Influence of Atg5 mutation in SLE depends on functional IL-10 genotype

PLoS One. 2013 Oct 18;8(10):e78756. doi: 10.1371/journal.pone.0078756. eCollection 2013.

Abstract

Increasing evidence supports the involvement of autophagy in the etiopathology of autoimmune diseases. Despite the identification of autophagy-related protein (Atg)-5 as one of the susceptibility loci in systemic Lupus erythematosus (SLE), the consequences of the carriage of these mutations for patients remain unclear. The present work analyzed the association of Atg5 rs573775 single nucleotide polymorphism (SNP) with SLE susceptibility, IFNα, TNFα and IL-10 serum levels, and clinical features, in 115 patients and 170 healthy individuals. Patients who where carriers of the rs573775 T* minor allele presented lower IFNα levels than those with the wild genotype, whereas the opposite result was detected for IL-10. Thus, since IL-10 production was regulated by rs1800896 polymorphisms, we evaluated the effect of this Atg5 mutation in genetically high and low IL-10 producers. Interestingly, we found that the rs573775 T* allele was a risk factor for SLE in carriers of the high IL-10 producer genotype, but not among genetically low producers. Moreover, IL-10 genotype influences SLE features in patients presenting the Atg5 mutated allele. Specifically, carriage of the rs573775 T* allele led to IL-10 upregulation, reduced IFNα and TNFα production and a low frequency of cytopenia in patients with the high IL-10 producer genotype, whereas patients with the same Atg5 allele that were low IL-10 producers presented reduced amounts of all these cytokines, had a lower prevalence of anti-dsDNA antibodies and the latest onset age. In conclusion, the Atg5 rs573775 T* allele seems to influence SLE susceptibility, cytokine production and disease features depending on other factors such as functional IL-10 genotype.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alleles
  • Autophagy-Related Protein 5
  • Cohort Studies
  • Female
  • Genetic Predisposition to Disease
  • Genotype*
  • Humans
  • Interferon-alpha / blood
  • Interleukin-10 / genetics*
  • Lupus Erythematosus, Systemic / blood
  • Lupus Erythematosus, Systemic / genetics*
  • Male
  • Microtubule-Associated Proteins / genetics*
  • Mutation*
  • Polymorphism, Single Nucleotide

Substances

  • ATG5 protein, human
  • Autophagy-Related Protein 5
  • Interferon-alpha
  • Microtubule-Associated Proteins
  • Interleukin-10

Grants and funding

This work was supported by European Union FEDER funds and the Fondo de Investigación Sanitaria (FIS, PI08/0570 and PI12/0053). J.R.-C. is a recipient of a FPU grant from the Ministerio de Educación. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.