The frequency of cytomegalovirus non-ELR UL146 genotypes in neonates with congenital CMV disease is comparable to strains in the background population.

BACKGROUND: Congenital cytomegalovirus disease (cCMV) is common and can be fatal or cause severe sequelae. Circulating strains of cytomegalovirus carry a high number of variable or disrupted genes. One of these is UL146, a highly diverse gene with 14 distinct genotypes encoding a CXC-chemokine involved in viral dissemination. UL146 genotypes 5 and 6 lack the conserved ELR motif, potentially affecting strain virulence. Here, we investigate whether UL146 genotypes 5 and 6 were associated with congenital CMV infection. METHODS: Viral DNA was extracted and UL146 sequenced from 116 neonatal dried blood spots (DBS) stored in the Danish National Biobank since 1982 and linked to registered cCMV cases through a personal identifier. These sequences were compared to UL146 control sequences obtained from CMV DNA extracted from 83 urine samples from children with suspected bacterial urinary tract infections. RESULTS: Three non-ELR UL146 genotypes (5 and 6) were observed among the cases (2.6%) and two were observed among the controls (2.4%; P > 0.99). Additionally, no significant association with cCMV was found for the other 12 genotypes in a post-hoc analysis, although genotype 8 showed a tendency to be more frequent among cases with 12 observations against three (P = 0.10). All fourteen genotypes were found to have little intra-genotype variation. Viral load, gender, and sample age were not found to be associated with any particular UL146 genotype. CONCLUSIONS: No particular UL146 genotype was associated with cCMV in this nationwide retrospective case-control study. Associations between CMV disease and disrupted or polymorph CMV genes among immunosuppressed people living with HIV/AIDS and transplant recipients should be investigated in future studies.

Features of human cytomegalovirus UL146 gene in asymptomatic children / 中华微生物学和免疫学杂志

Objective To investigate the polymorphisms of human cytomegalovirus ( HCMV ) UL146 gene in asymptomatic children. Methods Urine samples were collected from 47 asymptomatic chil-dren who were positive for HCMV DNA. PCR was performed to amplify the open reading frame ( ORF) of UL146 gene. Positive bands were sequenced and variations in UL146 gene were analyzed by using bioinfor-matics software. Results Seventeen samples were successfully amplified and sequenced. Variations spread all over the sequence of UL146 gene and the variability in nucleotide and amino acid sequences ranged from 0％ to 42. 5％ and 0％ to 67. 7％ respectively. Compared with the Towne strain, there was diversity in sig-nal sequence and C-terminal region. Phylogenetic analysis indicated that UL146 in the 17 asymptomatic chil-dren belonged to four genotypes, which were G1, G8, G9 and G11. Forms of post-translational modification varied greatly among the four genotypes, while the important functional region of ELRCXC chemokine was highly conservative. Secondary structure prediction showed that random-coli conformation was the predomi-nant structure of active proteins. Isoelectric point ( PI) and molecular weight ( MW) were dissimilar among the four genotypes. Conclusion HCMV UL146 gene in asymptomatic children was hypervariable in both nucleotide sequence and amino acid structure. However, the important functional region was highly con-served. The predominant genotypes of UL146 in these children were G1, G8, G9 and G11, and the geno-type distribution in them showed no significant difference with previous findings in children with symptomatic HCMV infection.

Features of human cytomegalovirus UL146 gene in asymptomatic children / 中华微生物学和免疫学杂志

Objective To investigate the polymorphisms of human cytomegalovirus ( HCMV ) UL146 gene in asymptomatic children. Methods Urine samples were collected from 47 asymptomatic chil-dren who were positive for HCMV DNA. PCR was performed to amplify the open reading frame ( ORF) of UL146 gene. Positive bands were sequenced and variations in UL146 gene were analyzed by using bioinfor-matics software. Results Seventeen samples were successfully amplified and sequenced. Variations spread all over the sequence of UL146 gene and the variability in nucleotide and amino acid sequences ranged from 0％ to 42. 5％ and 0％ to 67. 7％ respectively. Compared with the Towne strain, there was diversity in sig-nal sequence and C-terminal region. Phylogenetic analysis indicated that UL146 in the 17 asymptomatic chil-dren belonged to four genotypes, which were G1, G8, G9 and G11. Forms of post-translational modification varied greatly among the four genotypes, while the important functional region of ELRCXC chemokine was highly conservative. Secondary structure prediction showed that random-coli conformation was the predomi-nant structure of active proteins. Isoelectric point ( PI) and molecular weight ( MW) were dissimilar among the four genotypes. Conclusion HCMV UL146 gene in asymptomatic children was hypervariable in both nucleotide sequence and amino acid structure. However, the important functional region was highly con-served. The predominant genotypes of UL146 in these children were G1, G8, G9 and G11, and the geno-type distribution in them showed no significant difference with previous findings in children with symptomatic HCMV infection.

UL146 variability among clinical isolates of Human Cytomegalovirus from Japan

Human Cytomegalovirus (HCMV) is a herpesvirus associated with serious diseases in immunocompromised subjects. The region between ORF UL133 and UL151 from HCMV, named ULb' is frequently deleted in attenuated AD169 and in highly passaged laboratory strains. However, this region is conserved in low-passaged and more virulent HCMV, like the Toledo strain. The UL146 gene, which is located in the ULb' region, encodes a CXC-chemokine analogue. The diversity of UL146 gene was evaluated among fifty-six clinical isolates of HCMV from Japan. Results show that UL146 gene was successfully amplified by the polymerase chain reaction (PCR) in only 17/56 strains (30 percent), while the success rate for UL145/UL147 gene was 18/56 strains (32 percent). After DNA sequencing, the 35 amplified strains were classified into 8 groups. When compared, variability of UL146 ranged from 25.1 percent to 52.9 percent at the DNA level and from 34.5 percent to 67 percent at the amino acid level. Seven groups had the interleukin-8 (IL-8) motif ERL (Glu-Leu-Arg) CXC and one group had only the CXC motif, suggesting the absence of the IL-8 function of UL146. In conclusion, we found that UL146 gene of HCMV is hyper-variable in clinical strains from Japan suggesting the possibility of a different function in each sequence group.

The role of human cytomegalovirus UL146 gene-α chemokine in cytomegalovirus infection / 国际儿科学杂志

Human cytomegalovirus (HCMV) infection is very common in the population. The form of infection usually presents silent or latent infection in the persons with normal immune function, but it can lead to a high mortality in the fetuses and the patients with immune deficiency. At present,the pathogenesis of the congenital infection by HCMV is not very clear. In the α chemokine homologue encoded by HCMV UL146, the variation of the nucleotide and amino acid sequences and the highly conservative domain suggests that this domain is important for HCMV in biological significance. And the study on the gene polymorphism and the function of its encoding protein will play an important role to reveal the pathogenesis of HCMV.

Polymorphism of Human Cytomegalovirus （HCMV） UL146 Gene / 中国医科大学学报

Objective To investigate the polymorphism of human cytomegalovirus（HCMV）UL146 gene in clinical strains,and to evaluate its clinical diagnostic and therapeutic value of gene.Methods The UL146 gene of clinical strains was examined by quantitative polymerase chain reaction（Q-PCR）or general polymerase chain reaction（PCR）.Positive samples of PCR amplification were sequenced and analyzed.Results High variability of UL146 gene was found among 28 HCMV strains.According to phylogenetic analysis,all sequences of UL146 in clinical strains could be divided into three types and four subtypes.Chemokine ELRCXC region was highly conserved in all sequences.Conclusion HCMV-UL146 genes showed a high degree of polymorphism,and its encoded chemokine ELRCXC region was highly con-served.The relationship between HCMV-UL146 gene′s polymorphism and different clinical symptoms of HCMV infection was unclear.