Hamster Polyomavirus Research: Past, Present, and Future

Abstract

Hamster polyomavirus (Mesocricetus auratus polyomavirus 1, HaPyV) was discovered as one of the first rodent polyomaviruses at the end of the 1960s in a colony of Syrian hamsters (Mesocricetus auratus) affected by skin tumors. Natural HaPyV infections have been recorded in Syrian hamster colonies due to the occurrence of skin tumors and lymphomas. HaPyV infections of Syrian hamsters represent an important and pioneering tumor model. Experimental infections of Syrian hamsters of different colonies are still serving as model systems (e.g., mesothelioma). The observed phylogenetic relationship of HaPyV to murine polyomaviruses within the genus Alphapolyomavirus, and the exclusive detection of other cricetid polyomaviruses, i.e., common vole (Microtus arvalis polyomavirus 1) and bank vole (Myodes glareolus polyomavirus 1) polyomaviruses, in the genus Betapolyomavirus, must be considered with caution, as knowledge of rodent-associated polyomaviruses is still limited. The genome of HaPyV shows the typical organization of polyomaviruses with an early and a late transcriptional region. The early region encodes three tumor (T) antigens including a middle T antigen; the late region encodes three capsid proteins. The major capsid protein VP1 of HaPyV was established as a carrier for the generation of autologous, chimeric, and mosaic virus-like particles (VLPs) with a broad range of applications, e.g., for the production of epitope-specific antibodies. Autologous VLPs have been applied for entry and maturation studies of dendritic cells. The generation of chimeric and mosaic VLPs indicated the high flexibility of the VP1 carrier protein for the insertion of foreign sequences. The generation of pseudotype VLPs of original VP1 and VP2–foreign protein fusion can further enhance the applicability of this system. Future investigations should evaluate the evolutionary origin of HaPyV, monitor its occurrence in wildlife and Syrian hamster breeding, and prove its value for the generation of potential vaccine candidates and as a gene therapy vehicle.

Hamster polyomavirus-associated T-cell lymphomas in Syrian hamsters (Mesocricetus auratus)

“…17,25 However, in a previous study, virus particles were not present in the tumor cells of HaPyV-associated lymphomas. 15 The formation of lymphomas is a side effect of HaPyV infection and not critical to the virus life cycle. 4…”

“…In enzootically infected Syrian hamsters, HaPyV infects hair follicle keratinocytes and induces multicentric trichoepithelioma containing abundant HaPyV particles in the stratum corneum. 4,11,15 In naive young hamsters, HaPyV infection causes lymphoma. 3,4,15 Mortality rates among hamsters with lymphoma may reach 80% within 4 to 30 weeks of infection.…”

“…4,11,15 In naive young hamsters, HaPyV infection causes lymphoma. 3,4,15 Mortality rates among hamsters with lymphoma may reach 80% within 4 to 30 weeks of infection. 4 Once enzootic in laboratories, the virus cannot be effectively eliminated without euthanizing the entire population and thoroughly decontaminating the premises.…”

Functional Domains of the Early Proteins and Experimental and Epidemiological Studies Suggest a Role for the Novel Human Polyomaviruses in Cancer

“…The murine polyomavirus (MPyV) and hamster polyomavirus (HaPyV) can transform a wide variety of cells and can induce tumors in their natural host (Benjamin, 2001;Jandrig et al, 2021). In addition to LT-ag and sT-ag, MT-ag also contributes to neoplastic transformation and can cause tumors in transgenic animals (Templeton and Eckhart, 1982;Bautch et al, 1987;Freund et al, 1992;Cheng et al, 2009;Fluck and Schaffhausen, 2009).…”

Golden Syrian Hamster Models for Cancer Research

“…Hamsters are also susceptible to the development of hamster polyoma virus (HaPV) which can cause lymphomagenesis. HaPV is endemic in hamster colonies worldwide and its presence can compromise cancer studies [ 39 ]. It is therefore essential for investigators to routinely test for the presence of HaPV in their colonies and to clean up colonies to eliminate HaPV when necessary (we note that hamster colonies in our laboratories have been maintained HaPV-free).…”