LIGHT信号通路在鼠衣原体生殖道感染中的作用

Role of LIGHT signal pathway in Chlamydia muridarum urogenital infection in mice

摘要:

摘要:【目的】初步探讨与单纯疱疹病毒糖蛋白D竞争结合疱疹病毒侵入介体的淋巴毒素类似物(lymphotoxin-like inducible protein that competes with glycoprotein D for herpesvirus entry on T cells，LIGHT)在抗衣原体感染免疫及介导衣原体生殖道病理损伤过程的作用。【方法】用1×104 IFUs的MoPn经生殖道感染野生型(wild type，wt)、LIGHT KO小鼠，每组一半小鼠于感染后49d，再次感染相同剂量的MoPn。每隔3－4 d取生殖道分泌物，测定其中衣原体包涵体的数量。初次感染后80d，处死小鼠，眼眶取血，分离血清，用间接免疫荧光法测定其中抗体类型及效价;同时分离生殖道，肉眼观察其输卵管、子宫角水肿程度，然后甲醛固定、切片，H＆E染色后，显微镜下观察各组织炎性浸润程度和管腔水肿程度。分离小鼠脾细胞，体外用衣原体EB刺激，测定上清中IL-4、IL-5、IL-17和IFN-γ等细胞因子水平。【结果】LIGHT KO小鼠阴道带菌时间与wt组相当，大部分小鼠均在原发感染后28d左右完全清除感染，且均产生对再次感染的免疫力。LIGHT KO和wt小鼠子宫角和输卵管均出现一定程度的病变，但差异无统计学意义。两组小鼠在原发和继发感染MoPn后，均产生高效价的特异性抗MoPn IgG抗体，总抗体及各IgG抗体亚类效价差异均无统计学意义(P＞0.05)，且IgG2a/IgG1比值均大于1。和wt小鼠一样，LIGHT KO小鼠脾淋巴细胞经衣原体再次刺激后均可产生较高水平的IFN-γ和IL-17，且未能检测到IL-4和IL-5。【结论】小鼠抗MoPn生殖道感染及 MoPn引起的生殖道病理损伤不依赖于LIGHT信号通路。

Abstract:

Abstract:［Objective］ To study the role of lymphotoxin-like inducible protein that competes with glycoprotein D for herpesvirus entry on T cells (LIGHT) in the development of protective immunity and pathology during Chlamydia Muridarum urogenital infection in mice.［Methods］C57BL /6J wild type (wt) and mice deficient in LIGHT (LIGHT KO) were inoculated intravaginally with 1×104 IFUs of live C．muridarum organisms． Half mice of each group were reinfected on day 49 after primary infection． We took mice vaginal swabs every 3 or 4 days to monitor live organism shedding．On day 80 after the primary infection，mice were sacrificed，the vaginal tract was isolated for pathology analysis．The spleen cells were collected and IL-4，IL-5，IL-17 and IFN-γ were detected by ELISA in the spleen cells culture supernatant after restimulated by UV-MoPn EB． The titers of different Ab isotypes were measured in mice serum by Indirect Immunofluorescence Assay．［Results］The chlamydia shedding time of LIGHT KO mice was similar to wild type mice，which cleared the organisms within 28 days after primary infection，and acquired protective immunity against C．muridarum reinfection． All mice regardless of genotypes developed severe upper genital tract pathology and showed no significant difference between LIGHT KO and wild type mice． All mice developed robust anti-C．muridarum organism IgG antibody responses and the ratios of IgG2a versus IgG1 showed no significant difference between LIGHT KO and wild type mice．Splenocytes from MoPn-infected LIGHT KO and wild type mice produced high levels of IFN-γ and IL-17，but IL-4 and IL-5 couldn’t be detected．［Conclusions］ LIGHT signal pathway may not correlated with protection against C．muridarum urogenital tract infection and urogenital tract pathology induced by C．muridarum.