PRIMING OF NEUTROPHIL AND MONOCYTE ACTIVATION IN HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION - COMPARISON OF GRANULOCYTE-COLONY-STIMULATING FACTOR, GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR AND INTERFERON-GAMMA

Activation of human blood neutrophils and monocytes for enhanced relea se of toxic oxygen radicals may take place after priming with several cytokines including hematopoietic growth factors. The potential impact of human immunodeficiency virus (HIV) on this response and the relati ve potency of various cytokines remains unclear. Blood neutrophils and monocytes were isolated from 25 HIV outpatients with variable immunod eficiency. Oxidative burst response upon stimulation with N-formyl-met hionyl-leucyl-phenylalanine was assessed in neutrophils after priming with granulocyte colony-stimulating factor (G-CSF), granulocyte-macrop hage colony-stimulating factor (GM-CSF) and interferon-gamma (IFN-g), and in monocytes after priming with GM-CSF and IFN-g. Monocyte oxidati ve burst responses were not changed in patients or controls. In contra st, following priming with IFN-g, GM-CSF or medium (but not G-CSF) the neutrophils in HIV patients with CD4 counts >200 x 10(9)/L exhibited a significantly higher chemiluminescence response than was seen in hea lthy age-matched controls, whereas the response in patients with lower CD4 counts was not different from controls. At comparable concentrati ons, GM-CSF induced a significantly higher priming than G-CSF and IFN- g. A significant positive correlation between CD4 counts and priming a ctivity of GMCSF and IFN-g on neutrophils was observed. We conclude th at neutrophils in HIV infection have a normal or enhanced response to the oxidative metabolism priming activity of hematopoietic growth fact ors in vitro, whereas priming effect on monocytes was not seen.