Recombinant human immunodeficiency virus type 1 (HIV-1) Tat protein inhibits phagolysosomal fusion in human peripheral blood monocytes.
The effect of recombinant HIV-1 Tat protein on different functions of peripheral blood monocytes, such as candidacidal activity and phagolysosomal fusion, was evaluated. HIV-1 Tat protein caused a significant impairment of phagolysosomal fusion at 100 ng/ml (p = 0.018). The inhibitory effect of Tat on phagolysosomal fusion was blocked by the addition of 1 microgram/ml monoclonal anti-Tat antibody. Candidacidal activity of peripheral monocytes was not altered by HIV-1 Tat protein at the concentration of 1 microgram/ml. These results indicate the HIV-1 Tat protein can affect the monocyte microbicidal mechanisms at the phagolysosomal fusion step with little or not effect upon the lytic activity.
Laboratorio de Biología Celular y Retrovirus, Hospital de Pediatría Juan P. Garrahan, Buenos Aires, Argentina.
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D000963:Antimetabolites / Q000494:pharmacology*; D002478:Cells, Cultured; D015696:Gene Products, tat / Q000235:genetics / Q000494:pharmacology*; D015497:HIV-1 / Q000378:metabolism*; D006801:Humans; D009000:Monocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010588:Phagosomes / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000494:pharmacology; D054322:tat Gene Products, Human Immunodeficiency Virus
D000963:Antimetabolites; D015696:Gene Products, tat; D011993:Recombinant Fusion Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus