Sustained Vif-independent replication of CXCR4 tropic HIV-1.

<p>(A) Plasma viral load was monitored in NSG-BLT humanized mice infected with 3.6×10⁵ TCIU HIV_LAIΔ<i>vif</i> directly into the human thymic implant, spleen, liver, or lung. Direct injection of HIV_LAIΔ<i>vif</i> into the thymus resulted in plasma viremia in 4/4 infections. (B) Longitudinal analysis of plasma viral load in humanized mice infected intravenously with 3.6×10⁵ TCIU of HIV_LAIΔ<i>vif</i> (n = 7) or 3–9×10⁴ TCIU of wild-type HIV_LAI (n = 6). Data represent mean +/− SEM. (C) Longitudinal analysis of the percentage of CD4⁺ T cells in the peripheral blood of humanized mice infected in panel B. (D) Comparison of the G to A mutation frequency in the viral RNA from the plasma and the viral DNA from peripheral blood cells from mice intravenously infected with HIV_LAIΔ<i>vif</i>. Data represent mean +/− SEM from 18 sequences, ** p = 0.0066. (E) Detection of HIV DNA (+) by nested PCR from the tissues of BLT humanized mice in panels A and B. Negative tissues (−) yielded no amplified viral DNA using two independent nested PCR primer sets targeting separate regions of the viral genome. Direct injection of HIV_LAIΔ<i>vif</i> into the liver, lung or spleen resulted in limited tissue distribution of viral DNA. (F) Comparison of the G to A mutation frequency in viral DNA from the thymus compared to viral DNA from other tissues of mice infected intrathymically (n = 4) and intravenously (n = 7) with HIV_LAIΔ<i>vif</i>. Data represent mean +/− SEM from 83 sequences. (G) G to A mutational profile of all viral DNA from mice infected with HIV_LAIΔ<i>vif</i>. Percentages indicate the proportion of G to A mutations occurring at <u>G</u>G (blue), <u>G</u>A (red), or <u>G</u>Y (black) sites.