Showing posts with label Merkel cell polyomavirus. Show all posts
Showing posts with label Merkel cell polyomavirus. Show all posts

Monday, April 1, 2013

First description of Merkel Cell polyomavirus DNA detection in a patient with Stevens-Johnson syndrome.


First description of Merkel Cell polyomavirus DNA detection in a patient with Stevens-Johnson syndrome.


May 2013

Source

Institute for Maternal and Child Health, IRCCS Burlo Garofolo, University of Trieste, Trieste, Italy.

Abstract

Merkel Cell polyomavirus (MCPyV), a ubiquitous DNA tumor virus, has been found to be associated with Merkel cell carcinoma and chronic lymphocytic leukaemia while other associations are still being explored. MCPyV sequences have also been detected in normal tissues of tumor patients and in the blood of healthy donors. This report documents a new MCPyV association with the Stevens-Johnson syndrome, a rare immune-modulated mucocutaneous process particularly associated with specific drugs and infective agents. A high MCPyV viral load was detected simultaneously in fluid from skin lesions (2.0 × 10(4) copies/ml) and in matched blood (7.4 × 10(5) copies/ml) from a young adult patient after bone marrow transplant for a relapsed T-cell acute lymphatic leukaemia. MCPyV clearance concurred with the complete resolution of skin lesions after 5 days of cidofovir treatment. DNA sequencing classified the amplicons as the European/Italian MKL-1 strain. Given its ubiquitous nature, MCPyV could account for part of Stevens-Johnson syndrome idiopathic cases. J. Med. Virol. 85:918-923, 2013.

Friday, December 28, 2012

Merkel cell polyomavirus and trichodysplasia spinulosa-associated polyomavirus DNAs and antibodies in blood among the elderly

Merkel cell polyomavirus and trichodysplasia spinulosa-associated polyomavirus DNAs and antibodies in blood among the elderly

Merkel cell polyomavirus (MCPyV) and trichodysplasia spinulosa-associated polyomavirus (TSPyV) are recently found pathogens causing two rare skin disorders, Merkel cell carcinoma (MCC) and trichodysplasia spinulosa (TS). MCC is proportionally common in the elderly and most often is associated with immunosuppression.

TS is a folliculocentric infection seen in patients in an immunocompromised state. Little or no baseline information exists, however, on the prevalences of these two viruses among the elderly.

Epidemiologic data on this population could help in understanding their natural biology. We wished to determine the occurrences and blood levels of MCPyV and TSPyV DNAs among the elderly and any association between the prevalences of their corresponding antiviral IgG antibodies. 

Methods: From 394 hospitalized elderly individuals (age >=65 years) with respiratory symptoms, cardiovascular, and other diseases, we studied 621 serum samples by four different real-time quantitative (q) PCRs, two for the DNAs of MCPyV and two for TSPyV.

The IgG antibodies for both viruses among 481 serum samples of 326 subjects were measured with enzyme immunoassays (EIAs), using as antigen recombinant virus-like particles (VLPs). 

Results: Of the 394 patients, 39 (9.9%) were positive at least once for MCPyV DNA by the LT PCR, and 33 (8.4%) by the VP1 PCR, while 6 (1.5%) were positive by both PCR assays. In general, the viral DNA copy numbers were low.

In sharp contrast, no TSPyV DNA was detectable with qPCRs for the corresponding genomic regions. The IgG seroprevalence of MCPyV was 59.6% and of TSPyV, 67.3%. 

Conclusions: MCPyV DNA, unlike TSPyV DNA, occurs in low copy number in serum samples from a notable proportion of aging individuals.

Whether this reflects enhanced viral replication possibly due to waning immune surveillance, and is associated with increased MCC risk, deserves exploration.

Author: Mohammadreza SadeghiMatti AronenTingting ChenLaura JarttiTuomas JarttiOlli RuuskanenMaria Söderlund-VenermoKlaus Hedman
Credits/Source: BMC Infectious Diseases 2012, 12:383


7th Space

Sunday, December 23, 2012

Merkel cell polyomavirus: A newly discovered human virus with oncogenic potential.


Merkel cell polyomavirus: A newly discovered human virus with oncogenic potential.


Jan 2013


Source

Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin School of Medicine and Public Health, 1400 University Ave. Madison, WI 53706, USA.

Abstract


Keywords:

  • DNA tumor virus; 
  • Merkel; 
  • Tumor antigen; 
  • Merkel cell polyomavirus; 
  • MCV; 
  • MCPyV; 
  • Polyomavirus; 
  • Merkel cell carcinoma

A marked escalation in the rate of discovery of new types of human polyomavirus has occurred over the last five years largely owing to recent technological advances in their detection. Among the newly discovered viruses, Merkel Cell Polyomavirus (MCPyV or MCV) has gained the most attention due to its link with a rare human cancer. Infection with MCPyV is common in the human population, and the virus is detected in several anatomical locations, but most frequently in skin. Study of MCPyV molecular virology has been complicated by the lack of straightforward cell culture models, but recent in vitro studies are making strides towards understanding the virus life cycle, its cellular tropism, and mode of transmission. While MCPyV shares several traditional traits with other human polyomaviruses, the burst of research since its discovery reveals insight into a virus with many unique genetic and mechanistic features. The evidence for a causal link between MCPyV and the rare neuroendocrine cancer, Merkel Cell Carcinoma (MCC), is compelling. A majority of MCCs contain clonally integrated viral DNA, express viral T antigen transcripts and protein, and exhibit an addiction to the viral large T and small t antigen oncoproteins. The MCPyV large T antigen contains MCC tumor-specific mutations that ablate its replication capacity but preserve its oncogenic functions, and the small t antigen promotes an environment favorable for cap-dependent translation. The mechanisms of MCPyV-induced transformation have not been fully elucidated, but the likely etiological role of this new polyomavirus in human cancer provides a strong opportunity to expand knowledge of virus-host interactions and viral oncology.

Elsevier - Scielo

Friday, November 2, 2012

Detection of Merkel Cell Polyomavirus in the Human Tissues from 41 Japanese Autopsy Cases Using Polymerase Chain Reaction.


Detection of Merkel Cell Polyomavirus in the Human Tissues from 41 Japanese Autopsy Cases Using Polymerase Chain Reaction.


Sept 2012

Source

Division of Molecular Pathology, Department of Pathology, Tottori University Faculty of Medicine, Yonago, Japan.

Abstract


It has recently been shown that approximately 80% of Merkel cell carcinomas harbor a novel polyomavirus named Merkel cellpolyomavirus (MCPyV). MCPyV has been detected in human tissue samples. However, detailed distribution of MCPyV in non-neoplastic Japanese human tissues remains unclear. To address this, we used single or real-time quantitative polymerase chain reaction (PCR) for 41 autopsy cases. PCR revealed MCPyV-DNA in non-neoplastic samples: total, 29/41 (71%); adult, 29/39 (74%); fetus or infant, 0/2; men, 24/28 (86%); women, 5/13 (38%); total human tissues, 66/572 (12%); skin, 8/15 (53%); adrenal gland, 9/33 (27%), and other 16 organs (4-25%). This study first reported the presence of MCPyV-DNA in non-neoplastic tissues of thyroid gland, adrenal gland, spleen, bone marrow, stomach, gallbladder, pancreas, heart, and aorta. PCR revealed that viral load ranged from 0.00026 to 0.22 in all MCPyV-positive tissues compared with Merkel cell carcinoma samples. These detailed PCR data showed higher prevalence of MCPyV infection in Japanese men than women (p = 0.004) and broad distribution of MCPyV with low viral load in more non-neoplastic human tissues than in the previous reports. These data provide valuable insights for further studies of MCPyV infection and MCPyV-related diseases.

Thursday, October 18, 2012

Detection of Merkel cell polyomavirus in chronic lymphocytic leukemia T-cells.


Detection of Merkel cell polyomavirus in chronic lymphocytic leukemia T-cells.


Sept 2012

Source

Department of Pathology and Immunology, Division of Anatomic and Molecular Pathology, Washington University, Saint Louis, MO, United States. Electronic address: PCimino@path.wustl.edu.

Abstract


Chronic lymphocytic leukemia/small cell lymphoma (CLL/SLL) is the most common B-cell leukemia/lymphoma, effecting >15,000 patients/year. There has been a proposed limited antigenic etiology, at least in some cases, of CLL/SLL based upon immunoglobulin heavy chain stereotypy found across unrelated cases, suggesting viral source may provide such antigenic stimulation. With an established epidemiological link between CLL/SLL and Merkel cell carcinoma (MCC), there has been some interest in investigating a possible leukemogenic role of Merkel cell polyomavirus (MCPyV), which is found in 80% of MCC cases. Recent studies have shown that MCPyV is present in lymphocytes in a small percentage of CLL/SLL cases, but the specific tropism for lymphocytes has not been well-established. In this study, we used quantitative PCR to investigate the presence of MCPyV in fluorescence activated cell sorted purified B- and T-cells from 23 CLL/SLL cases. Three of 23 cases (13%) had detectable MCPyV in T-cells, and none of the cases had detectable MCPyV in B-cells. These findings suggest that MCPyV may have tropism for T-cells in addition to previously reported neoplastic B-cells.

Tuesday, August 28, 2012

Structures of Merkel Cell Polyomavirus VP1 Complexes Define a Sialic Acid Binding Site Required for Infection.


Structures of Merkel Cell Polyomavirus VP1 Complexes Define a Sialic Acid Binding Site Required for Infection.


July 2012

Source

Interfaculty Institute of Biochemistry, University of Tuebingen, Tuebingen, Germany.

Abstract

The recently discovered human Merkel cell polyomavirus (MCPyV or MCV) causes the aggressive Merkel cell carcinoma(MCC) in the skin of immunocompromised individuals. Conflicting reports suggest that cellular glycans containing sialic acid (Neu5Ac) may play a role in MCPyV infectious entry. To address this question, we solved X-ray structures of the MCPyV major capsid protein VP1 both alone and in complex with several sialylated oligosaccharides. A shallow binding site on the apical surface of the VP1 capsomer recognizes the disaccharide Neu5Ac-α2,3-Gal through a complex network of interactions. MCPyV engages Neu5Ac in an orientation and with contacts that differ markedly from those observed in other polyomavirus complexes with sialylated receptors. Mutations in the Neu5Ac binding site abolish MCPyV infection, highlighting the relevance of the Neu5Ac interaction for MCPyV entry. Our study thus provides a powerful platform for the development of MCPyV-specific vaccines and antivirals. Interestingly, engagement of sialic acid does not interfere with initial attachment of MCPyV to cells, consistent with a previous proposal that attachment is mediated by a class of non-sialylated carbohydrates called glycosaminoglycans. Our results therefore suggest a model in which sialylated glycans serve as secondary, post-attachment co-receptors during MCPyV infectious entry. Since cell-surface glycans typically serve as primary attachment receptors for many viruses, we identify here a new role for glycans in mediating, and perhaps even modulating, post-attachment entry processes.

Full text article:

Sunday, October 11, 2009

Detection of Merkel cell polyomavirus in Merkel cell carcinoma and Kaposi's sarcoma.

Detection of Merkel cell polyomavirus in Merkel cell carcinoma and Kaposi's sarcoma

J Med Virol. 2009 Nov

Department of Pathology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.

email: Harutaka Katano (katano@nih.go.jp)

Merkel cell carcinoma is a rare malignancy that sometimes occurs in the skin of elderly people. Recently, a new human polyomavirus, Merkel cell polyomavirus (MCPyV) was identified in Merkel cell carcinoma. In the present study, MCPyV-DNA was detected in 6 of 11 (55%) cases of Merkel cell carcinoma by nested PCR and real-time PCR. Histologically, MCPyV-positive cases showed round and vesicular nuclei with a fine granular chromatin and small nucleoli, whereas MCPyV-negative cases showed polygonal nuclei with diffusely distributed chromatin. Real-time PCR analysis to detect the MCPyV gene revealed that viral copy numbers ranged 0.04-0.43 per cell in cases of Merkel cell carcinoma. MCPyV was also detected in 3 of 49 (6.1%) cases of Kaposi's sarcoma (KS), but not in 192 DNA samples of other diseases including 142 autopsy samples from 20 immunodeficient patients. The MCPyV copy number in KS was lower than that in Merkel cell carcinoma. PCR successfully amplified a full-length MCPyV genome from a case of KS. Sequence analysis revealed that the MCPyV isolated from KS had 98% homology to the previously reported MCPyV genomes. These data suggest that the prevalence of MCPyV is low in Japan, and is at least partly associated with the pathogenesis of Merkel cell carcinoma.

Wiley InterScience


Merkel Cell Polyomavirus: A Specific Marker for Merkel Cell Carcinoma in Histologically Similar Tumors.

Merkel Cell Polyomavirus: A Specific Marker for Merkel Cell Carcinoma in Histologically Similar Tumors.


Departments of *Pathology and Immunology daggerMolecular Microbiology, Division of Anatomic and Molecular Pathology, Washington University School of Medicine, St Louis, MO.

The recently described Merkel cell polyomavirus (MCPyV) is reportedly present in 50% to 80% of Merkel cell carcinomas (MCC). Although the virus has been shown to be absent from other cutaneous neoplasms, its association with malignancies that are histologically similar to MCC, specifically small cell carcinoma of the lung and other high-grade neuroendocrine tumors, has yet to be thoroughly investigated. To address this issue, we identified a set of 74 cases of visceral high-grade neuroendocrine tumors from a variety of anatomic sites, including 32 cases from the lung, 16 cases from the gastrointestinal tract, 20 cases from the female reproductive system, 3 cases from soft tissue, 2 cases from the head and neck region, and 1 case from the bladder. Using a set of primers optimized to detect MCPyV in formalin-fixed tissue, polymerase chain reaction (PCR)-based testing showed evidence of MCPyV DNA in only 1 of the 74 tumors; however, clinicopathologic review of the positive case (a neuroendocrine tumor of the small intestine) disclosed that the patient had a history of primary MCC of the buttock. PCR-based testing also showed no evidence of the related WU and KI polyomaviruses in the set of 74 cases. We conclude that, when evaluated by PCR-based testing, MCPyV is a specific marker for MCC that can be helpful in distinguishing cases of metastatic MCC from other high-grade neuroendocrine tumors. Our results also suggest that MCPyV does not have a role in the oncogenesis of visceral high-grade neuroendocrine tumors.

Lippincott, Williams & Wilkins


Tuesday, September 29, 2009

Association of Merkel Cell Polyomavirus-Specific Antibodies With Merkel Cell Carcinoma

Association of Merkel Cell Polyomavirus-Specific
Antibodies With Merkel Cell Carcinoma

J Natl Cancer Inst. 2009 Sep 23

Affiliations of authors: Program in Cancer Biology (JJC, GCW, DM, DAG), Division of Human Biology (JJC, MMM, LGJ, DAG), Division of Public Health Sciences (JJC, MMM, LGJ, DAG), and Division of Clinical Research (PN), Fred Hutchinson Cancer Research Center, Seattle, WA; Department of Microbiology (DAG), Department of Pathology (KGP, SL, PN), Department of Epidemiology (MMM), Department of Dermatology/Medicine (KGP, BDL, SL, AHW, JGI, PN), University of Washington, Seattle, WA.

Correspondence to: Denise A. Galloway, PhD, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, M.S. C1-105, Seattle, WA 98109-1024 (e-mail: dgallowa@fhcrc.org).

Background Merkel cell polyomavirus (MCPyV) has been detected in approximately 75% of patients with the rare skin cancer Merkel cell carcinoma. We investigated the prevalence of antibodies against MCPyV in the general population and the association between these antibodies and Merkel cell carcinoma. Methods Multiplex antibody-binding assays were used to assess levels of antibodies against polyomaviruses in plasma. MCPyV VP1 antibody levels were determined in plasma from 41 patients with Merkel cell carcinoma and 76 matched control subjects. MCPyV DNA was detected in tumor tissue specimens by quantitative polymerase chain reaction. Seroprevalence of polyomavirus-specific antibodies was determined in 451 control subjects. MCPyV strain-specific antibody recognition was investigated by replacing coding sequences from MCPyV strain 350 with those from MCPyV strain w162. Results We found that 36 (88%) of 41 patients with Merkel cell carcinoma carried antibodies against VP1 from MCPyV w162 compared with 40 (53%) of the 76 control subjects (odds ratio adjusted for age and sex = 6.6, 95% confidence interval [CI] = 2.3 to 18.8). MCPyV DNA was detectable in 24 (77%) of the 31 Merkel cell carcinoma tumors available, with 22 (92%) of these 24 patients also carrying antibodies against MCPyV. Among 451 control subjects from the general population, prevalence of antibodies against human polyomaviruses was 92% (95% CI = 89% to 94%) for BK virus, 45% (95% CI = 40% to 50%) for JC virus, 98% (95% CI = 96% to 99%) for WU polyomavirus, 90% (95% CI = 87% to 93%) for KI polyomavirus, and 59% (95% CI = 55% to 64%) for MCPyV. Few case patients had reactivity against MCPyV strain 350; however, indistinguishable reactivities were found with VP1 from strain 350 carrying a double mutation (residues 288 and 316) and VP1 from strain w162. Conclusion Infection with MCPyV is common in the general population. MCPyV, but not other human polyomaviruses, appears to be associated with Merkel cell carcinoma.

Journal National Cancer institute

Thursday, September 17, 2009

Quantitation of human seroresponsiveness to Merkel cell polyomavirus.

Quantitation of human seroresponsiveness to Merkel cell polyomavirus.
PLoS Pathog. 2009 Sep

Pastrana DV, Tolstov YL, Becker JC, Moore PS, Chang Y, Buck CB.
Laboratory of Cellular Oncology, National Cancer Institute, Bethesda, Maryland, USA.

Merkel cell carcinoma (MCC) is a relatively uncommon but highly lethal form of skin cancer. A majority of MCC tumors carry DNA sequences derived from a newly identified virus called Merkel cell polyomavirus (MCV or MCPyV), a candidate etiologic agent underlying the development of MCC. To further investigate the role of MCV infection in the development of MCC, we developed a reporter vector-based neutralization assay to quantitate MCV-specific serum antibody responses in human subjects. Our results showed that 21 MCC patients whose tumors harbored MCV DNA all displayed vigorous MCV-specific antibody responses. Although 88% (42/48) of adult subjects without MCC were MCV seropositive, the geometric mean titer of the control group was 59-fold lower than the MCC patient group (p less then 0.0001). protein, Only 4% (2/48) of control subjects displayed neutralizing titers greater than the mean titer of the MCV-positive MCC patient population. MCC tumors were found not to express detectable amounts of MCV VP1 capsid protein, suggesting that the strong humoral responses observed in MCC patients were primed by an unusually immunogenic MCV infection, and not by viral antigen expressed by the MCC tumor itself. The occurrence of highly immunogenic MCV infection in MCC patients is unlikely to reflect a failure to control polyomavirus infections in general, as seroreactivity to BK polyomavirus was similar among MCC patients and control subjects. The results support the concept that MCV infection is a causative factor in the development of most cases of MCC. Although MCC tumorigenesis can evidently proceed in the face of effective MCV-specific antibody responses, a small pilot animal immunization study revealed that a candidate vaccine based on MCV virus-like particles (VLPs) elicits antibody responses that robustly neutralize MCV reporter vectors in vitro. This suggests that a VLP-based vaccine could be effective for preventing the initial establishment of MCV infection.

PubMed

Monday, June 8, 2009

Human Merkel cell polyomavirus infection I. MCV T antigen expression in Merkel cell carcinoma, lymphoid tissues and lymphoid tumors.

Human Merkel cell polyomavirus infection I. MCV T antigen expression in Merkel cell carcinoma, lymphoid tissues and lymphoid tumors.
Int J Cancer. 2009 Apr

Shuda M, Arora R, Kwun HJ, Feng H, Sarid R, Fernández-Figueras MT, Tolstov Y, Gjoerup O, Mansukhani MM, Swerdlow SH, Chaudhary PM, Kirkwood JM, Nalesnik MA, Kant JA, Weiss LM, Moore PS, Chang Y.
Molecular Virology Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA.


Merkel cell polyomavirus (MCV) is a recently discovered human virus closely related to African green monkey lymphotropic polyomavirus. MCV DNA is integrated in approximately 80% of Merkel cell carcinomas (MCC), a neuroendocrine skin cancer linked to lymphoid malignancies such as chronic lymphocytic leukemia (CLL). To assess MCV infection and its association with human diseases, we developed a monoclonal antibody that specifically recognizes endogenous and transfected MCV large T (LT) antigen. We show expression of MCV LT protein localized to nuclei of tumor cells from MCC having PCR quantified MCV genome at an average of 5.2 (range 0.8-14.3) T antigen DNA copies per cell. Expression of this putative viral oncoprotein in tumor cells provides the mechanistic underpinning supporting the notion that MCV causes a subset of MCC. In contrast, although 2.2% of 325 hematolymphoid malignancies surveyed also showed evidence for MCV infection by DNA PCR, none were positive at high viral copy numbers, and none of 173 lymphoid malignancies examined on tissue microarrays expressed MCV LT protein in tumor cells. As with some of the other human polyomaviruses, lymphocytes may serve as a tissue reservoir for MCV infection, but hematolymphoid malignancies associated with MCC are unlikely to be caused by MCV.


PubMed