Showing papers on "Human cytomegalovirus published in 1985"
TL;DR: The HCMV enhancer, which seems to have little cell type or species preference, is severalfold more active than the SV40 enhancers, a property that makes it a useful component of eukaryotic expression vectors.
1,336 citations
TL;DR: This observation specifically identifies lymphocytes as a cell population involved in natural HCMV infection and suggests that lymphocytes may be a reservoir for maintaining infection and may also serve as a vehicle for its spread by blood transfusion.
Abstract: In situ hybridization was used to detect human cytomegalovirus (HCMV) in the peripheral blood mononuclear cells of some naturally infected (seropositive) individuals. A subpopulation of cells hybridized specifically to a portion of the HCMV genome that is heavily transcribed during the immediate-early period of infection. The hybridization signal was markedly reduced by base hydrolysis and ribonuclease, and therefore the probe appears to be detecting viral RNA. A fluorescence-activated cell sorter was used to select lymphocytes bearing the OKT4 and OKT8 markers. Hybridization with the HCMV probe revealed a higher proportion of positive cells in the OKT4 than in the OKT8 subset. This observation specifically identifies lymphocytes as a cell population involved in natural HCMV infection and suggests that lymphocytes may be a reservoir for maintaining infection and may also serve as a vehicle for its spread by blood transfusion.
345 citations
TL;DR: The authors of as mentioned in this paper found that BW B759U-triphosphate accumulated in HCMV-infected cells with time; the rate of this increase was dependent upon the drug dose and virus multiplicity of infection.
Abstract: 9-[( 2-Hydroxy-1-(hydroxymethyl)ethoxy]-methyl)guanine (BW B759U) is a more potent inhibitor of human cytomegalovirus (HCMV) in vitro than is the related nucleoside analog acyclovir (ACV). BW B759U was selectively activated to the 5'-triphosphate (BW B759U-triphosphate) in cells infected with HCMV to levels at least 10-fold higher than those measured for ACV-triphosphate and up to as much as 100-fold higher than the levels found in uninfected cells. BW B759U-triphosphate accumulated in HCMV-infected cells with time; the rate of this increase was dependent upon the drug dose and virus multiplicity of infection. Enzyme activities that catalyzed the phosphorylation of thymidine and 2'-deoxycytidine increased 3- to 7-fold in extracts of cells early after HCMV infection but thereafter declined. No concomitant increase in the rate of BW B759U phosphorylation was detected under these assay conditions. Maximal rate of accumulation of both BW B759U-triphosphate and ACV-triphosphate after a short exposure to drug occurred in the late phase of the infective cycle, as the titer of extracellular virus reached a peak in untreated cultures, but after the decline of stimulated host deoxypyrimidine kinase activities. Once formed, the BW B759U-triphosphate pool decreased very slowly and thus it persisted for several days in both HCMV-infected and uninfected cells.
215 citations
TL;DR: DHPG was significantly more active than acyclovir against all but one of the strains tested, with 50% effective doses ranging from 5 to 13 microM, as determined by plaque reduction assays in human embryonic lung (MRC-5) and human embryonic tonsil cells.
Abstract: The activities of the purine acyclic nucleoside 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG) against two human and five animal strains of cytomegalovirus were compared with those of acyclovir. DHPG was significantly more active than acyclovir against all but one (mouse cytomegalovirus) of the strains tested, with 50% effective doses ranging from 5 to 13 microM, as determined by plaque reduction assays in human embryonic lung (MRC-5) and human embryonic tonsil cells. Both DHPG and acyclovir inhibited virus replication at concentrations considerably lower than those necessary to inhibit cell proliferation. In mode-of-action studies, the triphosphates of DHPG and acyclovir inhibited human cytomegalovirus DNA polymerase. DHPG phosphorylation to the active triphosphate was enhanced in infected cells; however, this enzymatic activity was unrelated to thymidine kinase. In animal studies, DHPG was slightly more effective than acyclovir in reducing mouse cytomegalovirus-induced mortality.
125 citations
TL;DR: It is demonstrated that HCMV is a competent helper virus for the complete replication of AAV and HCMv and AAV were synergistic in their cytopathic effects on cells, suggesting the possibility that AAV may play a role in the pathogenicity of H CMV infections.
111 citations
TL;DR: It is shown that infection of human monocytes with the AD169 strain of HCMV abrogates their production of interleukin 1 (IL-1) activity, which may account, at least in part, for the previously observed immunosuppressive properties of H CMV.
Abstract: It has previously been shown that human cytomegalovirus (HCMV) can exert immunosuppressive effects, and it has been suggested that these may be mediated by monocytes, although the mechanism is unclear. We showed that infection of human monocytes with the AD169 strain of HCMV abrogates their production of interleukin 1 (IL-1) activity. This was associated with the release from infected monocytes of an inhibitor of IL-1 activity which was also released after HCMV infection of the U937 macrophage-like cell line. The inhibitor of IL-1 activity is a protein with an apparent molecular weight of ca. 95,000. This action of HCMV strain AD169 was virus specific and required infectious virus but occurred without virus replication or detectable expression of viral proteins. This effect may account, at least in part, for the previously observed immunosuppressive properties of HCMV.
82 citations
79 citations
Journal Article•
TL;DR: It is suggested that single proteins of HCMV such as H CMVgp64 are capable of inducing T cell responses and may be important in the development of immune reactivity to HCMv.
Abstract: Human cytomegalovirus contains approximately 30 to 35 structural polypeptides. Although antibodies to several of these proteins are made during natural infection, their relationship to T cell recognition of this virus and subsequent control of infection is poorly understood. We have purified one of these proteins (HCMVgp64) that is found in abundance in infected cell lysates in order to delineate the relationship of single viral proteins to the immune response caused by the virus. HCMVgp64 induced T cell reactivity only in individuals with serologic evidence of past infection. In addition, HCMVgp64 elicited similar in vitro immune reactions as the whole virus including T cell proliferation, interleukin 2 production, and receptor expression as well as interferon production. These studies suggest that single proteins of HCMV such as HCMVgp64 are capable of inducing T cell responses and may be important in the development of immune reactivity to HCMV.
56 citations
Journal Article•
TL;DR: Human cytomegalovirus infection is a very common lifelong infection in South Africa, with intermittent periods of silent reactivation, and is an important but rare cause of congenital disease involving especially hearing and neurological deficits.
Abstract: Human cytomegalovirus (CMV) infection is a very common lifelong infection in South Africa, with intermittent periods of silent reactivation. Infection is spread by intimate contact with infected body fluids (urine, saliva, milk, semen and blood) and most commonly takes place silently in childhood. Clinical disease is rare but may be associated with one or more of the following: (i) a large dose of virus; (ii) a primary infection; and (iii) infection at a time of poor or impaired cellular immunity (developing fetus, after organ transplantation). CMV is an important but rare cause of congenital disease involving especially hearing and neurological deficits. It is often found after organ transplantation but its precise role is not clear. Interpretation of cytomegalovirus tests in connection with an undiagnosed illness is rendered very difficult by the ubiquitous, silently reactivating nature of the virus in both health and disease. An aetiological role is easily assumed but not easily proved.
42 citations
TL;DR: This article showed that retinoic acid did not induce a permissive state in human embryonal carcinoma (EC) cells, but HCMV did replicate in some of the differentiated cells arising following the exposure of TERA-2-derived human EC cells to retINOic acid.
Abstract: Summary
Whereas human cytomegalovirus (HCMV) did not replicate in human embryonal carcinoma (EC) cells, it did replicate in some of the differentiated cells arising following the exposure of TERA-2-derived human EC cells to retinoic acid. On the other hand, retinoic acid did not induce a permissive state in several other diverse human cell lines, including an EC line, 2102Ep, which did not differentiate in response to this agent. Also, both TERA-2 and 2102Ep EC cells differentiated to a limited extent when grown at low cell density and a few of these cells became permissive for HCMV. Thus, susceptibility is the result of differentiation and not due to a direct effect of retinoic acid on viral replication. The nature of the block to HCMV replication in human EC cells is unknown, but viral DNA could be detected in the nucleus within an hour of infection and there was an increased anchorage-independent growth of undifferentiated and differentiated cells following HCMV infection. Viral replication is not subject to a general block in these cells, since another herpesvirus, herpes simplex virus type 1, replicated well.
37 citations
TL;DR: In this paper, human cytomegalovirus (HCMV) cloned EcoRI fragments R and b hybridized strongly, under standard highstringency conditions, to uninfected cellular DNA of human, murine, or sea urchin origin.
Abstract: Human cytomegalovirus (HCMV) cloned EcoRI fragments R and b hybridized strongly, under standard high-stringency conditions, to uninfected cellular DNA of human, murine, or sea urchin origin. Less hybridization was detected with fragments, A, C, E, WL(F), WN(H), I, M, O, P, Q, V, c, d, and e. Southern blot analysis of the HCMV-related human DNA localized the major sites of hybridization of HCMV EcoRI fragments R, b, and d to defined regions of the 28S rRNA gene.
TL;DR: An in situ assay employing a biotin-labelled probe and fluorescein-conjugated avidin to detect CMV DNA in cultured cells is described.
Patent•
21 May 1985TL;DR: In this paper, a subunit vaccine employing glycoprotein A of human cytomegalovirus or fragments thereof was provided for inoculation of immunosuppressed infants and women of childbearing age.
Abstract: A novel subunit vaccine employing glycoprotein A of human
cytomegalovirus or fragments thereof is provided. The vaccine is
particularly suitable for inoculation of immunosuppressed indi
viduals and women of childbearing age to inhibit the transmission
of hCMV to the fetus.
TL;DR: The results suggest that the enhancing effect by DMSO is primarily expressed through some host cellular function(s) and the early stages in virus growth cycle are most likely under control by D MSO action.
TL;DR: This work has cloned and characterized subgenomic EcoRI fragments representative of the entire genome of HCMV strain AD169 and demonstrates how cloned molecular probes can be used to study the molecular biology, pathogenesis, and treatment of viral infections.
Abstract: Hybridization assays provide a sensitive and rapid means for studying the molecular biology of viral replication and for identifying viral nucleic acid in biological specimens. Such assays are attractive because the detection of virus does not require intact virions or concomitant viral protein synthesis, both of which may be absent in a latently infected cell or in a virus-associated tumor. For molecular and clinical studies on human cytomegalovirus (HCMV), we have cloned and characterized subgenomic EcoRI fragments representative of the entire genome of HCMV strain AD169. To study the epidemiology of HCMV infections and to identify the presence of HCMV nucleic acid in urine, blood, Kaposi's sarcoma, and other tissues, we have used various hybridization techniques, including DNA dot/slot-blot hybridization, Southern blot hybridization, and in situ cytohybridization. These studies demonstrate how cloned molecular probes can be used to study the molecular biology, pathogenesis, and treatment of viral infections.
TL;DR: A monospecific, polyclonal antiserum to the 69-kDa matrix protein of human cytomegalovirus (HCMV) was prepared in a guinea pig and indicates that it is concentrated in the nucleoplasm rather than within the intranuclear inclusions.
TL;DR: A number of liquid- and solid-phase immunoassays have been developed, of which immunofluorescence and ELISA are most commonly used, besides complement fixation and passive haemaglutination, which allow an exact epidemiological identification of risk groups for CMV infection.
Abstract: Cytomegalic inclusion disease (CID) is caused by a horizontally or vertically transmitted human herpes virus infection and may persist for life without obvious clinical symptoms. A serious course of horizontal primary and recurrent infections, however, is often observed in immunocompromised persons such as recipients of organ transplants and patients receiving fresh blood transfusions. Vertical infection may cause fetopathies. The human cytomegalovirus (HCMV) is thought to inherit an oncogenic potential as lately discussed for AIDS and M. Kaposi. Laboratory diagnosis of HCMV infection is performed by light microscopy (inclusion bodies), electron microscopy, virus isolation in cell culture, demonstration of viral DNA and antigen in clinical specimens, by histochemical methods (e.g. immunoperoxidase technique) and by DNA and peptide analysis for identification of different isolates and viral finger prints. Evaluation of cell-mediated immunity in HCMV infection is performed quantitatively (assessment of Thelper/Tsuppressor ratios) or qualitatively (specific lymphocyte stimulation by the antigen). In most cases laboratory diagnosis is achieved by serological methods, i.e. demonstration and quantitation of HCMV-specific antibodies. In this context, a number of liquid- and solid-phase immunoassays have been developed, of which immunofluorescence and ELISA are most commonly used, besides complement fixation and passive haemaglutination. These procedures on the one hand allow the use of different antigen preparations as early and late viral proteins, and on the other hand permit a specific determination of different Ig classes and subclasses. A variety of assays has been established especially for determination of virus-specific IgM antibodies, which are predominantly found in active infection. These, however, at least in part may show non-specific results caused by interference of rheumatoid factor or IgG competition. Such problems have now been dealt with and are avoided by IgG precipitation or IgM immunosorption (“μ-capture” technique). These recent methods allow an exact epidemiological identification of risk groups for CMV infection. Results from our laboratory revealed 13% HCMV-IgM positive patients among pregnant women, 16% IgM positive patients among renal transplant recipients, 4% igM positive cases in patients after cardiosurgery and 1.7% IgM positives among prostitutes. The prevalence of HCMV infection as indicated by specific IgG antibodies was 56%, 90%, 83%, and 90%, respectively. No IgM antibodies were found in haemophiliacs and healthy blood donours, which showed a prevalence of HCMV infection in 69% and 47% of tested serum samples.
TL;DR: Molecular epidemiology of cytomegalovirus infections in women and their infants and the postperfusion syndrome in premature twin infants and their mother and a longitudinal study of blood donors are studied.
TL;DR: It is concluded that nucleic acid hybridizations at high sensitivity with moleculary cloned HCMV DNA did not support the notion of a correlation between colorectal carcinomas and human cytomegalovirus.
Abstract: Numerous studies had linked human cytomegalovirus (HCMV) infections with neoplasia. Among various other malignant tumors, colonic carcinoma tissues were reported to contain DNA sequences hybridizing with DNA extracted from virus particles. Gene technology allowed us to use a cloned viral DNA library to measure HCMV in colorectal tumors more specifically. Four of 38 tissue specimens did contain DNA sequences homologous to cloned viral DNA probes; however, in each of those cases, identical hybridization patterns were seen with specimens from non-infiltrated surrounding intestinal wall. The amount of HCMV DNA in normal tissues was at least as much as in tumor biopsies. We conclude that nucleic acid hybridizations at high sensitivity with moleculary cloned HCMV DNA did not support the notion of a correlation between colorectal carcinomas and human cytomegalovirus.
TL;DR: Postmortem human brain extracts were examined for the presence of human cytomegalovirus DNA by molecular hybridization using a dot blot technique and it was not able to confirm the report that CMV is present in the brains of patients with Huntington's chorea, nor was CMV detected in the temporal cortex of brains from schizophrenic patients.
Abstract: Postmortem human brain extracts were examined for the presence of human cytomegalovirus (CMV) DNA by molecular hybridization using a dot blot technique. The method was able to detect picogram quantities of homologous DNA, but CMV specific hybridization was detected in only one of 83 brains examined. The positive case came from a patient who had received immunosuppressive therapy. We were not able to confirm the report that CMV is present in the brains of patients with Huntington's chorea, nor was CMV detected in the temporal cortex of brains from schizophrenic patients. Our findings are discussed in relation to the methodology for investigating a possible viral etiology of some neuropsychiatric diseases.
TL;DR: Investigation of the effect of heat shock on lymphoblastoid cell lines Raji and P3HR1 harbouring Epstein-Barr virus genomes and on Vero cells abortively infected with human cytomegalovirus found an approximately fourfold increase in the number of cells exhibiting early nuclear antigens and in the appearance of HCMV-induced Fc receptors.
Abstract: Summary
The effect of heat shock was investigated on lymphoblastoid cell lines Raji and P3HR1 harbouring Epstein-Barr virus (EBV) genomes, and on Vero cells abortively infected with human cytomegalovirus (HCMV). A heat shock at 44 °C for 10 min induced the appearance of EBV early antigens in Raji cells and increased the percentage of cells expressing EBV viral capsid antigens in P3HR1 cells. Heat shock performed on Vero cells just before HCMV infection resulted in an approximately fourfold increase in the number of cells exhibiting early nuclear antigens, and in the appearance of HCMV-induced Fc receptors.
TL;DR: A monoclonal antibody against human cytomegalovirus (HCMV) which recognizes a structural protein of 28 000 mol.
Abstract: Summary
We have produced a monoclonal antibody against human cytomegalovirus (HCMV) which recognizes a structural protein of 28 000 mol. wt. which is present in both the cytoplasm of infected cells during the late phase of the viral replication cycle and in the extracellular viral particles. This antigen was detected in all HCMV strains assayed and reacted with human sera having anti-HCMV antibodies.
TL;DR: The degree of relatedness between previously identified cross-hybridizing regions within human cytomegalovirus strain AD169 and the avian retrovirus oncogene v-myc were investigated by nucleotide sequence comparison and found that the homologous regions are limited to short G + C-rich regions in each genome.
Abstract: The degree of relatedness between previously identified cross-hybridizing regions within human cytomegalovirus strain AD169 and the avian retrovirus oncogene v-myc were investigated by nucleotide sequence comparison. We found that the homologous regions between the human cytomegalovirus genome and v-myc are limited to short G + C-rich regions in each genome and that the human cytomegalovirus genome shares little or no homology with the human c-myc gene.
TL;DR: It is indicated that acute MCMV infection of mice causes abnormalities in T-lymphocyte subset ratios and responsiveness to mitogen similar to the abnormalities observed in human cytomegalovirus infections.
Abstract: To study the effects of cytomegalovirus infection on T-lymphocyte subpopulations, we determined helper (Lyt 1.2) and suppressor (Lyt 2.2) T-lymphocyte subset numbers using monoclonal antibodies and measured lymphocyte responsiveness to mitogen during sublethal murine cytomegalovirus (MCMV) infection of 3-wk-old Balb/c mice. MCMV-infected mice had reduced Lyt 1.2 to Lyt 2.2 T-lymphocyte ratios on days 1, 3, 5, and 9 of infection. Alterations in T-lymphocyte subsets were accompanied by diminished lymphocyte response to concanavalin A. Lymphocyte responsiveness and Lyt 1.2 to Lyt 2.2 ratios were maximally reduced on day 5 of MCMV infection and correlated strongly with peak virus recovery from spleen, bone marrow, and peripheral blood leukocytes. These results indicate that acute MCMV infection of mice causes abnormalities in T-lymphocyte subset ratios and responsiveness to mitogen similar to the abnormalities observed in human cytomegalovirus infections. MCMV infection of mice is a useful model to study the mechanism by which cytomegalovirus infections induce altered T-lymphocyte subpopulations.
TL;DR: Differential hormonal enhancement of CMV replication in vitro suggests a possible mechanism for the increased incidence ofCMV infection observed during human pregnancy.
Abstract: The frequency of human cytomegalovirus (CMV) excretion during pregnancy denoting active infection has been demonstrated to increase as gestation advances and at term involves a significant percentage of women This increase enhances the risk of congenital infection of the fetus Thus it appears that some factor(s) unique to the condition of pregnancy favors susceptibility to maternal CMV infection We designed our studies to investigate the possible association of the continuously rising levels of selected hormones and this increased susceptibility Progesterone, 17 beta-estradiol, and cortisol were added to tissue culture media in final concentrations to match those occurring in term pregnancy serum Two strains of human foreskin cells, one neonatal and the other fetal, were treated with either single or paired combinations of hormone-containing media Lytic CMV replication in neonatal foreskin cells was enhanced by a maximum of 57-fold when these cells were treated with cortisol Such enhancement did not occur in the fetal cells No synergistic effects were seen when cortisol was used in combination with other hormones nor when neonatal foreskin cells were replicated for at least three generations in either single or paired combinations of hormones prior to use Differential hormonal enhancement of CMV replication in vitro suggests a possible mechanism for the increased incidence of CMV infection observed during human pregnancy
01 Jan 1985
TL;DR: At least four human herpesviruses, herpes simplex virus types 1 and 2, human cytomegalovirus (HCMV), and Epstein—Barr virus (EBV), have been implicated in the etiology of human neoplasia.
Abstract: The herpesviruses comprise one of the most diverse groups of DNA-containing viruses. Although the details of their replication cycles significantly differ, viruses within this family share not only physical characteristics but also the same range of host cell—virus interactions. Infection of cells in culture with any of the human herpesviruses leads to one of three biological consequencesL lytic growth, latency or persistence, or, less frequently, acquisition of a transformed phenotype. AT the level of the infected host these interactions are manifested as pathogenesis, a reservoir for recurrent infection and potential for malignancy. At least four human herpesviruses, herpes simplex virus types 1 (HSV-1) and 2 (HSV-2), human cytomegalovirus (HCMV), and Epstein—Barr virus (EBV), have been implicated in the etiology of human neoplasia.
TL;DR: Results suggest that ara-FU acts as a bifunctional inhibitor of HCMV replication, and inhibition of viral DNA polymerase by 1-beta-D-arabinofuranosyl-5-fluorouracil-5'-triphosphate becomes more efficient.
Abstract: Four kinds of 1-beta-D-arabinofuranosyl-5-halogenouracil were examined for inhibition of human cytomegalovirus (HCMV) and herpes simplex virus type 1 (HSV-1) and 2 (HSV-2) replication. 1-beta-D-Arabinofuranosyl-5-fluorouracil (ara-FU) was the most effective against HCMV, whereas 1-beta-D-arabinofuranosyl-5-bromouracil was the most effective against HSV-1 and HSV-2. The mechanism of action of ara-FU on HCMV replication was also studied. The dTTP pool size in human embryonic fibroblasts was increased 33-fold by HCMV infection. However, treatment with ara-FU decreased the size of the dTTP pool by approximately 50%. On the other hand, 1-beta-D-arabinofuranosyl-5-fluorouracil-5'-triphosphate inhibited HCMV DNA polymerase activity competitively with dTTP. These results suggest that ara-FU acts as a bifunctional inhibitor of HCMV replication. Ara-FU is phosphorylated by cellular thymidine kinase to 1-beta-D-arabinofuranosyl-5-fluorouracil-5'-monophosphate, which inhibits cellular thymidylate synthetase, which in turn decreases the dTTP pool size in infected cells. As the dTTP pool size is reduced, inhibition of viral DNA polymerase by 1-beta-D-arabinofuranosyl-5-fluorouracil-5'-triphosphate becomes more efficient.
TL;DR: The neutralization titers obtained with this assay on 92 serum samples were in accordance with the immune status as determined by enzyme-linked immunosorbent assay to cytomegalovirus-induced immediate early, early, and late antigens.
Abstract: Human cytomegalovirus induces the appearance of immediate early antigens in infected cells 1 h after infection. This provided the basis for the development of a rapid neutralization assay for cytomegalovirus antibody which was able to yield results within a single day. Indirect immunofluorescence to visualize immediate early antigen-positive cells was applied to the rapid determination of cytomegalovirus-neutralizing antibody. The neutralization titers obtained with this assay on 92 serum samples were in accordance with the immune status as determined by enzyme-linked immunosorbent assay to cytomegalovirus-induced immediate early, early, and late antigens.
TL;DR: The characteristics of four human cytomegalovirus (HCMV)-specific monoclonal antibodies as assessed by ELISA, immunofluorescence, immunoprecipitation and Western blotting are described.
Abstract: Summary
The characteristics of four human cytomegalovirus (HCMV)-specific monoclonal antibodies as assessed by ELISA, immunofluorescence, immunoprecipitation and Western blotting are described. Two antibodies recognized a 67K late polypeptide of HCMV, one recognized 43K and 79K polypeptides present early and late in HCMV-infected cells, and the fourth identified a 72K early nuclear protein of HCMV. The antibodies recognized these antigens in all HCMV isolates tested by immunofluorescence and ELISA, but demonstrated inter-isolate variations in polypeptides recognized by Western blotting.