Large-Scale Candidate Gene Analysis of Spontaneous Clearance of Hepatitis C Virus
JOURNAL OF INFECTIOUS DISEASES
Authors: Mosbruger, Timothy L.; Duggal, Priya; Goedert, James J.; Kirk, Gregory D.; Hoots, W. Keith; Tobler, Leslie H.; Busch, Michael; Peters, Marion G.; Rosen, Hugo R.; Thomas, David L.; Thio, Chloe L.
Abstract
Human genetic variation is a determinant of recovery from acute hepatitis C virus (HCV) infection; however, to date, single-nucleotide polymorphisms (SNPs) in only a limited number of genes have been studied with respect to HCV clearance. We determined whether SNPs in 112 selected immune response genes are important for HCV clearance, by genotyping 1536 SNPs in a cohort of 343 persons with natural HCV clearance and 547 persons with HCV persistence. PLINK (version 1.05) and Haploview (version 4.1) software packages were used to perform association, permutation, and haplotype analyses stratified by African American and European American race. Of the 1536 SNPs tested, 1426 (92.8%) were successfully genotyped. In African Americans, we identified 18 SNPs located in 11 gene regions that were associated with HCV infection outcome (empirical P value, < .01). In European Americans, there were 20 SNPs located in 8 gene regions associated with HCV infection outcome. Four of the gene regions studied (TNFSF18, TANK, HAVCR1, and IL18BP) contained SNPs for which the empirical P value was <.01 in both of the race groups. In this large-scale analysis of 1426 genotyped SNPs in 112 candidate genes, we identified 4 gene regions that are likely candidates for a role in HCV clearance or persistence in both African Americans and European Americans.
Inhibition of in vitro and in vivo T cell responses by recombinant human Tim-1 extracellular domain proteins
INTERNATIONAL IMMUNOLOGY
Authors: Mesri, M; Smithson, G; Ghatpande, A; Chapoval, A; Shenoy, S; Boldog, F; Hackett, C; Pena, CE; Burgess, C; Bendele, A; Shimkets, RA; Starling, GC
Abstract
Members of the T cell, Ig domain and mucin domain (Tim) family of proteins have recently been implicated in the control of T cell-mediated immune responses. Tim-1 (HUGO designation HAVCR1) polymorphisms have been linked to the regulation of atopy in mice and humans, suggestive of a role in immune regulation. Tim-1 is expressed upon activation of T cells. In concert with the increased expression of Tim-1, a binding partner for the extracellular domain of Tim-1 (eTim-1) was induced on activated T cells, and mRNA expression data was consistent with the binding partner being Tim-4. We found that co-immobilized recombinant eTim-1 was able to inhibit T cell activation mediated by CD3 + CD28 mAb. eTim-1 mediated its inhibitory effects on proliferation by arresting cell cycle at G(0)/G(1) phase through regulation of cell cycle proteins. In vivo, administration of eTim-1 proteins led to a decrease in both ear (contact hypersensitivity to oxazolone) and joint (methylated BSA antigen-induced arthritis) swelling. The inhibitory activity of eTim-1 in the T(h)1-dependent models was evidence that eTim-1 is able to modulate T cell responses. Manipulation of the Tim-1 interaction with its binding partner on T cells may therefore provide a novel target for therapeutic intervention in T cell-mediated diseases.