IL7R? expression and upregulation by IFN? in dendritic cell subsets is haplotype-dependent.
Ontology highlight
ABSTRACT: The IL7R? gene is unequivocally associated with susceptibility to multiple sclerosis (MS). Haplotype 2 (Hap 2) confers protection from MS, and T cells and dendritic cells (DCs) of Hap 2 exhibit reduced splicing of exon 6, resulting in production of relatively less soluble receptor, and potentially more response to ligand. We have previously shown in CD4 T cells that IL7R? haplotypes 1 and 2, but not 4, respond to interferon beta (IFN?), the most commonly used immunomodulatory drug in MS, and that haplotype 4 (Hap 4) homozygotes have the highest risk of developing MS. We now show that IL7R expression increases in myeloid cells in response to IFN?, but that the response is haplotype-dependent, with cells from homozygotes for Hap 4 again showing no response. This was shown using freshly derived monocytes, in vitro cultured immature and mature monocyte-derived dendritic cells, and by comparing homozygotes for the common haplotypes, and relative expression of alleles in heterozygotes (Hap 4 vs not Hap 4). As for T cells, in all myeloid cell subsets examined, Hap 2 homozygotes showed a trend for reduced splicing of exon 6 compared to the other haplotypes, significantly so in most conditions. These data are consistent with increased signaling being protective from MS, constitutively and in response to IFN?. We also demonstrate significant regulation of immune response, chemokine activity and cytokine biosynthesis pathways by IL7R? signaling in IFN? -treated myeloid subsets. IFN?-responsive genes are over-represented amongst genes associated with MS susceptibility. IL7R? haplotype may contribute to MS susceptibility through reduced capacity for IL7R? signalling in myeloid cells, especially in the presence of IFN?, and is currently under investigation as a predictor of therapeutic response.
SUBMITTER: McKay FC
PROVIDER: S-EPMC3797747 | biostudies-literature | 2013
REPOSITORIES: biostudies-literature
ACCESS DATA