Back to Search Start Over

Human membrane protein Tim-3 facilitates hepatitis A virus entry into target cells.

Authors :
Sui L
Zhang W
Chen Y
Zheng Y
Wan T
Zhang W
Yang Y
Fang G
Mao J
Cao X
Source :
International journal of molecular medicine [Int J Mol Med] 2006 Jun; Vol. 17 (6), pp. 1093-9.
Publication Year :
2006

Abstract

In this study, a cellular surface membrane protein of immunoglobulin (Ig) superfamily (IgSF) was identified from a human dendritic cell (DC) cDNA library by large-scale random sequencing, which is identical to previously reported Tim-3 (T-cell Ig- and mucin-domain-containing molecule 3). Recent data have suggested the association of the 281-residue mouse Tim-3 molecule with Th1-related T cell responses and disease in mice. Human Tim-3 is a 301-residue type I membrane protein whose extracellular region contains a Cys-rich Ig-like domain and a mucin domain, the characteristics of Tim proteins. It shows significant homology to human hepatitis A virus (HAV) cellular receptor-1 (HuHAVcr-1)/Tim-1. Human Tim-3 mRNA was highly expressed in monocytes or monocyte-derived cells, and the expression level decreased when DC underwent maturation and activation. There is no previous report on the biological functions of human Tim-3, especially the involvement in virus infection. We demonstrated that HeLa cells, which are refractory to HAV infection, acquired a limited susceptibility to HAV infection after stably overexpressing human Tim-3 as confirmed by Western blot analysis using anti-Tim-3 antibody, but Tim-3-Fc fusion protein had no direct HAV-binding activity. The results indicated that human Tim-3 can promote HAV entry into target cells but itself may not function as a cellular receptor of HAV.

Details

Language :
English
ISSN :
1107-3756
Volume :
17
Issue :
6
Database :
MEDLINE
Journal :
International journal of molecular medicine
Publication Type :
Academic Journal
Accession number :
16685421