Abstract：
Chemotactic cytokines (chemokines) are a group of around 40 small proteins which share a similar protein fold and are well known for their ability to direct the migration of leukocytes to a variety of tissue locations. CXCL17 was the last member of the chemokine family to be assigned and was admitted to the family based on theoretical modelling of the CXCL17 structure and chemotactic activity for monocytes and dendritic cells. Of Interest, CXCL17 expression appears to be restricted to mucosal tissues such as the tongue, stomach and lung, suggestive of specific roles at these locations. A putative CXCL17 receptor, GPR35 was reportedly identified and mice deficient in CXCL17 were generated and characterised. More recently, however, some apparent contradictions regarding aspects of CXCL17 biology have been raised by ourselves and others. Notably, GPR35 appears to be a receptor for the serotonin metabolite 5-hydroxyindoleacetic acid rather than for CXCL17 and modelling of CXCL17 using a variety of platforms fails to identify a chemokine-like fold. In this article, we summarize the discovery of CXCL17 and discuss key papers describing the subsequent characterisation of this protein. Ultimately, we pose the question, \'What defines a chemokine?\' (185 words).
摘要：
趋化性细胞因子(趋化因子)是一组约40个小蛋白质,它们共享相似的蛋白质折叠,并且众所周知它们能够引导白细胞迁移到各种组织位置。CXCL17是待分配的趋化因子家族的最后一个成员,并且基于CXCL17结构的理论建模以及单核细胞和树突细胞的趋化活性被接纳为该家族。感兴趣，CXCL17的表达似乎仅限于粘膜组织，如舌，胃和肺，暗示这些地点的具体角色。一种推定的CXCL17受体，据报道鉴定了GPR35,并产生并表征了CXCL17缺陷的小鼠。最近,然而,我们自己和其他人提出了一些关于CXCL17生物学方面的明显矛盾。值得注意的是,GPR35似乎是5-羟色胺代谢物5-羟基吲哚乙酸的受体，而不是CXCL17的受体，并且使用各种平台对CXCL17进行建模无法鉴定趋化因子样折叠。在这篇文章中,我们总结了CXCL17的发现，并讨论了描述该蛋白质随后表征的关键论文。最终,我们提出了一个问题，“趋化因子的定义是什么？”（185个单词）。
