衣原体噬菌体phiCPG1衣壳蛋白Vp1对豚鼠结膜炎衣原体及E型沙眼衣原体的抑制作用

Inhibitory effects of the Chlamydiaphage phiCPG1 capsid protein Vpl on Cldamydia psittaci strain guinea pig inclusion conjunctivitis and Chlamydia trachomatis serovar E

目的探讨豚鼠结膜炎衣原体（GPIC）噬菌体衣壳蛋白Vp1对GPIC及E型沙眼衣原体的抑制作用，为沙眼衣原体感染的治疗提供新的思路。方法用Vp1—pET30a（＋）重组质粒菌表达Vp1蛋白，Western印迹法鉴定蛋白，透析袋纯化蛋白，BCA法测定蛋白浓度，将GPIC、E型沙眼衣原体分别与Vp1蛋白、％s甘氨酸溶液、s蛋白及培养液室温孵育3h，衣原体培养过程中分别加入相同浓度的上述液体，72h或48h后，免疫荧光计数包涵体数。结果GPIC在Vp1蛋白组、Tris甘氨酸溶液组、S蛋白组及培养液组培养72h，包涵体计数分别为5．0±1．5、24±1．2、25±1．7及25±1．5，各组包涵体数比较，差异有统计学意义（F=476．632，P〈0．05）。Vp1蛋白组GPIC包涵体数显著低于Tris甘氨酸溶液组、s蛋白组及培养液组（P〈0．05），而后3组之间差异无统计学意义（P〉0．05）。与阴性对照组（培养液组）相比，Vp1蛋白对GPIC的抑制率为（80．2±3．99）％。此外，Vp1蛋白对E型沙眼衣原体的抑制率为（77．2±1．79）％，t检验示Vp1对GPIC的作用与对E型沙眼衣原体的作用差异无统计学意义（t=2．057，P〉0．05）。结论Vp1蛋白可明显抑制GPIC的感染，同时对E型沙眼衣原体有相似的抑制作用。

Objective To evaluate inhibitory effects of the Chlamydiaphage phiCPG1 eapsid protein Vpl on Chlamydia psittaci strain guinea pig inclusion conjunctivitis （GPIC） and Chlamydia trachomatis （Ct） serovar E, and to provide new ideas for the treatment of Ct infection. Methods The Chlamydiaphage phiCPG1 capsid protein Vpl was expressed in Escbedchia coli BL21 transfected with the recombinant plasmid Vpl-pET30a （＋）, identified by Western blot analysis and purified by using dialysis bags. Bicinchonininc acid （BCA） assay was performed to determine the concentration of Vpl protein. GPIC and Ct serovar E strains were both classified into 4 groups to be firstly incubated with Vpl protein （Vpl group）, Tris-glycine solution （Tris group）, S protein （S group） or Dulbecco＇s Modified Eagle Medium （DMEM, DMEM group） at room temperature for 3 hours, then were used to infect Hela cells followed by 72-hour （GPIC） or 48-hour （Ct serovar E） culture with the presence of Vp 1 protein （Vpl group）, Tris-glycine solution （Tris group）, S protein （S group） or DMEM （DMEM group）. Subsequently, immunofluorescence staining was conducted to observe and count chlamydial inclusions. Results The number of GPIC inclusions was significantly different between the 4 groups after 72-hour culture （F= 476.632, P〈 0.05）, and lower in the Vpl group （5.0 ± 1.5） than in the Tris group （24 ± 1.2, P〈 0.05）, S group （25 ± 1.7, P〈 0.05） and DMEM group （25 ± 1.5, P〈 0.05）, but insignificantly different between the latter 3 groups （P 〉 0.05）. Compared with the DMEM group, the Vpl group showed a significant decrease of 80.2%±3.99% and 77.2% ±1.79% in the number of GPIC and Ct serovar E inclusions respectively, with no significant difference in the inhibitory effect of Vpl on GPIC versus Ct serovar E （t = 2.057, P 〉 0.05）. Conclusion The phiCPG1 capsid protein Vpl can obviously inhibit GPIC and Ct serovar E infections to a similar degree.