Prevalence, tropism, and activity of cutavirus in circulating blood lymphocytes, stool, and skin biopsy specimens of patients with cutaneous T-cell lymphoma and parapsoriasis en plaques.

A significant association has been established between a newly emerging human parvovirus, cutavirus (CuV), and cutaneous T-cell lymphoma/mycosis fungoides (CTCL/MF) and its precursor parapsoriasis en plaques (PP). CTCL is a heterogeneous group of skin malignancies of T cells, the cause of which remains unknown. This study aimed to determine the activity, spread, and cell tropism of the skin-persistent CuV. CuV DNA was detected in both skin biopsies (6/20, 30%) and peripheral blood mononuclear cells (PBMCs) (4/29, 13.8%) from 49 CTCL/MF or PP patients, while none from 33 patients with any other type of skin disease or healthy subjects harbored CuV DNA. CuV DNA persisted in the skin or PBMCs for up to 15 years, despite circulating CuV-specific IgG. Spliced CuV mRNA was expressed in skin, indicating viral activity. Also, both of two available stool samples contained encapsidated CuV genomes, suggesting that the patients excrete infectious virus into the environment. Finally, CuV was observed to target circulating and skin-resident CD4 + T cells and some skin keratinocytes and macrophages. This is especially intriguing as malignant T cells in CTCL develop from CD4 + T cells. Hence, CuV should be further investigated for the overall role it plays in the complex tumor microenvironment of CTCL/MF.

Presence of herpesviruses, parvoviruses, and polyomaviruses in sinonasal lymphoma.

PURPOSE: Sinonasal lymphoma (SL) is a rare lymphatic neoplasm of the nasal cavities, paranasal sinuses and nasopharynx. Whereas some risk factors for SL subtypes have been identified, their aetiology is unknown. Along with other predisposing factors, the viral association of lymphomas, such as Epstein-Barr virus (EBV) and Burkitt and Hodgkin lymphomas, is well-established. Modern molecular biology techniques have enabled the discovery of novel human viruses, exemplified by the protoparvovirus cutavirus (CuV), associated with cutaneous T-cell lymphoma. These findings, and the anatomical location of the sinonasal tract with its rich microbiome and infectious agents, justify in-depth studies among SL. METHODS: We analysed the presence of 20 viruses of Orthoherpesviridae, Parvoviridae, and Polyomaviridae by qPCR in 24 SL tumours. We performed RNAscope in situ hybridisation (RISH) to localize the viruses. Parvovirus-specific IgG was analysed by enzyme immunoassay and targeted next-generation sequencing (NGS) was applied to detect CuV in plasma. RESULTS: We detected viral DNA in 15/24 (63%) tumours; nine of EBV, six of human herpesvirus (HHV) -7, four each of HHV-6B and parvovirus B19, two of cytomegalovirus, and one each of CuV and Merkel-cell polyomavirus. We found tumours with up to four viruses per tumour, and localized CuV and EBV DNAs by RISH. Two of the ten plasma samples exhibited CuV IgG, and one plasma sample demonstrated CuV viremia by NGS. CONCLUSION: Viruses were frequent findings in SL. The EBV detection rate was high in diffuse large B-cell lymphoma, and co-detections with other viruses were prevalent.

Viral DNA in submandibular gland tissue with an inflammatory disorder.

Background: The etiology behind different types of chronic sialadenitis (CS), some of which exhibit IgG4 overexpression, is unknown. Further, IgG4-related disease (IgG4-RD) commonly affects the submandibular gland, but its relationship to IgG4-overexpressing CS, and the antigen triggering IgG4 overexpression, remain unknown. Materials and Methods: By qPCR, we assessed the presence of 21 DNA-viruses causing IgG4 overexpression in submandibular gland tissue from patients with IgG4-positive and IgG4-negative CS. Healthy submandibular glands and glands with sialolithiasis without CS were used as controls. We examined the distribution of HHV-7, HHV-6B and B19V DNA, within virus PCR-positive tissues with RNAscope in-situ hybridization (RISH). Results: We detected DNA from seven viruses in 48/61 samples. EBV DNA was more prevalent within the IgG4-positive samples (6/29; 21%) than the IgG4-negative ones (1/19; 5.3%). B19V DNA was more prevalent within the IgG4-negative samples (5/19; 26%) than the IgG4-positive ones (4/29; 14%). The differences in virus prevalence were not statistically significant. Of the IgG4-RD samples (n = 3) one contained HHV-6B DNA. RISH only showed signals of HHV-7. Conclusions: None of the studied viruses are implicated as triggering IgG4-overexpression in CS. Although our results do not confirm viral etiology in the examined conditions, they provide valuable information on the prevalence of viruses in both diseased and healthy submandibular gland tissue.

WSV2023 - The second meeting of the world society for virology: One health - One world - One virology.

The Second International Conference of the World Society for Virology (WSV), hosted by Riga Stradins University, was held in Riga, Latvia, on June 15-17th, 2023. It prominently highlighted the recent advancements in different disciplines of virology. The conference had fourteen keynote speakers covering diverse topics, including emerging virus pseudotypes, Zika virus vaccine development, herpesvirus capsid mobility, parvovirus invasion strategies, influenza in animals and birds, West Nile virus and Marburg virus ecology, as well as the latest update in animal vaccines. Discussions further explored SARS-CoV-2 RNA replicons as vaccine candidates, SARS-CoV-2 in humans and animals, and the significance of plant viruses in the 'One Health' paradigm. The presence of the presidents from three virology societies, namely the American, Indian, and Korean Societies for Virology, highlighted the event's significance. Additionally, past president of the American Society for Virology (ASV), formally declared the partnership between ASV and WSV during the conference.