鼠衣原体在不同遗传背景小鼠中病变差异性与炎症细胞动态变化

Pathological difference and dynamic changes of inflammatory cells in Chlamydia muridarum infected mice with diverse genetic background

摘要:

【目的】初步分析鼠衣原体(Chlamydia muridarum，Cm)致不同遗传背景小鼠生殖道病变的原因，探讨炎症细胞动态变化在衣原体感染致不同人群病变差异的可能机制。【方法】用2×105 Inclusion forming units (IFUs)/小鼠的Cm剂量经子宫角(Intrauterine inoculation，iu)途径分别感染DBA/2J鼠和A/J鼠；在感染60 d处死两组小鼠，肉眼观察其输卵管水肿程度，显微镜下观察评估输卵管的扩张程度及炎症反应程度；每组小鼠在感染后3、7、14、21、28、35、42、49、56、60 d分别取阴道分泌物并检测其中衣原体包涵体的数量；在第14天每组各处死 5只小鼠，检测上生殖道(输卵管及卵巢)组织匀浆中衣原体包涵体数量及炎症因子水平；同时，在3、28、35 d每组分别处死5只小鼠，显微镜下鉴定病变组织炎症细胞种类及变化。【结果】两组小鼠在感染60 d肉眼观察下的生殖道病变率有明显统计学差异，且两组小鼠病变组织的输卵管扩张程度也具有统计学差异，但炎症反应程度评分无统计学差异；DBA/2J与A/J两组小鼠在阴道分泌物的衣原体包涵体检测及小鼠阳性检出率中并无显著性差异；感染后14 d两组小鼠在上生殖道组织匀浆中的包涵体检出量无统计学差异，但某些炎症因子水平具有统计学差异；感染早期两组小鼠病变组织中嗜中性粒细胞浸润增加，但无明显差异，第28天DBA/2J小鼠病变组织中出现较多嗜酸性粒细胞，并在第35天与A/J小鼠形成统计学差异。【结论】DBA/2J与A/J小鼠在以iu方式感染等量Cm后，引起小鼠的生殖道病变差异可能与嗜酸性粒细胞参与的炎症反应有关。

Abstract:

[Objective] To determine the cause of Chlamydia muridarum-induced pathology in urogenital tract of mice with various genetic background, and to explore the mechanism of inflammatory cells’ dynamic changes in pathological difference of mice infected with chlamydia. [Methods] Each of DBA/2J and A/J mice was inoculated via intrauterine route with 2×105 inclusion forming units (IFUs) of live C. muridarum organisms. Mice were sacrificed on 60 days post infection, and the severity of oviduct hydrosalpinx from each mouse was examined visually. The severity of inflammation and pathologies were scored under microscope. Vaginal swabs were taken on 3, 7, 14, 21, 28, 35, 42, 49, 56 and 60 days post infection from each group of mice and the total number of IFUs per swab was calculated. Five mice per group were sacrificed on 14 days post infection, each section of urogenital tract was made into homogenates for measuring the number of IFUs and the level of cytokines per sample. Meanwhile, 5 mice per group were sacrificed each time on 3, 28 and 35 dpi for diagnosis of the type and dynamic changes of inflammatory cells in the diseased tissues. [Results] Two groups of mice had statistically significant differences in hydrosalpinx incidence and severity of dilation whereas no statistically difference in the scores for the severity of inflammation. DBA/2J and A/J mice displayed same in number of chlamydial IFUs and pathology positive mice rate. The level of some inflammatory cytokines but not the number of IFUs detected in oviduct and ovary homogenate on 14 days had statistically difference. In early stage of infection neutrophils in pathological tissues increased in both DBA/2J and A/J mice whereas no obvious difference in two results. Many eosinophils occurred in pathological tissues of DBA/2J mice on 28 days and displayed statistically difference with A/J mice on 35 days. [Conclusion] The pathological difference of urogenital tract from DBA/2J and A/J mice with intrauterine inoculation of C. muridarum may have relationship with eosinophils-involved inflammatory reaction.