Figure 4. Potential colocalisation of HIV-specific CD8⁺ and CD4⁺ T-cells via integrin β7 but not CCR6.

(A–C) PBMC from five SP subjects were stimulated with different HIV peptide pools or recombinant HIV-p24 and analyzed by polychromatic flow cytometry for the expression of homing molecules, as described in Figures 2 and 3. HIV-specific CD4⁺ and CD8⁺ T-cells were analyzed for (A–C) the expression of the homing molecules β7 integrin, CCR6, CXCR3, and CCR4 (D) the proliferation potential. (A) Shown is the expression of homing molecules on matched CD4⁺ versus CD8⁺ T-cells specific for different HIV peptide pools in five different SP subjects. Shown are correlations between (B) the frequency of matched HIV-specific CD4⁺ and CD8⁺ T-cells expressing β7 integrin, CCR6, CXCR3, or CCR4 alone, and (C) co-expressing the β7 integrin and CXCR3 molecules (β7⁺CXCR3⁺ phenotype). (D) Shown is the percentage of matched CD4⁺ versus CD8⁺ T-cells proliferating (CFSE^low) in response to different HIV peptide pools. Paired T-test p-values are indicated in the Figures A and D. Spearman correlation r and p-values and linear regression r² values are indicated in the Figures B and C.