Abstract
The IRE1-XBP1 signalling pathway is part of a cellular programme that protects against endoplasmic reticulum (ER) stress, but also controls development and survival of immune cells. Loss of XBP1 in splenic type 1 conventional dendritic cells (cDC1s) results in functional alterations without affecting cell survival. However, in mucosal cDC1s, loss of XBP1 impaired survival in a tissue-specific manner-while lung cDC1s die, intestinal cDC1s survive. This was not caused by differential activation of ER stress cell-death regulators CHOP or JNK. Rather, survival of intestinal cDC1s was associated with their ability to shut down protein synthesis through a protective integrated stress response and their marked increase in regulated IRE1-dependent messenger RNA decay. Furthermore, loss of IRE1 endonuclease on top of XBP1 led to cDC1 loss in the intestine. Thus, mucosal DCs differentially mount ATF4- and IRE1-dependent adaptive mechanisms to survive in the face of ER stress.
MeSH terms
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Activating Transcription Factor 4 / genetics
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Activating Transcription Factor 4 / metabolism
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Animals
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Apoptosis
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Cell Survival
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Dendritic Cells / enzymology*
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Dendritic Cells / pathology
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Endoplasmic Reticulum Stress
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Genotype
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Intestinal Mucosa / enzymology*
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Intestinal Mucosa / pathology
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JNK Mitogen-Activated Protein Kinases / metabolism
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Mice, Transgenic
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Phenotype
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Protein Biosynthesis
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Protein Serine-Threonine Kinases / genetics
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Protein Serine-Threonine Kinases / metabolism*
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RNA Stability*
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RNA, Messenger / genetics
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RNA, Messenger / metabolism*
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Respiratory Mucosa / enzymology*
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Respiratory Mucosa / pathology
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Signal Transduction
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Time Factors
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Transcription Factor CHOP / genetics
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Transcription Factor CHOP / metabolism
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Unfolded Protein Response
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X-Box Binding Protein 1 / genetics
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X-Box Binding Protein 1 / metabolism
Substances
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Atf4 protein, mouse
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Ddit3 protein, mouse
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Membrane Proteins
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RNA, Messenger
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X-Box Binding Protein 1
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Xbp1 protein, mouse
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Activating Transcription Factor 4
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Transcription Factor CHOP
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Ern2 protein, mouse
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Protein Serine-Threonine Kinases
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JNK Mitogen-Activated Protein Kinases