Seroprevalence of Human Malawi Polyomavirus

Abstract

The seroprevalence of the recently discovered human Malawi polyomavirus (MWPyV) was determined by virus-like particlebased enzyme-linked immunosorbent assay (ELISA) in age-stratified Italian subjects. The findings indicated that MWPyV infection occurs early in life, and seroprevalence was shown to reach 42% in adulthood.T welve human polyomaviruses have been described to date, including JC and BK polyomaviruses (JCPyV and BKPyV), Karolinska Institute polyomavirus (KIPyV), Washington University polyomavirus (WUPyV), Merkel cell polyomavirus (MCPyV), human polyomaviruses 6 and 7 (HPyV6 and HPyV7), trichodysplasia spinulosa-associated polyomavirus (TSPyV), human polyomavirus 9 (HPyV9) (1), and three recently identified polyomaviruses, i.e., Malawi polyomavirus/human polyomavirus 10 (MWPyV/HPyV10), Saint Louis polyomavirus (STLPyV) isolated from stools (2-4), and human polyomavirus 12 (HPyV12) identified in the liver (5).Polyomavirus infections are ubiquitous, with seroprevalence ranging from 40 to 90% in adults, and asymptomatic infections occur early in childhood (6-12).Four human polyomaviruses are associated with disease. JCPyV causes progressive multifocal leukoencephalopathy, BKPyV is the cause of hemorrhagic cystitis in allogeneic hematopoietic stem cell transplant patients and induced nephropathy frequently followed by graft loss in renal transplant patients. MCPyV is responsible for Merkel cell carcinoma (MCC), which occurs mainly in elderly individuals and immunocompromised subjects, and TSPyV is associated with trichodysplasia spinulosa. JCPyV-, BKPyV-, and TSPyV-associated diseases have been observed only in immunocompromised subjects (1,13).In this study, we investigated the seroepidemiology of the recently identified Malawi polyomavirus in an Italian population using a virus-like particle (VLP)-based enzyme-linked immunosorbent assay (ELISA) and evaluated the existence of crossreactivity with MCPyV, HPyV6, HPyV7, TSPyV, and HPyV9 polyomaviruses.MWPyV seroprevalence was determined in 825 Italian subjects 1 to 100 years of age. This study population has previously been investigated for reactivity against five other polyomaviruses (12), and the approach here was similar. Antibodies against MWPyV were determined using a VLP-based ELISA (14). The MWPyV VP1 coding sequence (GenBank accession no. NC_018102.1) was codon optimized for expression in Spodoptera frugiperda cells (Genscript, Piscataway, NJ) and used to generate a recombinant baculovirus. The presence of 45-to 50-nm VLPs and smaller particles was observed by electron microscopy (Fig. 1). Purified MWPyV VLPs (100 ng/well in phosphate-buffered saline [PBS]) were used to sensitize microplates (Maxisorp; Nunc) overnight at 4°C. Briefly, sera were diluted 1:100, and peroxidase-conjugated anti-human IgG (Southern Biotech, Clinisciences, Nanterre, France) diluted 1:20,000 was used to detect human IgG binding (14). A histogram of the ELISA optical density (OD) values in 1-to 10-year-old children (data not shown) revealed a bimodal distribution of seroreacti...

Seroprevalence rates of HPyV6, HPyV7, TSPyV, HPyV9, MWPyV and KIPyV polyomaviruses among the healthy blood donors

“…Seroprevalence to MWPyV (84.4%) was the second highest from all of HPyVs tested. Two recent studies reported MWPyV 42–75% in adulthood [Nicol et al, ; Berrios et al, ], which is slightly lower number compared to our findings. Seroprevalence to KIPyV (58%) agrees with numbers (55–70%) reported by others [Nguyen et al, ; Neske et al, ; Nicol et al, , ].…”

“…So far, this phenomenon is not being observed frequently. Other studies did not find cross‐reactivity between MCPyV, TSPyV, HPyV9, and MWPyV VLPs or VP1s produced in bacteria [van der Meijden et al, ; Nicol et al, , ]. We found some degree of cross‐reactivity using HPyV6 and HPyV7 VLPs (r = 0.48), very similar to correlation (r = 0.43) between seropositive samples found in other study [Nicol et al, ].…”

Malawi Polyomavirus Is a Prevalent Human Virus That Interacts with Known Tumor Suppressors

“…1B). Similar findings for MWPyV were recently reported using a virus-like particle-based ELISA, with seroprevalence reaching 42% in an adult population (26). The moderately high levels of seroprevalence in children from age 3 to age 21 suggest that primary infection with MWPyV occurs in childhood, and the increasing frequency of elevated antibody titers that occurs with age is consistent with persistent lifelong infections.…”

Identification and Characterization of Novel Rat Polyomavirus 2 in a Colony of X-SCID Rats by P-PIT assay

“…Most mammalian polyomaviruses cause subclinical infections with lifelong persistence in their natural hosts. According to serological studies, asymptomatic infection occurs with 12 of the 13 known polyomaviruses detected in humans (5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Polyomavirus-related diseases, which include nephritis (BK virus [BKV]) (15), encephalitis (JC virus [JCV]) (16), Merkel cell carcinoma (Merkel cell polyomavirus [MCV]) (17), skin dysplasia (trichodysplasia spinulosa-associated polyomavirus [TSV] and human polyomavirus 7 [HPyV7]) (18,19), and pneumonitis (Washington University [WU] virus [WUV]) (20,21), can occur among immune-suppressed individuals, including posttransplanta-tion and AIDS patients.…”