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Biomedical subjects

L Gissmann

Publications and source records attributed to L Gissmann.

161 records · Page 9Linked to original sources
PubMed1980

NC37-R1 Epstein-Barr virus (EBV): a possible recombinant between intracellular NC37 viral DNA and superinfecting P3HR-1 EBV.

The NC37-R1 cell line, established after transformation of human cord blood lymphocytes with Epstein-Barr virus (EBV) recovered from P3HR-1 superinfected NC37 cells, spontaneously produces viral particles with transforming but without early antigen-inducing properties. Progeny virus of NC37-R1 has retained its biological characteristics of spontaneous virus release and transformation up to four cycles of transformation at present. Analysis of purified NC37-R1 virion DNA, after cleavage with restriction endonuclease Hind III and comparison of its fragments with P3HR-1 EBV as well as intracellular NC37 viral DNA using the blot hybridization technique, suggests that NC37-R1 originates from a recombination between superinfecting P3HR-1 and endogenous NC37 EBV DNA.

Antigens, Viral↗
PubMed1979

Lymphotropic papovaviruses isolated from African green monkey and human cells.

A lymphotropic papovavirus was isolated from a lymphoblastoid cell line of African green monkey (AGM) cells which also contained a herpesvirus and a paramyxovirus-like agent. The papovavirus was analyzed by restriction endonuclease cleavage; its biochemical and serological crossreactivity with SV40 and host range have been determined. Thus far, only B-lymphoblasts of primate and human origin have been found to be susceptible to infection. Although more than 50% of the tested monkey sera were reactive with antigens of this virus, all human sera tested failed to react. Cleavage patterns and hybridization studies with the viral DNA indicate that the virus represents a novel member of the papovavirus group that is characterized by its lymphotropic host range. Papovavirus particles were also demonstrated in a human lymphoblastoid cell line (CCRF-SB) originally derived from a leukemic child. These cells revealed nuclear fluorescence when tested with human sera, but failed to react with AGM sera. Although characterization of this agent has not yet been completed, available evidence suggests that it represents another lymphotropic papovavirus which seems to be spread within the human population.

Animals↗
PubMed1978

Physical characterization of deoxyribonucleic acids of different human papilloma viruses (HPV).

Different types of human papilloma viruses (HPV) had been identified by the use of bacterial restriction endonucleases (Gissmann et al., 1977). The DNAs of HPV 1, 2, and 3 showing a similar restriction enzyme pattern can be purified in sufficient quantities to permit further characterization. These viruses appear not to be identical, as far as molecular weight (4.9 X 10(6) d), buoyant density (1.700 mu/ml), and sedimentation values of the different DNA components (Co I: 22--23S; Co II: 17S; Co III: 16S) are concerned. HPV 4 DNA, which is entirely different from HPV 1--3 in its restriction enzyme pattern, does not hybridize with cRNA transcribed in vitro from HPV 1 DNA. The cRNA was shown to represent the whole viral genome.

Centrifugation, Density Gradient↗
PubMed1978

Mastomys natalensis papilloma virus (MnPV), the causative agent of epithelial proliferations: characterization of the virus particle.

A virus (MnPV) with the structural characteristics of papilloma viruses was isolated from benign and malignant proliferations of adult animals of the inbred line 'GRA Giessen' of Mastomys natalensis. The particles can be banded in CsCl gradients at densities of 1.34 g/ml (full particles) and 1.29 g/ml (empty particles). The virus DNA has a buoyant density of 1.7104 g/ml and can exist in three different conformations (supercoiled circular, nicked circular and linear), the sedimentation values of which have been determined as 23 to 24S, 16 to 17S and 14 to 15S, respectively. Although the mol. wt. of MnPV DNA is similar to that of HPV 1 DNA, the size of the fragments obtained after cleavage of MnPV DNA with the restriction endonuclease Hae III is quite different from the pattern seen with human papilloma virus. The virion contains 12 different polypeptides; the major structural protein has a mol. wt. of 56 000. MnPV is shown to be the causative agent of the skin proliferations, because tumours can be induced by inoculation of purified virus, whereas no cutaneous alterations are observed when the particles are inoculated in the presence of anti-MnPV serum. MnPV can be re-isolated from the experimentally induced tumours.

Animals↗
PubMed1978

Heterogeneity of human papilloma viruses.

Two types of human papilloma viruses (HPV-1 and HPV-4) were characterized, which show no relationship as far as the following criteria are concerned: the pattern of restriction enzyme fragments of their DNA, DNA-cRNA hybridization, and complement fixation with specific rabbit antisera. Furthermore, the molecular weights of the major proteins differed significantly. Both types of viruses could be isolated from plantar warts and from verrucae vulgares. This paper gives the molecular weights of the major proteins of a third type of HPV from skin warts, which reacts neither with HPV-1 nor with HPV-4 rabbit antiserum.

Complement Fixation Tests↗
PubMed1976

Human papilloma virus DNA: physical mapping and genetic heterogeneity.

The molecular weight of three preparations of human papilloma virus DNA derived from different plantar warts was determined by agarose gel electrophoresis or electron microscopic contour length measurement. It was found to amount to approximately 4.9 X 10(6). Analysis of this DNA after sequential digestion by four different restriction endonucleases (EcoRI, Bam, Hind II, and Hind III) permitted physical mapping of the cleavage sites. Two of the three DNA preparations revealed an identical cleavage pattern, whereas the third one contained two additional cleavage sites.

Chromosome Mapping↗
PubMed1975

Isolation and characterization of a rod-shaped bacteriocin from a strain of Rhizobium.

A bactericidal agent ('bacteriocin 16-2') produced by rhizobial strain 16-2 had been characterized as a sheathless rod-shaped particle with a length of 200 nm and a diam. of 8 nm. One end of the rod is pointed and carries short fibre-like appendages, while the other end appears square. The particles specifically adsorb with their pointed end to bacteriocin-sensitive, but not to bacteriocin-resistant, cells. The possible mode of action of this bacteriocin in discussed.

Bacteriocins↗
PubMedDate not supplied

Association of HPV with human genital tumors.

Human papillomaviruses (HPV) are clearly responsible for the induction of genital lesions like condylomata acuminata, bowenoid papules, and flat condylomas. Moreover, the DNA of particular virus types (HPV 16 and 18) is found in a substantial number of invasively growing squamous cell carcinomas of the genital tract, suggesting an etiologic involvement of these viruses in tumor development. Since HPV 16 and 18 as well as other papillomaviruses (HPV 6 or 11) usually present within the benign genital warts can be found in dysplastic lesions of the uterine cervix known as putative precancerous lesions, determination of the virus type might be of diagnostic relevance. Since no type-specific serologic reagents are available, viruses can be identified by nucleic acid hybridization using radioactively labeled HPV DNAs that have been molecularly cloned as probes.

Female↗
PubMedDate not supplied

Chimeric virus-like particles of the human papillomavirus type 16 (HPV 16) as a prophylactic and therapeutic vaccine.

Infection by certain human papillomaviruses (HPV), most notably HPV types 16 and 18, is the major risk factor for cervical cancer. Worldwide, this disease represents the second most frequent malignant tumor in women; thus, there is urgent need for efficient therapy and prevention. The natural history of cervical cancer and its precursors (cervical intraepithelial neoplasias), as well as animal experiments, strongly suggest that the immune system controls both the primary infection (by neutralizing antibodies directed against the major structural protein L1) and the progression of the disease (via cytotoxic T cells specific for the viral oncoproteins expressed in transformed cells, e.g., E7). By the expression of an HPV 16 L1E7 fusion protein, we have generated chimeric virus-like particles (CVLP). Immunization of mice with CVLPs induces neutralizing antibodies directed against L1 virus-like particles (devoid of the E7 portion) and E7-specific T cells as measured in vitro. Vaccinated animals are protected against tumor growth following inoculation of syngeneic HPV 16-transformed cells. In addition, we observed a therapeutic effect of vaccination on pre-existing tumors. This data allowed us to conclude that CVLPs are suitable for prevention and therapy of HPV infection. A vaccine based on HPV 16 L1E7 CVLPs is currently under development.

Animals↗
PubMedDate not supplied

Structure and transcription of human papillomavirus sequences in cervical carcinoma cells.

DNA of human papillomavirus (HPV) types 16 and 18 has been found closely associated with human genital cancer, supporting the concept that members of this virus group are key factors in the aetiology of genital cancer. HPV 18 DNA sequences were also detected in cell lines derived from cervical cancer. We have now analysed these cell lines, HeLa, C4-1 and 756, for the structural organization and transcription of the HPV 18 genome and we find that the HPV 18 DNA is integrated into the cellular genome and is amplified in HeLa and 756 cells. Almost the complete HPV 18 genome seems to be present in 756 cells, with the early region being disrupted into two portions in each integrated copy. In HeLa and C4-1 cells, a 2-3 kilobase (kb) segment of HPV 18-specific sequences is missing from the E2 to L2 region. HPV 18 sequences are specifically transcribed from the E6-E7-E1 region into poly(A)+ RNAs of 1.5-6.5 kb. Hybridization analysis of cDNA clones indicated that some of the transcripts are composed of HPV 18 and cellular sequences. In addition, poly(A)+ RNA hybridizing with HPV 16 DNA was found in two out of three cervical carcinoma biopsies.

Carcinoma↗
PubMedDate not supplied

Cervical carcinoma cells transfected with the CD80 gene elicit a primary cytotoxic T lymphocyte response specific for HPV 16 E7 antigens.

Cervical carcinoma is strongly associated with human papillomavirus (HPV) type 16, and the transforming viral genes E6 and F7 are steadily expressed by the tumor cells. Therefore these viral oncogenes may be regarded as tumor-associated antigens. Our previous studies showed that cervical cancer cells after introduction of the CD80 gene activated allogeneic cytotoxic T lymphocytes (CTLs). In this study, we tested whether HPV 16+ cervical tumor cells (CaSki) expressing CD80 were able to activate CTLs recognizing HPV 16 E7 antigen. To this end, CD80+ CaSki cells (HLA-A*0201+) were used to stimulate peripheral blood T lymphocytes from HLA-A*0201+ healthy donors. We found that the activated T cells were able to lyse parental CaSki cells as well as Epstein-Barr virus-immortalized autologous B cells loaded with HLA-A*0201-restricted E7 peptides (amino acids 11-19, 82-90, 86-93). In contrast, no lysis was observed against target cells loaded with a control HIV-reverse transcriptase peptide (amino acid 476-484, HLA-A 0201-restricted). Our data, for the first time, provide evidence that CD80-expressing cervical cancer cells are able to activate tumor-specific CTLs using HPV 16 E7 as tumor-associated antigens.

B-Lymphocytes↗