Journal article icon

Journal article

Silencing or inhibition of endoplasmic reticulum aminopeptidase 1 (ERAP1) suppresses free heavy chain expression and Th17 responses in ankylosing spondylitis.

Abstract:

Objective

Human leucocyte antigen (HLA)-B27 and endoplasmic reticulum aminopeptidase 1 (ERAP1) are strongly associated with ankylosing spondylitis (AS). ERAP1 is a key aminopeptidase in HLA class I presentation and can potentially alter surface expression of HLA-B27 free heavy chains (FHCs). We studied the effects of ERAP1 silencing/inhibition/variations on HLAB27 FHC expression and Th17 responses in AS.

Methods

Flow cytometry was used to measure surface expression of HLA class I in peripheral blood mononuclear cells (PBMCs) from patients with AS carrying different ERAP1 genotypes (rs2287987, rs30187 and rs27044) and in ERAP1-silenced/inhibited/ mutated HLA-B27-expressing antigen presenting cells (APCs). ERAP1-silenced/inhibited APCs were cocultured with KIR3DL2CD3ε-reporter cells or AS CD4+ T cells. Th17 responses of AS CD4+ T cells were measured by interleukin (IL)-17A ELISA and Th17 intracellular cytokine staining. FHC cell surface expression and Th17 responses were also measured in AS PBMCs following ERAP1 inhibition.

Results

The AS-protective ERAP1 variants, K528R and Q730E, were associated with reduced surface FHC expression by monocytes from patients with AS and HLA-B27-expressing APCs. ERAP1 silencing or inhibition in APCs downregulated HLA-B27 FHC surface expression, reduced IL-2 production by KIR3DL2CD3ε-reporter cells and suppressed the Th17 expansion and IL-17A secretion by AS CD4+ T cells. ERAP1 inhibition of AS PBMCs reduced HLA class I FHC surface expression by monocytes and B cells, and suppressed Th17 expansion.

Conclusions

ERAP1 activity determines surface expression of HLA-B27 FHCs and potentially promotes Th17 responses in AS through binding of HLA-B27 FHCs to KIR3DL2. Our data suggest that ERAP1 inhibition has potential for AS treatment.

Publication status:
Published
Peer review status:
Peer reviewed

Actions


Access Document


Publisher copy:
10.1136/annrheumdis-2014-206996

Authors


More by this author
Institution:
University of Oxford
Division:
MSD
Department:
NDORMS
Role:
Author
More by this author
Institution:
University of Oxford
Division:
MSD
Department:
NDORMS
Role:
Author
More by this author
Institution:
University of Oxford
Division:
MSD
Department:
NDORMS
Role:
Author


More from this funder
Funding agency for:
Chen, L
Grant:
20235
More from this funder
Funding agency for:
Al-Mossawi, M
More from this funder
Funding agency for:
Ridley, A
Bowness, P


Publisher:
BMJ Publishing Group
Journal:
Annals of the Rheumatic Diseases More from this journal
Volume:
75
Pages:
916-923
Publication date:
2015-06-01
Acceptance date:
2015-04-12
DOI:
EISSN:
1468-2060
ISSN:
0003-4967


Language:
English
Keywords:
Pubs id:
pubs:529378
UUID:
uuid:2e07f9cd-e5f6-448e-8b1d-eba856e34774
Local pid:
pubs:529378
Source identifiers:
529378
Deposit date:
2016-04-06

Terms of use



Views and Downloads






If you are the owner of this record, you can report an update to it here: Report update to this record

TO TOP