Abstract:

Abstract:Objective
To study the mechanism of fusion protein of hsp65-MOMP-T-epitopes(H-ctm1) against C.trachomatis(Ct) genital tract infections that will underlay further research for T-epitopes Ct vaccine. Methods Models for Ct genital tract infections of mice were established.In the experiment of delayed type hypersensitivity(DTH),14 C57BL/6 female mice were divided into two groups(H-ctm1 immunized mice,naive mice,7 mice every group). The thickness of bilateral hind footpad of every mouse was measured,then,the left hind footpad was injected with SPG,and the right hind footpad with heat-killed chlamydia（HK-EBs）.The thickness of hind footpad was remeasured at 72 h following injection. In  the experiment of flow cytometric quantitation,21 C57BL/6 female mice were divided into three groups(H-ctm1 immunized mice,HK-EBs immunized mice,PBS-immunized mice,7 mice every group).After immunization,these mice were infected by Ct. 6 d after infection,the CD4+ and CD8+ T cells were dectected with flow cytometry(FACS). Results For the experiment of DTH,in the group of naive mice,there was no significant difference in thickness between pre-injection and post-injection whatever right or left hind footpad（P>0.05）,also between right and left hind footpad whatever pre-injection and post-injection（P>0.05）.In the group
 of H-ctm1 immunized mice,there was no significant difference in thickness between right and left hind footpad before injection（P>0.05）,however,the difference was  significant  after injection（P<0.05）.For left hind footpad,the difference was not significant   between before and  after injection（P>0.05）;for right hind footpad,the difference was  significant  between before and after injection（P<0.05）.[JP3]In the FACS experiment,the mean ratio of CD4+ T cells in H-ctm1 group(18.9%±[JP]2.2%) was higher than that in HK-EB group(11.3%±3.1%,P<0.05)) and control group(0.05%±0.07%,P<0.01). And the mean ratio of CD8+ cells in H-ctm1 g
roup(5.7%±1.9%) was higher than that in HK-EB group(1.5%±0.5%,P<0.01) and control group(0.02%±0.01%,P<0.01). Conclusion DTH play a role in the process of immune response to H-ctm1 immunized mice.HSP65 fusion protein can stimulate the dendritic cells to up-regulate the levels of MHC（class Ⅰ and class　Ⅱ）and improve  MOMP-T-epitopes immunogenicity.

Key words: Chlamydia trachomatis；T cell epitopes；heat shock protein；vaccine