Time course of plasma viral load in PHI patients between the pre-inclusion visit (∼d-7) and inclusion of the study (d0).

<p>Values for patients who experienced a decline of at least 0.3 log in their viral load (arbitrary threshold) during this period are shown in red, and those from patients whose viral load remained stable are in blue.</p

Characteristics of groups of patients included in the study.

1<p>PHI, Primary HIV Infection;</p>2<p>HIC: HIV controllers;</p>3<p>NA: not applicable.</p

Modest capacity of CD8+ T cells from PHI-patients to suppress infection.

<p><b>A.</b> Capacity of CD8+ T-cells from PHI patients and HIC to suppress HIV infection of autologous CD4+ T-cells ex vivo, measured as the log fall in p24 production in culture supernatants when CD4+ T-cells superinfected in vitro with HIV-1 Bal were co-cultured with unstimulated autologous CD8+ T-cells at a ratio of 1∶1, by comparison with p24 production by superinfected CD4+ T-cells cultured alone. Each symbol represents one patient. Open circles represent patients carrying at least one HLA-B*27 or B*57 allele. <b>B.</b> Correlation between CD8+ T-cell-mediated HIV suppression and the frequency of IFNγ-producing CD8+ T-cells between HIC (black symbols) and PHI patients (red symbols). Linear regression is shown for HIC. <b>C.</b> Capacity of CD8+ T-cells from patients with acute or early PHI to suppress HIV infection ex vivo. <b>D.</b> Comparison of the capacity of CD8+ T-cells from PHI patients with decreasing and stable viral loads to suppress HIV infection of autologous CD4+ T-cells.</p

Similar HIV-specific T cell responses in PHI-patients and HIC.

<p><b>A.</b> PHI patients: frequency of CD4+ T-cells producing at least one cytokine (IFN-γ, MIP-1β or IL-2) in response to HIV-p24 stimulation, as determined by ICS (left); percentage of patients with a positive CD4+ T-cell response (centre); and frequency of HIV-specific CD4+ T-cells producing one, two or three cytokines (right) <b>B.</b> same experiments with CD8+ T-cells challenged with MHC-matched optimal HIV-1 peptides. <b>C.</b> Comparative frequency of IFNγ- (left) and IL2 (right)-producing CD4+ T-cells in PHI patients and HIC. D. <i>Idem</i> for CD8+ T-cells. Each symbol represents one individual. Medians are shown as horizontal lines.</p

Stimulation with a low antigen concentration induces the CD38⁻/HLA-DR⁺ phenotype on specific CD8⁺ T cells.

<p>(A) Graphs representing the frequency of (A) CD38⁻/HLA-DR⁺ cells (dark histograms) and (B) CD38⁺/HLA-DR⁺ cells (dark gray histograms) among activated EBV-specific healthy donor CD8⁺ T cells (i.e. those expressing CD38 and/or HLA-DR) after a four-day culture period (n = 8).</p

Study population.

<p>Median values [1^st–3^rd interquartile range] are shown for age, time since diagnosis, CD4⁺ and CD8⁺ T cell counts, and HIV RNA viral loads.</p>a<p>Viremic and HAART-treated patients' RNA viral loads were measured using an assay with a quantification limit of <50 copies/ml, while values in HIC were obtained with ultrasensitive assays.</p

CD38 and HLA-DR expression on bulk and HIV-specific CD8⁺ T cells.

<p>(A) Proportions of bulk CD8⁺ T cells from HD (n = 16, light gray bars), HAART-treated patients (n = 19, mid gray bars), viremic patients (n = 21, dark gray bars) and HIC (n = 79, black bars) expressing CD38 and HLA-DR. (C) Proportions of HIV-specific CD8⁺ T cells from HAART-treated patients (n = 13, mid gray bars), viremic patients (n = 39, dark gray bars) and HIC (n = 80, black bars) expressing CD38 and HLA-DR. Pie charts representing CD38⁻/HLA-DR⁻ (white), CD38⁻/HLA-DR⁺ (black), CD38⁺/HLA-DR⁻ (light gray) and CD38⁺/HLA-DR⁺ (dark gray) cells among bulk (B) and HIV-specific CD8⁺ T cells (D). Statistical differences shown in the pie charts are based on the difference in the frequency of the CD38⁻/HLA-DR⁺ subset between the different groups. * <i>P</i><0.05, ** <i>P</i><0.01, *** <i>P</i><0.001.</p

High antigen sensitivity is associated with a high frequency of CD38⁻/HLA-DR⁺ cells in HIC.

<p>The antigen sensitivity of HIV-specific CD8⁺ T cells was measured in ELISpot assays with serial limiting dilutions of antigenic peptides (from 10⁻⁵ to 10⁻¹¹ M) and was expressed as the log molar concentration of peptide yielding 50% of the maximum response (EC_50%). Correlations between the proportion of CD38⁻/HLA-DR⁺ (A) or CD38⁺/HLA-DR⁺ (B) and the antigen sensitivity of HIV-specific CD8⁺ T cells from HIC. Correlations were evaluated using the Spearman rank correlation coefficient. The Spearman r correlation and the Pearson correlation curve are indicated for significant correlations (n = 47).</p

Qualitative features of CD38⁻/HLA-DR⁺ and CD38⁺/HLA-DR⁺ HIV-specific CD8⁺ T cell subsets in HIC.

<p>(A) Bcl-2 expression on CD38⁻/HLA-DR⁺ and CD38⁺/HLA-DR⁺ HIV-specific CD8⁺ T cells (n = 11). (B) Proportion of CD38⁻/HLA-DR⁺ and CD38⁺/HLA-DR⁺ HIV-specific CD8⁺ T cells producing both IFN-γ and IL-2 among HIV-specific CD8⁺ T cells producing IFN-γ or IL-2 (n = 35). (C) Fold increase in CD38⁻/HLA-DR⁺ and CD38⁺/HLA-DR⁺ HIV-specific CD8⁺ T cell numbers after 5 days of culture with HIV peptides (2 µM) (n = 7). (D–E) Proportion of CD38⁻/HLA-DR⁺ and CD38⁺/HLA-DR⁺ HIV-specific CD8⁺ T cells producing perforin (D) and granzyme B (E) (n = 35). (F) Graphs representing percentage cytotoxicity (measured as granzyme-B-mediated intracellular cleavage of a fluorogenic substrate) of CD38⁻/HLA-DR⁺ and CD38⁺/HLA-DR⁺ HIV-specific CD8⁺ T cells (n = 11). * <i>P</i><0.05, ** <i>P</i><0.01, *** <i>P</i><0.001.</p

Influence of stimulatory conditions on the activation phenotype of specific CD8⁺ T cells.

<p>(A) Representative dot plots of HLA-DR and CD38 expression in unstimulated conditions (upper graph), after IFN-α stimulation (middle graph) or peptide stimulation (2 µM, lower graph) among specific (dark dots) and non-specific (gray dots) CD8⁺ T cells from healthy donors after a four-day culture period. CD38 and HLA-DR expression on bulk (C left panel) and specific CD8⁺ T cells (B and C right panel). (B) Flow cytometry histograms showing representative results for cells from one individual in unstimulated conditions (dark lines), after IFN-α stimulation (light gray histograms) or peptide stimulation (dark gray histograms). (C) Surface expression of CD38 (white bars) and HLA-DR (gray bars) on bulk and specific CD8⁺ T cells (n = 4).</p