Overlapping peptide pools of latency-associated protein Rv3407 stimulate IFNγ-expressing CD4+ T cells after 7 days and two rounds of restimulation.

PBMC from six LTBI (A–F) were restimulated with 15-mer synthetic peptide pools of Rv3407 for 7 days including two rounds of in vitro restimulation. IFNγ-expressing CD4+ CD45RO+ T cells are shown for stimulation with peptide pools 1 to 6 (grey bars) and pools 7 to 11 (black bars). Each peptide is constituent of one pool within pools 1 to 6 and of one pool within pools 7 to 11. Peptides inducing the most prominent responses are indicated for donors A–D. The horizontal line indicates the threshold for positive responses (0.2%). Background values of non-stimulated controls were subtracted.