Primary glia cells from bank vole propagate multiple rodent-adapted scrapie prions

Abstract

Since the beginning prion research has been largely dependent on animal models for deciphering the disease, drug development or prion detection and quantification. Thereby, ethical as well as cost and labour-saving aspects call for alternatives in vitro. Cell models can replace or at least complement animal studies, but their number is still limited and the application usually restricted to certain strains and host species due to often strong transmission barriers. Bank voles promise to be an exception as they or materials prepared from them are uniquely susceptible to prions from various species in vivo, in vitro and in cell-free applications. Here we present a mainly astrocyte-based primary glia cell assay from bank vole, which is infectible with scrapie strains from bank vole, mouse and hamster. Stable propagation of bank vole-adapted RML, murine 22L and RML, and hamster 263K scrapie is detectable from 20 or 30 days post exposure onwards. Thereby, the infected bank vole glia cells show similar or even faster prion propagation than likewise infected glia cells of the corresponding murine or hamster hosts. We propose that our bank vole glia cell assay could be a versatile tool for studying and comparing multiple prion strains with different species backgrounds combined in one cell assay.

A single protective polymorphism in the prion protein blocks cross‐species prion replication in cultured cells

“…Both the M109 and I109 polymorphic variants of BVPrP functioned as permissive substrates, enabling cross‐species prion replication when exposed to various strains of hamster and mouse prions. These results confirm and extend recent findings that BVPrP can permit cross‐species prion infection in cultured cells (Schwenke et al, 2022; Walia et al, 2019). However, the monoclonal BVPrP‐expressing CAD5‐PrP −/− lines described herein offer several important advantages.…”

“…This suggests that prions accumulate to higher levels in our cellular models, perhaps because of their monoclonal nature. Second, unlike primary glia derived from bank voles (Schwenke et al, 2022), which do not divide in culture, it is easy to distinguish between de novo PrP res produced by conversion of PrP C in the cultured cells and residual levels of PrP res because of persistence of the prion inoculum. Finally, since PrP −/− cells are used a starting point in our system, it is straightforward to test the effects of amino acid changes in PrP, such as G127V, on prion susceptibility.…”

“…This suggests that prions accumulate to higher levels in our cellular models, perhaps because of their monoclonal nature. Second, unlike primary glia derived from bank voles (Schwenke et al, 2022), which do not divide in culture, it is easy to distinguish between de novo PrP res produced by conversion In all panels, PrP was detected using the antibodies HuM-P or HuM-D13, as indicated.…”

“…While primary glial cultures from bank voles enable cross‐species prion replication (Schwenke et al, 2022), no immortalized bank vole cell lines currently exist, hindering our ability to understand and exploit the unique prion transmission properties exhibited by BVPrP. Expression of non‐mouse PrP alleles in cell lines lacking endogenous PrP expression has expanded the range of prion strains that can be propagated in cultured cells (Bian et al, 2010; Courageot et al, 2008; Vilette et al, 2001).…”

Convergent generation of atypical prions in knock-in mouse models of genetic prion disease

“…In recent years, bank voles ( Myodes glareolus ) have been increasingly used in prion disease research since they are susceptible to prion strains from several different species, including humans [1, 2, 21, 58, 59, 67]. Bank vole PrP (BVPrP) facilitates prion replication and formation in various in vitro , cellular, and animal paradigms, indicating that BVPrP is a highly permissive substrate for conversion into PrP Sc [3, 13, 19, 23–26, 53, 60, 73, 85]. Moreover, transgenic mice overexpressing wild-type BVPrP containing isoleucine at polymorphic codon 109 (I109) develop a spontaneous and transmissible neurological illness characterized by prion disease-specific neuropathological changes as well as the presence of a highly PK-resistant PrP fragment in the brain [61, 84, 86].…”