Expansion of CD172a⁺ cells in response to ESAT-6/CFP-10 stimulation.

<p>Isolated PBMC were stained with PKH67 and cultured for 6d with media only, rMPB83, a pool of overlapping ESAT-6 and CFP-10 peptides, or rESAT-6:CFP-10. Data are depicted as: (A) dot plots (CD172a-PE (y-axis) versus PKH67 (x-axis, green fluorescence), (B) histograms generated by Modfit Proliferation Wizard analysis of PKH67 staining intensity (gated on CD172a-PE⁺ cells within the live gate) and (C) mean (±SEM) percent CD172a⁺ cells within PBMC cultures (stimulation indicated in the lower margin) from non-infected (open bars, n = 9, includes non- (n = 3), BCG- (n = 3), and ΔRD1- (n = 3) vaccinates) or <i>M. bovis</i>-infected (closed bars, n = 20) cattle. Responses did not differ between controls, BCG- and ΔRD1- vaccinates; thus, these groups were combined. Gate R2 in panel A highlights the CD172a⁺, PKH67^lo proliferative fraction. For panels A and B, data from a single <i>M. bovis</i>-infected animal are provided that are indicative of a representative response.