IMPAIRED PHAGOLYSOSOMAL FUSION OF PERIPHERAL-BLOOD MONOCYTES FROM HIV-INFECTED SUBJECTS

We evaluated phagolysosomal fusion in peripheral blood monocytes from 20 HIV-infected individuals and 40 normal controls, using a fluorescen ce assay with acridine orange as marker. The percentages of phagolysos omal fusion of monocytes from HIV-infected subjects, after 30 and 60 m in of yeast ingestion, (mean +/- standard deviation) 57.2 +/- 17 and 6 3.2 +/- 18.6, respectively, when compared to normal controls (72.4 +/- 7.8 and 77 +/- 8.1), did not differ significantly. However, there was a direct linear association between the percentages of phagolysosomal fusion and CD4+ lymphocytes (P < 0.001) or CD4/CD8 T-cell ratio (P < 0.01). These results suggest that phagolysosomal dysfunction becomes e vident at late stages of HIV infection and progresses as CD4+ T-lympho cyte count and CD4/CD8 T-cell ratio decrease. On the other hand, recom binant gp120 inhibited significantly normal phagolysosomal fusion at c oncentrations ranging between 1 and 1000 ng/ml. Taking together the re sults obtained, we can conclude that gp120 could be responsible for mo nocyte phagolysosomal dysfunction observed in HIV infected patients.