351. Toll-like receptor 3 increases antigen-presenting cell responses to a pro-apoptotic stimulus, yet does not contribute to systemic lupus erythematosus genetic susceptibility.
- Author
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De Groof A, Ducreux J, Vidal-Bralo L, Tyteca D, Galant C, Marot L, Coulie PG, Van den Eynde BJ, Rodriguez-Martinez L, Santos MJ, Suarez A, Carreira P, Marchini M, Gonzàlez A, Houssiau FA, and Lauwerys BR
- Subjects
- Antigen-Presenting Cells, Apoptosis, Genetic Predisposition to Disease, HEK293 Cells, Humans, Polymorphism, Single Nucleotide, Lupus Erythematosus, Systemic genetics, Toll-Like Receptor 3 genetics
- Abstract
Objectives: TLR3 mediates skin solar injury by binding nuclear material released from apoptotic keratinocytes, resulting in the production of pro-inflammatory cytokines. Because the TLR3 gene is located in 4q35, a known systemic lupus erythematosus (SLE) susceptibility locus, we wondered whether TLR3 single nucleotide polymorphisms (SNPs) were associated with inflammatory mechanisms relevant to the development of SLE, and disease susceptibility., Methods: Functional assays were carried out in TLR3-transfected HEK293 cells and in monocyte-derived dendritic cells (moDCs). TLR3 and IFNβ immunofluorescence studies were performed in skin samples from 7 SLE patients and 3 controls. We performed a SNP association study in a discovery cohort of 153 patients and 105 controls, followed by a confirmation study in an independent cohort of 1,380 patients and 2,104 controls., Results: TLR3 and IFNβ are overexpressed in SLE skin lesions. TLR3 overexpression in HEK293 cells amplifies their sensitivity to a pro-apoptotic stimulus. Taking advantage of a naturally occurring polymorphic TLR3 variant (rs3775291) that weakly versus strongly responds to poly I:C stimulation, we found that TLR3 is associated with amplified apoptotic responses, production of the Ro/SSA autoantigen and increased maturation of myeloid-derived dendritic cells (moDC) after exposure to UV irradiation. However, TLR3 SNPs are not associated with susceptibility to SLE in a large population of patients and controls., Conclusions: TLR3 is overexpressed in SLE skin lesions and amplifies apoptotic and inflammatory responses to UV-irradiation in antigen-presenting cells in vitro. However, TLR3 SNPs do not impact susceptibility to the development of the disease.
- Published
- 2020