To purify the protein encoding the small capsid protein (SCP) of KSHV and analyze its immunogenicity, the carboxyl terminus of orf65 of Kaposi's sarcoma associated-herpesvirus (KSHV) was expressed in a prokaryotic expression system. The expression of recombinant E. coli containing pQE-80L-orf65 was induced by isopropyl-β-D-thiogalactopyranoside (IPTG) and the fusion protein was purified by chromatography. The expressed protein and its purified product were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and showed that 9 kDa was the expected size of the purified orf65 protein. The antiserum was produced in rabbit which was immunized by purified orf65 protein. An ELISA assay was established to analyze the immunogenicity of the purified orf65 protein. The ELISA analysis demonstrated that orf65 protein has strong immune activity, and the immune activity of polyclonal antibody against orf65 was more than 4 fold higher than that in the serum of the non-immunized rabbit. These results demonstrate that purified orf65 protein has very strong immunogenicity and can be used in screening KSHV infection in the general population using ELISA.

MicroRNAs (miRNAs) play important roles in eukaryotes,plants and some viruses.It is increasingly clear that miRNAs-encoded by viruses can affect the viral life cycle and host physiology.Viral miRNAs could repress the innate and adaptive host immunity,modulate cellular signaling pathways,and regulate the expression of cellular and viral genes.These functions facilitate viral acute and persistent infections,and have profound effects on the host cell survival and disease progression.Here,we discuss the miRNAs encoded by herpesviruses,and their regulatory roles involved in virus-host interactions.

Tumor angiogenesis is the uncontrolled growth of blood vessels in tumors,serving to supply nutrients and oxygen,and remove metabolic wastes.Kaposi's sarcoma (KS),a multifocal angioproliferative disorder characterized by spindle cell proliferation,neo-angiogenesis,inflammation,and edema,is associated with infection by Kaposi's sarcoma-associated herpesvirus (KSHV).Recent studies indicate that KSHV infection directly promotes angiogenesis and inflammation through an autocrine and paracrine mechanism by inducing pro-angiogenic and pro-inflammatory cytokines.Many of these cytokines are also expressed in KS lesions,implicating a direct role of KSI-IV in the pathogenesis of this malignancy.Several KSHV genes are involved in KSHV-induced angiogenesis.These studies have provided insights into the pathogenesis of KS,and identified potential therapeutic targets for this malignancy.

The ORFK8.1 of Kaposi's sarcoma associated-herpesvirus (KSHV) was expressed in a prokaryotic expression system. The expression of recombinant E.coli containing pQE-80L-orf K8.1 was induced by isopropyl-b-D-thiogalactopyranoside (IPTG). The fusion protein was purified by chromatyography. The expressed protein and its purified product were identified by sodium dodecyl sulfate-polyacrylamide gel eletrophoresis (SDS-PAGE). SDS-PAGE showed that a protein of 26 kDa was visualized as expected. A western blot assay was established to analyze the immunogenicity of purified recombinant 0RFK8.1 protein. The optimal condition of the recombinant ORFK8.1 ELISA assay was confirmed: the concentration of antigen was 5 ug/mL, the dilution of serum was 1:200. We used the ELISA method to investigate the recombinant ORF K8.1 protein's specificity, the data showed that the specificity of ORF K8.1 to detect KSHV was 100%. At the same time, 560 sera samples from Hubei province were detected by using ORFK8.1 ELISA to investigate KSHV seroprevalence in this region. The KSHV seroprevalence in Hubei province is shown to be 6.80%.

Kaposi's sarcoma-associated herpesvirus (KSHV) is causally related to Kaposi's sarcoma (KS),primary effusion lymphoma (PEL) and a proportion of cases of multicentric Castleman's disease (MCD). The ORF73 protein was cloned into pQE80L-orf73 and expressed in E.coli and purified. The expressed recombinant ORF73 was identified by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE). A protein of about 27 kDa was expressed as expected. Western Blotting showed that the purified recombinant ORF73 reacted with KSHV positive serum. The immunogenicity of the recombinant ORF73 was further analysed by ELISA and the optimal conditions were determined. The ORF73 ELISA was used to compare the KSHV seroprevalence between Hubei and Xinjiang Han people. The Hart people in Xinjiang have significantly higher KSHV seroprevalence than their counterparts in Hubei (6.7% vs 2.9%, P = 0.005).