Preferential activation of nuclear factor of activated T cells c correlates with mouse strain susceptibility to allergic responses and interleukin-4 gene expression.
Dysregulated expression of the T helper 2 cytokine interleukin (IL)-4 is thought to play a fundamental role in the pathogenesis of allergic asthma. The molecular basis for dysregulated IL-4 production is not well understood. We analyzed in detail the molecular factors involved in regulating IL-4 transcription in a well-characterized mouse model. In this model, A/J mice developed allergen-induced IL-4 cytokine gene expression, airway inflammation, and hyperresponsiveness, whereas C3H/HeJ (C3H) mice did not. Here we report that isolated splenocytes from A/J and C3H mice stimulated ex vivo with concanavalin A reproduced the cytokine phenotype observed in the airway after antigen challenge. We hypothesized that differences in splenocyte IL-4 production involved either polymorphisms in regulatory IL-4 promoter regions, or the expression and activation of transcription factors necessary for promoter transactivation in a strain-dependent manner. To address these questions, we first sequenced ~ 700 base pairs containing well-characterized IL-4 promoter regulatory elements using genomic DNA obtained from C3H and A/J mice. Next, we used electrophoretic mobility shift assays with relevant IL-4 promoter sequences to screen nuclear extracts isolated from A/J and C3H splenocytes for functional transcriptional factor complexes. Here we show that susceptibility to antigen-induced airway hyperresponsiveness is not due to polymorphisms in the IL-4 promoter, but is associated with preferential expression of nuclear factor of activated T cells c in splenocyte nuclear extracts obtained from A/J mice. In conclusion, our data link dysregulated activation of a specific transcription factor with susceptibility to allergic airway inflammation.
Keen
J C
JC
Departments of Medicine and Environmental Health Sciences, The Johns Hopkins University, Baltimore, Maryland, USA.
Sholl
L
L
Wills-Karp
M
M
Georas
S N
SN
D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000276:immunology; D006967:Hypersensitivity / Q000276:immunology* / Q000378:metabolism*; D016130:Immunophenotyping; D015847:Interleukin-4 / Q000096:biosynthesis* / Q000235:genetics; D046911:Macromolecular Substances; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008809:Mice, Inbred C3H; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013268:Stimulation, Chemical; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics
D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D003208:Concanavalin A; D015847:Interleukin-4