Sendai virus intra-host population dynamics and host immunocompetence influence viral virulence during in vivo passage

Peña, José; Chen-Harris, Haiyin; Allen, Jonathan E.; Hwang, Mona; Elsheikh, Maher; Mabery, Shalini; Bielefeldt-Ohmann, Helle; Zemla, Adam T.; Bowen, Richard A.; Borucki, Monica K.

Serial passage of a virus in laboratory animals is often used to increase pathogenicity of the virus for that host in order to generate a laboratory model of the disease (Aronson, Herzog, and Jerrells 1995; Tiwari et al. 2006) . For example, passage of the SARS virus in rats generated a viral variant with a point mutation in the spike protein, and this mutation increased the efficiency of interaction of the spike protein and the viral receptor on the rat cells (Nagata, et al. 2007 ). Interestingly, data from this same study showed that both host and viral factors are associated with increased virulence, as virulence was associated with increased age of the rodent as well as mutations in the viral genome.