ABSTRACT
Interferons (IFNs) are a family of cytokines that have many biological functions in the cell, including regulation of cellular growth, differentiation, immunomodulation, and viral replication by inducing a set of interferon stimulated genes (ISGs). Based on their structure and biological activities IFNs are subdivided into two groups: type I IFNs, which includes IFN-alpha and IFN-beta and type II IFNs, represented by IFN-gamma. The aim of this work was to investigate whether integrin alpha 11 (ITGA-11), a novel collagen-binding integrin, is responsive to type I IFN treatment. Our findings indicated that type I IFNs were able to induce the ITGA-11 mRNA levels in T98G cells. Increased levels of ITGA-11 protein were also observed in IFN-treated cells. The in vivo induction of ITGA-11 was detected in spleen and lungs of IFN-treated BALB/c mice. T98G cells infected with Murine encephalomyocarditis virus showed increased levels of ITGA-11 mRNA and protein. We observed that the ITGA-11 promoter has binding sites for transcriptional factors regulated by IFNs and the double-stranded RNA dependent protein kinase (PKR). Therefore we investigated the role of PKR in the induction of ITGA-11 by using a PKR deficient mouse embryo fibroblast cell line (MEFs). PKR(-/-) MEFs treated with IFN did not show increased levels of ITGA-11 protein nor mRNA although that could be promptly detected in wild type MEFs. Taken together our data suggest that ITGA-11 is a new interferon stimulated gene.