Incidence and persistence of carcinogenic genital human papillomavirus infections in young women with or without Chlamydia trachomatis co-infection.

We assessed whether infection with chlamydia increases the incidence of carcinogenic human papillomavirus (HPV) infections and if HPV persistence is affected by chlamydia co-infection. For 1982 women (16-29 years-old) participating in two consecutive rounds of a chlamydia screening implementation trial, swabs were polymerase chain reaction tested to detect chlamydia and 14 carcinogenic HPV genotypes. HPV type-specific incidence and persistence rates were stratified for chlamydia positivity at follow-up. Associations were assessed by multilevel logistic regression analyses with correction for sexual risk factors. HPV type-specific incidence ranged from 1.4% to 8.9% and persistence from 22.7% to 59.4% after a median follow-up of 11 months (interquartile range: 11-12). Differences in 1-year HPV persistence rates between chlamydia -infected and noninfected women were less distinct than differences in HPV incidence rates (pooled adjusted odds ratios of 1.17 [95% CI: 0.69-1.96] and 1.84 [95% CI: 1.36-2.47], respectively). The effect of chlamydia co-infection on HPV-infection risk did not significantly differ by HPV genotype. In conclusion, infection with chlamydia increases the risk of infection by carcinogenic HPV types and may enhance persistence of some HPV types. Although these findings could reflect residual confounding through unobserved risk factors, our results do give reason to explore more fully the association between chlamydia and HPV type-specific acquisition and persistence.

Chlamydia trachomatis load in population-based screening and STI-clinics: implications for screening policy.

OBJECTIVES: If the Chlamydia trachomatis (CT) bacterial load is higher in high-risk populations than in the general population, this negatively affects the efficacy of CT screening incentives. In the largest retrospective study to date, we investigated the CT load in specimens collected from 2 cohorts: (1) attendants of a sexually transmitted infection (STI)-clinic and (2) participants of the Dutch population-based screening (PBS). METHODS: CT load was determined using quantitative PCR in CT-positive male urine and female cervicovaginal swabs. CT loads were converted into tertiles. Using multinominal logistic regression, independent association of cohort, symptoms, risk behaviour and human cell count on load were assessed. RESULTS: CT loads were determined in 889 CT-positives from PBS (n = 529; 71.8% female) and STI-clinics (n = 360; 61.7% female). In men, STI-clinic-cohort, human cell count and urethral discharge were positively associated with CT load. In women, PBS-cohort and cell count were positively associated with CT load. Both cohorts had the same range in CT load. CONCLUSIONS: The general population has a similar range of bacterial CT load as a high-risk population, but a different distribution for cohort and gender, highlighting the relevance of population-based CT-screening. When CT loads are similar, possibly the chances of transmission and sequelae are too.

Prevalence, incidence and persistence of genital HPV infections in a large cohort of sexually active young women in the Netherlands.

BACKGROUND: We assessed age- and type-specific HPV prevalence, incidence and persistence and their associated risk factors in young women prior to vaccination, to enable monitoring of the impact of introduction of HPV vaccination in the years before participation in the cervical screening program. METHODS: The HPV status was assessed in 3282 women aged 16-29 who participated in a Chlamydia trachomatis screening implementation program, of which 2014 women (61%) participated in two rounds (one year apart). Self-collected vaginal swab were analyzed by SPF(10) LiPA on the presence of HPV DNA. Risk factors for prevalent, incident and persistent HPV infections were calculated using generalized estimating equation. RESULTS: The prevalence of any HPV in the first round amounted to 54%, while 34% of the women who participated in the second round had a persistent infection and 45% an incident infection. The five most common HPV types found in this study were HPV16, -51, -52, -31 and -53. HPV16 and/or HPV18 prevalence, incidence and persistence in the second round were 15%, 8% and 9%, respectively and for HPV6 and/or HPV11 6%, 4% and 2%, respectively. Relatively to other HPV genotypes, hrHPV types were found more often as a persistent infection than as an incident infection. Furthermore, there is an age-dependent increase within this age range for persistent infections but not for incident infections. CONCLUSION: The HPV prevalence (54%), incidence (45%) and persistence (34%) is high among sexually active young women in the Netherlands. The different HPV type distribution and risk factors for prevalent, incident and persistent infections, as well as the observed age-trends should be taken into account in interpreting data obtained after vaccine introduction. Repeating measurements post-immunization are particularly relevant until the age when screening starts (i.e. 30 years in the Netherlands).

Compartmentalization of acyclovir-resistant varicella zoster virus: implications for sampling in molecular diagnostics.

BACKGROUND: Acyclovir resistance of varicella zoster virus (VZV) may arise in stem cell transplant (SCT) recipients with VZV disease and is usually a result of mutations in VZV thymidine kinase (TK), which is the target protein of acyclovir. Early detection of such mutations is necessary to enable timely therapy adaptation, for example, to foscarnet. We aimed to investigate whether TK mutations arise over time, and what sample types might be the most useful for this method. METHODS: Spatially and temporally distinct samples from 3 SCT recipients with VZV disease unresponsive to acyclovir treatment were retrospectively investigated for the presence of TK mutations by polymerase chain reaction and sequence analysis. RESULTS: In all 3 patients, a mutation in the VZV TK coding region was found resulting in an amino acid substitution. TK mutations were not only temporally but also spatially compartmentalized. In particular, plasma samples frequently showed wild-type TK sequences, whereas cerebrospinal fluid or skin vesicle fluid acquired on the same day contained mutant sequences. CONCLUSIONS: This study shows the importance of careful sampling for molecular diagnostics of acyclovir resistance in VZV disease. All affected body sites should be sampled and plasma samples may not be representative for the viral mutation status.

Intra-operative rapid diagnostic method based on CK19 mRNA expression for the detection of lymph node metastases in breast cancer.

Staging by sentinel node (SN) biopsy is the standard procedure for clinically node-negative breast cancer patients. Intra-operative analysis of the SN allows immediate axillary lymph node (ALN) dissection in SN positive patients, but a quick, reliable and reproducible method is lacking. We tested the suitability of a quantitative cytokeratin 19 (CK19) mRNA one step nucleic acid amplification (OSNA#) technique (OSNA-CK19) for intra-operative SN analysis. OSNA-CK19 involves a short manual sample preparation step and subsequent fully automated amplification of CK19 mRNA based on reverse transcription loop-mediated isothermal amplification, with results available within 30-40 min. OSNA-CK19 was compared to histological staining (Hematoxylin&Eosin and CAM5.2 and CK19 immunostaining) of 346 frozen ALNs from 32 breast cancer patients, using half of the lymph node for each method. 267 samples were negative and 61 positive by both methods. Three samples were histology positive and OSNA-CK19 negative. Fifteen samples were histology negative and OSNA-CK19 positive, 11 of which had copy numbers close to the cut-off level of OSNA-CK19. Seven of these 15 samples were RT-PCR positive for epithelial markers and/or showed CK19 protein expression by Western blot suggesting the presence of tumor deposits in the lymph node part investigated by OSNA-CK19. Concordance with histology was 94.8%, and 96.8% after exclusion of the latter 7 discordant cases. Sensitivity was 95.3% and specificity was 94.7% before and 97.1% after discordant case investigation. Our results indicate that OSNA-CK19 can potentially be useful in an intra-operative clinical setting to detect SN tumor involvement in breast cancer patients.

HPV detection methods.

Given the causal relation between a persistent high-risk human papillomavirus (hrHPV) infection and the development of high-grade cervical intraepithelial neoplasia (CIN) and cervical cancer, hrHPV testing has been advocated in addition to cytology for the detection of clinically relevant cervical lesions. HrHPV testing is thought to improve cervical screening algorithms, the management of women with cytologically equivocal smears, and the management of women treated for high grade CIN. In this chapter we discuss different methods for HPV detection and genotyping and their respective applications.

Functional CD8+ T cells infiltrate into nonsmall cell lung carcinoma.

Infiltration of CD3(+)CD8(+) cytotoxic T cells was analyzed by multiparameter confocal laser microscopy in a panel of 16 randomly selected stage I nonsmall cell lung carcinomas. T-cell infiltration was observed in the stroma (range 57-2,093 T cells/mm(2)) but also in the tumor epithelium (range 21-892 T cells/mm(2)) and showed wide variation between individual tumors. Interestingly, a significantly higher percentage of CD3(+)CD8(+) T cells was detected in the tumor epithelium compared to the stroma illustrating that cytotoxic T cells may preferentially migrate into tumor epithelium. Aberrant HLA class I antigen expression was observed in 69% of the nonsmall-cell lung carcinoma (NSCLC) tumors. One tumor of a squamous cell lung carcinoma patient with the highest number of tumor infiltrating CD3(+) and CD3(+)CD8(+) cells was studied in detail and the majority (90%) of these cells were shown to be functionally activated granzyme B-positive cytotoxic T cells. DNA oligotyping of a lung carcinoma cell line established from this tumor revealed loss of one HLA haplotype corresponding with a translocation involving chromosome 6, as observed by COBRA-FISH. HLA class I-restricted tumor specific T cells could be isolated from PBMC. One further characterized cytotoxic CD8(+) T cell clone, that released TNF-alpha, IFN-gamma, and granzyme B upon co-incubation with the autologous tumor cells, was shown to be restricted by the remaining HLA-A11 allele, which was also shown to be expressed in the tumor tissue. Our data indicate that, despite HLA-haplotype loss a vigorous antitumor immune response mediated by CD8(+ )T-cells can be present in NSCLC offering possibilities for specific immunotherapy.

High concordance of results of testing for human papillomavirus in cervicovaginal samples collected by two methods, with comparison of a novel self-sampling device to a conventional endocervical brush.

A user-friendly self-sampling method for collecting representative cervical cell material would lower the threshold for women to respond to the invitation for cervical screening. In the present article, we introduce such a device; we have evaluated its sensitivity and specificity to detect high-grade cervical intraepithelial neoplasia (CIN), via high-risk human papillomavirus (hrHPV) detection and liquid-based cytology (LBC), compared to endocervical brush samples obtained by gynecologists. Women who had a cervical smear reading of moderate dyskaryosis or worse or a repeat equivocal Pap smear result in the cervical screening program (n=64) and healthy volunteers (n=32) took a self-obtained sample at home prior to their visit to the gynecological outpatient department. At the outpatient department, an endocervical brush smear was taken, followed by colposcopy and biopsy whenever applicable. Both self-obtained samples and endocervical brush samples were immediately collected in Surepath preservation solution and used for LBC and hrHPV testing (by general primer-mediated GP5+/6+PCR). hrHPV test results showed a good concordance between the two sample types (87%; kappa=0.71), with sensitivities for prevalent high-grade CIN that did not differ significantly (92% and 95%; P=1.0). The hrHPV test on self-obtained samples proved to be at least as sensitive for high-grade CIN as cytology on endocervical brush samples (34/37 versus 31/37; P=0.5). LBC showed a poor concordance between self-obtained and endocervical brush samples (60%; kappa=0.27). In conclusion, self-obtained samples taken by this novel device are highly representative of the hrHPV status of the cervix. In combination with hrHPV testing, the use of this device may have implications for increasing the attendance rate for cervical screening programs.

HPV testing in cervical screening.

High-risk human papillomavirus (hrHPV) bearing cervical intraepithelial neoplasia (CIN) is considered, as the real precursor lesion of cervical cancer and persistence of an hrHPV infection is necessary for the progression to cervical cancer. This knowledge warrants the use of hrHPV testing as an adjunct to cervical cytology in population-based screening programmes and for monitoring therapy efficacy of high-grade CIN lesions. Replacement of cytology by hrHPV testing altogether is considered, but for this to be (cost-) effective, accurate information about the specificity of the hrHPV test is required. Additional test systems that can be used to stratify women with a positive hrHPV test are HPV genotyping, viral load analysis and hrHPV mRNA analysis. The need for HPV genotyping of cervical smears is illustrated by the increased risk for high-grade cervical lesions associated with HPV types 16 and 18. In particular, for women who have normal but persistently (>1 year) HPV18-positive smears, endocervical curettage is suggested (evidently considering the age and possible future pregnancies of the respective woman) because HPV18 is associated with glandular lesions in the cervix, which are difficult to detect by cytology.

Development of a general-primer-PCR-reverse-line-blotting system for detection of beta and gamma cutaneous human papillomaviruses.

The beta and gamma genera of papillomaviruses consist of epidermodysplasia verruciformis-related human papillomaviruses (HPVs) and phylogenetically related cutaneous HPVs. Here, we have developed a consensus primer PCR assay and reverse line blot typing system coupled thereto (referred to as beta and gamma cutaneous HPV PCR [BGC-PCR]) for detection and typing of 24 beta and gamma HPVs (HPV types 4, 5, 8, 9, 12, 14, 15, 17, 19, 20, 21, 22, 23, 24, 25, 36, 37, 38, 47, 48, 49, 50, 60, and 65). Because the HPV-specific PCR products are only 72 bp in size, the system is suitable for formalin-fixed, paraffin-embedded specimens and other samples in which the DNA is of suboptimal quality. This system was able to detect and type as little as 100 ag to 1 fg HPV DNA per reaction (depending on the HPV type) in a background of 100 ng human DNA without any cross-reactivity between the tested types. Beta and gamma HPVs were detected in DNA extracted from plucked eyebrow hairs of 31 of 34 renal transplant recipients. In addition, formalin-fixed, paraffin-embedded specimens from nonmelanoma skin tumors of renal transplant recipients (n = 25) and immunocompetent individuals (n = 15) scored BGC-PCR positive in 21 and 6 cases, respectively, with HPV type 5 (HPV5) and HPV8 being the predominant types. The data indicate that this method can be a valuable, user-friendly tool for the detection and typing of cutaneous HPV in clinical specimens and may have implications for future monitoring of vaccines or alternative treatment modalities for diseases caused by these cutaneous HPVs.

Genomic stability and functional activity may be lost in telomerase-transduced human CD8+ T lymphocytes.

To obtain the large amount of T cells required for adoptive immunotherapy in a clinical setting, T-cell lifespan extension by human telomerase reverse transcriptase (hTERT) transduction is of particular interest. However, constitutive expression of hTERT is associated with malignant transformation and thus warrants a detailed evaluation of the safety of hTERT-transduced T cells before clinical application. In view of this, we performed an extensive cytogenetic analysis of hTERT-transduced MART-1 (melanoma antigen recognized by T cell 1)-and human papillomavirus type 16 (HPV16) E7-specific human CD8+ cytotoxic T lymphocytes (CTLs), reactive against melanoma and cervical carcinoma, respectively. Our results, obtained by (spectral) karyotyping and array comparative genomic hybridization, showed the development of minor chromosomal aberrations in an hTERT-transduced MART-1-specific CTL clone, whereas severe clonal aberrations were detected in an hTERT-transduced HPV16 E7-specific CTL clone. Furthermore, hTERT transduction did not protect CTLs from immunosenescence, because the HPV16 E7-specific, hTERT-transduced CTL clone showed a decreased functional activity on prolonged culture. Although the general frequency of major chromosomal aberrations in hTERT-transduced CTLs and the in vivo significance of our observations remain still unclear at this point, the currently available data suggest that clinical application of hTERT-transduced CTLs should proceed with caution.

HPV-mediated transformation of the anogenital tract.

Infection with high-risk human papillomavirus (HR-HPV) has been associated with intraepithelial neoplasia and carcinomas at various sites of the anogenital tract, including the cervix, vulva, vagina, penis and anus. Although HR-HPV is a necessary cause for cervical cancer, the majority of anal cancers and a subset of cancers at other genital sites, additional (epi)genetic events are required for malignant transformation. HPV-mediated transformation of human epithelial cells has been recognized as a multi-step process resulting from deregulated transcription of the viral oncogenes E6 and E7 in the proliferating cells. Interference of E6 and E7 with cell cycle regulators induces genetic instability, which drives the continuous selection of oncogenic alterations providing cells with a malignant phenotype. Early genetic events during cervical carcinogenesis associated with immortalization, include deletions at chromosomes 3p, 6 and 10p, whereas amongst others gain of chromosome 3q, loss of chromosome 11 and epigenetic alterations such as inactivation of the TSLC1 tumor suppressor gene represent later events associated with tumor invasion.

Complex biallelic IGH rearrangements in IgM-expressing Z-138 cell line: Involvement of downstream immunoglobulin class switch recombination.

Chromosomal translocations involving the immunoglobulin (Ig) receptor loci usually disrupt and silence these loci. On the basis of observations in follicular lymphoma (FL) with downstream Ig heavy chain (IGH) class switch recombination (CSR), we hypothesized that downstream CSR-mediated chromosomal translocations would leave the V(D)J-Cmu transcription unit intact, thereby still allowing IgM expression from the IGH allele involved in the translocation. To test this hypothesis, we analyzed biallelic IGH translocations in the IgM-expressing cell line Z-138 by interphase FISH, DNA fiber-FISH, long-distance vectorette PCR, and DNA sequencing. One IGH allele was involved in a t(11;14), showing a break in the JH region that juxtaposed the Emu enhancer and the 3' Calpha enhancers to the cyclin D1 gene. The other IGH allele contained a t(8;14) breakpoint involving the 3' end of a Sgamma region, whereas the reciprocal breakpoint at 8q24 was approximately 40 kb centromeric of MYC. Molecular analysis showed that this IGH allele harbored a normal V(D)J-Cmu complex, which is responsible for IgM expression. These data show that chromosomal breakpoints such as the t(8;14) can occur in downstream IGH constant regions and do not necessarily interfere with Ig expression.

Profiling of Epstein-Barr virus latent RNA expression in clinical specimens by gene-specific multiprimed cDNA synthesis and PCR.

We describe a two-step RT-PCR method for simultaneous detection of EBNA-1 (QK and Y3K splice variants), EBNA-2, LMP-1, LMP-2a and -2b, ZEBRA, and BARTs RNA encoded by Epstein-Barr virus. As a control for RNA integrity, the low-copy-number transcript derived from U1A snRNP, a cellular housekeeping gene, is coamplified. Copy DNA (cDNA) for these nine targets is simultaneously synthesized in a gene-specific, multiprimed cDNA reaction, which strongly reduces the amount of required clinical specimen and allows more sensitive detection than random hexamer or oligo-dT priming. For amplification, cDNA synthesis is followed by nine separate PCRs for the mentioned targets. Primers were designed either as intron-flanking, to avoid background DNA amplification, or in different exons, allowing identification of differentially spliced RNA molecules. To increase specificity, PCR products are detected by autoradiography after hybridization with radiolabeled internal oligonucleotide probes. The method described is highly suitable for profiling EBV latent RNA expression in tissue biopsies, cultured or isolated cells, and unfractionated whole blood and for definition of EBV latency type I, II, or III gene expression in these samples.

Positioning of cervical carcinoma and Burkitt lymphoma translocation breakpoints with respect to the human papillomavirus integration cluster in FRA8C at 8q24.13.

Molecular cytogenetic analysis frequently shows human papillomavirus (HPV) integration near translocation breakpoints in cervical cancer cells. We have recently described a cluster of HPV18 integrations in the distal end of the common fragile site FRA8C at 8q24 in primary cervical carcinoma samples. Chromosome band 8q24 contains the MYC gene (alias c-MYC), FRA8C, and FRA8D. The MYC gene is frequently deregulated--usually by translocation or amplification--in various tumor types. In the present study, we performed a molecular cytogenetic analysis of HPV18 integration patterns and the 8q24 translocation in a primary cervical carcinoma and in HeLa cells using combined binary ratio-fluorescence in situ hybridization. Our aim was to determine how the chromosomal breaks involved in these events relate physically to the MYC gene; whether they map to the FRA8C site, the FRA8D site, or both; and how they correlate with the occurrence of DNA flexibility domains. The 8q24 translocation breakpoints mapped between stretches of integrated HPV18 sequences in the distal end of FRA8C. This region contained DNA helix flexibility clusters, several of which mapped in the vicinity of HPV integration sites and translocation breakpoints in cervical carcinomas. DNA helix flexibility clusters were also found near known MYC translocation breakpoints in Burkitt lymphomas (BL), but most BL breakpoints mapped clearly outside FRA8C. Our data revealed that FRA8C is involved in HPV integration and chromosomal translocations in cervical carcinoma; however, this fragile site is not involved in classical MYC translocations in most BLs. In the context of the familial nature of cervical cancer, FRA8C may be considered a candidate susceptibility region for cervical carcinoma.

Comparison of hybrid capture 2 with in situ hybridization for the detection of high-risk human papillomavirus in liquid-based cervical samples.

BACKGROUND: The performance of two commercially available detection systems for high-risk HPV (hrHPV), Hybrid Capture 2 (HC2) and in situ hybridization (ISH), were compared on cervical scrapings. METHODS: Using general primer (GP)-mediated GP5+/6+-polymerase chain reaction (PCR)-enzyme immunoassay and reverse line blot genotyping, 76 liquid-based cervical samples were identified with > or = 1 of the 12 hrHPV types present in the probes of the HC2 and ISH assays. The positivity rate of the assays and the HC2 viral load were determined and related to cytologic findings (n = 76 samples) and histologic findings (n = 43 samples). RESULTS: Overall, HC2 scored significantly more samples positive compared with ISH (P < 0.01). Seventy-four of 76 samples (97%) were positive according to HC2. Forty-six of 76 samples (61%) were positive according to ISH, including 80% and 70% of samples that were classified cytologically as moderate dysplasia and severe dysplasia, respectively. All women with underlying cervical intraepithelial neoplasia (CIN) lesions and 67% of women without CIN had positive HC2 samples. ISH scored 33%, 66%, 88%, and 73% of samples positive of women with no CIN, Grade 1 CIN (CIN 1), CIN 2, and CIN 3, respectively. The HC2 viral load was significantly higher in women who had a cytologic diagnosis of dysplasia (P < 0.01) and in women who had an underlying diagnosis of CIN (P < 0.01) compared with women who had neither. In addition, the viral load was significantly higher in ISH positive samples compared with ISH negative samples (P < 0.01). CONCLUSIONS: An increased HC2 viral load was associated with an increased chance of underlying high-grade CIN disease in women who tested hrHPV GP5+/6+-PCR positive. Moreover, although positive ISH results were associated with an increased overall viral load in the sample, the analytic sensitivity of ISH was too low to detect all women with prevalent high-grade CIN.

Preferential integration of human papillomavirus type 18 near the c-myc locus in cervical carcinoma.

The development of cervical cancer is highly associated with human papillomavirus (HPV) infection. Greater than 99% of all cervical tumors contain HPV DNA. Integration of high-risk HPV has been temporally associated with the acquisition of a malignant phenotype. Recent work from our lab has shown that HPV16, the most common high-risk HPV associated with cervical carcinoma, preferentially integrates at loci containing human common fragile sites (CFSs). CFSs are regions of genomic instability that have also been associated with deletions, translocations, and gene amplification during cancer development. The current work shows that HPV18, the second most prevalent high-risk HPV type found in cervical tumors, preferentially targets the CFSs. We identified 27 unique HPV18 integrations in cervical tumors, of which 63% (P<0.001) occur in CFSs. However, the distribution of HPV18 integrations found were profoundly different from those found for HPV16. Specifically, 30% of all HPV18 integrations occurred within the chromosomal band 8q24 near the c-myc proto-oncogene. None of the HPV16 integrations occurred in this region. Previous low-resolution mapping suggested that c-myc may be a target of HPV integration. Our data at nucleotide resolution confirm that in HPV18-positive cervical tumors, the region surrounding c-myc is indeed a hot spot of viral integration. These results demonstrate that CFSs are preferred sites of integration for HPV18 in cervical tumors. In addition, we have identified multiple cellular genes that have been disrupted by HPV18 integration in cervical tumors. Our results suggest that the sites of HPV18 integration are nonrandom and may play an important role in the development of cervical tumors.

In vivo transcription of the Epstein-Barr virus (EBV) BamHI-A region without associated in vivo BARF0 protein expression in multiple EBV-associated disorders.

The in vivo expression of the Epstein-Barr virus (EBV) BamHI-A rightward transcripts (BARTs) as well as the putative BART-encoded BARF0 and RK-BARF0 proteins in various EBV-associated malignancies was investigated. RT-PCRs specific for the different splice variants of the BARTs and both a nucleic acid sequence-based amplification assay and an RT-PCR specific for the BARF0 ORF were used. Abundant transcription of BARTs was found in EBV-associated Hodgkin's lymphomas, Burkitt's lymphomas (BL), T-cell non-Hodgkin's lymphomas, post-transplant lymphoproliferative disorders, AIDS-related lymphomas and gastric carcinomas. Using RNA in situ hybridization (RISH), BARTs were detected within the neoplastic cells of these malignancies. BARTs encoding RK-BARF0 were not detected. The BARTs detected were shown possibly to encode the RPMS1 and BARF0 proteins, based on their splicing. However, BARTs actually harbouring the BARF0 ORF were detected only in specimens containing a relatively large number of EBV-positive cells. New monoclonal antibodies against the BARF0 protein were generated that efficiently recognized prokaryotic and eukaryotic recombinant BARF0. However, the BARF0 protein was not detected in clinical samples, nor in EBV-positive cell lines, even though these were positive for BARTs by RISH and/or BARF0 RNA in vitro analysis. Using immunoblot analysis, no antibodies against baculovirus-expressed BARF0 protein were detected in the sera of nasopharyngeal carcinoma patients, BL patients and Hodgkin's disease patients, patients with chronic EBV infection, infectious mononucleosis patients or EBV-positive healthy donors. Thus, BARTs containing the BARF0 ORF are expressed in vivo but the BARF0 protein cannot be detected and may be expressed only marginally. It is concluded that the BARF0 protein is unlikely to play a role in vivo in EBV-positive malignancies.

Pathogenic roles for Epstein-Barr virus (EBV) gene products in EBV-associated proliferative disorders.

Epstein-Barr virus (EBV) is associated with a still growing spectrum of clinical disorders, ranging from acute and chronic inflammatory diseases to lymphoid and epithelial malignancies. Based on a combination of in vitro and in vivo findings, EBV is thought to contribute in the pathogenesis of these diseases. The different EBV gene expression patterns in the various disorders, suggest different EBV-mediated pathogenic mechanisms. In the following pages, an overview of the biology of EBV-infection is given and functional aspects of EBV-proteins are discussed and their putative role in the various EBV-associated disorders is described. EBV gene expression patterns and possible pathogenic mechanisms are discussed. In addition, expression of the cellular genes upregulated by EBV in vitro is discussed, and a comparison with the in vivo situation is made.

Simultaneous mapping of human papillomavirus integration sites and molecular karyotyping in short-term cultures of cervical carcinomas by using 49-color combined binary ratio labeling fluorescence in situ hybridization.

Infection with high-risk type human papillomavirus (HPV) is a necessary causal factor in the pathogenesis of cervical carcinoma. In most invasive cervical cancers, HPV is integrated in the host cell genome, and additional genetic aberrations are observed among which are chromosomal aberrations. To analyze in detail such often complex chromosomal changes and simultaneously map HPV integration sites, we extended the multiplicity of the combined binary ratio labeling fluorescence in situ hybridization (COBRA-FISH) technique to 49 by inclusion of a large Stokes' shift fluorochrome as the third binary label. The technique allows mapping of the integrated HPV genome in the context of p- and q-arm COBRA-FISH, with a sensitivity of one copy of the HPV genome as tested for HPV 16 in SiHa cells. We investigated the molecular karyotypes and integration patterns of HPV types 16 and 18 in metaphase spreads from short-term cultures of primary cervical carcinomas (n=5). Of the tested cervical carcinomas, two contained integrated HPV at 8q24, one of which in addition harbored the integrated virus near a translocation breakpoint. Two carcinomas had integrated HPV at 17q21 through 23 in a morphologically normal chromosome 17. One carcinoma contained HPV at 1q42 in a morphologically normal chromosome 1. Our data illustrate the efficacy of 49-color COBRA-FISH to resolve complex karyotypes and simultaneously map specific sequences in metaphases obtained from short-term solid tumor cultures.