SL9 and SL9-cross-reactive microbial peptides differentially expand SL9-specific CD8⁺ T cells.

<p>Characterization of SL9-specific TCR repertoires after PBMC stimulation with SL9 or SL9CR peptides. PBMCs from HIV-1-positive HLA-A2⁺ subjects were stimulated with peptides for six days, and SL9-specific CD8⁺ T cells were sorted from fresh (unstimulated), SL9-stimulated, or SL9CR-stimulated PBMCs. Frequencies of unique TCR clones as measured by diversity in the TCR-β CDR3 region were quantified by ImmunoSEQ deep sequencing. Each dot shows the frequency of a single TCR clone in the specified SL9-specific CD8⁺ T cell populations. TCR clones that have the same frequency in both populations compared on a plot fall on the diagonal line. Magenta dots indicate TCR clones that are present at significantly different frequencies (minimum 20 reads in either condition, p<0.005, Fisher’s Exact test with Benjamini-Hochberg correction. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0192098#pone.0192098.s002" target="_blank">S2 Table</a> shows all associated p-values).