Guinea pig cytomegalovirus gene expression

Serum proteomics with SELDI-TOF-MS in congenital human cytomegalovirus hepatitis

Human cytomegalovirus (HCMV) is a widespread pathogen, the most common congenital viral infection, and the leading cause of infant hepatitis syndrome. In this study, serum samples were collected from 20 HCMV-infected infants with hepatitis and 25 controls. Of the 25 infants in the control group, 5 were infected with HCMV but without hepatitis, 10 had hepatitis but no HCMV infection, and 10 were healthy. Proteomic expression in the serum was detected by WCX2 chips and surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS), to identify serum protein biomarkers in infants with hepatitis syndrome resulting from HCMV. Fifteen protein peaks were distinctly different among the four groups in the mass range from 2,000 to 20,000 Da. Of these 15 peaks, 4 at 4,349.8, 5,808.7, 7,935.6, and 8,885.9 Da were significantly different between the congenital HCMV-infected infants with hepatitis and the controls. Five peaks were distinctly up-regulated in the infants with HCMV infection (3,266.8, 5,638.5, 5,909.1, 7,771.4, and 15,835.6 Da) compared to those without HCMV infection. Two proteins at 4,600.1 and 5,704.3 were up-regulated in infants with HMCV infection but no hepatitis. Four protein peaks were markedly different (7,567.0, 13,744.8, 15,100.7, and 15,915.0 Da) between the infants with hepatitis and the other controls. Comparison of the differentially expressed proteins' properties with those available on an international database suggest that specific serum proteins such as the augmenter of liver regeneration, pre-albumin, and haptoglobin closely related to liver function, and cytokines such as beta-defensins 31 and 8, and macrophage-derived chemokine, among others, are involved in HMCV infection and the pathogenesis of HMCV-induced hepatitis in infants.

Characterization of a cluster of late genes of guinea pig cytomegalovirus

Human cytomegalovirus (HCMV) is the most common congenital infection, and is associated with a high rate of morbidity and mortality in the newborn infant. Guinea pig cytomegalovirus (GPCMV) is transmitted through the placenta with resulting fetal infection, and provides an excellent model for the study of fetal cytomegalovirus infection. We have characterized a cluster of late GPCMV genes, identifying GPCMV homologs of the HCMV G protein-coupled receptor gene, UL33; the transcriptional repressor gene, UL34 and two genes encoding tegument proteins, UL32 and UL35. We also identified the GPCMV homolog of UL37, an antiapoptotic gene. Surprisingly, no GPCMV homolog to HCMV UL36 was identified in the same genomic region. Furthermore, two of the predicted GPCMV proteins share greater identity with HHV-6 and/or HHV-7 homologs than with other cytomegalovirus homologs. The identification of GPCMV homologs of conserved viral genes, particularly genes involved in pathogenicity such as the G protein-coupled receptors, will facilitate future analysis of the role of these genes in infections.

Human cytomegalovirus (HCMV) immediate-early enhancer/promoter specificity during embryogenesis defines target tissues of congenital HCMV infection

Congenital human cytomegalovirus (HCMV) infection is a common cause of deafness and neurological disabilities. Many aspects of this prenatal infection, including which cell types are infected and how infection proceeds, are poorly understood. Transcription of HCMV immediate-early (IE) genes is required for expression of all other HCMV genes and is dependent on host cell transcription factors. Cell type-specific differences in levels of IE transcription are believed to underlie differences in infection permissivity. However, DNA transfection experiments have paradoxically suggested that the HCMV major IE enhancer/promoter is a broadly active transcriptional element with little cell type specificity. In contrast, we show here that expression of a lacZ gene driven by the HCMV major IE enhancer/promoter -524 to +13 segment is restricted in transgenic mouse embryos to sites that correlate with known sites of congenital HCMV infection in human fetuses. This finding suggests that the IE enhancer/promoter is a major determinant of HCMV infection sites in humans and that transcription factors responsible for its regulation are cell type-specifically conserved between humans and mice. The lacZ expression patterns of these transgenic embryos yield insight into congenital HCMV pathogenesis by providing a spatiotemporal map of the sets of vascular, neural, and epithelial cells that are likely targets of infection. These transgenic mice may constitute a useful model system for investigating IE enhancer/promoter regulation in vivo and for identifying factors that modulate active and latent HCMV infections in humans.

Congenital Cytomegalovirus and Deafness

Although the incidence of medical and neurological problems resulting from congenital cytomegalovirus (CMV) infection is relatively low, the widespread and indiscriminate nature of this infection and the severity of these conditions when they do occur are such that it warrants the close attention of medical specialists, audiologists, and educators. The identification of congenital CMV is especially difficult because of its largely nonsymptomatic character, and because conditions associated with it, including hearing impairment, can be either progressive in nature or occur only later in life. Data reviewed in this study resemble those reported for children with impaired hearing from the 1964-65 maternal rubella epidemic: hearing loss in the severe to profound range, often accompanied by serious additional disabilities, especially mental retardation and cerebral palsy. Depressed achievement test results of children with CMV-induced hearing loss are further indications of the serious nature of this disease.The presence of any symptoms of CMV infection in infants or of risk factors associated with it-e.g., purplish skin rash, severe asphyxia, jaundice, low birth weight, swollen lymph glands, and other mononucleosis-like symptoms-signals the need for immediate testing, including audiological evaluation, and, if results are positive, the initiation of early medical and educational intervention.