Host gene expression profiles in ferrets infected with genetically distinct henipavirus strains
A) Upon infection of the upper and lower respiratory tract, the virus quickly spreads to a myriad of organs, including the central nervous system, liver, spleen, heart, kidney, bladder and blood (schematic representation of the data from HeV infection). B) In the lung tissue, the virus presents high growth rates and only after the inflammatory responses become fully active, at around day 4, the levels of virus stabilize but without significantly decreasing. Signaling and effector molecules of the innate immunity become expressed, innate immune cells migrate to the lung tissue, but, interestingly, gene expression data strongly suggest that lymphocytes are not migrating and expanding in the affected tissues. Additionally, the expression of genes related to the cell cycle, growth factors and growth factor signaling decline through the infectious process, possibly related to the degradation of the physiological functions of the lung tissue. C) In the brain tissue, the virus grows at a slower rate as compared to the lung tissue. The brain mounts a restricted immune response in accordance with the immunoprivileged status of this tissue that includes infiltration and/or local expansion of macrophages, and possibly of lymphocytes, but without leading to a noticeable alteration of the viral growth kinetics.