Superoxide anion production in influenza protein-activated NADPH oxidase of human polymorphonuclear leukocytes

There are conflicting reports regarding superoxide anion (O2-) production by human polymorphonuclear leukocytes (PMNL) that have been activated by influenza virus. In the present study, the output of O2- was determined by measuring superoxide dismutase-inhibitable cytochrome c reduction. Incubation of PMNL with purified influenza matrix (M) protein, neuraminidase (NA), or hemagglutinin (HA) enhanced the production of O2-: 4.93 nmol of O2-/4 x 10(5) cells/15 min was produced with M protein, 5.20 with NA, and 6.89 with HA. These values were significantly higher (P < .05) than that for untreated PMNL (1.51). Both nonglycosylated and glycosylated proteins had the potential to generate O2- in human PMNL. Neither the hemagglutinating activity of HA nor the enzymatic activity of NA were necessary for viral protein activation of PMNL.