Concomitant human papillomavirus (HPV) vaccination and screening for elimination of HPV and cervical cancer.

HPV vaccination with concomitant HPV-based screening of young women has been proposed for faster cervical cancer elimination. We describe the baseline results of a population-based trial of this strategy to reduce the incidence of HPV. All 89,547 women born 1994-1999 and resident in the capital region of Sweden were personally invited to concomitant HPV vaccination and HPV screening with 26,125 women (29.2%) enrolled between 2021-05-03 and 2022-12-31. Baseline HPV genotyping of cervical samples from the study participants finds, compared to pre-vaccination prevalences, a strong decline of HPV16 and 18 in birth cohorts previously offered vaccination, some decline for cross-protected HPV types but no decline for HPV types not targeted by vaccines. Our dynamic transmission modelling predicts that the trial could reduce the incidence of high-risk HPV infections among the 1994-1998 cohorts by 62-64% in 3 years. Baseline results are prevalences of HPV infection, validated transmission model projections, and power estimates for evaluating HPV incidence reductions at follow-up (+/-0.1% with 99.9% confidence). In conclusion, concomitant HPV vaccination and HPV screening appears to be a realistic option for faster cervical cancer elimination. Clinicaltrials.gov identifier: NCT04910802; EudraCT number: 2020-001169-34.

Assessment of bacterial and viral gut communities in healthy and tumoral colorectal tissue using RNA and DNA deep sequencing.

BACKGROUND: Colorectal cancer (CRC) is known to present a distinct microbiome profile compared to healthy mucosa. Non-targeted deep-sequencing strategies enable nowadays full microbiome characterization up to species level. AIM: We aimed to analyze both bacterial and viral communities in CRC using these strategies. MATERIALS & METHODS: We analyzed bacterial and viral communities using both DNA and RNA deep-sequencing (Novaseq) in colorectal tissue specimens from 10 CRC patients and 10 matched control patients. Following taxonomy classification using Kraken 2, different metrics for alpha and beta diversities as well as relative and differential abundance were calculated to compare tumoral and healthy samples. RESULTS: No viral differences were identified between tissue types, but bacterial species Polynucleobacter necessarius had a highly increased presence for DNA in tumors (p = 0.001). RNA analyses showed that bacterial species Arabia massiliensis had a highly decreased transcription in tumors (p = 0.002) while Fusobacterium nucleatum transcription was highly increased in tumors (p = 0.002). DISCUSSION: Sequencing of both DNA and RNA enables a wider perspective of micriobiome profiles. Lack of RNA transcription (Polynucleobacter necessarius) casts doubt on possible role of a microorganism in CRC. The association of F. nucleatum mainly with transcription, may provide further insights on its role in CRC. CONCLUSION: Joint assessment of the metagenome (DNA) and the metatranscriptome (RNA) at the species level provided a huge coverage for both bacteria and virus and identifies differential specific bacterial species as tumor associated.

Comparison of DNA and RNA sequencing of total nucleic acids from human cervix for metagenomics.

Although metagenomics and metatranscriptomics are commonly used to identify bacteria and viruses in human samples, few studies directly compare these strategies. We wished to compare DNA and RNA sequencing of bacterial and viral metagenomes and metatranscriptomes in the human cervix. Total nucleic acids from six human cervical samples were subjected to DNA and RNA sequencing. The effect of DNase-treatment before reverse transcription to cDNA were also analyzed. Similarities and differences in the metagenomic findings with the three different sequencing approaches were evaluated. A higher proportion of human sequences were detected by DNA sequencing (93%) compared to RNA sequencing without (76%) and with prior DNase-treatment (11%). On the contrary, bacterial sequences increased 17 and 91 times. However, the number of detected bacterial genera were less by RNA sequencing, suggesting that only a few contribute to most of the bacterial transcripts. The viral sequences were less by RNA sequencing, still twice as many virus genera were detected, including some RNA viruses that were missed by DNA sequencing. Metatranscriptomics of total cDNA provided improved detection of mainly transcribed bacteria and viruses in cervical swabs as well as detection of RNA viruses, compared to metagenomics.

Transcription of human papillomaviruses in nonmelanoma skin cancers of the immunosuppressed.

Nonmelanoma skin cancer (NMSC) has a greatly increased incidence among the immunosuppressed and the DNA of human papillomavirus (HPV) is commonly found in these tumors. To investigate if there are any actively transcribed HPV infections in these tumors, we identified all skin cancers diagnosed after solid organ transplantation in Sweden during 1964-2011 (n = 7614 NMSCs) and requested the diagnostic tumor blocks from the corresponding pathology archives. For the present study, we selected diagnostic specimens from 345 NMSC and performed whole genome transcriptome analysis using NovaSeq (Illumina), in comparison with three cervical cancers. Although we obtained an abundance of high-quality paired reads per sample (median of 35 million reads), only 15 NMSC specimens contained HPV transcription. Three specimens had transcription of oncogenic anogenital HPVs (HPV16 and 56), six tumors had transcription of HPVs from the beta-2 species (three HPV38, two with HPV23 and one with HPV107) and then there was one observation each of transcription of HPVs 3, 26, 57, 147, 158, 168 and of two nonestablished HPV types belonging to the gamma genus. In conclusion, transcription of specific HPV types can be found in NMSC among the immunosuppressed, but this is not common.

Antibodies to SARS-CoV-2 and risk of past or future sick leave.

The extent that antibodies to SARS-CoV-2 may protect against future virus-associated disease is unknown. We invited all employees (n = 15,300) at work at the Karolinska University Hospital, Stockholm, Sweden to participate in a study examining SARS-Cov-2 antibodies in relation to registered sick leave. For consenting 12,928 healthy hospital employees antibodies to SARS-CoV-2 could be determined and compared to participant sick leave records. Subjects with viral serum antibodies were not at excess risk for future sick leave (adjusted odds ratio (OR) controlling for age and sex: 0.85 [95% confidence interval (CI) (0.85 (0.43-1.68)]. By contrast, subjects with antibodies had an excess risk for sick leave in the weeks prior to testing [adjusted OR in multivariate analysis: 3.34 (2.98-3.74)]. Thus, presence of viral antibodies marks past disease and protection against excess risk of future disease. Knowledge of whether exposed subjects have had disease in the past or are at risk for future disease is essential for planning of control measures.Trial registration: First registered on 02/06/20, ClinicalTrials.gov NCT04411576.

High Amounts of SARS-CoV-2 Precede Sickness Among Asymptomatic Health Care Workers.

BACKGROUND: Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positivity among asymptomatic subjects reflects past or future disease may be difficult to ascertain. METHODS: We tested 9449 employees at Karolinska University Hospital, Stockholm, Sweden for SARS-CoV-2 RNA and antibodies, linked the results to sick leave records, and determined associations with past or future sick leave using multinomial logistic regression. RESULTS: Subjects with high amounts of SARS-CoV-2 virus, indicated by polymerase chain reaction (PCR) cycle threshold (Ct) value, had the highest risk for sick leave in the 2 weeks after testing (odds ratio [OR], 11.97; 95% confidence interval [CI], 6.29-22.80) whereas subjects with low amounts of virus had the highest risk for sick leave in the 3 weeks before testing (OR, 6.31; 95% CI, 4.38-9.08). Only 2.5% of employees were SARS-CoV-2 positive while 10.5% were positive by serology and 1.2% were positive in both tests. Serology-positive subjects were not at excess risk for future sick leave (OR, 1.06; 95% CI, .71-1.57). CONCLUSIONS: High amounts of SARS-CoV-2 virus, as determined using PCR Ct values, was associated with development of sickness in the next few weeks. Results support the concept that PCR Ct may be informative when testing for SARS-CoV-2. Clinical Trials Registration. NCT04411576.

De novo sequence assembly requires bioinformatic checking of chimeric sequences.

De novo assembly of sequence reads from next generation sequencing platforms is a common strategy for detecting presence and sequencing of viruses in biospecimens. Amplification artifacts and presence of several related viruses in the same specimen can lead to assembly of erroneous, chimeric sequences. We now report that such chimeras can also occur between viral and non-viral biological sequences incorrectly joined together which may cause erroneous detection of viruses, highlighting the importance of performing a chimera checking step in bioinformatics pipelines. Using Illumina NextSeq and metagenomic sequencing, we analyzed 80 consecutive non-melanoma skin cancers (NMSCs) from 11 immunosuppressed patients together with 11 NMSCs from patients who had only developed 1 NMSC. We aligned high-quality reads against a Human Papillomavirus (HPV) database and found HPV sequences in 9/91 specimens. A previous bioinformatic analysis of the same crude sequencing data from some of these samples had found an additional 3 specimens to be HPV-positive after performing de novo assembly. The reason for the discrepancy was investigated and found to be mostly caused by chimeric sequences containing both viral and non-viral sequences. Non-viral sequences were present in these 3 samples. To avoid erroneous detection of HPV when performing sequencing, we thus developed a novel script to identify HPV chimeric sequences.

Genome-wide transcriptome profiling of ex-vivo precision-cut slices from human pancreatic ductal adenocarcinoma.

Ex-vivo tumor tissue culture systems are used as models to test specific anti-cancer drugs. Their main advantage is that they are closely comparable with the in vivo tumor in their host organism. We previously reported that precision-cut organotypic tissue slices of pancreatic ductal adenocarcinoma (PDAC) can be successfully cultured ex-vivo for at least 4 days. In order to study how culturing might affect transcription patterns, we now performed genome-wide transcriptome profiling of both baseline (0 h) and explanted tumors at daily intervals (24, 48 and 72 h) after start of culturing. The total-RNA from five samples of surgically resected human PDAC tumors at baseline and at different time points in culture was sequenced. Differential gene expression analysis of the whole transcriptome, testing 58,713 genes and over 206,000 transcripts, found that only a small number of genes showed significant changes in expression between baseline and cultured samples. The cultured tumor slices showed upregulation of a median of 12, 10 and 15 genes and downregulation of a median of 15, 12 and 25 genes at 24, 48 and 72 h in culture, respectively. One sample had morphologically increasing loss of tissue viability (range 0-18%). The vascular endothelial growth factor A (VEGFA) was significantly upregulated during the entire culture period in this case. Pathway over-representation analysis suggested that VEGFA together with the PTGS2 gene were upregulated at the same time as HIF-1-triggered cell apoptosis via NF-ĸB and the AP-1 activating factor was induced. Indeed, increased areas of apoptotic lesions were visible in this sample after 24 hours of culture. In conclusion, genome-wide transcriptome analysis supports that ex-vivo cultured tissue slices of PDAC may be a representative model of the original tumor. Transcriptome analysis was found to be a valuable complement to morphology for evaluation of ex-vivo cultures of PDAC.

The HPV16 Genome Is Stable in Women Who Progress to In Situ or Invasive Cervical Cancer: A Prospective Population-Based Study.

The human papillomavirus (HPV) rate of evolution is essential for cancer-preventive strategies targeting HPV. We analyzed variability over time in a prospective, population-based nested case-control study of in situ (CIS) and invasive squamous cervical cancer (SCC). Among 757,690 women who participated in cervical screening in Sweden during 1969 to 2002, we identified 94 women who had HPV16 persistence in two serial cervical screening samples (median 24 months apart, range 0.5-178 months) and later were diagnosed with CIS (n = 59), SCC (n = 32), or remained healthy (n = 3). Whole-HPV16-genome sequencing and comparison of sequences in the serial samples revealed that all women had the same HPV16 lineage, particularly lineage A, in both serial smears. Fifty-six percent of women had an identical 7,906 base pair HPV16 sequence in both samples, and no woman had more than 15 nucleotide substitutions. The median substitution rate was 0 substitutions/site/year (95% confidence interval, 0-0.00008), with no variation between quartiles of follow-up. We concluded that in most women with HPV16 persistence preceding disease, the nucleotide substitution rate was not measurable within up to 15-years follow-up. This slow rate of evolution has important implications for both HPV-based screening and HPV vaccination. SIGNIFICANCE: These findings show there is no genomic variation over time in HPV16 infections progressing to cervical cancer, which could influence risk stratification of women when screening for cervical cancer and inform HPV vaccination strategies.

HPV transcription in skin tumors.

BACKGROUND: Although more than 95% of viral sequences found in skin tumors typically belong to human papillomaviruses (HPVs), HPV transcription has so far not been detected. As current technology allows very deep transcriptome sequencing, we examined skin tumors and precursor lesions for HPV transcription. METHOD: Fresh frozen biopsies from 12 skin specimens (11/12 were positive for HPV DNA) were subjected to total RNA sequencing. The cervical cancer cell line CaSki was included as a positive control for HPV transcription. RESULTS: HPV RNA was detected and confirmed in 1/12 skin lesions at a median depth of 66 million reads per sample. One specimen was positive for HPV 110 transcripts mapping to E6, E7, E2/E4 and L2 open reading frames, as well as to a spliced E1^E4 transcript. CONCLUSION: In conclusion, the study revealed that a minority of skin lesions contains HPV transcripts and that HPV DNA detection does not predict HPV transcriptional activity.

A novel human in vitro papillomavirus type 16 positive tonsil cancer cell line with high sensitivity to radiation and cisplatin.

BACKGROUND: Human papillomavirus (HPV) is an established risk factor for oropharyngeal squamous cell carcinoma (OSCC). The aim was to establish cell lines from HPV-positive tonsil carcinomas to be used for treatment development. METHODS: Fresh samples from 23 HPV-positive tonsil carcinomas were cultivated in vitro. The established cell line was analyzed for viral characteristics, cell karyotype, TP53 status, and growth capabilities in nude mice. In vitro studies of sensitivities to radiation, cisplatin and cetuximab were performed. RESULTS: After 19 months (eight passages), one cell line, LU-HNSCC-26, was established in vitro and also grew as xenografts. The tumor was from a 48 year old non-smoking man with non-keratinizing, p16 positive tonsil OSCC, stage T2N0M0 with HPV16. It contained 19.5 (CV% 3.7) HPV16 copies/cell (passage 8). The complete HPV16 genome sequence was obtained. Episomal HPV16 was present with an E2/E7 ratio of 1.1 (CV% 2.6). In addition, HPV16 mRNA specific for the intact E2 gene was detected. The viral expression manifested 1.0 (CV% 0.1) E7 mRNA copies per HPV16 genome. The karyotype was determined and the cell line demonstrated wild type TP53. The ID50 for radiation was 0.90 Gy and the IC50 for cisplatin was 0.99 µmol/L. The cell line was inhibited to a maximum of 18% by cetuximab. CONCLUSIONS: We established an in vitro tonsil carcinoma cell line containing episomal HPV16. This is an important step towards efficient treatment development.

Human papillomavirus type 16 genomic variation in women with subsequent in situ or invasive cervical cancer: prospective population-based study.

BACKGROUND: HPV genomic variation may be involved in viral carcinogenesis. METHODS: In a national register-based nested case-control study, we retrieved archival smears from baseline cytologically normal women who later developed cancer in situ (CIS), squamous cervical cancer (SCC) or remained free of disease. These smears were previously HPV tested by PCR and HPV16 was the strongest risk factor. We now used the Illumina NextSeq platform to sequence HPV16 genomes in cervical smears from 242 women who later developed CIS/CIN3 (n = 134), SCC (n = 92) or remained healthy (n = 16). RESULTS: The median sequence depth per sample was high (11,288×). For 218/242 samples (>90%), we covered ≥80% of the complete HPV16 genome with sequencing median depths of >200×. We identified a wide range of unique isolates and 147 novel SNPs across the 218 samples. Most women (97%) had HPV16 lineage A infection, with the sublineages being A1 (66.1%), A2 (28.9%) and A4 (1.8%), respectively. The least variable gene was the E7 (3.4% variability), where 170/204 case women (83%) displayed a fully conserved sequence. There were no obvious differences by disease outcome (CIS or SCC). CONCLUSIONS: We found a high number of novel SNPs. The E7 gene was hypovariable both among women later developing CIN3/CIS, and SCC, respectively.

Viremia preceding multiple sclerosis: Two nested case-control studies.

Infections have been suggested to be involved in Multiple Sclerosis (MS). We used metagenomic sequencing to detect both known and yet unknown microorganisms in 2 nested case control studies of MS. Two different cohorts were followed for MS using registry linkages. Serum samples taken before diagnosis as well as samples from matched control subjects were selected. In cohort1 with 75 cases and 75 controls, most viral reads were Anelloviridae-related and >95% detected among the cases. Among samples taken up to 2 years before MS diagnosis, Anellovirus species TTMV1, TTMV6 and TTV27 were significantly more common among cases. In cohort2, 93 cases and 93 controls were tested under the pre-specified hypothesis that the same association would be found. Although most viral reads were again related to Anelloviridae, no significant case-control differences were seen. We conclude that the Anelloviridae-MS association may be due to multiple hypothesis testing, but other explanations are possible.

Extension of the viral ecology in humans using viral profile hidden Markov models.

When human samples are sequenced, many assembled contigs are "unknown", as conventional alignments find no similarity to known sequences. Hidden Markov models (HMM) exploit the positions of specific nucleotides in protein-encoding codons in various microbes. The algorithm HMMER3 implements HMM using a reference set of sequences encoding viral proteins, "vFam". We used HMMER3 analysis of "unknown" human sample-derived sequences and identified 510 contigs distantly related to viruses (Anelloviridae (n = 1), Baculoviridae (n = 34), Circoviridae (n = 35), Caulimoviridae (n = 3), Closteroviridae (n = 5), Geminiviridae (n = 21), Herpesviridae (n = 10), Iridoviridae (n = 12), Marseillevirus (n = 26), Mimiviridae (n = 80), Phycodnaviridae (n = 165), Poxviridae (n = 23), Retroviridae (n = 6) and 89 contigs related to described viruses not yet assigned to any taxonomic family). In summary, we find that analysis using the HMMER3 algorithm and the "vFam" database greatly extended the detection of viruses in biospecimens from humans.

Viruses in cancers among the immunosuppressed.

Most cancer forms known to be caused by viruses are increased among the immunosuppressed, but several cancer forms without established viral etiology are also increased, notably nonmelanoma skin carcinoma (NMSC). We followed all 13,429 solid organ transplantation patients in Sweden for cancer occurrence after transplantation. We requested these tumor specimens and sequenced the first 89 specimens received (62 NMSCs, 27 other cancers). The sequences were analyzed for viruses based on two bioinformatics algorithms (paracel-blast (sensitive for detection of known viruses) and hidden Markov model (HMM; sensitive for distantly related viruses)). Among the 62 NMSCs, the virus family detected in the largest proportion of specimens was Mimiviridae (9/62 NMSCs). The majority of the virus-related reads belonged to Papillomaviridae. The HMM analysis identified 86 additional previously not described viral contigs related to 11 virus families, with reads related to Mimiviridae being the most common (detected in 28/62 NMSCs) with the most prevalent contig (Mimivirus SE906, 1937 bp) detected in 17/62 NMSCs. Among the 27 other cancers, viral sequences were detected in only 5 specimens by blast analysis, compared to in all 27 specimens by HMM (Mimiviridae, Poxviridae, Phycodnaviridae and virus-related sequences yet unclassified to any family). 99% of the virus reads belonged to a single previously not described sequence (Mimivirus SE996, 911 bp). A multitude of viruses is readily detectable in specimens with cancers occurring among the immunosuppressed, with sequences related to Mimiviridae being the most prevalent. Further research would be needed to elucidate the biological significance of the viruses.

Viruses in case series of tumors: Consistent presence in different cancers in the same subject.

Studies investigating presence of viruses in cancer often analyze case series of cancers, resulting in detection of many viruses that are not etiologically linked to the tumors where they are found. The incidence of virus-associated cancers is greatly increased in immunocompromised individuals. Non-melanoma skin cancer (NMSC) is also greatly increased and a variety of viruses have been detected in NMSC. As immunosuppressed patients often develop multiple independent NMSCs, we reasoned that viruses consistently present in independent tumors might be more likely to be involved in tumorigenesis. We sequenced 8 different NMSCs from 1 patient in comparison to 8 different NMSCs from 8 different patients. Among the latter, 12 different virus sequences were detected, but none in more than 1 tumor each. In contrast, the patient with multiple NMSCs had human papillomavirus type 15 and type 38 present in 6 out of 8 NMSCs.

Detection of DNA viruses in prostate cancer.

We tested prostatic secretions from men with and without prostate cancer (13 cases and 13 matched controls) or prostatitis (18 cases and 18 matched controls) with metagenomic sequencing. A large number (>200) of viral reads was only detected among four prostate cancer cases (1 patient each positive for Merkel cell polyomavirus, JC polyomavirus and Human Papillomavirus types 89 or 40, respectively). Lower numbers of reads from a large variety of viruses were detected in all patient groups. Our knowledge of the biology of the prostate may be furthered by the fact that DNA viruses are commonly shed from the prostate and can be readily detected by metagenomic sequencing of expressed prostate secretions.

Viremia during pregnancy and risk of childhood leukemia and lymphomas in the offspring: Nested case-control study.

A possible role for infections of the pregnant mother in the development of childhood acute leukemias and lymphomas has been suggested. However, no specific infectious agent has been identified. Offspring of 74,000 mothers who had serum samples taken during pregnancy and stored in a large-scale biobank were followed up to the age of 15 years (750,000 person years) through over-generation linkages between the biobank files, the Swedish national population and cancer registers to identify incident leukemia/lymphoma cases in the offspring. First-trimester sera from mothers of 47 cases and 47 matched controls were retrieved and analyzed using next generation sequencing. Anelloviruses were the most common viruses detected, found in 37/47 cases and in 40/47 controls, respectively (OR: 0.6, 95% CI: 0.2-1.9). None of the detected viruses was associated with leukemia/lymphoma in the offspring. Viremia during pregnancy was common, but no association with leukemia/lymphoma risk in the offspring was found.

Does human papillomavirus-negative condylomata exist?

Condylomata acuminata is caused by human papillomavirus (HPV). PCR with consensus primers will typically detect HPV in >96% of condylomata. Metagenomic sequencing has found that some "HPV-negative" condylomata do indeed contain HPV. We wished to perform a renewed evaluation of the "HPV-negative" condylomata using deeper metagenomics sequencing. Sequencing of whole genome amplified DNA from 40 apparently "HPV-negative" condylomata detected HPV in 37/40 specimens. We found 75 different HPV types, out of which 43 represented novel putative HPV types. Three types were cloned and established as HPV types 200, 201 and 202. Molluscum contagiosum virus was detected in 24 of the 40 samples. In summary, deep sequencing enables detection of HPV in almost all condylomata. "HPV-negative" condylomata might largely be explained by clinical misdiagnosis or the presence of viral variants, distantly related HPV types and/or low viral loads.