Format

Send to

Choose Destination
Arthritis Res Ther. 2016 Jan 22;18:27. doi: 10.1186/s13075-016-0914-4.

Stress granules and RNA processing bodies are novel autoantibody targets in systemic sclerosis.

Author information

1
Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, NH, USA. michael.e.johnson@dartmouth.edu.
2
Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, NH, USA. andrew.v.grassetti.gr@dartmouth.edu.
3
Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, NH, USA. jaclyn.n.taroni.gr@dartmouth.edu.
4
Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA, USA. smlyons@partners.org.
5
Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, NH, USA. dkschwep@uw.edu.
6
Department of Rheumatology, Hospital for Special Surgery, New York, NY, USA. gordonj@hss.edu.
7
Department of Rheumatology, Hospital for Special Surgery, New York, NY, USA. spierar@hss.edu.
8
Boston University School of Medicine, Boston, MA, USA. rlafyatis@gmail.com.
9
Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA, USA. panderson@rics.bwh.harvard.edu.
10
Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, NH, USA. scott.a.gerber@dartmouth.edu.
11
Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, NH, USA. michael.l.whitfield@dartmouth.edu.
12
Dartmouth Medical School, Hinman Box 7400, Hanover, NH, 03755, USA. michael.l.whitfield@dartmouth.edu.

Abstract

BACKGROUND:

Autoantibody profiles represent important patient stratification markers in systemic sclerosis (SSc). Here, we performed serum-immunoprecipitations with patient antibodies followed by mass spectrometry (LC-MS/MS) to obtain an unbiased view of all possible autoantibody targets and their associated molecular complexes recognized by SSc.

METHODS:

HeLa whole cell lysates were immunoprecipitated (IP) using sera of patients with SSc clinically positive for autoantibodies against RNA polymerase III (RNAP3), topoisomerase 1 (TOP1), and centromere proteins (CENP). IP eluates were then analyzed by LC-MS/MS to identify novel proteins and complexes targeted in SSc. Target proteins were examined using a functional interaction network to identify major macromolecular complexes, with direct targets validated by IP-Western blots and immunofluorescence.

RESULTS:

A wide range of peptides were detected across patients in each clinical autoantibody group. Each group contained peptides representing a broad spectrum of proteins in large macromolecular complexes, with significant overlap between groups. Network analyses revealed significant enrichment for proteins in RNA processing bodies (PB) and cytosolic stress granules (SG) across all SSc subtypes, which were confirmed by both Western blot and immunofluorescence.

CONCLUSIONS:

While strong reactivity was observed against major SSc autoantigens, such as RNAP3 and TOP1, there was overlap between groups with widespread reactivity seen against multiple proteins. Identification of PB and SG as major targets of the humoral immune response represents a novel SSc autoantigen and suggests a model in which a combination of chronic and acute cellular stresses result in aberrant cell death, leading to autoantibody generation directed against macromolecular nucleic acid-protein complexes.

PMID:
26801089
PMCID:
PMC4724133
DOI:
10.1186/s13075-016-0914-4
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for BioMed Central Icon for PubMed Central
Loading ...
Support Center