Productive infection of field strains of avian coronavirus infectious bronchitis virus in chicken peripheral blood-derived monocyte

Yueting Zhang; Gary Whittaker

Avian infectious bronchitis virus (IBV) is the prototype member of the Gammacoronavirus genus (1, 6) . Despite extensive vaccination, IBV poses a continued economic threat to the poultry industry. The primary site of IBV infection is the epithelium of the respiratory tract; however IBV can spread to other sites including the gastrointestinal tract, kidney, reproductive organs and Harderian glands (2, 9) . Viremia has been suggested as a way for internal spread, as evidenced by detection of virus in the blood of infected chickens (3, 5) . However, the mechanism remains unknown. Other coronaviruses, such as severe acute respiratory syndrome--coronavirus (4) and feline coronavirus (10) , exhibit well recognized systemic infection, with monocytes, macrophages and dendritic cells originating from a common myeloid progenitor disseminating the virus and acting as an important immunopathogenic component in disease (8) .