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H S GINSBERG

Publications and source records attributed to H S GINSBERG.

At least 19 recordsLinked to original sources
PubMed1963

STRUCTURE OF TYPE 5 ADENOVIRUS. I. ANTIGENIC RELATIONSHIP OF VIRUS-STRUCTURAL PROTEINS TO VIRUS-SPECIFIC SOLUBLE ANTIGENS FROM INFECTED CELLS.

Type 5 adenovirus was purified by fluorocarbon (freon 113) treatment followed by banding in a CsCl equilibrium density gradient. This method permitted separation of virus from normal host cell materials and virus-specific soluble antigens. Virus banded in CsCl with a mean bouyant density of 1.3349 gm/cm(3). The three virus-specific soluble antigens (group- and type-specific antigens and toxin) banded together with a mean bouyant density of 1.2832 gm/cm(3). The group-specific antigen was the predominant antigen of the purified virus particle, whereas the group- and type-specific antigens were present in equal titers in the antigen band. Infectious virus particles were inactivated by prolonged dialysis at pH 10.5. Centrifugation of inactivated virus preparations in a CsCl equilibrium density gradient resulted in separation of virus DNA from specific antigen: the antigens banded with a mean bouyant density of 1.2832 gm/cm(3) and the DNA sedimented to the bottom of the tube. The predominant antigen derived from purified virus particles was the group-specific antigen and it was in the same relative proportion to the type-specific antigen as measured in intact particles. The antigens derived from disrupted virus were immunologically identical with the soluble virus antigens present in infected cells.

Adenoviridae↗
PubMed1963

STRUCTURE OF TYPE 5 ADENOVIRUS. II. FINE STRUCTURE OF VIRUS SUBUNITIS. MORPHOLOGIC RELATIONSHIP OF STRUCTURAL SUBUNITS TO VIRUS-SPECIFIC SOLUBLE ANTIGENS FROM INFECTED CELLS.

Purified type 5 adenovirus was disrupted at pH 10.5 and the capsid shown to be comprised of two characteristic morphological subunits: (a) Hollow, polygonal structures corresponding to the virus capsomeres seen in preparation of purified virus and (b) thread-like strands also identifiable in preparations of purified virus. These structures were compared morphologically with purified preparations of the group- and type-specific soluble antigens characteristically produced in mammalian cells infected with adenoviruses. The group-specific soluble antigen was a homogeneous preparation of hollow, polygonal rods identical with the virus capsomeres. The type-specific soluble antigen corresponded to the thread- or fiber-like components of the purified virus particle. Inspection of disrupted virus preparations confirmed earlier immunological data which indicated that the major virus antigen was the group-specific soluble antigen. These data provide convincing evidence for the hypothesis that the adenovirus-induced soluble antigens represent virus subunits produced in excess.

Adenoviridae↗
PubMed1962

Synthesis of virus-specific polymers in adenovirus-infected cells; effect of 5-fluorodeoxyuridine.

Biochemical synthesis in adenovirus-infected HeLa cells was studied utilizing 5-fluorodeoxyuridine (5-FUDR), a potent inhibitor of deoxyribonucleic acid production. Synthesis of saline-soluble DNA and infectious virus was completely suppressed by addition of the analogue to cells as late as 10 hours after infection. The inhibitory effect of this compound was totally reversed by addition of 10(-6)M thymidine to the culture medium. Synthesis of DNA essential for virus production began 10 hours after infection and was completed by 16 hours after infection. These data support the hypothesis that the saline-soluble DNA is a precursor of infectious virus particles. Studies of antigen production indicated that formation of virus-specific proteins was directly dependent upon synthesis of DNA.

Adenoviridae↗
PubMed1962

Effect of proflavine on the synthesis of adenovirus, type 5, and associated soluble antigens.

Wilcox, Wesley C. (University of Pennsylvania, Philadelphia) and Harold S. Ginsberg. Effect of proflavine on the synthesis of adenovirus, type 5, and associated soluble antigens. J. Bacteriol. 84:526-533. 1962.-The synthesis of type 5 adenovirus in HeLa cells was suppressed to a considerable extent by low concentrations of proflavine, an acridine dye. In comparison, the processes leading to the production of soluble complement-fixing antigens and toxin were less sensitive to the action of this chemical. Addition of proflavine to infected cells at different times during the virus growth cycle revealed that the processes leading to the synthesis of soluble antigens began prior to the first appearance of newly synthesized virus. This observation is compatible with the hypothesis that the soluble antigens may represent virus subunits or precursor materials. In addition, these data indicate that it is possible to interrupt the latter stages of the virus synthetic process by addition of proflavine late in the eclipse period.

Acridines↗
PubMed1961

Nucleuc acid synthesis in types 4 and 5 adenovirus-infected HeLa cells.

Type 4 adenovirus infection of HeLa cells effected a marked increase in synthesis of the saline-soluble DNA fraction, but not the host-cell DNA (the water-soluble fraction). This was demonstrated by the marked increase in specific activity of saline-soluble DNA but not water-soluble DNA when P(32)-inorganic phosphate or sodium formate-C(14) was employed. When these isotopes were used to label cells before viral infection rather than during the process of viral propagation, the saline-soluble DNA from infected cells had a specific activity of 10 to 20 per cent less than that of uninfected cells, indicating that the saline-soluble DNA was synthesized both from prelabeled precursors of the cell pools and unlabeled materials from the medium. Saline-soluble DNA began to increase between 10 to 12 hours after viral infection and 3 to 4 hours before appearance of newly propagated infectious virus. The specific activity of the acid-soluble pool of infected cells also increased between 10 to 12 hours after viral inoculation when sodium formate-C(14) was used as a radioisotope. When P(32)-inorganic phosphate was utilized, the specific activity of infected-cell RNA was increased approximately the same relative amount as when total RNA was determined chemically; i.e., 30 to 40 per cent. With type 5 adenovirus, not only did a 3- to 5-fold increase in saline-soluble DNA occur, but also an increase was measured in specific activity of RNA when P(32)-inorganic phosphate was used.

Adenoviridae↗
PubMed1959

Sequential cellular changes produced by types 5 and 7 adenoviruses in HeLa cells and in human amniotic cells; cytological studies aided by fluorescein-labelled antibody.

The sequential cytological changes which develop in tissue culture cells infected with adenovirus types 5 and 7 are described and compared with those produced by adenovirus types 1, 2, 3, and 4. The evidence that is presented indicates that types 1, 2, and 5 belong to one major subdivision of the adenovirus group and types 3, 4, and 7 to another. That the host cell nucleus is the principal site of adenovirus synthesis has been confirmed by fluorescent antibody studies. They have demonstrated the occurrence of type-specific adenovirus antigen in the characteristic intranuclear inclusions and other virus-induced structures reported to contain virus-like particles or shown by electronmicroscopy.

Adenoviridae↗
PubMed1959

Deoxyribonucleic acid (DNA) and protein alterations in HeLa cells infected with type 4 adenovirus.

During a single cycle of multiplication of type 4 adenovirus in HeLa cells an average 2-fold increase in total DNA occurred over that measured in uninfected cells. Of the total DNA from infected cells about 23 per cent was extractable into 0.15 M NaCl, a quantity approximately four and a half times greater than that of the DNA obtained from normal cells in 0.15 M NaCl. Ninety to 99 per cent of infectious virus was also extracted into the 0.15 M NaCl fraction. Concurrently with the accumulation of DNA in virus-infected cells there occurred a 2-fold increase in total protein. The proportionate increases in protein were approximately equal in 0.15 M NaCl and water extracts of infected cells. High speed centrifugation indicated that the bulk of the DNA and protein was not directly associated with infectious viral particles. Although in virus-infected cells a markedly increased synthesis occurred of a DNA which had solubility properties different from the major portion of normal host DNA, nucleotide analysis did not reveal any other qualitative differences. However, a marked change in nucleotide molar ratios was observed in the 0.15 M NaCl-soluble DNA from virus-infected cells. It seems apparent from the findings that the biochemical alterations found in HeLa cells infected with type 4 adenovirus are intimately related to the infectious process.

Adenoviridae↗