Yamanaka Masahiro, Kato Yukinari, Angata Takashi, Narimatsu Hisashi
Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.
Glycobiology. 2009 Aug;19(8):841-6. doi: 10.1093/glycob/cwp052. Epub 2009 Apr 15.
Human Siglec-14, a member of the Siglec family of sialic acid-binding lectins, shows extensive sequence similarity to human Siglec-5. To analyze respective expression patterns of Siglec-14 and Siglec-5, we developed specific antibodies against each of them. We found that the former was expressed on granulocytes and monocytes, while the latter was on granulocytes and B-cells. Surprisingly, some individuals lacked the expression of Siglec-14, while they all expressed Siglec-5. We found that a fusion between SIGLEC14 and SIGLEC5 genes, resulting in the functional deletion of SIGLEC14, underlies this phenotype. The presence of the "SIGLEC14 null" allele in all human populations we tested implies an ancient origin, while its allelic frequency is higher in Asians compared with Africans and Europeans. The forced expression of Siglec-14 in a monocytic cell line-enhanced TNF-alpha secretion elicited by lipopolysaccharide. These results imply that Siglec-14 may play some role in bacterial infection.
人类唾液酸结合凝集素Siglec家族成员Siglec-14与人类Siglec-5具有广泛的序列相似性。为了分析Siglec-14和Siglec-5各自的表达模式，我们针对它们分别开发了特异性抗体。我们发现前者在粒细胞和单核细胞上表达，而后者在粒细胞和B细胞上表达。令人惊讶的是，一些个体缺乏Siglec-14的表达，而他们都表达Siglec-5。我们发现SIGLEC14和SIGLEC5基因之间的融合导致SIGLEC14功能缺失，是这种表型的基础。我们测试的所有人类群体中都存在“SIGLEC14缺失”等位基因，这意味着其起源古老，而与非洲人和欧洲人相比，其等位基因频率在亚洲人中更高。在单核细胞系中强制表达Siglec-14可增强脂多糖诱导的TNF-α分泌。这些结果表明Siglec-14可能在细菌感染中发挥某种作用。
