Baseline demographic and immune parameters of HIV-infected and uninfected Malawian adult study participants.

<p>Median and interquartile ranges (IQR) for age and immunological data are shown. Statistical significance of differences between the HIV negative group and all HIV-infected adults was tested using Fisher’s exact test (for categorical variables) or Mann Whitney <i>U</i> test (for continuous variables). † Data on <i>S. pneumoniae</i> carriage are missing for some patients for technical reasons.</p

Cytokine expression by Foxp3+ Treg in adenoidal cells.

<p>Percentage of Foxp3+ Treg in adenoidal MNC after stimulation with WCA compared with unstimulated medium control (A). Intracellular cytokine staining shows IL-10 (B) and IL-17 (C) production by Foxp3+ Treg and Foxp3− CD4+ T cells after WCA stimulation compared with unstimulated control. Only CD4+ T cell gate is shown in B and C. Result of one representative experiment of four replicates is shown.</p

Correlation between circulating IgM memory B-cells and CD4⁺ T-cells.

<p>(<b>A</b>) Scatter plots showing absolute IgM memory B-cell numbers & CD4⁺ T-cell counts and (<b>B</b>) % IgM memory B-cells & CD4⁺ T-cells measured using flow cytometry. The association between the two parameters (IgM memory B-cells and CD4 counts) was determined by Spearman’s correlation using Stata (Version 10). Each point represents the result from one subject. r_s is the Spearman rank correlation coefficient.</p

Expression of CD39 and CTLA4 by Foxp3+ Treg cells.

<p>Fluorescence histograms showing CD39 (A) and CTLA4 (B) expression by Foxp3+ Treg cells in PBMC (black) and adenoidal MNC (AdMNC) (red) from one representative of 20 replicate experiments summarized in panel C. (*p<0.01 compared to PBMC).</p

Association of pneumococcal carriage and Treg cells in adenoidal MNC.

<p>Percentages of CD4+Tcells which were Foxp3+ Treg (%Treg) (A) and their expression of CD39 (B) and intracellular CTLA4 (C) in PBMC and adenoidal MNC (AdMNC) in children who were culture positive (+) and negative (−) for pneumococcus. MFI – median fluorescence intensity. (*p<0.05 compared to culture negative children.) Culture+, n = 8; culture−, n = 12.</p

Proportion of Treg in CD4+T cells and percentages of Treg expressing CD45RO and CD69 in PBMC and adenoidal MNC.

<p>Mean percentages (SD) are shown. (*p<0.05, **p<0.01 compared to PBMC).</p

Adenoidal Treg exhibit strong inhibition of CD4+ T cell responses to WCA.

<p>CD4+ T cell proliferation (A+B) and cytokine production (C) in the presence or absence of Treg after stimulation with pneumococcal WCA. A). % CD4+ T cell proliferation in adenoidal MNC and Treg-depleted MNC from pneumococcal culture+ (n = 6) and culture− children (n = 6) (*p<0.01 compared to culture− group). B). CD4+ T cell proliferation induced by WCA in Treg-depleted MNC suppressed by the repletion of purified Treg (*p<0.01 compared to Treg-depleted MNC+WCA, n = 4. C). *p<0.01, #p<0.01 compared to Treg-depleted MNC+WCA.</p

IgM memory B-cells are depleted while isotype-switched memory B-cells are maintained in HIV-infected Malawian adults.

<p>(A) IgM memory B-cells (CD19⁺ CD27⁺ IgD⁺) absolute numbers, (B) percentages and (C) isotype-switched memory B-cell (CD19⁺ CD27⁺ IgD⁻) numbers, (D) percentages in the circulation of HIV⁻ controls (n = 44), HIV⁺ >350 (n = 16) and HIV⁺ ≤350 (n = 24) adult. Horizontal bars represent medium values. Statistical significance of differences between groups was assessed using the Mann Whitney <i>U</i> test.</p

Distribution of carriage density for serotype.

<p>Kernel Density plot showing the distribution of density plotted for different numbers of distinct serotypes recovered per child. The density of carriage does not differ with the number of serotypes found.</p

Serotype against observed absolute densities of pneumococcal serotypes.

<p>Serotype against observed absolute density for samples where a single serotype or strain was identified in the microarray (A) and for all samples (B). The red dots denote individual measurements of density. In the box and whisker plots, for each serotype, the central line denotes the median of the distribution, the box edges denote upper and lower quartiles and the whiskers extend 1.5 times the interquartile range past the quartiles. The black dots denote outliers (also shown in red), and the dotted vertical line marks the overall median as a guide to the eye. Numbers of measurements for each serotype are shown to the right of the y axis. Boxplots are ordered by median value, from lowest (bottom) to highest (top) of the solo serotypes in both panels.</p