美国杜克大学医学中心Soman N. Abraham研究组的最新研究发现，在膀胱内，感染诱导的高度极化的T _H 2细胞为阻止新感染而促进上皮修复。相关论文发表在2020年5月18日的《自然-免疫学》杂志上。

为了揭示尿路感染（UTI）异常高复发率的原因，研究人员检测了小鼠膀胱中的适应性免疫反应。在每次膀胱感染后，研究人员观察到高度特化2型辅助性T细胞（T_H2）的产生，其清除感染的能力有限，这些T_H2是由针对膀胱上皮再生的免疫反应诱导的。这种反应是由CD301b ⁺ OX40L ⁺树突状细胞造成的，在感染后，该树突状细胞迁移到膀胱上皮中，然后转移到淋巴结以优先激活T^_H2细胞。

膀胱上皮修复反应具有累积性且异常，与对照相比，在多次感染后上皮明显增厚并且膀胱容量降低。因此，UTI的复发性和相关的膀胱功能障碍是由适应性免疫反应为清除细菌而优先修复上皮的结果。

附：英文原文

Title: A highly polarized T H 2 bladder response to infection promotes epithelial repair at the expense of preventing new infections

Author: Jianxuan Wu, Byron W. Hayes, Cassandra Phoenix, Gustavo Sosa Macias, Yuxuan Miao, Hae Woong Choi, Francis M. Hughes, J. Todd Purves, R. Lee Reinhardt, Soman N. Abraham

Issue&Volume: 2020-05-18

Abstract: Urinary tract infections (UTIs) typically evoke prompt and vigorous innate bladder immune responses, including extensive exfoliation of the epithelium. To explain the basis for the extraordinarily high recurrence rates of UTIs, we examined adaptive immune responses in mouse bladders. We found that, following each bladder infection, a highly T helper type 2 (TH2)–skewed immune response directed at bladder re-epithelialization is observed, with limited capacity to clear infection. This response is initiated by a distinct subset of CD301b+OX40L+ dendritic cells, which migrate into the bladder epithelium after infection before trafficking to lymph nodes to preferentially activate TH2 cells. The bladder epithelial repair response is cumulative and aberrant as, after multiple infections, the epithelium was markedly thickened and bladder capacity was reduced relative to controls. Thus, recurrence of UTIs and associated bladder dysfunction are the outcome of the preferential focus of the adaptive immune response on epithelial repair at the expense of bacterial clearance.

DOI: 10.1038/s41590-020-0688-3

Source: https://www.nature.com/articles/s41590-020-0688-3