Auditory function analysis in immunodeficient STAT1 knock-out mice: Considerations for viral infection models.

The STAT1 knock-out (KO) mouse is a frequently used transgenic immunodeficient strain to model human viral and bacterial diseases. The Lassa fever model was established in the STAT1 KO mice mimicking phenotypes seen in human patients including deafness in survivors. This model develops hearing loss at high prevalence and is a valuable tool to investigate viral infection-induced hearing loss. However, Lassa virus is a highly contagious and regulated agent requiring the unique logistics of the biosafety level 4 posing limitations for experimental work. Therefore, we did a detailed auditory analysis of the STAT1 KO mice to assess baseline auditory function in preparation for further auditory behavioral studies. Auditory brainstem response and distortion product otoacoustic emission tests were performed on males and females of the STAT1 KO mice and was compared to 129S6/SvEv wild type (WT) mice. The male WT mice had the best auditory performance and the female WT mice had the worst hearing performance. The male and female STAT1 KO mice had similar auditory performance to each other, which was intermediate between WT males and females. We conclude that both male and female STAT1 KO mice are suitable for studying viral infection-induced hearing loss.