Peptide antisera generation against three Chlamydia trachomatis Hsp60 homologues to examine expression of each Hsp60 during iron restrictive growth

A Chlamydia trachomatis heat shock protein 60kDa (chsp60) exhibits increased expression in response to iron limitation. Genome sequencing revealed three genes encoding chsp60s. The objective of this study was to generate peptide antisera that would selectively recognize each chsp60. The DNA sequence for each C. trachomatis serovar E chsp60 was determined and compared with existing genome sequences. Predictive amino acid sequences were evaluated for peptides unique to each chsp60. Synthetic peptides were used to generate antisera; the resultant sera were purified by affinity chromatography and adsorbed to reduce cross-reactivity and increase monospecificity. Antisera were evaluated against each recombinant chsp60 protein by Western blotting. Reactivity against native chsp60s was visualized by transmission electron microscopy. Initial experiments indicate that expression of the second chsp60 (encoded by groEL_2) is increased during iron limitation. The production of chsp60 antibodies in human patients is associated with damaging sequelae in chlamydial genital and ocular infections.