Figure 4. A majority of the antibodies generated against chlamydial specific and conserved antigens recognize conformational determinants.

(A) RIP was performed with sera from all three infected NHP obtained from a single time point 13 weeks after re-challenge using A2497 infected cell lysates that were treated at 70°C for 30 min or kept at ambient temperature. Heat treatment of chlamydial antigens partially destroyed antibody recognition of MOMP in all three monkeys. Heating also destroyed or partially destroyed the antigenicity of the majority of the other IP antigens indicating that antibodies generated against the antigens in the context of primary and re-challenge infections were specific to conformational determinants. (B) IPs were performed on heated and unheated A2497 infected cell lysates using sera from monkey RML 134 and gels probed by Western blotting with chlamydial specific antibodies to identify heat sensitive and resistant conserved antigens. Heat treatment completely inhibited antibody reactivity against full length PmpD and its two proteolytically processed polypeptides and CPAF. Pgp3 and HSP60 antigenicity was partially affected or not affected by heating, respectively.