Journal of Leukocyte Biology 50:160-166 (1991) © 1991 Wiley-Liss, Inc. The Ability of Polymorphonuclear Leukocyte Priming Agents to Overcome Influenza A Virus-Induced

The major mortality and morbidity resulting from influenza virus infections are due to secondary bacterial infections which occur in association with virus-induced inhibition of polymorphonuclear leukocyte (PMNL) function. The present study was undertaken to determine if compounds which prime PMNL function to subsequent stimulation with N-formylmethionyl-leucylphenylalanine (FMLP) or phorbol 12-myristate 13-acetate (PMA) can overcome influenza A virus (IAV)-induced inhibition of the PMNL chemiluminescence response to these stimuli. Granulocyte-macrophage colony stimulating factor (GM-CSF), guanosine triphosphate (GTP), and 1-oleoyl-2-acetylglycerol(OAG)were able to prime the PMNL response to FMLP and/or PMA and totally or partially overcome IAV-induced PMNL dysfunction in cells stimulated with FMLP or PMA. A direct correlation was found between the extent of PMNL priming due to GM-CSF, GTP, and OAG and the capacity of these compounds to overcome virus-induced PMNL dysfunction. The implications of these findings in regard to the mechanism by which priming agents overcome IAV-induced cell dysfunction and the potential of these compounds as therapeutic agents to treat secondary bacterial infections are discussed. Key words: influenza virus infections, virus-induced PMNL dysfunction, GM-CSF, GTP