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Updated: Jun 10, 2026
08:57
Native Polyacrylamide Gel Electrophoresis Immunoblot Analysis of Endogenous IRF5 Dimerization
Published on: October 6, 2019
Exon 6 variants carried on systemic lupus erythematosus (SLE) risk haplotypes modulate IRF5 function
Feng Wen1, Sonja M Ellingson, Chieko Kyogoku
1Arthritis and Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
Autoimmunity
|August 11, 2010
Summary
Interferon regulatory factor 5 (IRF5) variants in exon 6 influence apoptosis and nuclear translocation. The splice-site variant (SV-16) is more potent than the in/del-10 variant, but co-expression can neutralize effects.
Area of Science:
- Immunology
- Genetics
- Molecular Biology
Background:
- Interferon regulatory factor 5 (IRF5) is crucial for innate immunity and viral response.
- Genetic variants in IRF5 are strongly linked to systemic lupus erythematosus (SLE) risk.
- The functional impact of specific IRF5 exon 6 structural variants (in/del-10 and SV-16) on SLE pathogenesis remains unclear.
Purpose of the Study:
- To investigate the functional roles of IRF5 exon 6 variants, specifically the 30-bp in/del (in/del-10) and 48-bp splice-site variant (SV-16).
- To determine how these variants affect apoptosis, nuclear translocation, and cytokine transactivation in response to immune stimuli.
Main Methods:
- Utilized IRF5-deficient mouse embryonic fibroblasts (MEFs) overexpressing human IRF5 (hIRF5) variants.
- Assessed apoptosis response and IRF5 nuclear translocation following DNA-damaging stimuli.
- Measured IL-6 production upon lipopolysaccharide stimulation to evaluate cytokine transactivation.
Main Results:
- IRF5 isoforms with SV-16 or in/del-10 impaired apoptosis and reduced nuclear translocation.
- The combined absence of both SV-16 and in/del-10 abrogated these effects.
- SV-16 expression increased IL-6 production, while in/del-10 alone had no significant effect; absence of both reduced IL-6.
Conclusions:
- Exon 6 variants SV-16 and in/del-10 modulate IRF5's role in apoptosis and cytokine production.
- SV-16 exhibits a stronger influence on anti-apoptotic function and IL-6 induction compared to in/del-10.
- Co-expression of in/del-10 can counteract the effects of SV-16 on IRF5 function.
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