Comparison of CD4+ T-cell levels in uninfected, HIV-1 infected and SIVcpz infected animals.

<p>Levels of peripheral blood CD4+ T-cells were quantified by flow cytometry in chimpanzees that were uninfected (Neg., n = 32), HIV-1 non-progressors (HIV-NP, n = 29), or SIVcpz infected (SIVcpz, n = 7). Levels were quantified as (A) Absolute CD4+ T-cell counts, (B) percentage CD4+ T-cells of the lymphocyte population, and (C) the CD4:CD8 T-cell ratios. Shading corresponds to CDC categorisation for CD4+ T-cell levels (absolute count and percentage of lymphocytes) in HIV-1 infected humans, where yellow indicates stage two and red indicates stage one. P value shown indicates that SIVcpz infection was a significant predictor of reduced CD4+ T-cell levels, in a general linear model including age, gender, and HIV-1 and SIVcpz status. Full details of analysis are available in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005146#ppat.1005146.s007" target="_blank">S1</a>–<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005146#ppat.1005146.s009" target="_blank">S3</a> Tables. Each SIVcpz infected animal is represented by a unique symbol, as indicated in the legend. Horizontal black bars indicate the mean value in each group. Data shown for the SIVcpz infected animals are the most recent available, detailed in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005146#ppat.1005146.t001" target="_blank">Table 1</a> as the time post infection for absolute T-cell count.