WP2 leader: Sara Hägglund, SLU, sara.hagglund@slu.se
On the basis of preliminary BRD diagnostic field data and results of our previous study on IDV infection of calves, we hypothesize that IDV acts synergistically with several other microorganisms. We recently corroborated this hypothesis by a preliminary short study indicating that IDV and Mycoplasma bovis (M. bovis) co-infection in young calves leads to a greater severity of respiratory clinical signs and fitness of the two pathogens.
Thus the objective of WP2 is to specify and detail the synergistic and antagonistic effects between IDV and other bovine respiratory pathogens upon co-infections in vitro, ex vivo and in vivo. WP1 will inform us about the most frequent IDV associated pathogens, but based on preliminary data, we will start to work with well-known bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCoV), bovine parainfluenza virus type 3 (PIV-3) and M. bovis. WP2 will provide detailed information on the influence of IDV on the replication and cytopathogenicity of selected respiratory pathogens and the immunological pathways that enhance or inhibit these events.
Specifically, four main aspects will be investigated: i) replication kinetics, ii) co-localization and cell tropism, iii) inflammation and innate immune response, and iv) markers of synergism or antagonism.