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C Grose

Publications and source records attributed to C Grose.

At least 109 records · Page 6Linked to original sources

Purification and molecular anatomy of the varicella-zoster virion.

Varicella-zoster virus (VZV) infected cell cultures were harvested and sonically disrupted when cytopathic effect was advanced. Infectious cell-free virus in the sonicates, as well as that in the culture medium, was further concentrated by precipitation with 8% (w/v) polyethylene glycol in the presence of high salinity (0.5 M). The virus-enriched pellet was layered onto 15-45% linear metrizamide gradients and sedimented for 18 h at 70,000 g. Of the three visible bands (designated upper, middle and lower), the middle band at a buoyant density of 1.156-7 g/cm3 was enriched for enveloped virions. Electron microscopic enumeration of particles demonstrated a total of 10.04 log10 enveloped particles and 8.26 log10 unenveloped particles from middle bands representing the yield from a 150 cm2 VZV-infected monolayer. Fractionation of radiolabeled virion preparations by SDS-PAGE revealed 30 polypeptides between 30 and 200 kilodaltons (K) with a total mol wt of 2,240,000. Prominent structural polypeptides included the major capsid protein (155K) and three glycoproteins--62K, 98K and 118K. Certain polypeptides better labeled by [14C] amino acids than by [35S] methionine included a higher mol wt polypeptide (174K) and 45K protein comigrating with actin. Immune precipitation of a Nonidet-extracted virion fraction again demonstrated the three major glycoproteins, as well as the 155K and 45K polypeptides. Comparison of structural polypeptides with the 16 constituents of the VZV-specific immunoprecipitation profile identified at least one polypeptide (145K) which was not represented in the virion and assumed, therefore, to be nonstructural.

Capsid↗

Varicella-zoster virus infection of diploid and chemically transformed guinea-pig embryo cells: factors influencing virus replication.

Factors influencing the replication of varicella-zoster virus (VZV) in guinea-pig embryo cells were evaluated using both diploid cells (GPEC) and a chemically transformed cell line (GPT). Wild-type and vaccine strains of VZV were successfully isolated and serially propagated in GPEC prepared from early gestation whole embryos (less than 2 cm in length). Low passage GPEC (less than or equal to 5 subcultivations) were more susceptible to VZV infection than high passage GPEC (greater than 5 subcultivations), and guinea-pig cells were consistently less permissive than human diploid cells. Cell-free virus was produced from VZV-infected GPEC cultures by sonication and peak yields of 10(3) p.f.u./ml were obtained. In addition, we report the isolation and propagation of VZV, as well as production of cell-free virus, in GPT. Both GPEC and GPT cells were less susceptible to VZV infection than human cells. However, viral replication was enhanced by incubation of VZV-infected GPT cultures at 32 degree C rather than 36 degree C.

Animals↗

Immunogenic glycoproteins of laboratory and vaccine strains of Varicella-Zoster virus.

High-titered antisera were prepared in guinea pigs and rabbits against two strains of varicella-zoster virus (VZV): VZV-32, a low-passage laboratory strain, and VZV-Oka, a vaccine strain attenuated by passage in both human and guinea pig embryo cells. When the animal VZV-immune sera, as well as a human zoster serum, were used to precipitate radiolabeled glycoproteins from VZV-infected cells and the immune precipitates were analyzed by polyacrylamide gel electrophoresis and fluorography, it was observed that cell cultures infected with either strain had similar electrophoretic profiles containing major glycoproteins of approximate molecular weights 62,000, 98,000, and 118,000. A prominent high-molecular-weight (approximately 150,000) nonglycosylated polypeptide was identified in both strains also. These determinants were demonstrable by both indirect (staphylococcal protein A-antibody adsorbent) and direct immunoprecipitation, as long as VZV-immune sera with an antibody titer greater than or equal to 1:128 were used. Further analysis of individual caviid VZV antisera demonstrated some heterogeneity which appeared to be related to the method of immunization rather than the level of virus-specific antibody. VZV extracts emulsified with complete Freund adjuvant elicited an antibody response to all major immunogenic viral glycoproteins, whereas guinea pigs inoculated with virus alone during the primary immunization initially produced VZV antibody which failed to precipitate the highest-molecular-weight glycoprotein (gp118). Thus, Freund-type adjuvants promoted the maturation of the humoral immune response after VZV immunization in outbred guinea pigs.

Animals↗

Immunization of inbred guinea pigs with varicella-zoster virus grown in a syngeneic transformed embryo cell line.

Varicella-zoster virus was serially propagated in a chemically transformed and cloned line of embryo cells (designated "104 C1") derived from the inbred strain 2 guinea pig. When strain 2 guinea pigs were immunized with varicella-zoster virus subcultivated in the syngeneic cell line, they produced high-titer virus-specific antiserum which lacked antibody against cellular determinants. This immunization procedure offers both practical and theoretical advantages over prior methods which involved inoculation of outbred laboratory animals with varicella-zoster virus grown in allogeneic or xenogeneic cell cultures.

Animals↗

Cryopreservation of varicella-zoster virions without loss of structural integrity or infectivity.

Varicella-zosterer virions present in infected cells or in a cell-free state were freeze-dried without loss of structural integrity of infectivity. Generally, yields of greater than 5 log10 foci/ml (infected cells) or greater than 4 log10 PFU/ml (cell-free virus) were recovered from varicella-zoster virus-infected human melanoma cells both before and after lyophilization in phosphate-buffered media containing 0.1-1.0 M sucrose. Virus frozen in solutions lacking sugar had little or no residual infectivity after vacuum sublimation was completed. Visualization by electron microscopy demonstrated large numbers of enveloped virions in the virus preparations lyophilized in media containing sucrose; in marked contrast, virus subjected to freeze-drying in buffered solutions without sugar consisted mainly of naked nucleocapsids. Water analyses by Karl Fischer titration suggested that residual moisture retained by sugar prevented disenvelopment of the varicella-zost virion.

Edetic Acid↗

Complement-enhanced neutralizing antibody response to varicella-zoster virus.

Humoral immunity following infection with varicella-zoster virus (VZV) was evaluated by a complement-enhanced neutralization test. The specificity of the test was examined and its sensitivity compared with that of the assay which measures antibody to VZV-induced membrane antigen (FAMA). Generally, the titer of neurtalizing antibody was two- to fourfold higher than the FAMA titer. The absence of neutralizing activity at a serum dilution of 1:4 indicated susceptibility of the donor to VZV infection and correlated with an absence of FAMA (titer, less than 1:2). A survey of susceptible leukemic children exposed to chicken pox revealed that several recipients of zoster immune globulin had a subclinical infection, as manifested by seroconversion and persistence of neutralizing antibody to VZV. Results of these studies indicate that the complement-enhanced neutralization test is a sensitive and specific assay for determination of humoral immune status with regard to VZV in healthy and immunosuppressed individuals.

Adult↗

Cell-free varicella-zoster virus in cultured human melanoma cells.

Varicella-zoster virus (VZV) has been isolated and serially propagated in a continuous cell line derived from a human malignant melanoma tumour. Human melanoma cells (HMC) have been further evaluated as a substrate for the production of cell-free virus and compare favourably with human embryo cells. Within 60 h after inoculation with VZV-infected cells, HMC monolayers incubated at 32 degrees C exhibited advanced syncytial cytopathic effect, and the overlying culture medium contained greater than 10(2) p.f.u./ml. The cell pellet from a mechanically dispersed 150 cm2 monolayer yielded 10(5) p.f.u. after sonic disruption, while the medium ('scraping medium') in which the cells had been harvested contained up to one log more infectious virus than was found in the cells from the same monolayer. When infected cells were subjected to Dounce homogenization, most of the infectivity was found in the nuclear fraction. The concentration and purification of cell-free virus were also investigated. Concentration was carried out by three methods: ultracentrifugation, dialysis against hydrophilic compounds and liquid polymer phase separation. The first two procedures caused considerable loss of biological activity, whereas precipitation with 8% polyethylene glycol resulted in a 50-fold increase in titre. Purification of cell-free virus with retention of infectivity was achieved by rate zonal centrifugation in linear potassium tartrate gradients. Infectious virus was also recovered after sedimentation in combination equilibrium-viscosity gradients of potassium tartrate and glycerol, but not after centrifugation to equilibrium in caesium chloride gradients.

Cell Line↗

Varicella-zoster virus: isolation and propagation in human melanoma cells at 36 and 32 degrees C.

Cell lines derived from human malignant melanoma tumors are susceptible to infection with varicella-zoster virus (VZV). Within 5 days after inoculation of vesicular fluid, cytopathic changes appeared in melanoma cell monolayer cultures that were incubated at either 36 or 32 degrees C. The VZV isolates at the two temperatures were serially propagated by passage of trypsin-dispersed infected cells. A plaque assay was developed utilizing melanoma cell monolayers overlaid with nutrient medium containing carboxymethylcellulose. By this assay method, the growth cycle of a VZV isolate propagated at 36 degrees C was studied and compared with that of another VZV isolate grown at 32 degrees C. With equivalent infected-cell inocula at a ratio on one inoculum cell to eight uninfected cells, the yield of cell-free virus at an incubation temperature of 32 degrees C was slightly higher than at 36 degrees C, although the peak occurred 60 h, rather than 36 h, postinfection. It was also found that the titer of low-passage VZV propagated at 36 degrees C was 0.5 to 1 log higher when assayed at 32 degrees C rather than at 36 degrees C.

Cell Line↗

Primary Epstein-Barr virus infection in a renal transplant recipient.

A young girl with familial nephronophthisis and chronic renal failure contracted a primary Epstein-Barr virus infection after renal transplantation. During the illness she developed a clinical picture of fever and pneumonitis which closely resembled the posttransplantation syndrome usually associated with cytomegalovirus, although she had no evidence of cytomegalovirus infection. A younger sibling with the same renal disease was found retrospectively to have apparently had an earlier subclinical Epstein-Barr virus infection.

Antibodies, Viral↗