Human Species D Adenoviruses Isolated from Diarrheal Feces Show Low Infection Rates in Primary Nasal Epithelial Cells.

Malik Aydin,Sebastian Schellhorn,Anja Ehrhardt,Wenli Zhang,Stefan Wirth

doi:10.3390/children8070563

Malik Aydin, Sebastian Schellhorn + Show 3 more

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https://doi.org/10.3390/children8070563

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Abstract

The importance of adenovirus (Ad) research is significantly increasing with respect to virotherapy for vaccine development, tumor, and gene therapy. Due to the different species and subtypes of this virus, the characterization of the biological significance of especially rare Ad is necessary. Previously, rare Ad types 70, 73, and 74 were originally isolated from fecal samples of immunocompromised patients and they represent recombinants of other Ad types. Here we investigated transduction experiments of these reporter gene tagged Ad types in primary cells exemplified by subject-derived primary nasal epithelial cells (NAEPCs). To analyze the transduction rates, we performed flow cytometry, quantitative polymerase chain reaction (PCR), and cytokine analyses 25 h post-infection. We found that, in contrast to Ad type 5 (as a positive control), the transduction rates of NAEPCs with Ad types 70, 73, and 74 were interestingly low. The major Ad receptor (coxsackievirus-adenovirus receptor and CD46) expression levels showed no significant change after infection with Ad types 70, 73 and 74. Moreover, Interleukin 6 (IL-6) was not released after in vitro Ad transduction. Due to the high risk of developing life-threatening complications in immunocompromised patients by these human species D Ads, even more attention needs to be investigated into the development of diagnostic and therapeutic concepts to prevent and treat those opportunistic infections in susceptible patients.

Highlights

Adenoviruses (Ads) are non-enveloped, icosahedral double-stranded DNA viruses, with genome sizes between 26 to 45 kilobase pairs [1]. They utilize different cell surface molecules, including the coxsackie and adenovirus receptor (CAR), cluster of differentiation (CD46), desmoglein-2, GD1a ganglioside and sialic acid residues for virus entry usually followed by integrin-mediated virus internalization, which explains the broad tissue tropism of Ads [2]
We found that Ad5, among others, showed the best transduction efficiency in primary, human nasal epithelial cell (NAEPCs) cultures and that major Ad receptors such as CAR and CD46 were expressed on these cells
We hypothesized whether the transduction efficiency in nasal epithelial cells (NAEPCs) can be dose-dependent

Summary

Introduction

Adenoviruses (Ads) are non-enveloped, icosahedral double-stranded DNA viruses, with genome sizes between 26 to 45 kilobase pairs (kbps) [1]. Ads can be pathogenic causing well-known clinical symptoms as for instance in the eye (keratoconjunctivitis), the gastrointestinal (gastroenteritis) and the respiratory tract [9,10,11,12,13,14] These infections are usually self-limiting, Ads can cause fatal disseminating diseases in immunocompromised patients [15,16,17,18,19,20]. In 2015, Hage and colleagues characterized for the first time a new Ad type 70 from stool samples of a stem cell transplanted patient with diarrhea [21] They determined its complete genome to consist of 35,186 base pairs (bps) coding for 39 putative open reading frames (ORFs). All four Ads were not found to be closely related to one another on the complete genome level, but on single gene and gene region level, e.g., penton, E1 and E4 [22]

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