William J. Britt

The outcome of congenital cytomegalovirus infection in relation to maternal antibody status.

Abstract Background. Intrauterine transmission of cytomegalovirus (CMV) can occur whether a mother has prior immunity or acquires CMV for the first time during pregnancy. The degree of protection afforded an infected infant by the presence of antibody in the mother before conception is uncertain. Methods. We compared the outcomes of CMV-infected infants born to mothers who acquired primary CMV infection during pregnancy (primary-infection group) with those of CMV-infected infants born to mothers with immunity (recurrent-infection group). Screening for viruria identified 197 newborns with congenital CMV infection. Stored serum samples were used to categorize maternal infection as either primary or recurrent. We followed 125 infants from the primary-infection group and 64 from the recurrent-infection group. Serial medical, audiologic, psychometric, and eye examinations were used to identify sequelae of CMV infection. Results. Only infants in the primary-infection group had symptomatic CMV infection at birth...

Intrauterine Transmission of Cytomegalovirus to Infants of Women with Preconceptional Immunity

Background Preconceptional immunity against cytomegalovirus (CMV) provides only partial protection against intrauterine transmission of the virus. Whether congenital CMV infection in the offspring of women who are seropositive for CMV can occur after maternal reinfection with a different strain of CMV is unknown. Methods Serum specimens from 46 women with preconceptional immunity against CMV that were obtained during the previous pregnancy and the current pregnancy were analyzed for antibodies against the strain-specific epitopes of CMV glycoprotein H. Virus-neutralizing activity in maternal serum samples was measured against the AD169 laboratory strain of CMV and the CMV isolates available from seven infected infants. In addition, the nucleotide sequences of the glycoprotein H gene from the seven CMV isolates were determined. Results Eleven of the 16 mothers with infected infants (69 percent) had antibodies against the glycoprotein H epitopes present on two laboratory strains of CMV, AD169 and Towne. Ten...

Identification of Proteins in Human Cytomegalovirus (HCMV) Particles: the HCMV Proteome

ABSTRACT Human cytomegalovirus (HCMV), a member of the herpesvirus family, is a large complex enveloped virus composed of both viral and cellular gene products. While the sequence of the HCMV genome has been known for over a decade, the full set of viral and cellular proteins that compose the HCMV virion are unknown. To approach this problem we have utilized gel-free two-dimensional capillary liquid chromatography-tandem mass spectrometry (MS/MS) and Fourier transform ion cyclotron resonance MS to identify and determine the relative abundances of viral and cellular proteins in purified HCMV AD169 virions and dense bodies. Analysis of the proteins from purified HCMV virion preparations has indicated that the particle contains significantly more viral proteins than previously known. In this study, we identified 71 HCMV-encoded proteins that included 12 proteins encoded by known viral open reading frames (ORFs) previously not associated with virions and 12 proteins from novel viral ORFs. Analysis of the relative abundance of HCMV proteins indicated that the predominant virion protein was the pp65 tegument protein and that gM rather than gB was the most abundant glycoprotein. We have also identified over 70 host cellular proteins in HCMV virions, which include cellular structural proteins, enzymes, and chaperones. In addition, analysis of HCMV dense bodies indicated that these viral particles are composed of 29 viral proteins with a reduced quantity of cellular proteins in comparison to HCMV virions. This study provides the first comprehensive quantitative analysis of the viral and cellular proteins that compose infectious particles of a large complex virus.

Symptomatic congenital cytomegalovirus infection : neonatal morbidity and mortality

Knowledge of the natural history of symptomatic congenital cytomegalovirus (CMV) infection in the newborn is essential in order to anticipate complications and assess the potential benefit from antiviral therapy. To define the disease course we reviewed data on 106 neonates with symptomatic congenital CMV infection diagnosed and managed by the investigators. Petechiae, jaundice and hepatosplenomegaly were each noted in 70% or more patients. Microcephaly was noted in 54 of 102 (53%) at birth. Elevated alanine aminotransferase, conjugated hyperbilirubinemia and thrombocytopenia were seen in 83, 81 and 77%, respectively. Eighty-six percent had at least two of the manifestations highly suggestive of congenital infection. Platelet count fell to its nadir during the second week of life whereas elevated alanine aminotransferase and direct bilirubin persisted past the first month. In spite of the difficulty in assessing central nervous system function in the newborn, evidence of damage was present in the majority. Seventy-two had microcephaly, poor suck, lethargy/hypotonia or seizures. Abnormal computerized tomographic scan was present in 16 of 20 (80%) and decreased hearing in 20 of 39 (56%). Cerebrospinal fluid protein was greater than 120 mg/dl in 24 of 52 (46%) and this elevation was associated with neurologic abnormalities as well as hearing loss. The mean length of hospital stay was 13 and 22.4 days for term and preterm infants, relatively. Thirteen infants (12%) died during the first 6 weeks of life. Disseminated CMV infection with multiorgan involvement was evident in 7 of 9 at postmortem examination. We conclude that neonates with symptomatic congenital CMV infection have a multi-system disease with significant morbidity and mortality.

Progressive and fluctuating sensorineural hearing loss in children with asymptomatic congenital cytomegalovirus infection

OBJECTIVE To determine the prevalence and temporal changes of sensorineural hearing loss (SNHL) among children with clinically inapparent (asymptomatic) congenital cytomegalovirus (CMV) infection identified from a cohort of newborn infants screened for congenital CMV infection. METHODS The study population consisted of 307 children with documented asymptomatic congenital CMV infection, 76 uninfected siblings of children with asymptomatic congenital CMV infection, and 201 children whose neonatal screen for congenital CMV infection showed negative results. Audiologic evaluations were completed for all children to determine their hearing status. RESULTS SNHL occurred only in children with congenital CMV infection. Of the children with asymptomatic congenital CMV infection, 22 (7.2%; 95% confidence interval, 4.5% to 10.6%) had SNHL. Among the children with hearing loss, further deterioration of hearing occurred in 50.0%, with the median age at first progression at 18 months (range, 2 to 70 months). Delayed-onset SNHL was observed in 18.2% of the children, with the median age of detection at 27 months (range, 25 to 62 months). Fluctuating SNHL was documented in 22.7% of the children with hearing loss. CONCLUSIONS Asymptomatic congenital CMV infection is likely a leading cause of SNHL in young children. The continued deterioration of hearing and delayed onset of SNHL in these children emphasizes the need for continued monitoring of their hearing status.

Symptomatic Congenital Cytomegalovirus Infection in Infants Born to Mothers With Preexisting Immunity to Cytomegalovirus

Objectives. To determine the frequency of symptomatic congenital cytomegalovirus (CMV) infection in the offspring of women with a recurrent maternal CMV infection and to characterize the demographic and newborn findings. Methods. Study subjects consisted of infants with symptomatic congenital CMV infection identified by a newborn virologic screening program at the University of Alabama Hospital between 1991 and 1997 and were enrolled in a long-term follow-up study. Maternal infections were categorized by an analysis of archival serum specimens collected before pregnancy and at the time of delivery. Demographic data and clinical findings at birth were collected from maternal and newborn hospital records and from parents at the time of initial evaluation. Results. Of the 47 infants with symptomatic congenital CMV infection identified during the study period, 8 were born to mothers with a confirmed nonprimary or recurrent CMV infection. The type of maternal infection could be ascertained in only ∼43% (20/47) of the children with symptomatic congenital CMV infection born at the University of Alabama Hospital during the study period. There were no significant differences in demographic characteristics of the recurrent infection group and the infants who were born to mothers with either primary CMV infection during pregnancy or unclassified maternal infection. Similarly, the range of severity of clinical abnormalities during the newborn period did not differ in the two groups of children. Furthermore, there were no significant differences in the incidence of sequelae at long-term follow-up in the two groups of children. Conclusions. Symptomatic congenital CMV infection can occur after a nonprimary or recurrent maternal infection. However, the exact incidence of symptomatic congenital CMV infection among children born to women with preexisting immunity remains to be defined.

Accumulation of Virion Tegument and Envelope Proteins in a Stable Cytoplasmic Compartment during Human Cytomegalovirus Replication: Characterization of a Potential Site of Virus Assembly

ABSTRACT The assembly of human cytomegalovirus (HCMV) is thought to be similar to that which has been proposed for alphaherpesviruses and involve envelopment of tegumented subviral particles at the nuclear membrane followed by export from the cell by a poorly defined pathway. However, several studies have shown that at least two tegument virion proteins remain in the cytoplasm during the HCMV replicative cycle, thereby suggesting that HCMV cannot acquire its final envelope at the nuclear envelope. We investigated the assembly of HCMV by determining the intracellular trafficking of the abundant tegument protein pp150 (UL32) in productively infected human fibroblasts. Our results indicated that pp150 remained within the cytoplasm throughout the replicative cycle of HCMV and accumulated in a stable, juxtanuclear structure late in infection. Image analysis using a variety of cell protein-specific antibodies indicated that the pp150-containing structure was not a component of the endoplasmic reticulum, (ER), ER-Golgi intermediate compartment, cis or medial Golgi, or lysosomes. Partial colocalization of the structure was noted with thetrans-Golgi network, and it appeared to lie in close proximity to the microtubule organizing center. Two additional tegument proteins (pp28 and pp65) and three envelope glycoproteins (gB, gH, and gp65) localized in this same structure late infection. This compartment appeared to be relatively stable since pp150, pp65, and the processed form of gB could be coisolated following cell fractionation. Our findings indicated that pp150 was expressed exclusively within the cytoplasm throughout the infectious cycle of HCMV and that the accumulation of the pp150 in this cytoplasmic structure was accompanied by at least five other virion proteins. These results suggested the possibility that this virus-induced structure represented a cytoplasmic site of virus assembly.

Specific localisation of human cytomegalovirus nucleic acids and proteins in human colorectal cancer

BACKGROUND Colorectal cancer is the second most frequent cause of death from cancer in the USA, and most tumours arise sporadically with no clear cause or genetic predisposition. Human cytomegalovirus is a beta-herpesvirus that is endemic in the human population and can cause life-threatening disease in immunosuppressed adults. In vitro, human cytomegalovirus can transform cells and dysregulate many cellular pathways relevant to colon adenocarcinoma pathogenesis, especially those affecting the cell cycle, mutagenesis, apoptosis, angiogenesis, and cyclo-oxygenase-2 (COX-2) expression. We aimed to assess whether gene products of human cytomegalovirus could be detected in colorectal cancers. METHODS We obtained formalin-fixed, paraffin-embedded pathological specimens of colorectal polyps, adenocarcinomas, and adjacent normal mucosa from 29 patients. To detect human cytomegalovirus proteins and nucleic acids, we used immunohistochemistry with two different monoclonal antibodies, in-situ hybridisation, and PCR with DNA sequencing. FINDINGS Human cytomegalovirus proteins IE1-72 and pp65 were detected in a tumour cell-specific pattern in 14 (82%) of 17 and seven (78%) of nine colorectal polyps, respectively, and 12 (80%) of 15 and 11 (92%) of 12 adenocarcinomas, respectively, but not in adjacent non-neoplastic colon biopsy samples from the same patients (none of seven and none of two, respectively). Human cytomegalovirus infection of colon-cancer cells (Caco-2) in vitro resulted in specific induction of Bcl-2 and cyclo-oxygenase-2 proteins, both of which are thought to contribute to progression of colon cancer. INTERPRETATION Human cytomegalovirus nucleic acids and proteins can be found that specifically localise to neoplastic cells in human colorectal polyps and adenocarcinomas, and virus infection can induce important oncogenic pathways in colon-cancer cells.

Ganciclovir Treatment of Symptomatic Congenital Cytomegalovirus Infection: Results of a Phase II Study

Congenital cytomegalovirus (CMV) infection occurs in approximately 1% of newborns in the United States. A phase II evaluation was done of ganciclovir for the treatment of symptomatic congenital CMV infection. Daily doses of 8 or 12 mg/kg were administered in divided doses at 12-h intervals for 6 weeks. Clinical and laboratory evaluations sought evidence of toxicity, quantitative virologic responses in urine, plasma drug concentrations, and clinical outcome. A total of 14 and 28 babies received 8 and 12 mg/kg/day, respectively. Five additional babies received ganciclovir on a compassionate plea basis. Significant laboratory abnormalities included thrombocytopenia (< or = 50,000/mm3) in 37 babies and absolute neutropenia (< or = 500 mm3) in 29 babies. Quantitative excretion of CMV in the urine decreased; however, after cessation of therapy, viruria returned to near pretreatment levels. Hearing improvement or stabilization occurred in 5 (16%) of 30 babies at 6 months or later, indicating efficacy.

A Subunit Cytomegalovirus Vaccine Based on Recombinant Envelope Glycoprotein B and a New Adjuvant

A phase I randomized, double-blind, placebo-controlled trial was done with a cytomegalovirus (CMV) vaccine based on the envelope glycoprotein, gB, combined with a novel adjuvant, MF59. Participants received CMV gB vaccine with MF59 or CMV gB with alum or placebo at 0, 1, and 6 months. A fourth vaccine was given at 12 months to a subgroup. Levels of neutralizing antibody and antibody to gB 2 weeks after the third dose of vaccine exceeded those in seropositive control subjects. the formulation with MF59 was more immunogenic than that with alum. The optimal dose of gB appeared to be between 5 and 30 microg. The fourth dose produced a prompt rise in antibody level. There were no serious adverse events associated with vaccine. Local and systemic reactions were generally mild and, except for pain at the injection site, occurred with similar frequency in recipients of placebo and CMV vaccine.