[Analysis of p22-phox and p47-phox subcellular localization and distribution in neutrophils from human immunodeficiency virus (HIV) infected patients].
BACKGROUND
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.


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.
Instituto de Inmunología Clínica, Universidad de Los Andes Mérida-Venezuela.
Siham
S
Salmen
Daniela
D
Montilla
Maryuri
M
London
Dánely
D
Velázquez
Lisbeth
L
Berrueta
D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D003593:Cytoplasm / Q000737:chemistry; D003600:Cytosol / Q000737:chemistry; D004789:Enzyme Activation; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D015658:HIV Infections / Q000097:blood / Q000201:enzymology* / Q000276:immunology; D006801:Humans; D018613:Microscopy, Confocal; D019255:NADPH Oxidases / Q000097:blood*; D009504:Neutrophils / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure; D021381:Protein Transport; D017382:Reactive Oxygen Species / Q000378:metabolism; D016897:Respiratory Burst; D012995:Solubility; D013347:Subcellular Fractions / Q000737:chemistry
D017382:Reactive Oxygen Species; D019255:NADPH Oxidases; C086986:CYBA protein, human; C060505:neutrophil cytosolic factor 1