KI Polyomaviruses Research Articles

DNA from BK Virus and JC Virus and from KI, WU, and MC Polyomaviruses as Well as from Simian Virus 40 Is Not Detected in Non-UV-Light-Associated Primary Malignant Melanomas of Mucous Membranes

The single most important causative factor for malignant melanomas of the skin is UV radiation. However, this is not true for melanomas on body surfaces sheltered from the sun; thus, it is important to seek new causative factors of melanoma genesis. Human papillomaviruses and gammaherpesviruses are associated with human skin cancer; for example, human papillomavirus types 5 and 8 are associated with epidermodysplasia verruciformis, and human herpesvirus 8 is associated with Kaposi's sarcoma. Recently, a newly described human polyomavirus, Merkel cell polyomavirus (MCPyV), has been associated with Merkel cell carcinoma, an unusual form of neurotropic skin cancer. Moreover, melanocytes are of neuroepithelial origin. This background impelled us to investigate if human polyomavirus DNA could play a role in the development of extracutaneous melanomas. Sixty-four extracutaneous melanomas were initially collected and dissected. Of these, 38 could be successfully used for further testing for the presence of the five human polyomaviruses known so far-BK virus (BKV), JC virus (JCV), KI polyomavirus (KIPyV), WU polyomavirus (WUPyV), and MCPyV-and of simian virus 40 (SV40). No polyomavirus DNA could be detected in any of the samples tested by use of a nested PCR detecting BKV, JCV, and SV40; a newly designed PCR detecting KIPyV and WUPyV; or a newly designed PCR for MCPyV. We conclude that since no human polyomavirus DNA was detected in primary malignant melanomas on non-sun-exposed body surfaces, these polyomaviruses presumably are not major factors for the development of extracutaneous melanomas.

Prevalence of Human KI and WU Polyomaviruses in Children with Acute Respiratory Tract Infection in China

The KI and WU polyomaviruses were found in 11 (2.7%) and 17 (4.2%) of 406 nasopharyngeal aspirates, respectively, from children with acute respiratory tract infection (ARTI). The phylogenetic analysis indicates that they are all in the same cluster as the prototype strains. Our findings suggest that they are common in children with ARTI in China.

Detection and discrimination of WU/KI polyomaviruses by real-time PCR with melting curve analysis

WU and KI polyomaviruses are novel viruses of the Polyomaviridae family, which have been identified recently in respiratory secretions from patients with acute respiratory tract infection. Their potential role in respiratory disease is still unclear and requires additional investigation. To facilitate further studies and diagnosis, a real-time PCR with melting curve analysis was optimized and evaluated to detect WU and KI polyomaviruses. Primers specific for the VP1 gene were designed from regions conserved among WU and KI polyomaviruses which provided amplification products of 198 and 231 bp corresponding to WU and KI, respectively and thus yielded a difference in melting temperature ( T m) between WU and KI polyomaviruses. The assay proved highly specific for WU and KI polyomaviruses as no cross amplification was detected with other respiratory viruses or human genomic DNA. The assay was also highly sensitive with a detection limit as low as 10 copies/μL for both WU and KI polyomaviruses. The performance of the real-time PCR assay was evaluated in terms of amplification efficiency (92%). Finally, the assay was validated using DNA extracted from clinical respiratory specimens for WU and KI polyomaviruses and the results were confirmed by direct nucleotide sequencing. The results obtained by melting curve analysis were in perfect agreement with nucleotide sequencing. In conclusion, this method is advantageous because it is rapid, specific, sensitive, reproducible, accurate, cost-effective and thus, would be feasible and attractive for large-scale analysis aimed at investigating the clinical role of WU and KI polyomaviruses.

Prevalence and molecular characterization of WU/KI polyomaviruses isolated from pediatric patients with respiratory disease in Thailand

WU and KI polyomaviruses represent novel viruses discovered in respiratory secretions from human patients with acute respiratory tract infection. However, the association between WU/KI polyomaviruses and human disease has remained unclear. In this study, the prevalence of these two novel viruses and occurrence of co-infection with other respiratory viruses were determined in Thai pediatric patients with respiratory disease. Previously described PCR assays were applied to detect WU/KI polyomaviruses as well as other respiratory viruses in 302 nasopharyngeal suction specimens collected from February 2006 through February 2007. The results revealed the anneal prevalence of WU and KI polyomaviruses in the Thai population was 6.29% and 1.99%, respectively. The frequency of co-detection of WU and KI polyomaviruses with other respiratory viral pathogens was 42.11% and 33.33%, respectively. Moreover, each of the two complete genome sequences of WU (CU_295 and CU_302) and KI (CU_255 and CU_258) polyomaviruses were genetically and phylogenetically characterized. Sequence analysis showed that they contained features common to those found in previous studies. However, there were several nucleotide variations within the non-coding regulatory regions and various non-synonymous mutations within the coding regions which may influence virulence and pathogenesis of these viruses. Nevertheless, it is still possible that these viruses are not the causative agents of clinical respiratory disease. Therefore, judging the association of WU/KI polyomavirus infections with a particular disease will be challenging and require more comprehensive case control investigations.

KI and WU Polyomaviruses in Children, France

To the Editor: Two new members of the Polyomaviridae family, provisionally named Karolinska Institutet virus (KIPyV) and Washington University virus (WUPyV), have been recently discovered (1,2). These new polyomaviruses were identified by screening human respiratory secretions with molecular tools. KIPyV and WUPyV are genetically related to the BK virus and the JC virus, the 2 known members of the family Polyomaviridae that affect humans.

Presence of the newly discovered human polyomaviruses KI and WU in Australian patients with acute respiratory tract infection

BackgroundCurrently, the role of the novel human polyomaviruses, KI (KIV) and WU (WUV) as agents of human disease remains uncertain. ObjectivesWe sought to determine the prevalence of these viruses and their rate of co-detection with other viral respiratory pathogens, in an Australian population. Study designPolymerase chain reaction assays previously described were used to examine the presence of KIV and WUV in 2866 respiratory specimens collected from January to December 2003 from Australian patients with acute respiratory infections. ResultsKIV and WUV were present in our population with an annual prevalence of 2.6% and 4.5%, respectively. There was no apparent seasonal variation for KIV, but a predominance of infection was detected during late winter to early summer for WUV. The level of co-infection of KIV or WUV with other respiratory viruses was 74.7% and 79.7%, respectively. Both viruses were absent from urine and blood specimens collected from a variety of patient sources. ConclusionsKIV and WUV circulate annually in the Australian population. Although there is a strong association with the respiratory tract, more comprehensive studies are required to prove these viruses are agents causing respiratory disease.

No evidence for an association between infections with WU and KI polyomaviruses and respiratory disease

Background WU virus (WUV) and KI polyomavirus (KIPyV) are newly discovered related human polyomaviruses detected in respiratory samples. To investigate their potential role in respiratory disease, we determined their frequencies of detection, clinical presentations and epidemiological characteristics among samples referred for diagnostic respiratory virus testing. Methods Anonymised samples and accompanying study subject information were obtained from the Edinburgh respiratory specimen archive. Samples were screened by nested PCR using two sets of primers conserved between WUV and KIPyV, as well for other respiratory viruses (respiratory syncytial virus [RSV], adenoviruses [AdV], influenza A/B and parainfluenza viruses 1–3, human bocavirus, B19). Results and Conclusions WUV and KIPyV were detected in 10 and 14 samples, respectively from 983 specimens (from 9 to 10 different individuals from 612 study subjects). Infections occurred in two types of study subject; those who were young (<2 years) with lower respiratory tract infections ( n = 8), and almost invariably co-infected with other respiratory viruses (RSV, AdV), and a second, generally older group either without respiratory disease ( n = 6) or with mild upper respiratory tract infections ( n = 5) but who were generally clinically severely immunosuppressed from leukaemia or transplant therapy. Findings from either group do not support an aetiological link between infection with WUV or KIPyV and respiratory disease.

Infections respiratoires virales émergentes

RésuméLes infections respiratoires virales sont des affections particulièrement fréquentes et de sévérité variable. Ces dernières années, les progrès des techniques de biologie moléculaire ont permis d'identifier des virus respiratoires présents depuis longtemps chez l'homme mais jusqu'alors inconnus. II s'agit notamment du metapneumovirus humain (HMPV), des < nouveaux > coronavirus humains HCoV-NL63 HCoV-NH et HCoV-HK, du bocavirus humain (HBoV) et des nouveaux polyomavirus humains KI et WU. A côté de ces virus nouvellement identifiés, on a pu observer au cours de ces dernières années l'émergence chez l'homme de nouveaux virus responsables d'infections respiratoires. Ces virus récemment introduits dans l'espèce humaine proviennent d'un réservoir animal. IIs présentent généralement un pouvoir pathogène majeur avec un taux élevé de mortalité. Ces virus sont les henipavirus (virus Hendra et Nipah), les hantavirus du nouveau monde responsables du syndrome pulmonaire à hantavirus, le coronavirus du syndrome respiratoire aigu sévère (SARS-CoV) et le virus de la grippe aviaire H5N1. Ce dernier virus fait planer la menace d'une pandémie meurtriére faisant ressurgir le spectre de la grippe espagnole de 1918–1919, responsable de 20 à 50 millions de morts

Development and evaluation of real-time PCR assays for the detection of the newly identified KI and WU polyomaviruses

Background Recently, novel human polyomaviruses, KI (KIV) and WU (WUV) were described. Their role in human disease has not yet been determined. Objectives The aim of this study was to develop sensitive and specific assays for the detection of KIV and WUV. Study Two KIV (KI-A and KI-B) and three WUV (WU-A, WU-B and WU-C) real-time polymerase chain reaction (rtPCR) assays were developed and evaluated. Clinical sensitivities and specificities were determined by testing 200 respiratory specimens and the results compared to those for previously described conventional PCR assays. Limits of detection were determined, and the analytical specificities of the assays were investigated. Results No cross-reactivity was observed between the rtPCR methods and unrelated organisms. All five rtPCR assays could reliably detect 10 copies of genomic DNA equivalents per reaction, which was more sensitive than conventional methods. Compared to the conventional PCR assays, the sensitivity of the KI-A, KI-B, WU-A, WU-B and WU-C assays was 100%, 86.7% 95.5%, 100% and 100%, respectively. Specificity was 94.6%, 97.3%, 96.6%, 97.7% and 97.2%, respectively. Conclusions The KI-A, WU-B and WU-C assays provide the most sensitive detection of KIV and WUV in clinical specimens and may be used for further research into these viruses.