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P G Fuchs

Publications and source records attributed to P G Fuchs.

16 recordsLinked to original sources
PubMed1992

Late promoter of human papillomavirus type 8 and its regulation.

Human papillomavirus type 8 (HPV8) belongs to the HPV types associated with skin carcinomas of patients with epidermodysplasia verruciformis (EV). Its noncoding regulatory sequences (NCR) were shown to drive the expression of the reporter gene chloramphenicol acetyltransferase (cat) in transient assays with human epithelial cells (HT3 cells). This constitutive activity could be enhanced by coexpression of the HPV8 transactivator protein E2. The analysis of 5' deletions of the NCR showed that the EV-specific sequence motif M33 and the neighboring AP1 site are essential for the promoter activity, whereas 44 nucleotides located immediately upstream of M33 are strongly inhibitory. The same effects were observed in simian virus 40-immortalized fetal keratinocytes (SV61 cells) and spontaneously immortalized skin keratinocytes (HaCaT cells). By using primer extension and RNase protection analyses two promoters could be identified within the HPV8 NCR. A nested set of weak signals, corresponding to start sites between positions 175 to 179, represented the previously described E6 promoter. The vast majority of transcripts was initiated at position 7535 and shown to undergo processing at an NCR-internal splice donor (positions 1 to 8). The promoter P7535 is similar to late promoters of other skin-associated papillomaviruses as far as localization, transcript structure, and sequence characteristics are concerned. To confirm that P7535-initiated transcripts proceed indeed to the L1 gene for the major capsid protein, viral mRNAs from an HPV8-induced lesion of a patient with EV were characterized by RNase protection and sequence analysis of polymerase chain reaction-amplified cDNAs. The NCR leader (positions 7535 to 4) appeared in two messages with three exons each. The third exon started with the second ATG codon of L1 in both cases; the short central exons from the 3' part of the early coding region were defined by a common splice acceptor site (position 3303) and different splice donor sites (positions 3443 and 3704).

Adult↗
PubMed1991

Unique topography of DNA-protein interactions in the non-coding region of epidermodysplasia verruciformis-associated human papillomaviruses.

The non-coding region (NCR) of the epidermodysplasia verruciformis (EV)-associated human papillomavirus 8 (HPV-8) has been investigated for sequence-specific DNA-protein interactions with nuclear proteins from epithelial HeLa cells. Using DNase I protection analysis 18 footprints could be found within the HPV-8 NCR, covering altogether over 60% of both DNA strands. Several footprints coincided with the known binding sites of transcription factors (NF1, AP1, octamer and PEA3 consensus sequences); the other displayed no obvious similarities in this regard. The overall distribution of sequences involved in DNA-protein interactions differed clearly from the binding patterns reported for other HPVs. Parts of the two binding sites for the viral trans-activator protein E2 were shown to interact with non-E2 factors. The EV-specific NCR motifs M33, M29 and A/T box were all involved in protein binding. By comparing the footprints within the respective motifs of the closely related types HPV-8 and -19, quantitative and qualitative differences were detected for M33 and the A/T box.

Base Sequence↗
PubMed1991

Relation of papillomaviruses to anogenital cancer.

A variety of HPV types infect the anogenital mucosa, giving rise to lesions that differ in clinical appearance, histology, and risk of malignant progression. Human papillomavirus type 16 is distinguished by a strong association with high-grade intraepithelial neoplasia and the greatest prevalence in anogenital malignancy. Most cancers appear to have a multifactorial cause, and HPV infection alone is probably insufficient for malignant transformation. The consistent association between HPV infection and anogenital cancers emphasizes that the papillomaviruses may have a necessary role in carcinogenesis, however. Hence, there is a prospect that vaccination programs may one day allow public health control of HPV infection, thereby eliminating an important risk factor.

Animals↗
PubMed1989

Human papillomavirus 16 DNA in cervical cancers and in lymph nodes of cervical cancer patients: a diagnostic marker for early metastases?

Human papillomavirus (HPV) 16 is most prevalent in cervical cancers and also persists in metastases. We examined HPV16-DNA-positive primary cancers and several lymph nodes from each of 14 patients to evaluate the use of HPV16 DNA as a diagnostic marker for the detection of early node involvement. The HPV16 DNA was exclusively integrated in 39% of the primary cancers, predominantly episomal in 36%, and integrated and extrachromosomal to a similar extent in 25%. Thirteen of 16 involved lymph nodes contained HPV16 sequences. Integrated viral DNA showed the same pattern in primary tumors and in metastases. The level of extrachromosomal HPV16 DNA, however, appeared to be considerably reduced in some nodes. HPV16 DNA was also detected in 18 out of 59 histologically negative lymph nodes. This result recommends nucleic acid hybridization as a sensitive method for the detection of HPV-DNA-positive cancer cells. The prognostic significance of viral sequences in histologically negative nodes remains to be established.

Biomarkers, Tumor↗
PubMed1988

Human papillomavirus DNA in normal, metaplastic, preneoplastic and neoplastic epithelia of the cervix uteri.

Colposcopically directed cervical punch biopsies from 362 patients were screened by Southern blot hybridization for the presence of DNA of human papillomavirus (HPV) 6, 10, 11, 16, 18, 31 and 33. The biopsies represented original squamous epithelium, epithelium of metaplastic origin, different stages of cervical intraepithelial neoplasia (CIN) and invasive carcinomas. HPV6/11, 16, 18 and 31 were detected in 2.9% to 13.7% of histologically normal epithelia. HPV6/11 prevailed in CIN I. HPV16 was clearly more abundant than other HPV types in high-grade CIN and invasive cancers (50%-60%), compared with healthy epithelium. Restriction enzyme cleavage analysis of DNA from primary cancers and corresponding metastases proved the stable association of HPV16 DNA with invasive tumor cells. Preliminary follow-up studies of CIN II patients suggested that HPV16-associated lesions are relatively more likely to persist or to progress. Taken together, the data support the notion of a higher oncogenic potential of HPV16.

Cervix Uteri↗
PubMed1988

Epidermodysplasia verruciformis in a patient with Hodgkin's disease: characterization of a new papillomavirus type and interferon treatment.

A new human papillomavirus (HPV) was discovered in disseminated, macular, pityriasis versicolor-like lesions on the skin of the neck, face, scalp, and pubic region of a 42-year-old male suffering from Hodgkin's disease. Histopathology revealed features characteristic of epidermodysplasia verruciformis (ev). In contrast to classical ev, the lesions were almost exclusively seen in previously irradiated and UV-exposed skin areas. Papillomavirus capsid antigen was demonstrated with the genus-specific antiserum and the patient's serum, which had IgM and IgG antibody titers. HPV DNA was isolated from biopsies and cloned into the vector pIC20H. It proved to be related to ev-associated viruses, showing 23% cross-hybridization with DNA of the closest relative HPV14. The new HPV type was named HPV46. The genome was physically mapped and colinearly aligned with HPV8 DNA to establish its gene organization. Interferon treatment of the patient did not significantly change the clinical picture nor was the concentration of viral DNA per lesion affected. However, no virus capsid antigen was detectable after starting treatment.

Adult↗
PubMed1986

Classification of the papillomaviruses--mapping the genome.

Papillomaviruses form one genus of the Papovaviridae family. They share common antigenic determinants and their DNAs cross-hybridize under conditions of low stringency. The classification of papillomaviruses is at present based on the host range and the relatedness of the nucleic acids. Isolates are considered independent types if there is less than 50% cross-hybridization in the liquid phase according to a standard protocol. At least 31 human and six bovine papillomavirus types can be differentiated on this basis. The host range does not reflect the natural relationship between the viruses. Subgenera, which differ in biological properties, can be distinguished in outline. Data on overall sequence homology are insufficient for a meaningful classification because two types of virus may be closely related within one genome region and rather heterogeneous in other areas. Some new isolates appear as intermediates between previously well-separated types and complicate the system. A reasonable classification of such types of papillomavirus should be based on homologies between genes that are relevant for differences in the biology of the viruses. A functional mapping of the rather uniformly organized, colinear genomes of papillomaviruses has been started. Genetic studies with bovine papillomavirus type 1 have assigned functions in replication, transformation, gene expression and capsid synthesis to individual open reading frames.

Amino Acid Sequence↗
PubMed1986

Epidermodysplasia verruciformis-associated human papillomavirus 8: genomic sequence and comparative analysis.

Human papillomavirus (HPV) 8 induces skin tumors which are at high risk for malignant conversion. The nucleotide sequence of HPV8 has been determined and compared to sequences of papillomaviruses with different oncogenic potential. The general organization of the HPV8 genome is similar to that of other types. Highly conserved, genus-specific sequences were found in open reading frames (ORFs) E1, E2, and L1. In ORFs E6, E7, and L2, HPV8 is more distantly related, but it was possible to differentiate subgenera in which HPV8 belonged to the HPV1-cottontail rabbit papillomavirus group. Sequences within ORF E4 and part of ORF L2 are rather type specific. HPV8 stands out by several unique features: the considerably reduced size of the noncoding region (397 base pairs), with a seemingly low potential for forming complex secondary structures; a cluster of putative promoter elements in the 3' half of ORF E1; an RNA polymerase III promoter-like sequence close to the C terminus of ORF E2; and of particular interest, the homology between the putative protein encoded by ORF E4 and the Epstein-Barr virus nuclear antigen 2 protein, which may reflect similar mechanisms in virus-mediated transformation.

Amino Acid Sequence↗
PubMed1985

Human papillomavirus DNA in conjunctival papilloma.

A histologically proven conjunctival papilloma was examined for the presence of papillomavirus DNA by nucleic acid hybridization under relaxed conditions. It harbored papilloma-virus-specific DNA, which showed no detectable relationship with that of known virus types when tested under stringent conditions. This demonstrates that conjunctival papillomas are associated with more than one papillomavirus type. Viral diagnosis may turn out to be of prognostic value.

Adult↗
PubMed1985

Genome organization of herpesvirus aotus type 2.

Herpesvirus aotus type 2, a virus commonly found in owl monkeys without overt disease, has a similar genome structure to the oncogenic herpesviruses of nonhuman primates (herpesvirus saimiri, herpesvirus ateles). Virion DNA of herpesvirus aotus type 2 (M-DNA) has an unique 110-kilobase-pair region of low G + C content (40.2%, L-DNA), inserted between stretches of repetitive H-DNA (68.7% G + C, about 41 kilobase pairs per molecule) that are variable in length. A minority of virions contain defective genomes that consist of repetitive H-DNA only. The H-DNA is composed of various types of repeat units that are related in sequence with each other. The two dominant types of repeats (2.3 and 2.7 kilobase pairs) were cloned and compared by restriction enzyme cleavages and partial nucleotide sequencing. They are homologous in at least 1.3 kilobase pairs. The two forms of repeat units are randomly arranged and oriented in tandem. Reassociation kinetics did not allow detection of sequence homologies between H- and L-DNA of herpesvirus aotus type 2 and the respective sequences of oncogenic primate herpesviruses.

Animals↗
PubMed1978

Enchancement of streptococcal transformation yield by proteolytic enzymes.

Trypsin and other proteolytic enzymes, added together with transforming DNA or during cell-DNA contact to competent cultures of several streptococcal strains, enchanced (10 to 600%) the yield of genetic transformation (stimulation). With few exceptions, the level of stimulation was high (over 100%) when competence was low (below 2%). Stimulation was caused by the action of an enzyme on competent cells and not on any other component of transformation mixture. The phenomenon occurred when the enzyme was added to the culture not earlier than 7 min before and not later than 5 min after the period of cell-DNA contact. The presence of trypsin during cell-DNA contact caused: (i) the alterations at cell surface, demonstrated by electron microscopy, increased release of 3H-amino acid-labeled material, and higher cell susceptibility to autolysis; (ii) the increase of both total and irreversible binding of DNA by the cells; and (iii) the decrease of early nucleolytic degradation of DNA by cells. These and other data point to the importance of a delicate balance of recipient cell's surface nuclease activities in the effectiveness of transformation process. It is also possible that trypsin eliminates an unknown cellular factor which obstructs DNA-cell receptors interaction.

DNA, Bacterial↗
PubMed1978

Competence-related increased enzyme release from Streptococcus sanguis (Wicky) cells.

The ablity of competent and noncompetent Streptococcus sanguis (strain Wicky) cells to release enzymes to the environment was studied. Both competent and noncompetent cells leaked the enzymes tested (aldolase, phosphatase and deoxyribonuclease), but the activities liberated from the competent cells were always roughly 2-fold higher than those released from noncompetent cells. This increased enzyme leakage from competent cells occured in all kinds of media and procedures employed. The leakage of enzymes followed a time-dependent kinetics (different for aldolase and phosphatase), was temperature sensitive and had a pH optimum. The increased enzyme release was most likely not due to cell disruption, but seemed to be rather a consequence of alteration in cell barrier permeability. These results strongly support the "unmasking" model proposed for explanation of competence development in bacteria.

Deoxyribonucleases↗
PubMed1975

Competitive inhibition of transformation in group H Streptococcus strain Challis by heterologous deoxyribonucleic acid.

Glucosylated deoxyribonucleic acid (DNA) from phages T4 and T6 competes poorly with homologous DNA causing only a slight decrease of transformation in Group H Streptococcus strain Challis. Other types of heterologous DNAs (Micrococcus luteus, Clostridium perfringens, Escherichia coli, calf thymus and non-glucosylated phage T6 DNA), in contrast to glucosylated T4 and T6 DNAs, compete with transforming DNA to the normal, high extent. These results indicate that as in transformation of Bacillus subtilis, the presence of glucose attached to 5-hydroxymethylcytosine in phage T6 DNA considerably decreases the interaction of such DNA with competent cells of the Challis strain. It also indicates that the guanine plus cytosine content of DNA is not decisive in determining its interaction with competent cells.

Animals↗