Pivotal Advance: CD45RB glycosylation is specifically regulated during human peripheral B cell differentiation

Journal of Leukocyte Biology

Susanne Koethe¹  Linda Zander¹  Mats Bemark,3¹  Adelaide Annan²  Jo Spencer  and²  Anders Ebenfelt³  Sofia Köster¹ 

[1] Mucosal Immunobiology and Vaccine Center, Department of Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden; Peter Gorer Department of Immunobiology, King²s College London, London, United Kindgom;Department of Otorhinolaryngology, Head and Neck Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden Mucosal Immunobiology and Vaccine Center, Department of Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden;

关键词: sialic acids;    O-linked;    cell surface marker;   

DOI  :  10.1189/jlb.0710404

学科分类：生理学

来源: Federation of American Societies for Experimental Biology

【 摘 要 】

A screen of cell surface markers differentially expressed during peripheral B cell differentiation identified that the CD45RB epitope detected by the mAb MEM-55 was highly expressed on CD27+ memory B cells and absent on CD27– naïve B cells. IgG+CD27– memory and a previously unacknowledged CD27– population in blood also expressed high levels of CD45RBMEM55. Naïve and memory B cells from tonsils followed the pattern observed in blood, and CD38high B cells had a bimodal expression pattern when analyzed using flow cytometry. No CD38high GC B cells, however, expressed the CD45RBMEM55 epitope when assayed using immunohistochemistry. Rather, CD38highCD45RBMEM55high B cells had a distinct cellular phenotype and were localized outside of GCs. CD45RB epitopes, detected by other antibody clones, were expressed at high levels through B cell differentiation, and no changes in splicing of the CD45RB exon were observed during B cell differentiation. Instead, B cells regulated their expression of the CD45RBMEM55 epitope through site-specific modifications of an O-linked glycochain. CD4+ T cells differentially spliced CD45 but did not vary the glycosylation of the CD45RBMEM55 epitope, and CD8+ cells modified CD45RBMEM55 expression in a similar manner as B cells. Monocytes expressed the CD45RB exon but not the CD45RBMEM55 epitope. As CD45 is a highly expressed tyrosine phosphatase that regulates antigen receptor signaling strength in lymphocytes, we conclude that regulated O-linked glycosylation of CD45RB can be used to follow B cell differentiation and that this regulation may be involved in fine-tuning antigen signaling in the cell.

【 授权许可】

Unknown