Effects of K1 protein from different Kaposi's sarcoma associated herpesvirus/ Human herpesvirus type 8 genotypes on the gene expression of human endothelial cells in vitro

Abstract

The Kaposi's sarcoma-associated herpesvirus / human herpesvirus 8 (KSHV/HHV-8) has been linked to the development of Kaposi's sarcoma and some lymphoproliferative disorders, notably in immunodeficient patients. Although the virus is commonly found in latent form in most of the malignant infected cells, some products from lytic viral life cycle may also contribute in the pathogenesis of KSHV/HHV-8-associated cancers. In this regard, the K1 protein is one of the most relevant viral lytic products due to its interference in intercellular signaling pathways, with consequences in the proliferation, differentiation and survival of infected cells. K1 is encode by the viral ORF-K1, which has the highest degree of sequence variability compared to other segments of the KSHV/HHV-8 genome. Noteworthy, the ORF-K1 has been commonly evaluated for KSHV/HHV-8 genotyping. Currently it is unknown whether different KSHV/HHV-8 genotypes have distinctive biological features, with potential consequences in the viral oncogenicity. Therefore, the present study aims to evaluate whether primary human endothelial cells expressing different forms of the viral K1 protein show changes in the expression of critical cellular genes with participation in carcinogenesis and in the biology of human endothelial cells. Recombinant vectors carrying the KSHV/HHV-8 ORF-K1 from viral genotypes A, B and C will be transfect into human umbilical endothelial cells (HUVECs). Once the K1 expression is verified, the cells will be evaluated for the expression of transcripts of selected cellular genes using real-time quantitative PCR. The results will be analyze in order to identify possible changes in the phenotype of the transfected endothelial cells in vitro, as well as in the expression profile of selected genes upon activity of the different forms of the viral K1 protein. (AU)