Replication and Pathogenic Potential of XMRV in Humans

我们最近发现XMRV的复制可被人A3G、人A3F和小鼠APOBEC3抑制，这表明XMRV不能在表达这些宿主蛋白的细胞中有效复制和传播，可能依赖于表达低水平这些因子的细胞的感染。为了确定XMRV是否在人的PBMC中复制，我们将量化XMRV在PBMC中的复制。我们还将量化A3蛋白在正常前列腺组织和前列腺癌中的表达程度。为了确定XMRV在前列腺癌中的发生率，我们将获得前列腺癌组织，并进行敏感的PCR检测以确定XMRV感染的程度。我们还将建立检测XMRV的酶联免疫吸附试验和免疫印迹试验。为了验证与HIV-1混合感染将导致A3蛋白降解并使XMRV更有效复制的假设，我们将确定患有淋巴瘤和其他恶性肿瘤的HIV-1感染者合并感染XMRV的发生率。我们先前证明XMRV复制对HIV-1整合酶抑制剂Raltegravir敏感。我们将对XMRV整合酶进行突变分析，以确定导致Raltegravir耐药的突变。我们还将在细胞系中选择耐raltegravir的XMRV变体，并将这些突变与HIV-1中选择的突变进行比较。

We have recently shown that XMRV replication is inhibited by human A3G, human A3F, and murine APOBEC3, suggesting that XMRV does not efficiently replicate and spread in cells that express these host proteins, and may depend on infection of cells that express low levels of these factors. To determine whether XMRV replicates in human PBMCs, we will quantify XMRV replication in PBMCs. We will also quantify the extent of A3 protein expression in normal prostate tissues and prostate carcinomas. To determine the incidence of XMRV in prostate cancer, we will obtain prostate tumors and carry out sensitive PCR assays to determine the extent of XMRV infection. We will also develop ELISA and western blot assays for XMRV detection. To test the hypothesis that co-infection with HIV-1 will lead to the degradation of A3 proteins and allow XMRV to replicate more efficiently, we will determine the incidence of XMRV co-infection in HIV-1 infected individuals with lymphomas and other malignancies. We previously showed that XMRV replication is sensitive to the HIV-1 integrase inhibitor raltegravir. We will carry out mutational analysis of XMRV integrase to identify mutations that confer raltegravir resistance. We will also select for raltegravir-resistant XMRV variants in cell lines and compare the mutations to those selected in HIV-1.