Mapping and expression of a human cytomegalovirus major viral protein

We constructed a DNA fragment map of low-passage Towne strain cytomegalovirus by analyzing cross-blot hybridization and hybridizations of isolated recombinant clones. The abundant late transcripts were located on this map by hybridization of labeled total RNA of virus-infected cells to blotted DNA fragments. The most abundant late transcript, carried by the 11.7-kilobase EcoRI fragment (EcoRI-G), was precisely mapped. The EcoRI fragment was fragmented and subcloned in a plasmid carrying simian virus 40 sequences (pSV-OH, constructed by Chi-Bom Chae, Department of Biochemistry, University of North Carolina, Chapel Hill). One resulting recombinant plasmid, pHD713SV2, was transferred to simian virus 40-transformed monkey kidney cells (COS-1) by DNA transfection. Synthesis of a cytomegalovirus-specific 67-kilodalton protein was detected in these cells by reaction of blotted proteins with virus-specific monoclonal antibody. The 67-kilodalton protein is a major phosphorylated protein found in virions; it is not glycosylated. The location of the gene for this 67-kilodalton protein is therefore assigned to the center of the L-unique region of human cytomegalovirus, at 0.37 to 0.39 map units.

Nonurban male homosexuals: epidemiologic, immunologic and virologic characteristics

Twenty asymptomatic male homosexuals living in North Carolina were evaluated looking at epidemiologic, immunologic and virologic characteristics. In ten subjects selected for inhalant nitrite use a significantly higher frequency of multiple drug abuse and a trend toward greater sexual promiscuity was found in comparison with ten nonnitrite users. None of the 20 subjects had chronic lymphadenopathy. Cytomegalovirus (CMV) was not found in urine, blood or throat washings, but was found in 29% of the subjects' semen specimens--a finding that was significantly linked (P less than .05) to the presence of CMV IgM antibody in serum. There were no abnormal helper lymphocytes: suppressor T lymphocyte ratios (all greater than 1.3) and lymphocyte mitogen stimulations were not different from heterosexual controls in contrast to frequent abnormalities reported in male homosexuals in metropolitan areas. If these immunologic findings are reproducible, they may be important in understanding why the Acquired Immunodeficiency Syndrome has clustered in large cities.

Porcine ovarian inhibin preparations sensitize cultured ovine gonadotrophs to luteinizing hormone-releasing hormone

Treatment of ovine pituitary cell cultures with an acetone powder of porcine follicular fluid (APPFF; 50 micrograms/ml) decreased FSH secretion 60%, did not alter basal LH secretion, but increased by 2- to 3-fold the effectiveness of LHRH or D-Lys6-LHRH (10(-8) M) in releasing LH. Chromatography of APPFF on Matrex Gel Red A (MGRA) yielded a protein fraction (MGRA-IV) in which both FSH-inhibiting and LHRH-enhancing activities were enriched 8-fold. Both activities were destroyed by trypsin, but both were highly resistant to heat. The apparent mol wt of the active substance(s) was greater than 10,000. The LHRH-enhancing effect of MGRA-IV was reversible and declined, with an apparent half-life of 7 h, when MGRA-IV treatment was discontinued. There was too little estrogen in either APPFF or MGRA-IV to account for any of the activities. These results demonstrate that porcine follicular fluid contains LHRH-enhancing activity along with classical inhibin activity and that both activities may be linked in one molecule. These dual activities may be important in a number of species.

Effects of certain nucleoside analogues on human cytomegalovirus replication in vitro

Four nucleoside analogues, 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-methyluracil (FMAU), -5-iodouracil (FIAU), -5-methylcytosine (FMAC) and -5-iodocytosine (FIAC), were studied for their effect on human cytomegalovirus (HCMV) replication in vitro. FMAU, FIAU, FMAC and FIAC showed antiviral activities for four strains of HCMV (Major, Clegg, D550 and Towne) in a plaque reduction assay, with a dose required for 50% inhibition (ED50) in the range of 0.1 to 0.65 microM. At a concentration of 1 microM-FMAU or -FIAC, the synthesis of five virus-specific late polypeptides of molecular weights 150 000, 120 000, 67000, 54000 and 27000 was entirely blocked. Quantification of Towne viral DNA synthesis, using complementary RNA-DNA hybridization with a Towne-specific cRNA probe, demonstrated a complete inhibition of HCMV DNA replication at 1 microM of FMAU or FIAC. After the removal of the inhibitors, however, viral DNA synthesis resumed, and infectious virus reappeared, indicating that the inhibition of HCMV replication by these nucleoside analogues was of a virostatic reversible type.

Murine cytomegalovirus-induced congenital defects and fetal maldevelopment

The effects of congenital infection with cytomegalovirus on fetal development were studied by injection of murine cytomegalovirus (MCMV) into the endometrial lumina of mice in the early stages of pregnancy. The mice were later killed, and the sites of embryonic implantation were examined. Litter size was reduced and the incidence of abnormal fetuses was significantly increased among MCMV-infected animals. Morbid, moribund, severely growth-retarded, asynchronously developed, and malformed fetuses were found. Virus was reisolated from infected mothers, placentas, and fetal tissues but not from control animals that had received either heat-inactivated virus or culture medium. The recovered virus was identical to the original virus, as verified by restriction enzyme analysis. MCMV-specific DNA was detected in experimental tissue sections by in situ nucleic-acid hybridization. Seroconversion occurred in infected female mice. Thus, the presence of MCMV in the genital tract at the time of embryonic implantation causes not only embryonic infection but also fetal maldevelopment.

Effect of 9-(1,3-dihydroxy-2-propoxymethyl)guanine on human cytomegalovirus replication in vitro

We studied the effect of a novel purine acyclic nucleoside, 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG), on human cytomegalovirus (HCMV) replication. The susceptibility of HCMV to this drug was monitored in cell culture by plaque reduction assay. HCMV replication of various strains was inhibited to the extent of 50% by 1 to 5 microM DHPG. DHPG was highly specific in its anti-HCMV activity, since at concentrations as high as 100 microM it did not exert any detectable inhibitory effect on uninfected cell macromolecular synthesis and cell growth. At concentrations of 2 to 4 microM, the drug inhibited the synthesis of six virus-specific polypeptides with molecular weights of 200,000 (VP200), 150,000 (VP150), 67,000 (VP67), 54,000 (VP54), 32,000 (VP32), and 27,000 (VP27) up to 96 h after infection. HCMV DNA synthesis was also considerably suppressed at concentrations of 2 to 4 microM DHPG. Upon removal of the inhibitor, however, viral DNA synthesis resumed and infectious virus reappeared, indicating that this inhibition was a virostatic reversible-type inhibition.

Human cytomegalovirus and herpes simplex type 2 virus in normal and adenocarcinomatous prostate glands

Normal prostate, benign prostate hypertrophy (BHP), and prostate adenocarcinoma (ACP) biopsy specimens were analyzed for the presence of human cytomegalovirus (HCMV) and herpes simplex virus type 2 (HSV-2)-specific macromolecules. HCMV DNA homologous sequences were detected in 2 of 13 normal prostate, 2 of 9 BHP, and 3 of 10 ACP tissues, and HSV-2 DNA homologous sequences were found in 1 normal prostate tissue and 2 ACP tissues. In situ DNA-RNA hybridizations indicated HCMV-specific RNA in 3 of 8 BHP and 4 of 9 ACP tissues. No positive in situ hybridization for HCMV RNA was observed in normal prostate tissues. Parallel in situ DNA-RNA hybridization localized HSV-2-specific RNA in only 1 of 8 tumor sections. No HSV-2-specific RNA was observed in sections of normal and BHP tissues. Anticomplement immunofluorescence (ACIF) tests of BHP and ACP specimens showed specific HCMV immunofluorescence in 3 of 8 BHP and 4 of 9 ACP tissues. ACIF results correlate closely with in situ hybridization results and imply some degree of HCMV association with prostatic abnormality. The results also suggest that latent HCMV may be harbored by the human prostate gland.

Unique spectrum of activity of 9-[(1,3-dihydroxy-2-propoxy)methyl]-guanine against herpesviruses in vitro and its mode of action against herpes simplex virus type 1

A guanosine analog, 9-[(1,3-dihydroxy-2-propoxy)methyl]guanine (DHPG), was found to inhibit herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2, cytomegalovirus, and Epstein-Barr virus replication by greater than 50% at concentrations that do not inhibit cell growth in culture. The potency of the drug against all of these viruses is greater than that of 9-[(2-hydroxyethoxy)methyl]guanine (acyclovir). DHPG was active against HSV-1 growth during the early phase of virus replication and had no activity when added at a later time after infection. Its antiviral activity was irreversible. Thymidine partially neutralized its action. The anti-HSV-1 activity of DHPG was dependent on the induction and the properties of virus-induced thymidine kinase. Virus variants that induced altered virus thymidine kinase and became resistant to acyclovir were still as sensitive to DHPG as the parental virus. DHPG is active against five different HSV variants with induced altered DNA polymerase and resistance to acyclovir.

Cytomegalovirus infection of murine testicular interstitial Leydig cells

We studied the susceptibility of mouse testicular interstitial Leydig cells to cytomegalovirus both in vivo and in vitro. The in vivo studies included intratesticular and intraperitoneal infection of 6-week-old mice with murine cytomegalovirus (MCMV); the in vitro studies involved an MCMV-Leydig cell interaction using a Leydig tumor cell line (I-10). MCMV-specific antigens were detected in interstitial Leydig cells in sections of MCMV-inoculated testes by an indirect immunofluorescence test. MCMV DNA was also localized in the same testes cells derived from mice, which received intratesticular and intraperitoneal MCMV inoculations, respectively, by in situ DNA-RNA hybridization. Cytopathic effects were seen in MCMV-infected I-10 cell cultures 2 or more days after exposure to MCMV. The infected cells showed intranuclear inclusions characteristic of cytomegalovirus when stained with May-Grunwald-Giemsa stain. The indirect immunofluorescence test was also positive with MCMV-infected I-10 cells. MCMV DNA was detected in these cells by in situ DNA-RNA cytohybridization, and the presence of viral particles in MCMV-infected I-10 cells was confirmed by electron microscopy. Thus, we conclude that the interstitial Leydig cell is susceptible to MCMV infection both in vivo and in vitro.

Estrogenic and antiestrogenic effects of enclomiphene and zuclomiphene on gonadotropin secretion by ovine pituitary cells in culture

17 beta-Estradiol (E2) alters gonadotropin secretions in ovine pituitary cell cultures by 1) augmenting the LH response to LHRH and 2) inhibiting the basal secretion of FSH. These responses were used to study the estrogenic and antiestrogenic effects of enclomiphene, zuclomiphene, and their commercial mixture, Clomid. In terms of the LH response to LHRH, Clomid and enclomiphene (10(-6) M) acted as E2 antagonists because they blocked the action of E2 (10(-10) M). By themselves they did not alter the LHRH response. Previous studies using rat pituitary cultures showed opposite results, since both enclomiphene and Clomid acted as estrogens in rat cultures. Apparently, species differences are involved. One conclusion from these data, therefore, is that it would be unwise to predict how Clomid acts in any species without direct experimentation. Zuclomiphene (10(-7)--10(-5) M) acted as a E2 agonist, in terms of the LH response to LHRH, because it sensitized cultures to LHRH. Surprisingly, all of the clomiphenes, including zuclomiphene, acted primarily as E2 antagonists when FSH secretion was observed. At a concentration of 10(-6) M, they blocked the inhibitory effects of E2 (10(-10 M) on FSH secretion, but enclomiphene and Clomid also exhibited minor estrogenic action when administered alone. The clear but unexpected role of zuclomiphene as both E2 agonist (as measured by LH secretion) and antagonist (as measured by FSH secretion) suggests that zuclomiphene may be an especially useful compound for dissociating the effects of E2 on FSH and LH in vivo, at least in sheep. Of more theoretical interest is the fact that zuclomiphene can affect two E2-responsive systems oppositely. Both systems appear to reside in the same subset of pituitary cells.

Regulation of beta-chain mRNA of ovine follicle-stimulating hormone by 17 beta-estradiol

17 beta-Estradiol (E2) rapidly and reversibly decreases the synthesis of follicle-stimulating hormone (FSH) in primary dispersed cell cultures of ovine pituitaries. Similarly, E2 also causes a decrease in the messenger RNA for the beta subunit of ovine FSH (FSH beta-mRNA) as measured in an in vitro translation assay. These results are consistent with the concept that E2 directly regulates either transcription of the FSH beta gene or processing of FSH beta-mRNA in sheep. Of additional interest is the observation that pituitary cultures from various species respond differently to E2 in terms of FSH synthesis. For example, E2 stimulates FSH synthesis in rat pituitary cultures, has no effect in similar rabbit cultures, and inhibits FSH synthesis in ovine cultures. Thus, a set of eukaryotic 'mutants' may exist to aid studies of the effect of E2 on FSH synthesis and secretion.

Analysis of the Spodoptera frugiperda Nuclear Polyhedrosis Virus Genome by Restriction Endonucleases and Electron Microscopy

Restriction endonuclease analysis was used to differentiate between four strains of Spodoptera frugiperda nuclear polyhedrosis virus from different geographical areas. In addition, partial denaturation was performed, and a partial denaturation map was constructed for the Ohio strain of this virus.

Restriction endonuclease analysis of cytomegalovirus deoxyribonucleic acid as an epidemiologic tool

The possibility of transmission of cytomegalovirus (CMV) from congenitally infected infants to susceptible medical personnel produces anxiety because the risks have not been defined. A physician conceived her first child while caring for an infant in the intensive care nursery who died with congenital CMV infection. The physician had serologic evidence of active CMV infection confirmed by isolation of virus from multiple sites. She elected to have her pregnancy interrupted. CMV was isolated from the placenta and fetal brain. Restriction enzyme analysis was employed to test all the CMV isolated for genetic relatedness. Virus isolated from the physician and her fetus was identical. The virus from the index nursery infant was different from the strain infecting the physician and her fetus. These data indicate that the physician acquired her virus from a source other than the index infant.

Effect of 9-(2-hydroxyethoxymethyl)guanine on viral-specific polypeptide synthesis in human cytomegalovirus-infected cells

Plaque-forming assay resulted in a 50 percent inhibitory dose by 9-(2-hydroxyethoxymethyl)guanine (acyclovir) against Towne strain human cytomegalovirus (HCMV) of approximately 98 mumol. At the drug concentration of 200 mumol, we did not detect any significant inhibition of viral DNA synthesis by cRNA-DNA hybridization. However, at this drug concentration, the synthesis of at least two viral-specific late polypeptides (150K and 67K) was significantly retarded up to 48 hours after infection, but resumed at 72 hours. These data suggest that acyclovir or its in vivo transformed derivative had a transient effect on viral-specific polypeptide synthesis in HCMV-infected human fibroblasts at a high drug concentration.

Cytomegalovirus and Kaposi's sarcoma in young homosexual men

10 homosexual men with Kaposi's sarcoma (KS) were studied for evidence of cytomegalovirus (CMV) infection. IgG and IgM antibodies to CMV were detected in 9 out of 9 and in 7 out of 9 of these patients, respectively. CMV was recovered from body secretions or peripheral blood of 7 patients. Viral cultures of KS tumour biopsy specimens were negative in 8 out of 8 patients, but CMV RNA was detected by in-situ hybridisation in 2 out of 3 and CMV antigen(s) by immunofluorescence in 6 out of 9. Normal tissue specimens from 3 KS patients were negative for CMV antigen. These observations suggest an association of CMV with KS.

Human cytomegalovirus-associated DNA polymerase and protein kinase activities

Human cytomegalovirus (HCMV), purified exclusively from the extracellular media, contained a DNA polymerase activity in addition to a protein kinase activity. The DNA polymerase expressed its maximum activity in the presence of 5 to 10 mM-MgCl2. The enzyme was able to use effectively activated calf thymus DNA, poly(dA).oligo(dT)12--18 and poly(dC).oligo(dG)12--18 as the template primers. The DNA polymerizing activity was eluted with 0.18 to 0.2 M-KCl from a phosphocellulose column. It was relatively resistant to phosphonoacetic acid inhibition even at a high concentration of 100 micrograms/ml with activated calf thymus DNA as the template primer, but the DNA polymerase activity was totally suppressed at this concentration when poly(dA).oligo(dT)12--18 was used as the template primer. The enzyme activity was inhibited by ammonium sulphate at 0.01 to 0.3 M with either activated calf thymus DNA or poly(dA).oligo(dT)12--18 as the template primer. The protein kinase has maximum activity in the presence of 10 to 20 mM-MgCl2, and preferred virion proteins as phospho-acceptor to protamine sulphate. Histone, caesin and bovine serum albumin (BSA) were found to be poor substrates. The phosphorylated protein pattern of the in vivo [32P]orthophosphate-labelled virions was not identical to that of the in vitro phosphorylated Nonidet P40-dissociated virions, although seven phosphorylated polypeptides did co-migrate in SDS--polyacrylamide gel electrophoresis (SDS--PAGE). Procedures known to solubilize virions showed that the DNA polymerase and protein kinase were internal components of the virion.

Kaposi's sarcoma. IV. Detection of CMV DNA, CMV RNA and CMNA in tumor biopsies

In order to determine whether human cytomegalovirus- (CMV) DNA homologous sequences as well as CMV-specific RNA(s) and antigen(s) exist in tumor biopsies of Kaposi's sarcoma (KS) DNA-DNA reassociation, RNA-DNA in situ cytohybridization and anticomplement immunofluorescence test (ACIF) tests were applied. Three of 10 DNAs extracted from Kaposi sarcoma biopsies contained DNA sequences homologous to radioactively labelled human CMV DNA probe. The amount of CMV DNA in these sarcoma tissues was calculated to range from 0.7 to 1 genome equivalent per diploid cell. The presence of virus-specific RNA was also demonstrated in section from five of 10 tumor biopsies. CMV-determined nuclear antigen(s) CMNA) present in variable degrees were also demonstrated. In contrast, we could not detect any herpes simple virus type II (HSV-2) or Epstein-Barr virus (EBV) DNA sequences in DNA of these tumor biopsies. Furthermore, there were no detectable HSV-2 or EBV-specific RNA or virus-specific antigens in sections of these biopsies. These results provide new lines of evidence for the relationship between CMV and Kaposi's sarcoma.

Infection of mouse ectoplacental cone cells with murine cytomegalovirus

In order to understand the mechanism of congenital cytomegalovirus (CMV) infection, we studied the effect of murine cytomegalovirus (MCMV) on murine ectoplacental cone (EPC) cells in vitro. Cytopathic effects (c.p.e.) were seen in many MCMV-infected EPC cell cultures 5 to 7 days after exposure to MCMV. The infected cells showed intranuclear inclusions characteristic of CMV infection when stained with May-Grunwald-Giemsa. Culture fluids collected from MCMV-infected EPC cells after 4 or more days of culture caused c.p.e. when co-cultivated with mouse embryo fibroblasts (MEF). Employment of the anti-complement immunofluorescence (ACIF) test detected MCMV-specific antigens, in situ hybridization localized MCMV DNA and electron microscopy detected the presence of the viral particles in the MCMV-infected EPC cells. Thus, exposure of EPC cells to MCMV in vitro resulted in a productive infection.

Spodoptera frugiperda Nuclear Polyhedrosis Virus Genome: Physical Maps for Restriction Endonucleases Bam HI and Hin dIII

The physical map for the genome of Spodoptera frugiperda nuclear polyhedrosis virus was constructed for restriction endonucleases Bam HI and Hin dIII. The ordering of the restriction fragments was accomplished by cross-blot hybridization of Bam HI, Hin dIII, and Eco RI fragments. The alignment of the Hin dIII fragments within the Bam HI map was achieved by double digestion with the two restriction endonucleases followed by cross-blot hybridization. The results showed that the viral genome consisted of mainly unique sequences. In addition, the circular nature of the viral genome was reaffirmed.

Cytomegalovirus: detection in human colonic and circulating mononuclear cells in association with gastrointestinal disease

The specificity and strength of the reported association between cytomegalovirus (CMV) and colonic adenocarcinoma were tested by analysis of a consecutive series of surgically resected colons for: CMV-DNA by a DNA-DNA reassociation kinetics (hybridization) procedure; latent virus by co-cultivation of fresh tissue with indicator fibroblasts; and CMV viral antigens by immunofluorescence. Ten of 13 cancer patients whose colonic tissue was able to be examined by all techniques showed evidence of active or prior CMV infection. Four cancer specimens were CMV-DNA (hybridization)- positive; an additional specimen from a cancerous colon was culture-positive. In six instances, CMV DNA was detected in mucosal cells adjacent to colon adenocarcinoma. In tissue from one of three patients with ulcera tive colitis and two of seven patients with other non-neoplastic colonic disease, CMV DNA was also detected. No fresh colonic tissues were demonstrated to have CMV surface or nuclear antigens when examined by immunofluorescence. Culture of peripheral lymphocytes was positive for CMV in three of 14 cancer patients. A CMV specific defect in humoral immunity could not be documented in that most cancer patients, as well as cancer-free patients, exhibited circulating specific antibody to CMV and had a normal capacity for CMV-specific antibody-dependent cellular cytotoxicity. We conclude that CMV, probably in a latent form, is readily detectable in colonic cells of man, including those derived from malignant, pre-malignant and non-malignant tissues. Neither preferential replication in damaged tissue nor carriage of CMV by peripheral lymphocytes homing to gut appear to explain the presence of CMV in colon cells.

Antiestrogens and ovine gonadotrophs: antagonism of estrogen-induced changes in gonadotropin secretions

17 beta-Estradiol (E2) was found to affect gonadotrophs in long term ovine pituitary cell culture in several ways which were easily measured. It inhibited basal FSH secretion and, concomitantly, stimulated LH secretion. High physiological levels of E2 (10(-10) M; 27 pg/ml) were able to elicit about 70% of the maximal responses, and the effects were developed fully between 6-24 h after the addition of E2. In culture, the antiestrogens (AEs) tamoxifen, nafoxidine, and CI-680 antagonized both the inhibitory and stimulatory effects of E2 (10(-10) M) on gonadotropin secretion in a dose-dependent manner, and 10(-6) M AE was fully effective. At concentrations of 10(-6) M or lower, the AEs showed no significant intrinsic estrogenicity. At higher concentrations, the AEs progressively altered gonadotropin secretion in an apparently nonspecific fashion. Preincubations of cultures with AEs (3.3 X 10(-6) M) antagonized E2 action (10(-10) M) for approximately 18-24 h after the removal of AEs. Tamoxifen appeared to be the most potent AE tested. In conclusion, long term ovine pituitary cell cultures have provided a useful in vitro system for testing the biological potencies of AE analogs. AEs appeared to act as pure estrogen antagonists in ovine gonadotrophs.

Detection of cytomegalovirus genomes in human skin fibroblasts by DNA hybridization

A previous isolation of a human cytomegalovirus (CMV) from fibroblasts derived from intact skin of a Charcot-Marie-Tooth disease patient has prompted examination of six blind-coded cultured human skin lines by CMV DNA hybridization. The detection of CMV genome equivalents in three of the lines suggests that, in some cases, intact human skin may be a site of CMV latency.

Cytomegalovirus: genetic variation of viral genomes

Genomic complexity of human CMV is one of the largest among various DNA viruses. With such genome complexity and widespread distribution, even a minimal frequency of mutation will be enough to create a complicated genetic heterogeneity in this virus. The virus genome is relatively stable during subcultivation in tissue culture. Variants with minor modification in restriction enzyme sites do gradually develop. These variants share substantial restriction fragment pattern homology with the parental virus. Virus DNA has a molecular weight of 150 X 10(6) daltons for a complete genome. The DNA contains 2 covalently linked L and S components which are separated by internal inverted repetitious sequences of both terminal-end sequences. L and S components are oriented invertably with 4 isomeric arrangements. No tandem repeated sequences have been found. Based on DNA restriction pattern analysis, we conclude that the majority of recurrent infections represent reactivation of existing latent viruses; however, reinfections by a new virus strain do occur occasionally. By studying virus strains isolated from the consecutive congenitally infected infants and strains from mothers and their congenitally infected offspring, we furthermore conclude that the latent virus in women is relatively stable genetically. Moreover, the virus strains after being transmitted to the offspring are still genetically similar to that of the mothers. As in vitro, spontaneous minor variations occur after the in vivo residence. In a long period of evolution the accumulation of minor variations might create great diversity with major similarity.

Molecular epidemiology of cytomegalovirus infections in women and their infants

We studied cytomegaloviruses (CMV's) isolated from mothers and their children to determine whether recurrent infections and transmission to the fetus in immune women are due to reinfection or reactivaton of endogenous virus. Twenty-one strains of CMV from six mother-baby pairs, from two congenitally infected siblings, and from repeat isolates from four women were examined for genetic relatedness, by means of restriction endonuclease analysis of purified viral DNA. Although CMV's from unrelated persons were always different, strains from five to six congenitally infected babies were identical or very closely related to those from their mothers. Strains from congenitally infected siblings were also concordant, as were repeat isolates form three of four women. Major differences in viral DNA were detected in strains recovered from the same woman or from a mother-baby pair in only two cases. Endogenous CMV appears to be most frequent source of recurrent infection and intrauterine transmission in immune women; reinfection also occurs, but less commonly.

Kaposi's sarcoma and its relationship to cytomegalovirus (CMNV). III. CMV DNA and CMV early antigens in Kaposi's sarcoma

DNA-DNA reassociation kinetics, anti-complement immunofluorescence (ACIF) and ACIF-blocking tests were used to search for cytomegalovirus (CMV) gene products in Kaposi's sarcoma (DS) biopsies and early cell cultures deriving from them. Three of eight tumor biopsies were positive for CMV DNA; two of them at 0.35 genome/cell and one at one copy 25% genome/cell. CMV-related antigens, mainly localized in the nucleus, were found in cryostat sections of seven of 31 tumor biopsies and four of 12 KS cell lines at early passage level. It appears that the antigen is present in a high number of tumor cells, like the Epstein-Barr virus nuclear antigen (EBNA) in EBV-transformed cells. Inevitably, the increasing data concerning the oncogenic potential of CMV lead on to consideration of the increasing evidence of its association with Kaposi's sarcoma, a multiple hemorrhagic sarcoma with an epidemiologic distribution in Africa similar to that of Burkitt's lymphoma.

Isolation of a new strain of cytomegalovirus from explanted normal skin

Forty-three fibroblast cell line were initiated from normal skin biopsies. One cell line from a patient with Charcot--Marie--Tooth disease (CMT) spontaneously developed c.p.e. suggestive of cytomegalovirus (CMV). Characterization of the virus showed it to be a new strain of CMV and the results suggested that skin fibroblasts from CMT patients may carry latent CMV.

Murine cytomegalovirus: detection of latent infection by nucleic acid hybridization technique

The technique of nucleic acid hybridization was used to detect the presence of murine cytomegalovirus (MCMV)-specific deoxyribonucleic acid (DNA) in cell cultures and salivary gland tissues. The presence of approximately 4.5 and 0.2 genome equivalents per cell of MCMV-specific DNA was identified in cultures of salivary (ISG2) and prostate gland (IP) cells, respectively. These cells, derived from animals with experimentally induced latent infections, were negative for virus-specific antigens by immunofluorescence and on electron microscopy revealed no visible evidence of the presence of herpesviruses. A cell line derived from the salivary gland of an uninoculated animal (NSG2) was also found to possess MCMV-specific DNA (0.2 genome equivalents per cell). For this reason, salivary gland tissues from uninoculated animals supplied as "specific pathogen-free" mice by three commercial sources were tested upon arrival for the presence of MCMC-specific DNA. MCMV-specific DNA was detectable in pooled salivary gland extracts from uninoculated animals derived from two commercial sources. All of these animals were seronegative and virus negative by conventional infectivity assays.

Live cytomegalovirus vaccination of renal transplant candidates. A preliminary trial

Significant morbidity and mortality are associated with primary cytomegalovirus infections in renal-transplant recipients. In the hope that immunity to cytomegalovirus could safely be established before transplantation, we vaccinated 12 seronegative renal-transplant candidates with the Towne 125 strain of live human cytomegalovirus. Before transplantation, there were no significant reactions except for erythema and induration at the site of inoculation. All vaccinees seroconverted, and the three patients tested acquired a cytomegalovirus-specific cellular immune response. Ten vaccinees underwent transplantation: Nine have completed at least 3 months of follow-up, and eight retain functioning allografts up to 1 year later. Although cytomegalovirus was isolated from six patients after transplantation, the restriction endonuclease patterns of the viral DNA of four of these isolates differed significantly from those of the vaccine strain. Therefore, it appears that the vaccine strain did not become latent in the host, at least in a form that could be reactivated.

Cytomegalovirus isolation from a chimpanzee with acute demyelinating disease after inoculation of multiple sclerosis brain cells

A strain of cytomegalovirus (CMV) was isolated during the third subcultivation of explants from the left frontal lobe of a chimpanzee that developed paralysis more than 3 years after intracerebral inoculation at birth with brain cell cultures derived from a patient with multiple sclerosis. Another strain of CMV was also isolated from a lymph node culture taken from the same chimp. The isolates, designated MZM-13 and MZM-14, produced a cytopathic effect characteristic for CMV when inoculated into brain, ganglion, or fibroblast cultures of human or simian origin. Infected cells contained characteristic Cowdry A intranuclear as well as intracytoplasmic inclusion bodies, and 100-nm spherical herpes-like virus particles were detected by electron microscopy in the nucleus and cytoplasm of infected cells. Virus was further identified as CMV with convalescent human anti-CMV serum. Complement-fixing antibody to CMV was present at a titer of 1:32 when the acutely ill chimpanzee was sacrificed. No antibody was detected at birth or at 1 or 2 years of age. A newborn chimpanzee inoculated intracerebrally with MZM-13 developed clinically asymptomatic lesions in the central nervous system characterized by acute and chronic inflammation and degeneration of myelin in cranial and spinal nerve roots. Restriction endonuclease analysis of viral deoxyribonucleic acid isolated from these two viruses indicated that MZM-13 and MZM-14 are identical and are closely related to chimpanzee CMV. No similarity in restriction endonuclease fragment patterns was found between MZM virus and the Towne and Clegg strains of human CMV.

Testosterone synthesis by chicken follicular cells

The roles of theca and of granulosa cells in the synthesis of testosterone (T) in ovarian follicle of hens have been studied. Theca cells alone synthesized no progesterone (P), and no or only negligible amounts of T. Granulosa cells, in contrast, without stimulation produced large amounts of P and small amounts of T. When incubated with ovine gonadotrophins, theca cells showed greater response than granulosa cells in synthesizing more T (2- to 2.5-fold increase). Combination of the two follicular cell types decreased synthesis of P, but increased that of T (9- to 17-fold). When 0.1 microgram of ovine luteinizing hormone (oLH) was added to the combined cells, T concentrations increased most dramatically, a 83-fold increase was seen after 12 h of incubation. Theca cells incubated with exogenous P also produced large amounts of T. These results indicated that in hens, theca cells may be the major site of follicular T synthesis, however, theca cells alone cannot synthesize T unless granulosa cells or P were added. It is suggested that granulosa cells may use P as a precursor, and that P is converted to T in the theca cells.

Comparative study of herpes group virus-induced DNA polymerases

A comparative biochemical study of virus-induced DNA polymerases was made among the herpes group viruses: namely, herpes simplex virus (HSV) type 1 and type 2, human cytomegalovirus (HCMV) and varicella-zoster virus (VZV). Although these virus-induced enzymes shared some biochemical properties, they differed in several important aspects. All these virus-induced DNA polymerases could efficiently use poly(dC) . oligo(dG)12--18 and poly(dA) . oligo(dT)12--18 as template-primers. However, in phosphocellulose chromatography, HSV-1- and HSV-2-induced enzymes were eluted at the low concentration of 0.18--0.20 M NaCl and the counterparts of HCMV and VZV were eluted at 0.30--0.32 M. The former two enzymes were more sensitive to lower concentrations of phosphonoacetate and ethyl phosphonoacetate than the latter two enzymes. Moreover, the activity of HSV-1- and HSV-2-specified DNA polymerases was 5 times greater in the presence of 60 mM ammonium sulfate if poly(dA) . oligo(dT)12--18 was used as template-primer, while HCMV- and VZV-induced enzyme activities were only about twice as great under the same conditions. Futhermore, DNase activity was conspicuous in both HSV-1- and HSV-2-infected WI-38 cells, but was not detectable in HCMV- and VZV-infected cells. After storage for 1 year at 4 degrees, the HSV-1-induced DNA polymerase was the most thermostable of the four viral enzymes.

Chromatin pattern consisting of repeating bipartite structures in WI-38 cells infected with human cytomegalovirus

A novel chromatin structural pattern displaying bipartite and oblate ellipsoid structures orderly arranged along a fiber axis has been observed in WI-38 cells infected with human cytomegalovirus. This chromatin type coexists with chromatin fibers showing conventional nucleosomes. Each bipartite-oblate structure is 40 nm in length, about four times as long as an ordinary nucleosome, and the number of these structures per micrometer (11/micrometer) is clearly less than that of typical cellular nucleosomes (32/micrometer).

Genetic analysis of a cytomegalovirus-like agent isolated from human brain

An unusual cytomegalovirus (CMV, strain Colburn) isolated from brain biopsy of a boy with clinical encephalopathy was studied for genetic relatedness to human and simian CMV. Cross-examination of the purified viral DNA by DNA-DNA reassociation kinetics analyses showed more than 90% homology between Colburn virus and simian CMV (strain GR2757) and a lack of detectable homology between Colburn virus and human CMV (strains AD-169 and TW-87). Restriction endonuclease analysis of Colburn DNA showed some similarity of the DNA fragment pattern with that of simian CMV DNA, although the DNA fragment patterns were not identical, and showed no similarity to that of human CMV DNA. The molecular size and density of viral DNA were close to those of simian CMV DNA. The antigenic study, as performed by complement fixation and neutralization tests, showed strong cross-reactivity of Colburn virus to simian GR2757 virus. One-way cross-reaction of Colburn virus to several human CMV isolates (AD-169, Davis, and Town) was detected by complement fixation; this one-way cross-reaction was not obvious in a plaque neutralization test. It was concluded that Colburn is a simian CMV-related virus.

Cytomegalovirus D.N.A. and adenocarcinoma of the colon: Evidence for latent viral infection

The cause of adenocarcinoma of the colon has not been proven and a viral association has not been reported with this disease. A sensitive biochemical technique for the detection of viral nucleic acid was used to determine whether one type of herpesvirus, namely a human strain of cytomegalovirus, was uniquely present in tumour tissue. 24 specimens of colon, obtained at surgery from 14 patients, were analysed by membrane CR.N.A.-D.N.A. hybridisation. 4 of 7 tumours of the colon were definitely positive for C.M.V. D.N.A. (2greater than or equal to 2 genome-equivalents/cell), or repeatedly showed more than 1 genome-equivalent/cell. Macroscopically normal colon 5 cm from the tumour, as well as histologically normal and abnormal colon from a control population with Crohn's disease were uniformly negative for C.M.V. D.N.A., except for 1 specimen which was macroscopically normal tissue from a patient with carcinoma of the colon. Among patients with conditions that predispose to adenocarcinoma of the colon, 1 of 2 patients with familial polyposis and 1 of 3 with ulcerative colitis harboured in their colon greater than or equal to 2 genome-equivalents of C.M.V. D.N.A. per cell, and another ulcerative colitis patient had 1-2 genome-equivalents/cell.

Purification and characterization of varicella-zoster virus-induced DNA polymerase

Infection of WI-38 human fibroblasts with varicella-zoster virus led to the stimulation of host cell DNA polymerase synthesis and induction of a new virus-specific DNA polymerase. This virus-induced DNA polymerase was partially purified and separated from host cell enzymes by DEAE-cellulose and phosphocellulose column chromatographies. This virus-induced enzyme could be distinguished from host cell enzyme by its chromatographic behavior, template specificity, and its requirement of salt for maximal activity. The enzyme could efficiently use poly(dC).oligo(dG)12-18 as well as poly(dA).oligo(dT)12-18 as template-primers. It required Mg2+ for maximal polymerization activity and was sensitive to phosphonoacetic acid, to which host alpha- and beta-DNA polymerase were relatively resistant. In addition, this induced DNA polymerase activity was enhanced by adding 60 mM (NH4)2SO4 to the reaction mixture.

Epstein-Barr virus-associated thymidine kinase

Superinfection of Raji cells with Epstein-Barr virus induced a new thymidine kinase that was distinguishable from both adult and fetal kinases of the host cell by discontinuous electrophoresis on polyacrylamide gels and glycerol gradients.

Human cytomegalovirus genome: partial denaturation map and organization of genome sequences

Contour-length measurements of both nondenatured and partially denatured DNA from purified extracellular human cytomegalovirus indicate that more than one size class of viral DNA is encapsidated. In addition to a size class averaging about 100 x 10(6) daltons, a much less abundant class of larger viral DNA molecules, 150 x 10(6) to 155 x 10(6) daltons, was extracted from purified extracellular virus. As predicted by melting-curve analysis, partial denaturation of human cytomegalovirus DNA generates denaturation maps showing distinctive adenine plus thymidine (A+T)-rich and guanine plus cytosine (G+C)-rich localizations. Alignment of partial denaturation maps of both 100 x 10(6)- and 150 x 10(6)- to 155 x 10(6)-dalton molecules from maximum overlap of common A+T- and G+C-rich zones clearly shows six unique zones contained in a length equal to the longest class, 150 x 10(6) to 155 x 10(6) daltons. However, various alignments of the smaller class of the molecules within the confines of the approximately 100 x 10(6)-dalton-length equivalent are nondistinctive. Of the six unique A+T- and G+C-rich zones, five are linked in a specific sequence and maintain the same relative orientation; these features indicate the absence of major inversions within these zones. The sixth unique zone may occur at either end of this five-zone series, but it was never found at both ends of the same molecule. Additionally, this terminal zone appears to undergo complete inversions at least at one end of the alignment, and perhaps at both. These data indicate that 150 x 10(6)- to 155 x 10(6)-dalton molecules comprise human cytomegalovirus-specific genetic information.

Stimulation of cellular thymidine kinases by human cytomegalovirus

Thymidine kinase (TK) activity in WI-38 and MRC-5 human fibroblasts was analyzed by discontinuous polyacrylamide gel electrophoresis (disc-PAGE) and discontinuous glycerol gradient electrophoresis (disc-GEP) after subculture or human cytomegalovirus (HCMV) infection. Two peaks of TK activity with different relative fraction-of-migration (R(f)) values were resolved by disc-PAGE or disc-GEP in extracts from log-phase and infected cells. Growing WI-38 cells expressed a slowly migrating (R(f) = 0.14 PAGE, R(f) = 0.4 GEP) peak of TK activity, which was partially inhibited by 1.0 mM dCTP, but which retained little activity at pH 4.5. Growing MRC cells also displayed a slowly migrating peak (R(f) = 0.10 PAGE) with similar properties. Both cell types expressed a faster-migrating TK activity (R(f) = 0.45 PAGE, R(f) = 0.7 GEP) in the growing and resting state that was strongly inhibited by 1 mM dCTP but retained 50% activity at pH 4.5. When either cell type was infected with HCMV, there was a rapid and high-level stimulation of the slowly migrating form of TK and a slight stimulation of the faster-migrating form. Two strains of HCMV (AD169 and Town) failed to produce an electrophoretically distinct virus TK in either cell type after infection. TK enzymes were partially purified by disc-GEP from extracts of log-phase WI-38 or AD169-infected WI-38 cells. Characterization of these enzymes with respect to phosphate donor specificity, pH optima, thermostability, and salt inhibition showed the HCMV-stimulated TKs to be of cellular origin.

Congenital cytomegalovirus infection

The overall prevalence of congenital cytomegalovirus infection among the offspring of a highly immune young female population was 2.4 per cent (23 of 939). To ascertain whether the presence of anticytomegalovirus antibodies protects the developing fetus, we examined the offspring of 239 prospectively studied women. Despite substantial levels of preconceptional antibodies, intrauterine cytomegalovirus infection occured in seven of 208 (3.4 per cent) seroimmune women. Three neonates with congenital infection were born to 31 initially seronegative women. All the congenitally infected infants had subclinical involvement. Maternal humoral immunity may not protect the fetus against congenital cytomegalovirus infection. Neutralization kinetics and restriction enzyme analysis with endonucleases (EcoR-1 and HinD 111) demonstrated antigenic and genetic homology between viral strains isolated from two siblings consecutively infected in utero, indicating that repeat maternal infection with the same virus is transmissible to sequential products of conception.

Viral DNA in inflammatory bowel disease. CMV-bearing cells as a target for immune-mediated enterocytolysis

Althouth serological studies have revealed a high incidence and mean titer of antibody to cytomegalovirus (CMV) in some patients with inflammatory bowel disease, electron microscopy has not confirmed the presence of mature virus in diseased tissue. Sensitive biochemical techniques for detection of viral nucleic acid were applied therefore to test the proposed disease-virus association. Membrane cRNA-DNA hybridization showed that CMV DNA was not detectable in 3 cases of Crohn's disease, nor was it present in 3 or 4 cases of ulcerative colitis examined. Five tissue specimens taken 5 cm away from a colonic tumor were also negative. An in situ hybridization study of diseased tissue, including specimens from 6 inflammatory bowel disease patients in addition to those above, showed a few grains distributed over cells superficial to the muscularis mucosa, but was not regarded as significantly different from controls. The association of CMV with Crohn's disease (0 positives in 4 patients by either test) is not supported by this study; the association with ulcerative colitis (1 positive in 9 patients by either test) requires further study before a definitive conclusion can be made.

Analysis of cytomegalovirus genomes with restriction endonucleases Hin D III and EcoR-1

Cleavage of genomes of eleven human, one simian, and one simian-related cytomegalovirus (CMV) isolate by the restriction endonucleases HinD III and EcoR-1 generated reproducible DNA fragments. The size range of CMV DNA fragments as estimated by contour length measurements in comparison with simian virus 40 form II DNA and by coelectrophoresis with EcoR-1 fragments of herpes simplex virus DNA varied between 15 X 10(6) and 0.5 X 10(6) daltons. Comparison of the cleavage products of each isolate in 1% agarose slab gels showed extensive comigration of fragments among the human CMV isolates. In the HinD III digests, three fragment bands comigrated among all human CMV isolates, and six fragments comigrated among most, but not all, human CMV isolates. In the EcoR-1 digests, nine fragment bands comigrated among all human CMV isolates, and five bands comigrated among most, but not all human isolates. Each isolate had a distinctive electrophoretic profile with either HinD III or EcoR-1 digests. No two isolates had identical HinD III or EcoR-1 patterns although some isolates did share more general pattern similarities than others. No clear-cut subgrouping of isolates based on cleavage pattern characteristics could be discerned. Comparison of HinD III and EcoR-1 patterns showed that human isolates differ greatly from nonhuman CMV isolates. HinD III and EcoR-1 digests of each isolate contained both major and minor molar classes of DNA fragments that ranged from about 1 and multiples of 1 M down to about 0.25 M; however, the summed molecular weights for major molar fragments resulting from HinD III or EcoR-1 digests of several isolates closely approximated the molecular weight of 10(8) of the intact genome.

Preferential inhibition of herpes-group viruses by phosphonoacetic acid: effect on virus DNA synthesis and virus-induced DNA polymerase activity

In tissue culture phosphonoacetic acid (PAA) specifically inhibited DNA synthesis of human cytomegalovirus (CMV), murine CMV, simian CMV, Epstein-Barr virus, and Herpesvirus saimiri. Fifty to one hundred micrograms per milliliter PAA completely inhibited viral DNA synthesis with no significant damage to host cell DNA synthesis. In vitro DNA polymerization assays showed that 10 μg/ml of PAA specifically inhibited partially purified human CMV-induced DNA polymerase, while little inhibition of host-cell DNA polymerase activity was found. The specific inhibition of herpes-group virus DNA synthesis with little toxicity to host cells suggests that PAA has great potential as an antiherpesvirus therapeutic agent.

Detection of human cytomegalovirus and analysis of strain variation

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Human cytomegalovirus. IV. Specific inhibition of virus-induced DNA polymerase activity and viral DNA replication by phosphonoacetic acid

Phosphonoacetic acid specifically inhibited human cytomegalovirus DNA synthesis in virus-infected human fibroblasts as detected by virus-specific nucleic acid hybridization. Inhibition was reversible; viral DNA synthesis resumed upon the removal of the drug. The compound partially inhibited DNA synthesis of host cells in the log phase of growth but had little effect on confluent cells. Studies of partially purified enzymes indicated that phosphonoacetic acid specifically inhibited virus-induced DNA polymerase and had only a slight effect on normal host cell enzymes. The drug was shown to interact directly with virus-induced enzyme but not with the template-primers.