Ojcius D M, Bravo de Alba Y, Kanellopoulos J M, Hawkins R A, Kelly K A, Rank R G, Dautry-Varsat A
Unité de Biologie des Interactions Cellulaires, CNRS 1960, Institut Pasteur, Paris, France.
J Immunol. 1998 Feb 1;160(3):1297-303.
Chlamydia species are the causative agents of trachoma, various forms of pneumonia, and the most common sexually transmitted diseases. Although the infection cycle has been extensively characterized in epithelial cells, where the Chlamydia entry-vacuoles avoid fusion with host-cell lysosomes, the cellular immune response has received less attention. Moreover, despite the abundant presence of dendritic cells (DC) in the sites of infection, the interaction between Chlamydia and DC has never been studied. We observe that DC kill Chlamydia trachomatis and Chlamydia psittaci. The chlamydiae are internalized by the DC in a nonspecific manner through macropinocytosis, and the macropinosomes fuse subsequently with DC lysosomes expressing MHC class II molecules. The interaction induces maturation of the DC, since presentation of an exogenous Ag is severely inhibited after a 1-day incubation, although chlamydial Ags are still presented and recognized by Chlamydia-specific CD4+ T cells. Thus, DC most likely play a role in initiating the T cell response in vivo and could potentially be used in adoptive transfer therapies to vaccinate against Chlamydia.
衣原体属是沙眼、多种形式肺炎以及最常见性传播疾病的病原体。尽管衣原体在上皮细胞中的感染周期已得到广泛描述，在这些上皮细胞中衣原体进入空泡可避免与宿主细胞溶酶体融合，但细胞免疫反应却较少受到关注。此外，尽管在感染部位存在大量树突状细胞（DC），但衣原体与DC之间的相互作用从未被研究过。我们观察到DC可杀死沙眼衣原体和鹦鹉热衣原体。衣原体通过巨吞饮作用以非特异性方式被DC内化，随后巨吞饮小泡与表达MHC II类分子的DC溶酶体融合。这种相互作用会诱导DC成熟，因为在孵育1天后外源性抗原的呈递会受到严重抑制，尽管衣原体抗原仍可被衣原体特异性CD4 + T细胞呈递和识别。因此，DC很可能在体内启动T细胞反应中发挥作用，并有可能用于过继性转移疗法来预防衣原体感染。
