Production of R-Type Virus-Like Particles in Hamster Cells

Abstract

The production and release of R-type virus-like particles (VLP) was studied in several Syrian hamster cell lines. Most but not all hamster cell lines contain detectable levels of R-type VLP. However, only BHK-21 clone F (CF) cells would release the VLP into culture fluids. Treatment with dexamethasone enhanced to a limited extent the production and release of VLP from BHK-21 CF cells. Actinomycin D inhibited the production and release of R-type VLP in hamster cells, suggesting that some transcription from DNA is necessary for VLP production. Furthermore, 5-iododeoxyuridine induced the production of R-type VLP in Syrian hamster embryo cells. These results suggest that R-type VLP are endogenous to Syrian hamsters.

Biological and molecular studies on Syrian hamster intracisternal R-type particles

“…The description of putative extracellular IRP particles found in some reports [2] could be explain by the fact that SH cells possess endogeneous retroviruses [ 13], with a morphology evoking that of IRP.…”

Scalable Recombinant Adeno-Associated Virus Production Using Recombinant Herpes Simplex Virus Type 1 Coinfection of Suspension-Adapted Mammalian Cells

“…The lineage and safety of mammalian-derived cell lines are important for regulatory filings in support of biotherapeutic manufacturing methods for clinical trials. BHK cells have been shown to generate (Albu and Holmes, 1973) and release (Bergmann and Wolff, 1981) endogenously produced viruslike particles (VLPs); however, the BHK cell line has been used both in a Huntington's disease phase 1 clinical trial to deliver ciliary neurotrophic factor (CNTF) (Bloch et al, 2004) and for the manufacture of recombinant factor VIII to treat hemophilia A. The latter is a U.S. Food and Drug Administration (FDA)-licensed, commercial process (Boedeker, 2001), validating the use of BHK cell-based manufacturing as a viable method for the production of human therapeutics.…”

Three new cases of R-type virus-like particles in hamster tumours

“…Up to now in different rodent tumours and transformed cell lines these endogenous retrovirus-related sequences could be classified as C-type, intracisternal A~particles (lAP), virus-like (VL-30) and mouse mammary tumour virus (MMTV) families [5,7,8,11]. As for the Rtype VLP, they are considered as EV and classified as intracisternat R-type by Bergmann and Wolff [1] and Lasneret et al [9], who found them in activated by 5-iododeoxyuridine or demethylating drug hamster cell lines. In their experiments these particles were sometimes accompanied by intracisternal A-type, intracytoplasmic A-type, intramitochondrial A-type and type C VLP.…”