A cytokine gene screen uncovers SOCS1 as genetic risk factor for multiple sclerosis
GENES AND IMMUNITY
Authors: Vandenbroeck, K.; Alvarez, J.; Swaminathan, B.; Alloza, I.; Matesanz, F.; Urcelay, E.; Comabella, M.; Alcina, A.; Fedetz, M.; Ortiz, M. A.; Izquierdo, G.; Fernandez, O.; Rodriguez-Ezpeleta, N.; Matute, C.; Caillier, S.; Arroyo, R.; Montalban, X.; Oksenberg, J. R.; Antigueedad, A.; Aransay, A.
Abstract
Cytokine and cytokine receptor genes, including IL2RA, IL7R and IL12A, are known risk factors for multiple sclerosis (MS). Excitotoxic oligodendroglial death mediated by glutamate receptors contributes to demyelinating reactions. In the present study, we screened 368 single-nucleotide polymorphisms (SNPs) in 55 genes or gene clusters coding for cytokines, cytokine receptors, suppressors of cytokine signaling (SOCS), complement factors and glutamate receptors for association with MS in a Spanish Basque resident population. Top-scoring SNPs were found within or nearby the genes coding for SOCS-1 (P = 0.0005), interleukin-28 receptor, alpha chain (P = 0.0008), oncostatin M receptor (P = 0.002) and interleukin-22 receptor, alpha 2 (IL22RA2; P = 0.003). The SOCS1 rs243324 variant was validated as risk factor for MS in a separate cohort of 3919 MS patients and 4003 controls (combined Cochran-Mantel-Haenszel P = 0.00006; odds ratio (OR) = 1.13; 95% confidence interval (CI) = 1.07-1.20). In addition, the T allele of rs243324 was consistently increased in relapsing-remitting/secondary progressive versus primary-progressive MS patients, in each of the six data sets used in this study (P-CMH = 0.0096; OR = 1.24; 95% Cl 1.05-1.46). The association with SOCS1 appears independent from the chr16MS risk locus CLEC16A. Genes and Immunity (2012) 13, 21-28; doi:10.1038/gene.2011.44; published online 30 June 2011
The inhibitory cytokine IL-35 contributes to regulatory T-cell function
NATURE
Authors: Collison, Lauren W.; Workman, Creg J.; Kuo, Timothy T.; Boyd, Kelli; Wang, Yao; Vignali, Kate M.; Cross, Richard; Sehy, David; Blumberg, Richard S.; Vignali, Dario A. A.
Abstract
Regulatory T (T-reg) cells are a critical sub-population of CD4(+) T cells that are essential for maintaining self tolerance and preventing autoimmunity(1,2), for limiting chronic inflammatory diseases, such as asthma and inflammatory bowel disease(3,4), and for regulating homeostatic lymphocyte expansion(5). However, they also suppress natural immune responses to parasites(6) and viruses(7) as well as anti-tumour immunity induced by therapeutic vaccines(8). Although the manipulation of T-reg function is an important goal of immunotherapy, the molecules that mediate their suppressive activity remain largely unknown. Here we demonstrate that Epstein-Barr-virus-induced gene 3 (Ebi3, which encodes IL-27 beta) and interleukin-12 alpha (Il12a, which encodes IL-2 alpha/p35) are highly expressed by mouse Foxp3(+) ( forkhead box P3) Treg cells but not by resting or activated effector CD4(+) T (T-eff) cells, and that an Ebi3-IL-12 alpha heterodimer is constitutively secreted by T-reg but not T-eff cells. Both Ebi3 and Il12a messenger RNA are markedly upregulated in T-reg cells co-cultured with T-eff cells, thereby boosting Ebi3 and IL-12 alpha production in trans. T-reg-cell restriction of this cytokine occurs because Ebi3 is a downstream target of Foxp3, a transcription factor that is required for T-reg-cell development and function. Ebi3(-/-) and Il12a(-/-) T-reg cells have significantly reduced regulatory activity in vitro and fail to control homeostatic proliferation and to cure inflammatory bowel disease in vivo. Because these phenotypic characteristics are distinct from those of other IL-12 family members, this novel Ebi3-IL-12 alpha heterodimeric cytokine has been designated interleukin-35 ( IL-35). Ectopic expression of IL-35 confers regulatory activity on naive T cells, whereas recombinant IL-35 suppresses T-cell proliferation. Taken together, these data identify IL-35 as a novel inhibitory cytokine that may be specifically produced by T-reg cells and is required for maximal suppressive activity.