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Down-modulation of the antigen receptor by a superantigen for human B cells

Viau, M; Cholley, B; Björck, Lars LU and Zouali, M (2004) 12th Symposium on Signals and Signal Processing in the Immune System In Immunology Letters 92(1-2). p.91-96
Abstract
B cell superantigens (SAgs) have been implicated in human diseases by demonstrating non-clonotypic expansion of B cells bearing certain immunoglobulin variable region genes. One possibility is that, during infection with microorganisms secreting SAgs, these potent molecules might modulate BcR expression. To test this hypothesis, we investigated the potential effects of a SAg, protein L from Peptostreptococcus magnus, on antigen B cell receptor (BcR) surface expression in vitro. Using fluorescence microscopy, we found that this SAg induced down-regulation of BcR expression. This effect was time-, dose-, and temperature-dependent, and shedding of cell surface IgM molecules into the culture supernatant was not detected. These data demonstrate... (More)
B cell superantigens (SAgs) have been implicated in human diseases by demonstrating non-clonotypic expansion of B cells bearing certain immunoglobulin variable region genes. One possibility is that, during infection with microorganisms secreting SAgs, these potent molecules might modulate BcR expression. To test this hypothesis, we investigated the potential effects of a SAg, protein L from Peptostreptococcus magnus, on antigen B cell receptor (BcR) surface expression in vitro. Using fluorescence microscopy, we found that this SAg induced down-regulation of BcR expression. This effect was time-, dose-, and temperature-dependent, and shedding of cell surface IgM molecules into the culture supernatant was not detected. These data demonstrate that SAg-mediated down-regulation of the BcR expression occurs primarily as a result of BcR internalization. In addition, two specific inhibitors of protein tyrosine kinases were found to retard the BcR modulation on the cell surface and inhibit SAg-induced receptor internalization, showing that tyrosine phosphorylation is required for subsequent internalization of mIg-ligand complexes. The down-modulation of BcR expression may have pathological consequences in patients infected with microorganisms secreting SAgs. (C) 2003 Elsevier B.V. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
B cell receptor, receptor internalization, protein L
in
Immunology Letters
volume
92
issue
1-2
pages
91 - 96
publisher
Elsevier
conference name
12th Symposium on Signals and Signal Processing in the Immune System
external identifiers
  • wos:000221166400014
  • pmid:15081532
  • scopus:1842814004
ISSN
0165-2478
1879-0542
DOI
10.1016/j.imlet.2003.10.016
language
English
LU publication?
yes
id
0632739b-7409-4ff6-9969-771a187b2158 (old id 279855)
date added to LUP
2007-11-07 12:14:34
date last changed
2017-01-01 04:26:36
@inproceedings{0632739b-7409-4ff6-9969-771a187b2158,
  abstract     = {B cell superantigens (SAgs) have been implicated in human diseases by demonstrating non-clonotypic expansion of B cells bearing certain immunoglobulin variable region genes. One possibility is that, during infection with microorganisms secreting SAgs, these potent molecules might modulate BcR expression. To test this hypothesis, we investigated the potential effects of a SAg, protein L from Peptostreptococcus magnus, on antigen B cell receptor (BcR) surface expression in vitro. Using fluorescence microscopy, we found that this SAg induced down-regulation of BcR expression. This effect was time-, dose-, and temperature-dependent, and shedding of cell surface IgM molecules into the culture supernatant was not detected. These data demonstrate that SAg-mediated down-regulation of the BcR expression occurs primarily as a result of BcR internalization. In addition, two specific inhibitors of protein tyrosine kinases were found to retard the BcR modulation on the cell surface and inhibit SAg-induced receptor internalization, showing that tyrosine phosphorylation is required for subsequent internalization of mIg-ligand complexes. The down-modulation of BcR expression may have pathological consequences in patients infected with microorganisms secreting SAgs. (C) 2003 Elsevier B.V. All rights reserved.},
  author       = {Viau, M and Cholley, B and Björck, Lars and Zouali, M},
  booktitle    = {Immunology Letters},
  issn         = {0165-2478},
  keyword      = {B cell receptor,receptor internalization,protein L},
  language     = {eng},
  number       = {1-2},
  pages        = {91--96},
  publisher    = {Elsevier},
  title        = {Down-modulation of the antigen receptor by a superantigen for human B cells},
  url          = {http://dx.doi.org/10.1016/j.imlet.2003.10.016},
  volume       = {92},
  year         = {2004},
}