Protocols for "STING dampens the unfolded protein response to enable mitochondrial antigen presentation on MHC-I during inflammation"

Ahmed M. Fahmy; Ali  Ahmadi; Joel Lanoix; Moustafa  Elemeery; Benoit  Barrette; Michel  Desjardins

Apr 24, 2026

Protocols for "STING dampens the unfolded protein response to enable mitochondrial antigen presentation on MHC-I during inflammation"

DOI

https://dx.doi.org/10.17504/protocols.io.5qpvoezxdl4o/v1

Ahmed M. Fahmy¹,
Ali Ahmadi¹,
Joel Lanoix²,
Moustafa Elemeery³,
Benoit Barrette¹,
Michel Desjardins¹

¹Département de pathologie et biologie cellulaire, Université de Montréal, Montréal, Québec, Canada;
²Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Québec, Canada;
³Département de neuroscience, Université de Montréal, Montréal, Québec, Canada

Lilia Rodriguez

Université de Montréal

DOI: https://dx.doi.org/10.17504/protocols.io.5qpvoezxdl4o/v1

Collection Citation: Ahmed M. Fahmy, Ali Ahmadi, Joel Lanoix, Moustafa Elemeery, Benoit Barrette, Michel Desjardins 2026. Protocols for "STING dampens the unfolded protein response to enable mitochondrial antigen presentation on MHC-I during inflammation". protocols.io https://dx.doi.org/10.17504/protocols.io.5qpvoezxdl4o/v1

License: This is an open access collection distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Protocol status: Working

We use this collection and it's working

Created: April 24, 2026

Last Modified: April 24, 2026

Collection Integer ID: 315664

Keywords: ASAPCRN, mitochondrial antigen presentation on mhc, adaptive immune system in parkinson, mitap activation in mice, mitochondrial antigen presentation, mitochondrial antigen, presentation of mitochondrial antigen, associated protein pink1, mitap activation, unfolded protein response, protein pink1, potential role in immunosurveillance, key immune regulator, cell surface during inflammation, immune system, inflammation, repertoire of peptide, upr as key immune regulator, mitap, following tlr4 activation, parkinson, autoimmune disease, tlr4 activation, absence of pink1, immunosurveillance, peptide

Funders Acknowledgements:

Aligning Science Across Parkinson’s

Grant ID: ASAP 000525

Abstract

A growing body of evidence supports the contribution of the long-lasting adaptive immune system in Parkinson’s disease (PD). We showed that the PD-associated protein PINK1 negatively regulates the presentation of mitochondrial antigens (MitAP) on MHC-I molecules. In vivo evidence indicated that MitAP activation in mice, in the absence of PINK1, led to cytotoxic CD8+ T cell stimulation and severe motor impairments, reversible by L-DOPA. We show here that following TLR4 activation, MitAP is engaged through a pathway involving cGAS-STING, which acts as a rheostat to dampen the unfolded protein response (UPR). Without STING, the stress response is amplified, leading to a translational attenuation that inhibits the expression of XBP1s, a transcription factor required for MitAP. STING activity also regulates the repertoire of peptides displayed at the cell surface during inflammation, highlighting a potential role in immunosurveillance. These findings establish STING and the UPR as key immune regulators targetable for therapeutic intervention during autoimmune diseases and PD.

Files

Bacterial Infection of RAW 264.docx

RAW Macrophage Cell Culture Protocol.docx

Western Blot.docx

Immunofluorescence.docx

Raw 264.7 KO cell line generation by CRISPR_Cas9 genomic editing.docx

Quantification of mtDNA by qPCR.docx

CD8+ T cell co-culture and flow cytometry.docx

Nascent protein synthesis detection.docx

Cytokine Measurement (IL-6 and IFN-β) by ELISA from RAW Macrophages.docx

Stable cell line generation.docx