Interferon a/b receptor deficient (IFNAR -/-) mice were previously found to be susceptible to the live attenuated vaccine strain of Rift Valley fever virus (RVFV) MP12 , providing a BSL-2 model to study RVFV. In this model mice are challenged with 104 pfu of MP-12-Luc, delivered by intraperitoneal infection. MP12-Luc encodes renilla luciferase in place of the viral protein NSs , allowing in vivo monitoring of viral replication using the IVIS Lumina II from Caliper Life Sciences. MP12-Luc is replication competent and routinely induces uniform mortality in mice 4-5 days post infection at 10^4 pfu. Animals develop symptoms that are reflective of severe human disease including high viral titers in the liver which can be visualized by a robust luminescence signal in liver. Additional readouts for this model include weight, survival, health observations, serum and organ titers, and cytokine analysis.
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