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Title: Syntaxin-4 is essential for IgE secretion by plasma cells

Highlights: •Knock-down of syntaxin-4 in U266 plasma cells resulted in reduction of IgE secretion. •Knock-down of syntaxin-4 also leads to the accumulation of IgE in the cell. •Immuno-fluorescence staining shows co-localisation of IgE and syntaxin-4 in U266 cells. •Findings suggest a critical requirement for syntaxin-4 in IgE secretion from plasma cells. -- Abstract: The humoral immune system provides a crucial first defense against the invasion of microbial pathogens via the secretion of antigen specific immunoglobulins (Ig). The secretion of Ig is carried out by terminally differentiated B-lymphocytes called plasma cells. Despite the key role of plasma cells in the immune response, the mechanisms by which they constitutively traffic large volumes of Ig out of the cell is poorly understood. The involvement of Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in the regulation of protein trafficking from cells has been well documented. Syntaxin-4, a member of the Qa SNARE syntaxin family has been implicated in fusion events at the plasma membrane in a number of cells in the immune system. In this work we show that knock-down of syntaxin-4 in the multiple myeloma U266 human plasma cell line results in a loss of IgE secretion and accumulation of IgE withinmore » the cells. Furthermore, we show that IgE co-localises with syntaxin-4 in U266 plasma cells suggesting direct involvement in secretion at the plasma membrane. This study demonstrates that syntaxin-4 plays a critical role in the secretion of IgE from plasma cells and sheds some light on the mechanisms by which these cells constitutively traffic vesicles to the surface for secretion. An understanding of this machinery may be beneficial in identifying potential therapeutic targets in multiple myeloma and autoimmune disease where over-production of Ig leads to severe pathology in patients.« less
Authors:
; ;  [1] ; ;  [2] ;  [1]
  1. Immunomodulation Group, School of Biotechnology, Dublin City University (Ireland)
  2. School of Biotechnology and National Centre for Sensor Research, Dublin City University (Ireland)
Publication Date:
OSTI Identifier:
22242135
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 440; Journal Issue: 1; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; CATTLE; IMMUNOGLOBULINS; LEAD; LYMPHOCYTES; NECROSIS; PHOSPHATES; PLASMA CELLS; RECEPTORS; RNA; SECRETION