Reduced tumor necrosis factor signaling in primary human fibroblasts containing a tumor necrosis factor receptor superfamily 1A mutant.
OBJECTIVE
Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is an autoinflammatory syndrome associated with mutations in the gene that encodes tumor necrosis factor receptor superfamily 1A (TNFRSF1A). The purpose of this study was to describe a novel TNFRSF1A mutation (C43S) in a patient with TRAPS and to examine the effects of this TNFRSF1A mutation on tumor necrosis factor alpha (TNFalpha)-induced signaling in a patient-derived primary dermal fibroblast line.


METHODS
TNFRSF1A shedding from neutrophils was measured by flow cytometry and enzyme-linked immunosorbent assay (ELISA). Primary dermal fibroblast lines were established from the patient with the C43S TRAPS mutation and from healthy volunteers. Activation of NF-kappaB and activator protein 1 (AP-1) was evaluated by electrophoretic mobility shift assays. Cytokine production was measured by ELISA. Cell viability was measured by alamar blue assay. Apoptosis was measured by caspase 3 assay in the fibroblasts and by annexin V assay in peripheral blood mononuclear cells.


RESULTS
Activation-induced shedding of the TNFRSF1A from neutrophils was not altered by the C43S TRAPS mutation. TNFalpha-induced activation of NF-kappaB and AP-1 was decreased in the primary dermal fibroblasts with the C43S TNFRSF1A mutation. Nevertheless, the C43S TRAPS fibroblasts were capable of producing interleukin-6 (IL-6) and IL-8 in response to TNFalpha. However, TNFalpha-induced cell death and apoptosis were significantly decreased in the samples from the patient with the C43S TRAPS mutation.


CONCLUSIONS
The C43S TNFRSF1A mutation results in decreased TNFalpha-induced nuclear signaling and apoptosis. Our data suggest a new hypothesis, in that the C43S TRAPS mutation may cause the inflammatory phenotype by increasing resistance to TNFalpha-induced apoptosis.
Siebert
Stefan
S
Section of Infection and Immunity, Wales College of Medicine, Cardiff University, Cardiff, UK. sieberts@cardiff.ac.uk
Amos
Nick
N
Fielding
Ceri A
CA
Wang
Eddie C Y
EC
Aksentijevich
Ivona
I
Williams
Bryan D
BD
Brennan
Paul
P
D017209:Apoptosis; D002460:Cell Line; D002470:Cell Survival; D020405:Dermis; D024202:Electrophoretic Mobility Shift Assay; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D009154:Mutation; D016328:NF-kappa B / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism* / Q000494:pharmacology
D015850:Interleukin-6; D016209:Interleukin-8; D016328:NF-kappa B; D047888:Receptors, Tumor Necrosis Factor, Type I; D018808:Transcription Factor AP-1; D014409:Tumor Necrosis Factor-alpha