Variant G57E of Mannose Binding Lectin Associated with Protection against Tuberculosis Caused by Mycobacterium africanum but not by M. tuberculosis (original) (raw)
Figure 2
Comparison of MBL binding to M. africanum vs. M. tuberculosis strains by flow cytometry.
Representative clinical isolates of M. africanum and M. tuberculosis strains were processed for flow-cytometric analysis by labeling with recombinant human MBL, biotinylated anti-human MBL antibody and Cy5-conjugated streptavidin). The percentage of positive cells for MBL binding was analyzed in triplicates for three different clinical isolates of M. africanum and M. tuberculosis along with the laboratory strain H37Rv. Calcium dependence of binding was examined by the addition of EDTA to the TBS/Ca2+ buffer. Negative controls were processed in the absence of MBL. The mean percentage of positive cells of these controls was subtracted from the corresponding percentages of positive cells of MBL-treated mycobacteria (A). Representative flow-cytometric profiles of MBL binding to clinical isolates (depicted in A) in the presence of Ca2+ (B). The Ghanaian MTBC strains used for the binding assays were M. africanum West African 2 strains 10415/02, 10476/01, 10514/01 and M. tuberculosis Cameroon strains 5390/02, 5400/02 and 1417/02.