Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
PLoS Negl Trop Dis. 2013;7(2):e2020. doi: 10.1371/journal.pntd.0002020. Epub 2013 Feb 14.
Trachoma, caused by Chlamydia trachomatis (Ct), is the leading infectious blinding disease worldwide. Chronic conjunctival inflammation develops in childhood and leads to eyelid scarring and blindness in adulthood. The immune response to Ct provides only partial protection against re-infection, which can be frequent. Moreover, the immune response is central to the development of scarring pathology, leading to loss of vision. Here we review the current literature on both protective and pathological immune responses in trachoma. The resolution of Ct infection in animal models is IFNγ-dependent, involving Th1 cells, but whether this is the case in human ocular infection still needs to be confirmed. An increasing number of studies indicate that innate immune responses arising from the epithelium and other innate immune cells, along with changes in matrix metalloproteinase activity, are important in the development of tissue damage and scarring. Current trachoma control measures, which are centred on repeated mass antibiotic treatment of populations, are logistically challenging and have the potential to drive antimicrobial resistance. A trachoma vaccine would offer significant advantages. However, limited understanding of the mechanisms of both protective immunity and immunopathology to Ct remain barriers to vaccine development.
沙眼是由沙眼衣原体（Ct）引起的，是全球主要的传染性致盲疾病。慢性结膜炎症在儿童时期发展，并导致成年人眼睑疤痕和失明。对 Ct 的免疫反应仅能提供部分免受再感染的保护，这种再感染可能很频繁。此外，免疫反应是疤痕病理发展的核心，导致视力丧失。在这里，我们回顾了沙眼保护性和病理性免疫反应的现有文献。动物模型中 Ct 感染的消退依赖于 IFNγ，涉及 Th1 细胞，但这种情况是否适用于人类眼部感染仍需证实。越来越多的研究表明，上皮和其他先天免疫细胞产生的先天免疫反应以及基质金属蛋白酶活性的变化，在组织损伤和疤痕形成中很重要。目前以人群反复大规模抗生素治疗为中心的沙眼控制措施在后勤方面具有挑战性，并有引发抗微生物药物耐药性的潜力。沙眼疫苗将具有显著优势。然而，对 Ct 的保护性免疫和免疫病理学机制的理解有限，仍然是疫苗开发的障碍。
