replication competent HIV-1 is possible. Interestingly, we have also shown for the first time that low levels of virus are present in the plasma of these individuals. We demonstrated a striking discordance between the sequence of gag in plasma versus resting CD4+ T cells. Substitutions in T cell epitopes were found in all clones amplified from the plasma, but were rare in clones amplified from the resting CD4+ T cells. Immunologic analyses has confirmed that these substitutions are escape mutations which develop as a response to the strong selective pressure exerted by HIV-1 specific CD8+ T cells. In spite of these escape mutations, the virus does not replicate at a high enough level for the viral load to exceed more than 50 copies/ml. The objective of this proposal is to determine the mechanisms by which immunolgic control of this replication competent virus is achieved. The complete HIV-1 proteome will be analyzed for T cell epitopes and the sequences of these epitopes in plasma and resting CD4 T cells will be analyed to help determine whether some critical epitopes remain unmutated. This could potentially explain why immune control is achieved even though escape mutations occurs at some epitopes. An alternative hypothesis is that viral fitness is greatly reduced by the presence of escape mutations. This will be tested by the construction of recombinant HIV-1 containing sequences from isolates obtained from plasma. The replication capacity of these isolates will be compared to that of wild type virus. Finally we will compare the ability of peptides representing wild type epitopes and escape mutants to induce several aspects of T cell activation including cytokine secretion, proliferation and gene transcription. This well help define the immune correlates of protection in HIV-1 disease. This work will be important for the development of vaccines that can be used to improve the HIV specific immune responses in HIV-1 infected individuals. This may allow some patients to control the virus without antiretroviral therapy for prolonged periods of time.