Constructing a recombinant adenovirus carrying human cytomegalovirus UL138 gene and evaluating the effects of UL138 gene on the functions of monocytes / 中华微生物学和免疫学杂志

Objective To construct a recombinant adenovirus carrying UL138 gene, which was re-lated to the latent infection of human cytomegalovirus, and to investigate the effects of UL138 gene on the functions of THP-1 mononuclear cells. Methods The recombinant adenovirus expressing the UL138 gene was packaged. The titer of the recombinant adenovirus was determined by calculating 50% tissue culture in-fective dose ( TCID50 ) . THP-1 mononuclear cells were infected with the recombinant adenovirus at different multiplicity of infection (MOI) and the optimal MOI was determined (100 PFU/cell) by observing the ex-pression of green fluorescent protein ( GFP ) . Changes in the expression of proinflammatory cytokines by THP-1 mononuclear cells that was induced by overexpressed UL138 were analyzed by quantitative PCR. The expression of chemokines and their receptors were measured by quantitative PCR array. Results The re-combinant adenovirus carrying the UL138 gene was successfully constructed with a titer of 1×1011 PFU/ml. The rate of THP-1 mononuclear cells that was infected with the recombinant adenovirus was 60% at the MOI of 1 ∶ 100. Results of the RT-PCR analysis and Western blot assay further confirmed that the recombinant adenovirus could infect THP-1 mononuclear cells successfully and the expression of UL138 protein increased gradually over time. The overexpressed UL138 in THP-1 mononuclear cells significantly inhibited the expres-sion of IL-18, IL-1β, IL-6, IL-8 and TNF-α as indicated by the results of quantitative PCR. Results ob-tained from the quantitative PCR array analysis showed that most of the chemokines and their receptors were downregulated in the transfected THP-1 mononuclear cells except for the chemokines of CCL17, CCL21, CCL2 and XCL2 and the receptors of CCR2, CXCR1, CXCR2, CXCR4 and CX3CR1 which were upregulat-ed. Conclusion We successfully constructed the recombinant adenovirus carrying UL138 gene which could be used to infect THP-1 mononuclear cells. Overexpressed UL138 in THP-1 mononuclear cells significantly affected the functions of THP-1 mononuclear cells.

Analysis of nucleotide sequences and genetic polymorphisms of UL138 gene of low passage human cy-tomegalovirus strains in Guangzhou / 中华微生物学和免疫学杂志

Objective To analyze the nucleotide sequences and genetic polymorphisms of UL138 gene of low passage human cytomegalovirus ( HCMV) strains isolated from infants in Guangzhou province. Methods The low passage strains of HCMV were isolated from urine samples of 10 infants with HCMV in-fection in Guangzhou province and identified by multiplex PCR.The UL138 genes were amplified, cloned and identified with sequencing.The sequences were analyzed together with the homologous sequences of 10 clinical isolates published in GenBank.The sequences of UL138 genes were analyzed by using bioinformatics softwares for investigation of the post-translational modification sites, isoelectric points and second structures of UL138 proteins.Results Three low passage strains of HCMV ( D2, D3 and D52) were isolated from in-fants with congenital HCMV infection.The complete sequences of UL138 genes of the three strains were sub-mitted to GenBank after sequencing identification with the GenBank accession numbers of DQ180375, DQ180387 and DQ180359, respectively.The UL138 gene sequences of the three clinical isolates were high-ly conservative.Among the 841 base pairs of the UL138 gene sequences, mutations were identified in 16 sites with base substitution, no any insertion and deletion mutation was found.The 16 mutations resulted in 7 amino acid changes.No additional or deleted sites were found with regard to the post translational modifi-cation sites of UL138 protein in all clinical isolates except the Toledo strain.The isoelectric point of UL138 protein was 6.51 for all clinical isolates.Conclusion The UL138 genes and the deduced amino acid se-quences of HCMV strains isolated from infants in Guangzhou were highly conservative, regardless of the poly-morphism of UL138 gene.This study paved the way for further investigation on HCMV infection and its path-ogenic mechanism.

Down-regulation of human cytomegalovirus UL138, a novel latency-associated determinant, by hcmv-miR-UL36.

MicroRNAs (miRNAs) are small RNAs, 19–23 nucleotides in length, which regulate a variety of cellular processes. Human cytomegalovirus (HCMV) encodes only one intronic miRNA: human cytomegalovirus microRNA UL36 (hcmv-miR-UL36). In this study, we found that over-expression of hcmv-miR-UL36 resulted in a more than threefold increase in HCMV DNA synthesis at 24 h post infection. Fifteen putative targets of hcmv-miR-UL36 were identified using hybrid PCR, one being the HCMV UL138 gene that has previously been identified as a novel latency-associated determinant of HCMV infection. Down-regulation of UL138 expression by hcmv-miR-UL36 was validated using luciferase reporter assays and Western blot analysis in HEK293 cells. In the presence of hcmv-miR-UL36, we observed a 74.6% decrease in luciferase activity and a 46.2% decrease in HCMV UL138 protein expression. Our results indicate that hcmv-miR-UL36 may be a viral miRNA contributing to HCMV replication.

Progress in biological functions of encoded proteins in human cytomegalovirus UL/b' region / 国际儿科学杂志

Human cytomegalovirus(HCMV) is a ubiquitous herpesvirus.It is always a serious pathogen in immunosuppressed individuals,and also the most common and harmful agent causing congenital infection and birth defects.Biological functions of the encoded proteins in HCMV UL/b' region,which is deleted in the HCMV laboratory AD169 strain,have been explored in depth in recent years,and the results demonstrate that the proteins have important roles in HCMV virulence,transmission,tropisms and immune escape and so on.UL133-UL138 locus can promote to establish and maintain HCMV latent infections,and pUL1 38 is the first HCMV protein demonstrated to promote infection with the hallmarks of latency in CD34 + hematopoietic progenitor cells (HPC).Therefore,the products expressed by the gene of HCMV UL/b' region are crucial in the course of HCMV infection.This article reviews the genetic structure and biological functions of encoded proteins in HCMV UL/b' region,especially pULl38 which is related with HCMV latent infections.It will be greatly significant to clarify the pathogenesis of HCMV infection.