Identification of the Fcalpha/muR isoform specifically expressed in the kidney tubules.
Fcalpha/muR is expressed not only in lymphoid, but also in non-lymphoid organs, including kidney. However, molecular and functional characteristics of Fcalpha/muR, particularly expressed in non-lymphoid organs, have remained unclear. Here we identified an isoform of Fcalpha/muR in the murine kidney on the C57BL/6J background. The kidney expressed only the isoform, which was not expressed in other lymphoid and non-lymphoid organs, and this isoform binds both IgA and IgM. Immunohistochemical analyses suggested that the Fcalpha/muR isoform was expressed in the tubular epithelial cells, but not in the glomeruli. This was confirmed by flow cytometry analysis of isolated tubular epithelial cells and by RT-PCR analyses using the separately excised glomerular and tubular regions by the laser microdissection system. These results suggest that Fcalpha/muR may not be involved in IgA deposition in glomerular mesangium cells in IgA nephropathy. Rather, it may play an important role in immunity in the renal tubular regions.
Kurita
Naoki
N
Department of Immunology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, and Center for TARA, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba, Ibaraki 305-8575, Japan.
Honda
Shin-Ichiro
S
Usui
Kenta
K
Shimizu
Yoshio
Y
Miyamoto
Akitomo
A
Tahara-Hanaoka
Satoko
S
Shibuya
Kazuko
K
Shibuya
Akira
A
D000818:Animals; D004847:Epithelial Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D007070:Immunoglobulin A / Q000276:immunology / Q000378:metabolism; D007075:Immunoglobulin M / Q000276:immunology / Q000378:metabolism; D007678:Kidney Glomerulus / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D007684:Kidney Tubules / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D020033:Protein Isoforms / Q000276:immunology / Q000378:metabolism; D011961:Receptors, Fc / Q000276:immunology / Q000378:metabolism*
C526791:Fcalpha-mu protein, mouse; D007070:Immunoglobulin A; D007075:Immunoglobulin M; D020033:Protein Isoforms; D011961:Receptors, Fc