ABSTRACT
INTRODUCTION: During human immunodeficiency virus (HIV) infection a dysfunction of polymorphonuclear (PMN) cells has been described including a progressively altered superoxide production as disease progression. The NADPH oxidase has been described as a major source of superoxide. The neutrophil NADPH oxidase comprises a plasma membrane-bound cytochrome b558 (which is a heterodimer of one p22-phox and one gp91-phox subunit) and cytosolic subunits, namely p47-phox, p67-phox and p40-phox. During neutrophil activation in response to various agonists, the cytosolic subunits translocate to and associate with the cytochrome b558, a process that results in oxidase activation. Therefore, an altered superoxide production could be a consequence of abnormal distribution or translocation of NADPH oxidase components in response to HIV infection. MATERIAL AND METHODS: We used several strategies including: confocal microscopy, subcellular fractionation and sucrose gradients, to analyze the cellular distribution of two of the NADPH oxidase components (p22-phox and p47-phox). RESULTS: We observed that in resting cells, a substantial proportion of p22-phox from HIV positive patients is distributed in regions close to the cytoplasmic membrane, sediment in high density sucrose fractions and is located in the cytoplasmic insoluble fraction. Additionally, a diffuse cytosolic distribution of p47-phox was observed in neutrophils from HIV infected patients. The results demonstrate an inappropriate cell distribution of NADPH-complex in PMN from HIV positive patients.
