OBJECTIVE: Variations in gene copy number (CNV) have been recognised as a hereditable source of susceptibility in human complex diseases. Recent studies have shown that Tlr7 gene dosage has a significant contribution in the autoimmune-enhancing effect in mouse models of systemic lupus erythematosus (SLE). A study was therefore performed to investigate whether CNVs in TLR7 contribute to the genetic component of childhood-onset SLE. METHODS: A case-control association study was performed in 328 Mexican children with SLE and 403 healthy controls. Determination of CNVs of TLR7 was achieved by real-time PCR using the ΔΔCt method. Expression levels of TLR7 and interferon α (IFNα) were determined in 23 patients. In addition, a stratification analysis was performed to investigate the association of TLR7 gene copy number (CN) with lupus nephritis. RESULTS: A significant increase was found in the relative TLR7 gene CN in females patients with SLE compared with female controls (p<0.0001). However, logistic regression analysis by gender showed a higher OR (OR 6.61, p=0.005) in male patients with >1 copy of TLR7 than in female patients with >2 copies (OR 3.07, p<0.0001). This association was not observed with lupus nephritis. TLR7 mRNA levels correlated significantly with TLR7 CN and with IFNα mRNA levels. CONCLUSION: These results show that an increase in TLR7 CN is a risk factor for childhood-onset SLE and provide new evidence for a role for X-linked gene dosage in SLE susceptibility. There is also evidence to suggest that TLR7 may be involved in the pathogenesis of SLE through the induction of IFNα.
OBJECTIVE: Variations in gene copy number (CNV) have been recognised as a hereditable source of susceptibility in human complex diseases. Recent studies have shown that Tlr7 gene dosage has a significant contribution in the autoimmune-enhancing effect in mouse models of systemic lupus erythematosus (SLE). A study was therefore performed to investigate whether CNVs in TLR7 contribute to the genetic component of childhood-onset SLE. METHODS: A case-control association study was performed in 328 Mexican children with SLE and 403 healthy controls. Determination of CNVs of TLR7 was achieved by real-time PCR using the ΔΔCt method. Expression levels of TLR7 and interferon α (IFNα) were determined in 23 patients. In addition, a stratification analysis was performed to investigate the association of TLR7 gene copy number (CN) with lupus nephritis. RESULTS: A significant increase was found in the relative TLR7 gene CN in females patients with SLE compared with female controls (p<0.0001). However, logistic regression analysis by gender showed a higher OR (OR 6.61, p=0.005) in male patients with >1 copy of TLR7 than in female patients with >2 copies (OR 3.07, p<0.0001). This association was not observed with lupus nephritis. TLR7 mRNA levels correlated significantly with TLR7 CN and with IFNα mRNA levels. CONCLUSION: These results show that an increase in TLR7 CN is a risk factor for childhood-onset SLE and provide new evidence for a role for X-linked gene dosage in SLE susceptibility. There is also evidence to suggest that TLR7 may be involved in the pathogenesis of SLE through the induction of IFNα.
Authors: James T Rosenbaum; April Woods; Jelena Kezic; Stephen R Planck; Holly L Rosenzweig Journal: Invest Ophthalmol Vis Sci Date: 2011-08-17 Impact factor: 4.799
Authors: Zachary R Newman; Janet M Young; Nicholas T Ingolia; Gregory M Barton Journal: Proc Natl Acad Sci U S A Date: 2016-02-22 Impact factor: 11.205
Authors: Sun-Hee Hwang; Huiyin Lee; Miwako Yamamoto; Leigh A Jones; Jivanaah Dayalan; Richard Hopkins; Xin J Zhou; Felix Yarovinsky; John E Connolly; Maria A Curotto de Lafaille; Edward K Wakeland; Anna-Marie Fairhurst Journal: J Immunol Date: 2012-11-12 Impact factor: 5.422