Center for Immunity and Infection Lausanne, Department of Biochemistry, University of Lausanne, Epalinges, Switzerland.
Department of Oncology, University of Lausanne and University Hospital, Epalinges, Switzerland.
PLoS Biol. 2019 Jul 15;17(7):e3000072. doi: 10.1371/journal.pbio.3000072. eCollection 2019 Jul.
Lymphoid T-zone fibroblastic reticular cells (FRCs) actively promote T-cell trafficking, homeostasis, and expansion but can also attenuate excessive T-cell responses via inducible nitric oxide (NO) and constitutive prostanoid release. It remains unclear how these FRC-derived mediators dampen T-cell responses and whether this occurs in vivo. Here, we confirm that murine lymph node (LN) FRCs produce prostaglandin E2 (PGE2) in a cyclooxygenase-2 (COX2)-dependent and inflammation-independent fashion. We show that this COX2/PGE2 pathway is active during both strong and weak T-cell responses, in contrast to NO, which only comes into play during strong T-cell responses. During chronic infections in vivo, PGE2-receptor signaling in virus-specific cluster of differentiation (CD)8 cytotoxic T cells was shown by others to suppress T-cell survival and function. Using COX2flox/flox mice crossed to mice expressing Cre recombinase expression under control of the CC chemokine ligand (CCL19) promoter (CCL19cre), we now identify CCL19+ FRC as the critical source of this COX2-dependent suppressive factor, suggesting PGE2-expressing FRCs within lymphoid tissues are an interesting therapeutic target to improve T-cell-mediated pathogen control during chronic infection.
淋巴滤泡区纤维母细胞网状细胞(FRC)可积极促进 T 细胞的迁移、稳态和扩增,但也可通过诱导型一氧化氮(NO)和组成型前列腺素释放来减弱过度的 T 细胞反应。目前尚不清楚这些源自 FRC 的介质如何抑制 T 细胞反应,以及这种情况是否在体内发生。在这里,我们证实了小鼠淋巴结(LN)FRC 以环氧化酶-2(COX2)依赖性和炎症独立性的方式产生前列腺素 E2(PGE2)。我们表明,与仅在强 T 细胞反应中发挥作用的 NO 相反,该 COX2/PGE2 途径在强和弱 T 细胞反应中均活跃。在体内慢性感染期间,其他人已经表明,病毒特异性分化群(CD)8 细胞毒性 T 细胞中的 PGE2 受体信号通过抑制 T 细胞存活和功能来发挥作用。我们使用 COX2flox/flox 小鼠与在 CC 趋化因子配体(CCL19)启动子(CCL19cre)控制下表达 Cre 重组酶的小鼠杂交,现在确定 CCL19+ FRC 是这种 COX2 依赖性抑制因子的关键来源,这表明淋巴组织中表达 PGE2 的 FRC 是一个有趣的治疗靶点,可以在慢性感染期间改善 T 细胞介导的病原体控制。