RRC ID 21413
Author Takahara K, Arita T, Tokieda S, Shibata N, Okawa Y, Tateno H, Hirabayashi J, Inaba K.
Title Difference in fine specificity to polysaccharides of Candida albicans mannoprotein between mouse SIGNR1 and human DC-SIGN.
Journal Infect Immun
Abstract C-type lectin SIGNR1 directly recognizes Candida albicans and zymosan and has been considered to share properties of polysaccharide recognition with human DC-SIGN (hDC-SIGN). However, the precise specificity of SIGNR1 and the difference from that of hDC-SIGN remain to be elucidated. We prepared soluble forms of SIGNR1 and hDC-SIGN and conducted experiments to examine their respective specificities. Soluble SIGNR1 (sSIGNR1) bound several types of live C. albicans clinical isolate strains in an EDTA-sensitive manner. Inhibition analyses of sSIGNR1 binding by glycans from various yeast strains demonstrated that SIGNR1 preferentially recognizes N-glycan α-mannose side chains in Candida mannoproteins, as reported in hDC-SIGN. Unlike shDC-SIGN, however, sSIGNR1 recognized not only Saccharomyces cerevisiae, but also C. albicans J-1012 glycan, even after α-mannosidase treatment that leaves only β1,2-mannose-capped α-mannose side chains. In addition, glycomicroarray analyses showed that sSIGNR1 binds mannans from C. albicans and S. cerevisiae but does not recognize Lewis(a/b/x/y) antigen polysaccharides as in shDC-SIGN. Consistent with these results, RAW264.7 cells expressing hDC-SIGN in which the carbohydrate recognition domain (CRD) was replaced with that of SIGNR1 (RAW-chimera) produced comparable amounts of interleukin 10 (IL-10) in response to glycans from C. albicans and S. cerevisiae, but those expressing hDC-SIGN produced less IL-10 in response to S. cerevisiae than C. albicans. Furthermore, RAW-hDC-SIGN cells remarkably reduced IL-10 production after α-mannosidase treatment compared with RAW-chimera cells. These results indicate that SIGNR1 recognizes C. albicans/yeast through a specificity partly distinct from that of its homologue hDC-SIGN.
Volume 80(5)
Pages 1699-706
Published 2012-5-1
DOI 10.1128/IAI.06308-11
PII IAI.06308-11
PMID 22331432
PMC PMC3347427
MeSH Animals Candida albicans / immunology* Candida albicans / metabolism* Cell Adhesion Molecules / metabolism* Gene Expression Regulation HEK293 Cells Humans Interleukin-10 / genetics Interleukin-10 / metabolism Lectins, C-Type / metabolism* Macrophages Mice Polysaccharides / chemistry Polysaccharides / metabolism* Protein Binding Receptors, Cell Surface / metabolism* Recombinant Proteins Saccharomyces cerevisiae
IF 3.201
Times Cited 18
General Microbes JCM 1542