Rapid identification and typing of herpes simplex virus by a new enzyme immunoassay with peroxidase-labeled complement C1q.

A new enzyme-linked immunoassay system (TC-ELISA) was developed for the rapid, specific detection and typing of herpes simplex virus (HSV) using anti-HSV immune sera and enzyme-labeled complement component C1q (P*-C1q). The method is based on viral antigen produced in HSV-infected cells being detected by simultaneous addition of immune serum and P*-C1q (ELISA-CF). With this assay, it was found that HSV was detected with anti-HSV immune serum and P*-C1q and that HSV type 1 and HSV type 2 could be differentiated with anti-HSV-1 and anti-HSV-2 immune sera and P*-C1q.

Variation of R1 repeated sequence present in open reading frame 11 of varicella-zoster virus strains.

We molecularly cloned the tandem direct reiteration (R1) present in open reading frame (ORF) 11 from three independent strains of varicella-zoster virus. Comparison of the R1 sequences among varicella-zoster virus strains revealed that, although the portion of R1 near the 5' terminus of ORF 11 was conserved among strains, the 3'-terminal portion varied remarkably. This variation was due to the different arrangement of two elements (A and B) and a segment produced by fusion of A and B and to a single-base change in the A element.

New complement fixation test with peroxidase-labeled complement Clq for direct and quantitative determination of antibodies to herpes simplex virus.

An enzyme-labeled complement fixation (ELISA-CF) test for the direct and quantitative determination of complement fixing (CF) antibodies has been developed. This paper described the introduction of the ELISA-CF test that used peroxidase-labeled Clq component of complement to detect CF antibodies which had reacted with herpes simplex virus (HSV), as a virus model. Equal volumes of heat-inactivated serum and the peroxidase-labeled Clq (P*-Clq) were simultaneously added to wells of microplates which had been coated with HSV CF antigen or with cell control antigen.

Characterization of JHMV variants isolated from rat brain and cultured neural cells after wild type JHMV infection.

After intracerebral inoculation of wild type (wt) JHMV into 4 to 5 week-old Lewis rats, only variants with larger mRNA3 were selectively propagated and no wt JHMV was reisolated from the brain. Detailed analysis of a cloned virus from infected rat brain, c1-2, showed that the virus had larger mRNAs 2, 2a and 3 as compared with those of wt JHMV, while there was no such difference for other mRNAs. The E2 glycoprotein of a variant virus was also shown to be larger as compared with that of wt JHMV.

Characterization of a variant virus isolated from neural cell culture after infection of mouse coronavirus JHMV.

Our previous experiments showed that a variant virus with a larger envelope glycoprotein encoded by a larger mRNA3 (cl-2) multiplied predominantly in the brain of rats after wild type (wt) JHMV infection (F. Taguchi, S. Siddell, H.

Sequence reiteration required for the efficient growth of BK virus.

Compared with wild-type BK virus DNA having tandem triplication of a 68 base pair (bp) element in its transcriptional control region, a mutant viral DNA with a single copy of the 68 bp element induced remarkably delayed virus production in human embryonic kidney (HEK) cells. We molecularly cloned the DNA of progeny viruses using plasmid vector pAT153. Nucleotide sequence analysis of representative clones revealed that all of the altered viral DNAs examined duplicated various segments extending over origin-distal portions of the 68 bp element and their flanking regions.

Difference in sensitivity to interferon among mouse hepatitis viruses with high and low virulence for mice.

Mouse hepatitis viruses (MHV) of different virulence for mice were studied with respect to interferon (IFN) sensitivity. The growth of low-virulent MHV-S and intermediately virulent MHV-JHM was significantly suppressed in IFN-treated L cells compared with untreated cells. However, a comparable suppression of the growth of highly virulent MHV-2 was not observed in IFN-treated cells.

Presence of interferon and antibodies to BK virus in amniotic fluid of normal pregnant women.

Paired samples of maternal sera, umbilical cord sera and amniotic fluids were tested for antibodies to BK virus (BKV) and for interferon content. It was found that two out of 14 pregnant women were antibody negative, the latter were estimated to be susceptible to BKV primary infection. In contrast, there was no foetal case among those which were at risk of foetal infection with BKV as judged from the presence of BKV antibody in maternal sera and interferon in the placentas.

Characterization of a variant virus selected in rat brains after infection by coronavirus mouse hepatitis virus JHM.

The intracerebral inoculation of Lewis rats with the murine coronavirus MHV-JHM leads in the majority of animals to acute encephalitis and death within 14 days. Viral RNAs isolated from the brains of animals 5 to 7 days after infection were compared by Northern blot analysis with the RNAs produced during the lytic infection of Sac(-) or DBT cells with wild-type MHV-JHM (wt virus). Reproducibly, the subgenomic mRNAs 2 and 3 but no other viral RNAs were significantly larger in the brain-derived material.

Analysis of genomic and intracellular viral RNAs of small plaque mutants of mouse hepatitis virus, JHM strain.

The genomic RNA and intracellular RNA of mouse hepatitis virus, strain JHM (MHV-JHM) and two plaque mutants (1a and 2c), which have been isolated from a persistently infected culture (JHM-CC), have been analyzed by T1-resistant oligonucleotide finger-printing. The genomic RNA of the virus population (JHM-CC virus) released from different passage levels of the same persistent infection has also been analyzed. The analysis shows the locations within the genomic and intracellular RNAs of more than 45 T1-resistant oligonucleotides and confirm earlier studies (J.

Defective interfering particles of mouse hepatitis virus.

After six to eight serial undiluted passages of mouse hepatitis virus (JHM strain) in DBT cell culture, a decrease in the yield of infectious virus occurred, and with further passages fluctuating yields of infectious virus were observed. The serially passaged virus interfered with the multiplication of the standard JHM virus, but not with vesicular stomatitis virus. After sucrose equilibrium centrifugation of high passage virus, a single peak contained both infectious virus and interfering activity.

Effect of ethylene diamine tetraacetate (EDTA) on the interferon-inducing activity of Newcastle disease virus (NDV) in vivo. Brief report.

Circulating interferon levels increased and persisted for prolonged periods of time when groups of mice were stimulated with a mixture of Newcastle disease virus (NDV) and EDTA, or pretreated with EDTA and then injected with NDV, instead of injection with NDV alone.

Induction and enhancement of endocytosis in HeLa cells by use of liposomes and Sendai virus envelopes.

Phosphatidylserine liposomes were interacted with cultured HeLa cells to investigate the ingestion of the liposomes into the cells. It was shown by electron microscopy that great enhancement in entrappment of the liposomes into the cells was induced by adding reassembled Sendai virus envelopes. In the presence of the reassembled virus envelopes the ratio of liposome-endocytic cells was over the half of the examined cells in thin sections.

Growth of Tyzzer's organism in primary monolayer cultures of adult mouse hepatocytes.

The Tyzzer's disease organism was grown in primary monolayer cultures of adult mouse hepatocytes prepared by collagenase perfusion. The organisms produced a plaque-like cytopathic effect involving almost the whole culture around 72 h post-infection when the bacterial growth reached a maximum. The organisms showed specific immunofluorescence, and electron microscopy revealed that intracellular organisms had peritrichous flagella and underwent cell division.

Replication of mouse hepatitis viruses with high and low virulence in cultured hepatocytes.

Ten strains of mouse hepatitis virus with different levels of virulence and hepatotropism were examined for the ability to replicate in cultured mouse hepatocytes. All of these viruses multiplied well in hepatocytes, attaining a maximum of 10(5) to 10(7) PFU per 0.2 ml, with cytopathic effects characterized by the formation of polykaryocytes.

Plaque formation by Tyzzer's organism in primary monolayer culture of mouse hepatocytes.

Tyzzer's disease organism propagated on primary monolayer cultures of mouse hepatocytes and produced definite plaques. In phase contrast microscopy, the organisms were motile in the plaques. Plaque formation was inhibited by antiserum.

Characterization of small plaque mutants of mouse hepatitis virus, JHM strain.

Two small plaque mutants designated as 1a and 2c were isolated from DBT cells persistently infected with the JHM strain of mouse hepatitis virus. Unlike the wild type JHM, these two mutant viruses grew more slowly with no prominent cell fusion. The buoyant densities of the mutants were slightly lower and 2c was revealed to have fewer peplomers than JHM by electron microscopy.

Effects of a heat-labile factor(s) in normal serum on the interferon-inducing activity of Newcastle disease virus (NDV). Brief report.

The effect of fresh serum on the interferon-inducing activity of Newcastle disease virus (NDV) was studied. Infectivity in fertile eggs, hemolytic activity in human erythrocytes and interferon-inducing activity in mouse L cells and mouse spleen cells were all reduced by treatment of NDV with fresh serum from humans or guinea pigs, while hemagglutinating (HA) activity remained unchanged. The interferon-inducing ability of UV-inactivated NDV was also similarly reduced after treatment with serum.