Format

Send to

Choose Destination
Int Immunol. 2010 Mar;22(3):149-56. doi: 10.1093/intimm/dxp121. Epub 2009 Dec 30.

Identification of TOSO/FAIM3 as an Fc receptor for IgM.

Author information

1
Division of Immunobiology, Graduate School of Nanobioscience, Yokohama City University, Yokohama, Kanagawa 230-0045, Japan.

Abstract

Fc receptors specifically bind to the Fc region of Igs to mediate the unique functions to each class of Igs. To identify a novel Fc receptor for IgM, we searched expressed sequence tag database for molecules containing Ig domains with homology to those of known Fc receptors for IgM, Fcalpha/muR and polymeric Ig receptor. As a result, we identified TOSO/Fas apoptotic inhibitory molecule 3 (FAIM3) as a possible Fc receptor for IgM. HeLa cells transfected with a TOSO/FAIM3-expression vector bound to IgM but not IgG and were able to internalize IgM-conjugated beads but not IgG-conjugated beads, suggesting that TOSO/FAIM3 is indeed a receptor for IgM (FcmuR). FcmuR protein was expressed predominantly on B-lineage cells; expression of the Fcmr transcripts was observed from the pre-B-cell stage and maintained thereafter during B-cell development. These results identify TOSO/FAIM3 as a receptor for IgM and suggest that FcmuR may serve as an uptake receptor for IgM-opsonized antigens by B cells.

PMID:
20042454
DOI:
10.1093/intimm/dxp121
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center