Rapid B cell receptor-induced unfolded protein response in nonsecretory B cells correlates with pro- versus antiapoptotic cell fate

Alison H. Skalet, Jennifer A. Isler, Leslie B. King, Heather P. Harding, David Ron, John G. Monroe

Research output: Contribution to journalArticle

42 Scopus citations


The adaptive unfolded protein response (UPR) is essential for the development of antibody-secreting plasma cells. B cells induced by lipopolysaccharide (LPS) to differentiate into plasma cells exhibit a nonclassical UPR reported to anticipate endoplasmic reticulum stress prior to immunoglobulin production. Here we demonstrate that activation of a physiologic UPR is not limited to cells undergoing secretory cell differentiation. We identify B cell receptor (BCR) signaling as an unexpected physiologic UPR trigger and demonstrate that in mature B cells, BCR stimulation induces a short lived UPR similar to the LPS-triggered nonclassical UPR. However, unlike LPS, BCR stimulation does not induce plasma cell differentiation. Furthermore, the BCR-induced UPR is not limited to cells in which BCR induces activation, since a UPR is also induced in transitional immature B cells that respond to BCR stimulation with a rapid apoptotic fate. This response involves sustained up-regulation of Chop mRNA indicative of a terminal UPR. Whereas sustained Chop expression correlates with the ultimate fate of the BCR-triggered B cell and not its developmental stage, Chop-/- B cells undergo apoptosis, indicating that CHOP is not required for this process. These studies establish a system whereby a terminal or adaptive UPR can be alternatively triggered by physiologic stimuli.

Original languageEnglish (US)
Pages (from-to)39762-39771
Number of pages10
JournalJournal of Biological Chemistry
Issue number48
StatePublished - Dec 2 2005


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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