Intelectin (ITLN) is a type of glycan-binding lectin involved in many physiological processes and some human diseases. Here we report a common carp intelectin (cITLN). Like other orthologs, cITLN also contains a conserved fibrinogen-related domain (FReD) and a unique intelectin domain, expresses in all the tissues tested with the highest level in the hindgut, and responds to bacterial challenge in the acute phase. We also expressed cITLN in Escherichia coli (E. coli) system, and the purified recombinant cITLN could neither affect the surface of bacteria nor inhibit the growth of bacteria, but it can agglutinate both gram-positive and gram-negative bacteria in a calcium-dependent manner. The cITLN's ability of agglutination of gram-positive bacteria is stronger than that of gram-negative bacteria. This is probably because recombinant cITLN could binding peptidoglycan (PGN) with a higher degree to lipopolysaccharide (LPS). Our results of cITLN provided new insight into the function of intelectin in the intestinal mucosal immunity.

Intelectin（ITLN）是一种参与多种生理过程和某些人类疾病的聚糖结合凝集素。在这里，我们报告了一种常见的鲤鱼intelectin（cITLN）。像其他直向同源物一样，cITLN还包含一个保守的纤维蛋白原相关结构域（FReD）和一个独特的intelectin结构域，在后肠中表达水平最高的所有组织中表达，并在急性期对细菌攻击做出反应。我们也表示cITLN在大肠埃希氏菌（大肠杆菌）系统，纯化的重组cITLN既不影响细菌表面也不抑制细菌的生长，但可以以钙依赖性方式凝集革兰氏阳性菌和革兰氏阴性菌。cITLN的革兰氏阳性菌凝集能力强于革兰氏阴性菌。这可能是因为重组cITLN可以与脂多糖（LPS）更高程度地结合肽聚糖（PGN）。我们的cITLN结果提供了intelectin在肠道粘膜免疫中的功能的新见解。