Impaired macrophage phagocytosis of apoptotic neutrophils in patients with human immunodeficiency virus type 1 infection
| Autor: | Luisa Gennero, Donato Torre, Agostino Pugliese, Francesco M. Baccino, Filippo Speranza, Gilberto Biondi |
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| Rok vydání: | 2002 |
| Předmět: |
Microbiology (medical)
Adult Neutrophils Phagocytosis Clinical Biochemistry Immunology Inflammation Apoptosis HIV Infections Gene Products nef Immune system medicine Immunology and Allergy Humans nef Gene Products Human Immunodeficiency Virus Candida albicans biology Macrophages virus diseases Chemotaxis biology.organism_classification Apoptotic body Respiratory burst Immune-Mediated Responses and Disorders HIV-1 medicine.symptom Oxidation-Reduction |
| Zdroj: | Clinical and diagnostic laboratory immunology. 9(5) |
| ISSN: | 1071-412X |
| Popis: | Neutrophil (polymorphonuclear leukocytes [PMNL]) function, including chemotaxis, phagocytosis, oxidative burst capacity, and bacterial killing, is impaired in the course of human immunodeficiency virus type 1 (HIV-1) infection, particularly in the later stages of the disease, and this abnormal function may predispose to some secondary bacterial infections and/or to opportunistic infections (4, 8, 10, 11, 12). PMNL have the shortest half-life of all circulating leukocytes and are programmed to die within 1 day. These aging leukocytes spontaneously undergo apoptosis and are recognized and phagocytosed by macrophages (15). Pitrak et al. (13) have demonstrated that the rate of PMNL apoptosis is accelerated in AIDS patients, and this defect is intrinsic and not an effect of endogenous serum factors. Moreover, it has been proposed that the ingestion of apoptotic PMNL triggers production of anti-inflammatory mediators from macrophages (6, 9), whereas persistent PMNL-rich inflammatory infiltrates have been associated with unresolved inflammatory reactions, including adult respiratory distress syndrome and rheumatoid arthritis (16). Thus, the removal of apoptotic cells appears to be critical in the resolution of inflammation. We have previously demonstrated that macrophages from HIV-positive subjects have a reduced ability to phagocytose Candida albicans cells, and there is a significant decrease in oxidative processes for the intracellular killing. These phenomena seem to be induced, at least in part, by HIV Nef protein (14). Since the effects of macrophage phagocytosis of apoptotic PMNL have not been completely investigated, especially in HIV-positive subjects, the purpose of this study was to evaluate phagocytosis of PMNL apoptotic bodies performed by macrophagic cells obtained from HIV-1-positive subjects and in parallel by the macrophages obtained from healthy individuals. Furthermore, we studied the effect of Nef protein on PMNL apoptotic body macrophagic phagocytosis, since this viral protein is able to depress both specific and nonspecific immune responses in HIV-infected patients, particularly microbial phagocytosis (1, 14). |
| Databáze: | OpenAIRE |
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