Newcastle disease virus-induced functional impairments and biochemical changes in chicken heterophils

The GB strain of Newcastle disease virus (NDV) is used to infect chicken heterophils in vitro. Heterophils have a decreased ability to phagocytize bacteria 3 h after infection, and those that did engulfed fewer bacteria relative to non-infected heterophils. Infected heterophils have a decreased H₂O₂ production as shown by flow cytometry, but an increased nitric oxide production, suggesting that NDV can stimulate heterophils to produce and/or utilize nitrogen intermediates but not oxygen intermediates. DNA extracted from the infected heterophils shows a marked fragmentation, suggesting that NDV infection may cause heterophils to undergo apoptosis.