Cytokine mRNA Expression Profile in Target Organs of IFNAR (-/-) Mice Infected with African Horse Sickness Virus

Abstract

African horse sickness (AHS) is a highly severe disease caused by a viral etiological agent, African horse sickness virus (AHSV). It is endemic in sub-Saharan Africa, while sporadic outbreaks have occurred in North Africa, Asia, and Europe, with the most recent cases in Thailand. AHSV transmission between equines occurs primarily by biting midges of the genus Culicoides, especially C. imicola, with a wide distribution globally. As research in horses is highly restricted due to a variety of factors, small laboratory animal models that reproduce clinical signs and pathology observed in natural infection of AHSV are highly needed. Here, we investigated the expression profile of several pro-inflammatory cytokines in target organs and serum of IFNAR (-/-) mice, to continue characterizing this established animal model and to go deep into the innate immune responses that are still needed.

IFNAR(-/-) Mice Constitute a Suitable Animal Model for Epizootic Hemorrhagic Disease Virus Study and Vaccine Evaluation

“…EHDV replication in macrophages and endothelial cells triggers the release of proinflammatory cytokines such as IL-1β and IL-6, exacerbating inflammation that leads to tissue injury adding to the direct viral damage caused by replication in the endothelium of infected WTD 14 . The uncontrolled expression of these two cytokines is positively associated with disease severity in other viral infections, being a hallmark of cytokine storms 64 - 67 . EHDV-infected IFNAR(-/-) mice displayed elevated circulating levels of IL-6 as well as augmented transcription levels of IL-1β and IL-6 in the spleen and lung, tissues where EHDV replicates at high levels.…”

“…The real-time RT-qPCR specific for EHDV segment 9 was performed using primers and probe described by Maan et al 93 . Data are expressed as PFU equivalents/g of tissue by comparison with previously titrated samples as previously described 67 .…”