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Biomedical subjects

K K Takemoto

Publications and source records attributed to K K Takemoto.

At least 37 records · Page 2Linked to original sources
PubMed1978

Differences in the capacity of simian virus 40 (SV40) tumor antigens on cells, membranes and in soluble form to induce transplantation immunity in hamsters and mice.

The immunogenicity of the SV40 tumor-specific transplantation antigen (TSTA) on cells, cell particulates and solubilized membranes was studied in mice and in Syrian hamsters. Immunizations were done with various concentrations of tissue-culture-passaged, non-virus-releasing transformed cells, purified cell membranes and in some cases purified nuclei and papain-solubilized membranes obtained from several species, including the mouse, hamster, man, and sheep. All transformed cell lines were T-antigen-positive. The immunosensitive mKSA line of BALB/c mice and the immunosensitive SV34 cell line of the hamster were used for tumor challenge. All materials, regardless of source and of type of preparation, were strikingly immunogenic in the mouse but only SV40 virus and SV34 (hamster) cells provided protection against tumor cell challenge in the hamster. Also, in a limited study, BKV-transformed hamster cells and purified cell membranes and JCV-transformed hamster cells were found to be immunogenic by the tumor rejection assay in the mouse but not in the hamster. SV40 immunization did not protect the hamster against BKV- and JCV-transformed hamster cells. These results are discussed in terms of possible different specificities resident on the TSTA molecule.

Animals↗
PubMed1978

Polyoma virus-human cell interactions: persistence of T-antigen in two cell lines with and without transformation.

The interaction of polyoma virus and human cells was investigated. Abortive infection as evidenced by the synthesis of T-antigen was observed in normal fibroblast and abnormal (transformed) cells but not in normal epithelial cells. A high percentage of simian virus 40-transformed WI-18 Va2 and spontaneously transformed BE skin cells produced T-antigen after high-multiplicity infection, but most of the cells rapidly lost antigen-producing capacity upon cell passage, and the cultures became negative by passage 3. All fibroblast cells displayed varying degrees of susceptibility to infection, but most of the cell lines became negative for T-antigen except for two. In one, T-antigen persisted in a small percentage of the cells throughout the lifetime of the culture, without cellular transformation occurring. In the other, the entire culture became morphologically transformed and eventually consisted of 100% T-antigen-positive cells. This is the first time that normal diploid human fibroblast cells have been transformed by polyoma virus.

Animals↗
PubMed1978

Characterization of K virus and its comparison with polyoma virus.

The antigenic relationship between the two murine papovaviruses, K virus and polyoma virus, was examined by serological techniques to determine whether they shared any antigenic components. No cross-reactivity was found associated with the viral (V) antigens by the indirect immunofluorescence, neutralization, or hemagglutination-inhibition tests. The tumor (T) antigens expressed in transformed cells or cells productively infected by either K or polyoma virus did not cross-react by indirect immunofluorescence. An antigenic relationship was detected, however, among the late proteins of K virus, polyoma virus, simian virus 40, and the human papovavirus BKV, when tested with either hyperimmune sera prepared against polyoma virus and simian virus 40 or sera prepared against disrupted virions. The nucleic acids of K and polyoma viruses were compared by agarose gel electrophoresis and restriction endonuclease analysis. No nucleotide sequence homology between the genomes of these two viruses was detectable by DNA-DNA hybridization techniques under stringent conditions. The genome of K virus was found to be slightly smaller than that of polyoma virus, and the cleavage patterns of the viral DNAs with six restriction endonucleases were different. These findings indicate that there is little relationship between these two murine papovaviruses.

Antigens, Viral↗
PubMed1977

Transformation of rabbit kidney cells by BKV(MM) human papovavirus.

Primary rabbit kidney cells were transformed by BKV(MM), a papovavirus isolated from the urine of a child with the Wiskott-Aldrich syndrome. The transformed cells contained BK T-antigen, but no antigen that reacted with SV40 U-antiserum. The transformed cells failed to produce tumors in nude mice, and BKV (MM) was not rescued from transformed cells by cell fusion or chemical induction methods. The transformed cells supported the growth of rabbit kidney vacuolating virus (RKV), and could be used to quantitate RKV by plaque formation under an agar overlay.

Agar↗
PubMed1977

Isolation of simian virus 40 from rhesus monkeys (Macaca mulatta) with spontaneous progressive multifocal leukoencephalopathy.

Isolates of virus from the brain tissue of two naturally occurring cases of progressive multifocal leukoencephalopathy in rhesus monkeys (Macaca mulatta) have been characterized. Both isolates were demonstrated to be simian virus 40 (SV40) by serological tests and analysis of cleavage fragments of viral deoxyribonucleic acid produced by restriction endonuclease from Haemophilus influenzae. SV40 virions and the nonvirion T antigen were demonstrated in the brain lesions of one monkey by the fluorescent antibody staining technique. SV40 was not demonstrated in the brain of normal rhesus monkeys from the same colony with use of the same methods of viral isolation or demonstration of antigen.

Animals↗
PubMed1977

Induction of simian virus 40 (SV40) transplantation immunity in mice by SV40-transformed cells of various species.

Specific tumor rejection was obtained with the use of simian virus 40 (SV40)-transformed cells from several species including man, rat, ape, sheep, and hamster. Growth of the syngeneic sarcoma mKSA in BALB/c mice was strikingly inhibited following a single immunization with as few as 10(3) intact, viable cells. Non-SV40-transformed cells did not induce tumor rejection activity nor did SV40-transformed lines induce immunity against the 3-methylcholanthrene-induced sarcoma Meth A, syngeneic with BALB/c mice. A close relationship existed between the tumor rejection antigen, the tumor-specific transplantation antigen (TSTA) located on the plasma membrane, and the intranuclear tumor antigen (T-ag). Both were associated with the DNA sequence of the early region of the SV40 genome, and TSTA activity was found in the nucleus. However, we did not observe a close parallelism between T-ag activity and TSTA. Neverthesless, the results strongly suggested that TSTA, like T-ag, was encoded by the virus.

Animals↗
PubMed1977

Relationship between the methionine tryptic peptides of simian virus 40 and BK virus tumor antigens.

The monomer form of BK virus (BKV) tumor antigen (T Ag) was immunoprecipitated from extracts of BKV-transformed cells and had a molecular weight of approximately 113,000. This compared with 97,000 for the molecular weight of either BKV or simian virus 40 (SV40) T Ag from lytically infected cells. The SV40 and BKV T Ag's from productively infected cells were compared by examining their methionine-labeled tryptic peptides. Out of a total of 20 SV40-and 21 BKV-specific peptides, there were seven pairs of similar peptides on the basis of ion-exchange chromatography, These coeluting peptides contained approximately 25 to 30% of the total methionine radioactivity. Similar results were obtained when the tryptic peptides of SV40 T Ag from lytically infected cells were compared with those of BKV T Ag from virally transformed cells.

Antigens, Neoplasm↗
PubMed1975

Homology and relationship between the genomes of papovaviruses, BK virus and simian virus 40.

A number of hybridization techniques have been used to assess the homology between the genomes of BK virus (BKV) and simian virus 40 (SV40). A noncontiguous set of homologous sequences has been localized primarily within the late region of the SV40 genome, and these sequences presumably account for the cross-reaction between V-antigens of the two viruses. The reason for the relatively strong crossreaction between SV40 and BKV T-antigens is still unclear. The sequence homology and similarity in genomic organization suggest a close relationship between these papovaviruses.

BK Virus↗
PubMed1975

Characterization of human papovavirus BK DNA.

The DNA of the BK virus (BKV) human papovavirus was found to be heterogeneous, consisting of at least four discrete species of DNA. Only the largest of these four species, BKV DNA (i), which has a molecular weight calculated to be 96% that of simian virus 40 (SV40) DNA, was infectious. Homogeneous preparations of BKV DNA were obtained, however, from virions purified after low multiplicity infections of human embryonic kidney cells. BKV DNA (i) was shown to contain a single R-Eco RI and four R-Hind cleavage sites. The R-Eco RI site was localized in the largest R-Hind cleavage fragment. Radiolabeled BKV DNA reassociated slightly faster than SV40 DNA; 20 to 30% polynucleotide sequence homology was demonstrated between the genomes of BKV and SV40 when the reaction was monitored by chromatography on hydroxyapatite.

Animals↗
PubMed1975

Physical map of the BK virus genome.

Two new human papovavirus isolates (JMV and MMV) from the urines of patients with Wiskott-Aldrich syndrome were morphologically and serologically identical to BK virus (BKV). The genomes of these two new isolates were found to be indistinguishable from prototype BKV DNA in a variety of nucleic acid hybridization experiments. Like BKV DNA, JMV and MMV DNAs share approximately 20% of their polynucleotide sequences with simian virus 40 DNA. The genome of JMV was indistinguishable from that of BKV by restriction endonuclease analysis; MMV DNA contained three instead of four R-Hind cleavage sites and one rather than no R-HpaII cleavage sites. Physical maps of the BKV and MMV genomes were constructed using restriction endonucleases, and these maps were oriented to the map of simian virus 40 DNA.

BK Virus↗
PubMed1975

Transformation of hamster kidney cells by BK papovavirus DNA.

Supercoiled BK papovavirus DNA was shown to transform hamster kidney cells using the calcium phosphate co-precipitation technique. The transformed cells contained intranuclear T-antigen(s) and rescuable virus and produced progressively growing tumors when inoculated into hamsters. A novel finding was the production in tumor-bearing animals of antinuclear antibody, which reacted against normal, untransformed cells; in addition, tumor serum contained antibody against virus-specific T-antigen(s).

Animals↗
PubMed1975

Biochemical properties of a hamster syncytium-forming ("foamy") virus.

A hamster syncytium-forming ("foamy") virus (HFV) was characterized. The HFV sedimented in isopyknic sucrose density gradients at 1.16-1.165 g/ml. It had RNA but no DNA, its replication was inhibited by actinomycin D, and it contained virion-associated, RNA-dependent DNA polymerase. Analysis of the RNA from purified virus showed several species: 62S, 40S, 28-30S, 18-20S, and 4-7S.

Animals↗