BACKGROUND: Coevolution between pathogens and their hosts decreases host morbidity and mortality. Bats host and can tolerate viruses which can be lethal to other vertebrate orders, including humans. Bat adaptations to infection include localized immune response, early pathogen sensing, high interferon expression without pathogen stimulation, and regulated inflammatory response. The immune reaction is costly, and bats suppress high-cost metabolism during torpor. In the temperate zone, bats hibernate in winter, utilizing a specific behavioural adaptation to survive detrimental environmental conditions and lack of energy resources. Hibernation torpor involves major physiological changes that pose an additional challenge to bat-pathogen coexistence. Here, we compared bat cellular reaction to viral challenge under conditions simulating hibernation, evaluating the changes between torpor and euthermia. RESULTS: We infected the olfactory nerve-derived cell culture of Myotis myotis with an endemic bat pathogen, European bat lyssavirus 1 (EBLV-1). After infection, the bat cells were cultivated at two different temperatures, 37 °C and 5 °C, to examine the cell response during conditions simulating euthermia and torpor, respectively. The mRNA isolated from the cells was sequenced and analysed for differential gene expression attributable to the temperature and/or infection treatment. In conditions simulating euthermia, infected bat cells produce an excess signalling by multitude of pathways involved in apoptosis and immune regulation influencing proliferation of regulatory cell types which can, in synergy with other produced cytokines, contribute to viral tolerance. We found no up- or down-regulated genes expressed in infected cells cultivated at conditions simulating torpor compared to non-infected cells cultivated under the same conditions. When studying the reaction of uninfected cells to the temperature treatment, bat cells show an increased production of heat shock proteins (HSPs) with chaperone activity, improving the bat's ability to repair molecular structures damaged due to the stress related to the temperature change. CONCLUSIONS: The lack of bat cell reaction to infection in conditions simulating hibernation may contribute to the virus tolerance or persistence in bats. Together with the cell damage repair mechanisms induced in response to hibernation, the immune regulation may promote bats' ability to act as reservoirs of zoonotic viruses such as lyssaviruses.

• Klíčová slova
• Antiviral state, Chiroptera, EBLV-1, Heat shock proteins (HSPs), Hibernation, In vitro infection model, Innate immunity, Lyssaviruses, Myotis myotis, Transcriptome,
• MeSH
• Chiroptera * fyziologie   MeSH
• hibernace * MeSH
• Lyssavirus * MeSH
• transkriptom MeSH
• viry * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Rabies is a zoonosis ending fatally in all mammals, including humans. Unlike the other mammals, this disease is usually not fatal in bats. Rabies is caused by lyssaviruses which are divided into several distinct phylogroups comprising 15 known viruses. It is believed that the original hosts of all lyssaviruses are bats. Classical rabies virus (RABV) occurs in bats across Americas and represents the major cause of rabies in humans and domestic animals there. European bat lyssavirus type 1 (EBLV-1) and European bat lyssavirus type 2 (EBLV-2) are the most frequently diagnosed lyssaviruses in Eurasia. The transmission of EBLV-1 and EBLV-2 from bats to other mammals is very rare. As of now, more detailed information is missing about the other Eurasian lyssaviruses - West Caucasian bat virus (WCBV), Bokeloh bat lyssavirus (BBLV), Aravan virus (ARAV), Irkut virus (IRKV), Khujand virus (KHUV) and Lleida virus. The lyssavirus most frequently found in Africa is Lagos bat virus (LBV). In Australia, only Australian bat lyssavirus (ABLV) has been demonstrated as yet. In the Czech Republic, a total of five cases of rabies in bats were confirmed between 1994 and 2015. Rabies can be transmitted from bats mainly by biting or scratching. Clinically ill bats suffer from nervous disorders or produce abnormal sounds. If rabies is suspected, laboratory tests are essential. Protection of human health is based on pre-exposure and/or post-exposure vaccination. However, the available vaccines do not protect against some newly identified lyssaviruses such as WCBV. Nevertheless, most bat species pose a minimal risk to humans.

• MeSH
• Chiroptera virologie   MeSH
• lidé MeSH
• Lyssavirus izolace a purifikace   MeSH
• rabies epidemiologie   veterinární   MeSH
• zoonózy epidemiologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH