Cloning and cellular localization of pORF8 plasmid protein of Chlamydia trachomatis / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To clone the plasmid protein pORF8 of Chlamydia trachomatis and localize its expression in Chlamydia-infected cells.</p><p><b>METHODS</b>pORF8 gene was amplified and cloned into pGEX-6p vector, and the pORF8 fusion protein was expressed in E.coli XL1 Blue. After purification with glutathione-conjugated agarose beads, the pORF8 fusion protein was used to immunize BALB/c mice to generate polyclonal antibodies against pORF8 protein. The antibodies obtained were used to localize the plasmid protein pORF8 in Chlamydia-infected cells with immunofluorescence assay (IFA).</p><p><b>RESULTS</b>The pORF8 gene 744 bp in length was successfully cloned and the GST fusion protein with a relative molecular mass of 54 000 was obtained. The cellular distribution pattern of the plasmid protein pORF8 was similar to that of the major outer membrane protein (MOMP), a known C. trachomatis inclusion body protein, but not to that of chlamydial protease-like activity factor (CPAF, a secreted protein).</p><p><b>CONCLUSION</b>The plasmid protein pORF8 is localized on the bacterial organism as an inclusion body protein in C. trachomatis-infected cells. The cellular location of pORF8 protein can potentially provide important insights into the pathogenesis of C. trachomatis.</p>