血清淀粉样蛋白A是可诱导2型免疫的可溶性模式识别受体，这一成果由美国约翰霍普金斯大学Marsha Wills-Karp和Ursula Smole研究团队经过不懈努力而取得。 该研究于2020年6月22号发表于《自然-免疫学》杂志。

研究人员发现脂肪酸结合蛋白（FABP）家族的螨虫第13组过敏原是由在进化保守的急性期蛋白-血清淀粉样蛋白A1（SAA1）识别的，该蛋白可促进2型肺免疫。从机理上讲，SAA1与过敏性螨虫FABP直接相互作用（Der p 13和Blo t 13）。螨虫FABPs与SAA1之间的相互作用激活了SAA1结合受体-甲酰基肽受体2（FPR2），从而以SAA1依赖性的方式加速促2型细胞因子白介素（IL）-33从上皮释放。

重要的是，在慢性鼻-鼻窦炎患者的鼻上皮细胞中，SAA1-FPR2-IL-33通路上调。这些发现揭示了在常见螨虫过敏原中，SAA1作为已知保守FABP可溶性模式识别受体的不可识别作用，这些抗原在粘膜表面引发2型免疫。

据悉，很大程度上，部分环境蛋白引起过敏反应的分子基础是未知的。

附：英文原文

Title: Serum amyloid A is a soluble pattern recognition receptor that drives type 2 immunity

Author: Ursula Smole, Naina Gour, Jordan Phelan, Gerhard Hofer, Cordula Khler, Bernhard Kratzer, Peter A. Tauber, Xiao Xiao, Nu Yao, Jan Dvorak, Luis Caraballo, Leonardo Puerta, Sandra Rosskopf, Jamila Chakir, Ernst Malle, Andrew P. Lane, Winfried F. Pickl, Stephane Lajoie, Marsha Wills-Karp

Issue&Volume: 2020-06-22

Abstract: The molecular basis for the propensity of a small number of environmental proteins to provoke allergic responses is largely unknown. Herein, we report that mite group 13 allergens of the fatty acid-binding protein (FABP) family are sensed by an evolutionarily conserved acute-phase protein, serum amyloid A1 (SAA1), that promotes pulmonary type 2 immunity. Mechanistically, SAA1 interacted directly with allergenic mite FABPs (Der p 13 and Blo t 13). The interaction between mite FABPs and SAA1 activated the SAA1-binding receptor, formyl peptide receptor 2 (FPR2), which drove the epithelial release of the type-2-promoting cytokine interleukin (IL)-33 in a SAA1-dependent manner. Importantly, the SAA1–FPR2–IL-33 axis was upregulated in nasal epithelial cells from patients with chronic rhinosinusitis. These findings identify an unrecognized role for SAA1 as a soluble pattern recognition receptor for conserved FABPs found in common mite allergens that initiate type 2 immunity at mucosal surfaces.

DOI: 10.1038/s41590-020-0698-1

Source: https://www.nature.com/articles/s41590-020-0698-1