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. 2018 Mar 21:9:463.
doi: 10.3389/fmicb.2018.00463. eCollection 2018.

Experimental Inoculation in Rats and Mice by the Giant Marseillevirus Leads to Long-Term Detection of Virus

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Experimental Inoculation in Rats and Mice by the Giant Marseillevirus Leads to Long-Term Detection of Virus

Sarah Aherfi et al. Front Microbiol. .

Abstract

The presence of the giant virus of amoeba Marseillevirus has been identified at many different sites on the human body, including in the bloodstream of asymptomatic subjects, in the lymph nodes of a child with adenitis, in one adult with Hodgkin's disease, and in the pharynx of an adult. A high seroprevalence of the Marseillevirus has been recorded in the general population. Whether Marseillevirus can disseminate and persist within a mammal after entry remains unproven. We aimed to assess the ability of the virus to disseminate and persist into healthy organisms, especially in the lymphoid organs. Parenteral inoculations were performed by intraperitoneal injection (in rats and mice) or intravenous injection (in rats). Airway inoculation was performed by aerosolization (in mice). Dissemination and persistence were assessed by using PCR and amebal co-culture. Serologies were performed by immunofluorescent assay. Pathological examination was conducted after standard and immunohistochemistry staining. After intraperitoneal inoculation in mice and rats, Marseillevirus was detected in the bloodstream during the first 24 h. Persistence was noted until the end of the experiment, i.e., at 14 days in rats. After intravenous inoculation in rats, the virus was first detected in the blood until 48 h and then in deep organs with infectious virus detected until 14 and 21 days in the liver and the spleen, respectively. Its DNA was detected for up to 30 days in the liver and the spleen. After aerosolization in mice, infectious Marseillevirus was present in the lungs and nasal associated lymphoid tissue until 30 days post inoculation but less frequently and at a lower viral load in the lung than in the nasal associated lymphoid tissue. No other site of dissemination was found after aerosol exposure. Despite no evidence of disease being observed, the 30-day long persistence of Marseillevirus in rats and mice, regardless of the route of inoculation, supports the hypothesis of an infective potential of the virus in certain conditions. Its constant and long-term detection in nasal associated lymphoid tissue in mice after an aerosol exposure suggests the involvement of naso-pharyngeal associated lymphoid tissues in protecting the host against environmental Marseillevirus.

Keywords: Megavirales; NCLDV; experimental infection; giant viruses; marseillevirus; murine model; pathogenicity.

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Figures

Figure 1
Figure 1
Representative photomicrographs of co-culture of mice and rats samples on Acanthamoeba castellanii. Pictures (a–d) show positive samples by co-culture as indicated by the visible infected amoebas with Marseillevirus. These samples include NALT from aerosol inoculated mice and spleen from rats after IV inoculation with Marseillevirus. The arrows indicate viral factories and N indicate the nucleus of amoeba. Pictures (e,f) show negative samples by amoebal co-culture: the amoebas are not infected and do not contain viral factories.
Figure 2
Figure 2
Overall detection and persistence of Marseillevirus DNA by PCR after an intraveinous inoculation in rats, during the 43 day long experiment.
Figure 3
Figure 3
Positive (A) NALT and (B) lung samples, according to the technique (PCR or amoebal co-culture), after pulmonary inoculation. The percentage of positive samples is indicated on the y axis. The absolute numbers of positive samples are indicated by labels on the plots.
Figure 4
Figure 4
Positive (A) liver and (B) spleen samples, according to the technique (PCR or amoebal co-culture), after intravenous inoculation in rats. The percentage of positive samples is indicated on the y axis. The absolute numbers of positive samples are indicated by labels on the plots.
Figure 5
Figure 5
Standardized viral loads (viral copies per million murine cells) in the lungs and the NALT of aerosol-inoculated mice by Marseillevirus suspension. Diamonds represent the viral loads in the NALT and circles represent the viral loads in the lungs for each animal. The mean viral loads are represented for each time point by thick dashes. The viral loads in lungs and NALT, and at different time points were compared by using Wilcoxon-Mann Whitney test, using sigmaplot 13 SYSTAT software Inc. software. Single asterisks show the time points with significant differences between NALT and lung viral loads. Double asterisks show significant differences between the NALT viral loads at different time points.

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References

    1. Aherfi S., Boughalmi M., Pagnier I., Fournous G., La Scola B., Raoult D., et al. . (2014). Complete genome sequence of Tunisvirus, a new member of the proposed family Marseilleviridae. Arch. Virol. 159, 2349–2358. 10.1007/s00705-014-2023-5 - DOI - PubMed
    1. Aherfi S., Colson P., Audoly G., Nappez C., Xerri L., Valensi A., et al. . (2016a). Marseillevirus in lymphoma: a giant in the lymph node. Lancet Infect. Dis. 16, e225–e234. 10.1016/S1473-3099(16)30051-2 - DOI - PubMed
    1. Aherfi S., Colson P., Raoult D. (2016b). Marseillevirus in the pharynx of a patient with neurologic disorders. Emerg. Infect. Dis. 22, 2008–2010. 10.3201/eid2211.160189 - DOI - PMC - PubMed
    1. Aherfi S., Pagnier I., Fournous G., Raoult D., La Scola B., Colson P. (2013). Complete genome sequence of Cannes 8 virus, a new member of the proposed family “Marseilleviridae”. Virus Genes 47, 550–555. 10.1007/s11262-013-0965-4 - DOI - PubMed
    1. Boughalmi M., Pagnier I., Aherfi S., Colson P., Raoult D., La Scola B. (2013). First isolation of a marseillevirus in the diptera Syrphidae Eristalis tenax. Intervirology 56, 386–394. 10.1159/000354560 - DOI - PubMed

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