Identification of a Cell Population That Produces Alpha/Beta Interferon In Vitro and In Vivo in Response to Noncytopathic Bovine Viral Diarrhea Virus

In vitro infection of bovine cells of many origins with the cytopathogenic bovine viral diarrhea virus (cpBVDV) results in the induction of alpha/beta interferon (IFN-α/β), whereas noncytopathogenic BVDV (ncpBVDV) isolates have been shown not to induce IFN-α/β in vitro. Similarly, cpBVDV induces IFN-α/β in the early bovine fetus, but ncpBVDV does not. However, acute infection of naive cattle with ncpBVDV results in IFN-α/β production. In this study, we identified and characterized a minor population of cells, present in lymph nodes that produce IFN-α in response to ncpBVDV. These cells expressed the myeloid markers CD14, CD11b, and CD172a but did not express CD4 and CD45RB. We also established that these cells produced IFN-α in the absence of detectable productive infection.