ABSTRACT
Objective To investigate the effect of recombinant chlamydiaphage phiCPG1 capsid protein Vp1 on Chlamydia trachomatis(Ct) after Vp1 was co-cultured with Ct (reference strains and clinical strains).Methods The recombinant chlamydiaphage phiCPG1 capsid protein Vp1 was expressed and purified.Equal amount of Ct standard strains (E/UW-5/Cx and D/UW-3/Cx) or clinical strains,which had been incubated with Vp1 protein at the concentration of 53 μg/ml for 3 h at room temperature,were inoculated into McCoy.After cell culture,idione stain and transmission electron microscope were used to observe the effect of Vp1 on the Ct.The effect of Vp1 protein on the cell line McCoy was determined by MTT assay,the responses of Escherichia coli BL21 and DH5α toward Vp1 protein were determined using broth microdilution assays.Results Vp1 had obviously inhibitive effect on Ct,the inhibition ratios were about 40％-70％in clinical strains,72％ in reference strain D and 78％ in E,respectively.Abnormally enlarged RBs were observed after Vp1-treatment and Vp1 could arrest chlamydial developmental cycle using electron microscope.There was no effect of Vp1 on McCoy cells or bacteria BL21 or DH5α.Conclusion The recombinant Vp1 from phiCPG1 has obviously inhibitive effect on the growth of Ct,it will be helpful for the treatment of Ct infection in clinic.