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Biomedical subjects

D Di Luca

Publications and source records attributed to D Di Luca.

54 records · Page 3Linked to original sources
PubMed1991

Reciprocal in vitro interactions between human herpesvirus-6 and HIV-1 Tat.

The transactivation induced by human herpesvirus 6 (HHV-6) on the HIV-1 promoter was studied both in the presence and in the absence of the retroviral transactivator protein (Tat) constitutively expressed in Jurkat cells. Jurkat-tat cells were infected with HHV-6, transfected with a plasmid containing HIV-1 long terminal repeat (LTR)/chloramphenicol acetyltransferase (CAT), and CAT assays were performed. HHV-6 infection in the presence of Tat resulted in significantly higher LTR activation than that observed by Tat or HHV-6 alone, indicating that HHV-6 and Tat interact synergically. Furthermore, it was demonstrated that expression of HIV-1 tat inhibits HHV-6 replication, as shown by a 3.6-15.4-fold reduction in infectious yield. We suggest that HHV-6 could trigger HIV reactivation in HIV-seropositive patients which, in turn, could inhibit HHV-6 production.

Cell Line, Transformed↗
PubMed1990

Experimental keratitis in rabbits by human HSV-1 variants: prevention and treatment.

The efficacy of different therapies and vaccine preparations was assessed for treating or preventing herpetic ocular keratitis induced by experimental inoculation in rabbits with two HSV-1 variants that display different pathogenetic potential. Early administration of acyclovir (ACV) promoted fast healing and prevented neurologic involvements: alpha-interferon (alpha-IFN) was less efficient than ACV; combined therapy with both drugs increased the antiviral effects. In an attempt to prevent the disease, rabbits were vaccinated with a slightly pathogenic HSV-1 variant or with a secreted form of an engineered HSV-1 glycoprotein gB (gB-1s) and were subsequently challenged with a highly pathogenic HSV-1 variant. Immunization of rabbits with gB-1s was much more efficient than immunization with live virus in reducing the severity of herpetic keratitis and in preventing CNS disease.

Acyclovir↗
PubMed1990

The replication of viral and cellular DNA in human herpesvirus 6-infected cells.

Human herpesvirus 6 (HHV-6) is a newly identified lymphotropic herpesvirus. We have analyzed viral and host DNA replication in peripheral blood lymphocytes infected in the absence of drugs or infected in the presence of phosphonoacetic acid (PAA) or acyclovir (ACV). The results revealed the following: (i) Infection with HHV-6 resulted in the shutoff of host DNA replication. (ii) PAA at concentrations of 100 and 300 micrograms/ml significantly reduced virus replication. The drug inhibited viral DNA replication, whereas host cell DNA replication was not affected. This strongly suggests that HHV-6 encodes a PAA sensitive viral DNA polymerase. (iii) ACV at 20 microM did not interfere with virus production and virus spread. ACV at 100 microM only partly interfered with virus replication, whereas at 400 microM the block was more complete. Viral DNA replication was not affected by ACV at 20 microM. However, approximately 60 and 85% inhibition in viral DNA replication was observed in the presence of 100 and 400 microM of ACV. (iv) Assays for viral thymidine kinase (TK) revealed no significant increase in TK activity, whereas increased TK activity was noted following infection of the same peripheral blood lymphocytes with herpes simplex virus. Thus, either HHV-6 does not encode a tk enzyme which can phosphorylate ACV or the inefficient block may reflect lower sensitivity of the HHV-6 DNA polymerase to the drug.

Acyclovir↗
PubMed1990

Protection from herpes simplex virus type 1 lethal and latent infections by secreted recombinant glycoprotein B constitutively expressed in human cells with a BK virus episomal vector.

The herpes simplex virus type 1 (HSV-1) glycoprotein B (gB-1) gene, deleted of 639 nucleotides that encode the transmembrane anchor sequence and reconstructed with the extramembrane and intracytoplasmic domains, was cloned under control of the Rous sarcoma virus long terminal repeat in the episomal replicating vector pRP-RSV, which contains the origin of replication and early region of the human papovavirus BK as well as a cDNA for a mutant mouse dihydrofolate reductase that is resistant to methotrexate. gB-1 (0.15 to 0.25 pg per cell per 24 h) was constitutively secreted into the culture medium of pRP-RSV-gBs-transformed human 293 cells. Treatment of transformed cells with methotrexate at high concentrations (0.6 to 6 microM) increased gB-1 production 10- to 100-fold, because of an amplification of the episomal recombinant. Mice immunized with secreted gB-1 produced HSV-1- and HSV-2-neutralizing antibodies and were protected against HSV-1 lethal, latent, and recurrent infections. Constitutive expression of secreted gB-1 in human cells may establish a system to develop diagnostic material and a subunit vaccine for HSV infections.

Animals↗
PubMed1990

Vulvar carcinomas: search for sequences homologous to human papillomavirus and herpes simplex virus DNA.

Ten cases of intraepithelial carcinoma, five with Bowenoid features and five with early invasion, and ten cases of invasive vulvar carcinoma were examined by in situ hybridization and Southern blot analysis using DNA probes for human papillomavirus (HPV) types 6, 11, 16, 18 and 31. HPV DNA was detected in 90% of the intraepithelial cases and in 10% of the invasive cases. All positive cases showed the presence of DNA of HPV type 16. The cases with intraepithelial lesions revealed a strong correlation between the presence of HPV type 16 DNA, cigarette smoking habit, other potential cofactors such as herpes simplex (HSV) DNA sequences and the use of contraceptive drugs, and clinicopathologic features of Bowen's type in situ squamous cell carcinoma. Similar associations were not observed among the cases with invasive disease. While HPV-16 is associated with differentiated Bowenoid type vulvar intraepithelial neoplasia, which appears to be the most common form of early carcinoma of the vulva, the same association was not seen with respect to advanced vulvar invasive squamous cell carcinoma.

Base Sequence↗
PubMed1990

Search for herpes simplex virus 2 and human papillomavirus genetic expression in vulvar neoplasia.

Specimens from vulvar carcinomas and vulvar intraepithelial neoplasia (VIN) of various degrees were analyzed for the presence of herpes simplex virus 2 (HSV 2) and human papillomavirus (HPV) genetic information. A search for the HPV 16 E6 protein as well as the HSV 2 antigenic determinant LA1 and ICSP 11/12 protein was carried out with an immunoperoxidase assay on 12 vulvar carcinomas and 6 VINs. Seven invasive cancers and four VINs were screened for the presence of homology to HPV 16 DNA and HSV 2 DNA transforming sequences with Southern blot hybridization. We used specimens from labial tumors and from normal vulvas and cervixes as controls. The preliminary results showed that one vulvar carcinoma and two VINs contained HPV 16 DNA. Four vulvar carcinomas expressed the E6 protein, while all the VINs were negative. Homology to HSV 2 DNA transforming sequences was detected in one vulvar cancer but not in any VIN cases. Positivity to HSV 2 ICSP 11/12 was observed in 33.3% of VIN cases and 75% of invasive cancers. HSV 2 LA1 antigenic determinant was expressed in 33.3% of VIN and 66.6% of cancer cases.

Adult↗
PubMed1989

Search for human papillomavirus, herpes simplex virus and c-myc oncogene in human genital tumors.

We tested grade III cervical intra-epithelial neoplasms (CIN III), genital invasive carcinomas and healthy genital tissues for the presence of a number of viral and cellular parameters, considered to be risk factors in genital oncogenesis. The results show that: (I) about 30% of genital tumors had homology to HSV-2 BglII N and/or BamHI E DNA fragments; (2) positivity to HSV-2-specific protein ICP10, encoded by sequences within the HSV-2 BamHI E DNA fragment, was detected in 29/55 neoplastic genital tissues but not in healthy genital tissues or tumors at other sites; (3) HPV-16 DNA was found in about 50% of tumor samples, but none of the positive tissues reacted to HPV capsid protein or to the protein encoded by the HPV-16 E6 ORF; (4) 6/8 tumor samples showing homology to HSV-2 DNA fragments also hybridized to HPV-16 DNA; (5) c-myc amplification was not detected in any of the analyzed samples, but tissues from 4 patients were positive for c-myc expression. None of the considered factors was present in all the analyzed samples; nevertheless, some tissues showed the simultaneous involvement of several parameters, suggesting that a number of risk factors may be involved in different steps of human genital oncogenesis.

Adenocarcinoma↗
PubMed1989

Episomal HPV 16 DNA isolated from a cervical carcinoma presents a partial duplication of the early region.

An invasive cervical carcinoma was found to harbor an episomal variant of human papillomavirus (HPV) type 16 DNA, with a size of about 10.1 kb. A genomic library of the tumor was constructed in bacteriophage lambda and a recombinant phage clone was isolated by screening with HPV 16 probe. Analysis by restriction mapping and Southern hybridization showed that the isolate contained a 2.2 kb duplication of the early region, which included part of E6, all E7 and part of E1 open reading frames. Possible consequences of this duplication for oncogenesis are discussed.

DNA Probes, HPV↗
PubMed1988

Comparative study of two strains of Bovid herpesvirus-4.

Two strains of Bovid herpesvirus-4 (BHV-4), i.e. the prototype strain DN-599, obtained from a steer suffering of a respiratory disease, and the strain 85/BH 16TV, originated from a cow with vulvovaginitis, were compared in studies which included restriction endonuclease analysis, experimental infection and reciprocal cross protection tests. The restriction endonuclease analysis revealed that the resultant DNA patterns of the isolates were generally similar with only a difference in one fragment. The two strains were capable of causing respiratory tract infection in calves, even if they displayed a different level of virulence: the strain 85/BH 16TV being the most virulent while the strain DN-599 the least. The two viral strains were mutually protective in that the calves were generally found to be refractory to challenge inoculation with either the homologous or the heterologous virus. Finally, both viral strains failed to evoke the production of neutralizing antibody in the experimental calves.

Animals↗
PubMed1987

Simultaneous presence of herpes simplex and human papilloma virus sequences in human genital tumors.

Herpes simplex virus (HSV) and human papillomavirus (HPV) sequences were analyzed in tumors of the female lower genital tract, by probing DNA from 13 intraepithelial and 30 invasive neoplastic lesions with radiolabelled HPV-16 and HPV-18 DNA as well as cloned fragments of HSV-2 DNA. Careful removal of stromal tissue from the pathological specimens allowed authentic tumor DNA to be processed. Normal genital tissue obtained from the patients and genital condylomata were included as internal controls. The presence of HPV-16 or 18 DNA was detected in 12/13 (92.3%) intraepithelial neoplasms and in 16/30 (53.3%) invasive carcinomas. No significant difference was detected in titer or frequency of antibodies to HPV group-specific antigen in sera from patients and controls. Hybridization to BgIII N fragment of HSV-2 DNA was detected in 4/13 (30.8%) intraepithelial neoplasms and 4/30 (13.3%) invasive carcinomas but in none of the control tissues. All the 8 samples harboring HSV-2 homologous sequences were also positive for HPV, supporting the hypothesis of a synergistic association between the 2 viruses. The hybridization analyses performed to study c-myc involvement in genital oncogenesis did not reveal c-myc amplification in either invasive or pre-invasive lesions.

Antibodies, Viral↗
PubMed1986

Sequences homologous to two separate transforming regions of herpes simplex virus DNA are linked in two human genital tumors.

Ten human genital invasive squamous cell carcinomas and five human premalignant tissues were analyzed for the presence of selected sets of herpes simplex virus 2 (HSV-2) DNA sequences. Two vulvar tumors and one vulvar dysplastic tissue were found to contain DNA sequences homologous to the BglII O fragment (coordinates 0.38-0.42) and the BglII N fragment (coordinates 0.58-0.63) of HSV-2 DNA. These two fragments overlap the subsets of HSV-1 and HSV-2 DNA sequences (respectively) shown previously to transform cells in culture. Sequences homologous to an additional HSV-2 DNA probe (BglII G) were not detected in the same tumors. Surprisingly, in each of the two positive vulvar tumors, the BglII N and BglII O sequences appeared to be linked, whereas in the standard HSV-2 genome the two fragments are separated by approximately 26 kb. This finding suggested that the two sets of sequences may have rearranged prior to or following the association of the HSV DNA sequences with the tumor cells. The same set of 10 tumors were analyzed for the presence of sequences complementary to human papillomavirus 16 (HPV16) DNA. The HPV16 DNA probe hybridized to three of six cervical tumors, whereas no hybridization was detected with the two vulvar tumors which contained the HSV DNA sequences.

Cell Transformation, Viral↗
PubMed1986

Search for HSV DNA in genital, cerebral and labial tumors.

DNA sequences homologous to HSV-1 and HSV-2 DNA fragments were searched in 64 genital, 35 labial and 34 cerebral tumors. Southern blot transfers of tumor and control DNAs were hybridized in stringent conditions with 32P labelled probes from HSV-1 and HSV-2 cloned DNA fragments. Specific hybridization to HSV-2 BglII N fragment was observed in six (9.4%) genital tumors. Labial and cerebral tumors did not show hybridization to any of the probes used. The technique employed allowed the detection of 0.1 copies of viral fragments per diploid genome.

Base Sequence↗
PubMed1986

Human papillomavirus type 16 DNA in genital tumours: a pathological and molecular analysis.

The presence of human papillomavirus type 16 (HPV16) DNA in 34 genital tract tumours of Italian female patients was investigated by Southern blot hybridization in high stringency conditions. HPV16 DNA was detected in 16 neoplasias, including cervical invasive and intraepithelial lesions as well as vulvar intraepithelial neoplasias and, to a lesser extent, vulvar invasive carcinomas. Appropriate control tissues included in the study were negative. The data suggest that integration of viral DNA had occurred in most tumours, both in invasive and in intraepithelial lesions. HPV16 variants or defective genomes, lacking the BamHI restriction site, were detected in three tumours.

Carcinoma, Squamous Cell↗
PubMed1984

Herpes simplex virus latency in immunosuppressed mice.

To determine the role of antibodies in establishing Herpes simplex virus (HSV) latency, immunosuppressed Swiss mice were experimentally infected in the right hind footpad with a HSV-1 x HSV-2 recombinant (C6D) with low virulence. Immunosuppression was induced by repeated intraperitoneal inoculations of Cyclophosphamide (CY) and the production of antibodies to C6D in immunosuppressed animals was monitored by Enzyme Linked Immunosorbent Assay (ELISA). Within 21 days after inoculation, C6D was able to establish a latent infection of lumbosacral spinal ganglia in both normal and CY-treated immunosuppressed animals. The data presented indicate that detectable production of antibodies is not necessary to induce HSV latency in spinal ganglia.

Animals↗
PubMed1983

Herpes simplex virus and human cancer. III. Search for relationship of herpes simplex antibodies and cervical dysplasia and labial neoplasia.

We employed the enzyme-linked immunosorbent assay (ELISA), indirect hemagglutination (IHA), and complement fixation (CF) methods to measure antibody titer to herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in patients affected by labial tumors or cervical dysplasias. No relationship of antibody titer to HSV-1 and labial tumors was detected by any of the three methods. Association between antibody titer to HSV-2 and cervical dysplasias was revealed by IHA (p less than 0.05) and ELISA (p less than 0.001); CF tests were negative. Moreover, we assayed for HSV-specific antigens in cell cultures derived from labial tumors and cervical dysplasias. In cultures from labial tumors, it was not possible to detect HSV-specific antigens. Of the 25 cultures derived from cervical dysplasias, HSV antigens were found in only 3 cultures.

Adult↗
PubMed1980

Comparative analysis of the virion polypeptides specified by herpes simplex virus type 2 strains.

This paper reports on the variability of structural polypeptides of 32 strains of Herpes simplex virus 2 (HSV-2) isolated from various locations in the United States and Italy. Most strains were passaged a limited number of times at low multiplicity outside the human host; a few strains were characterized by numerous passages at variable multiplicities in cell culture. The acrylamide gel electrophoresis of polypeptides from purified virions revealed very few differences. Considering these differences the HSV-2 strains analysed can be classified into 3 groups according to the variability of three polypeptides. The study of polypeptides in HSV-2 infected cells revealed more differences than those seen in the structural proteins. Comparisons of the structural proteins specified by HSV-2 and HSV-1 virions, revealed clear variant features of the electrophoretic profiles, especially when pH of main gel was 8.9.

Electrophoresis, Polyacrylamide Gel↗
PubMedDate not supplied

[HHV-6, new perspectives].

HHV-6 is the etiological agent of Exanthema subitum, and its role in human infection is well known. Recently, molecular diagnostics tools showed for HHV-6 new pathogenetic features and new clinical implication. The present paper highlights recent knowledge on HHV-6 infection and presents a number of results concerning HHV-6 infection in children who had undergone BMT and concerning the roles of endothelial cells as viral reservoir.

Adult↗