The immunoglobulin superantigen-binding site of HIV-1 gp120 activates human basophils

Citation
C. Florio et al., The immunoglobulin superantigen-binding site of HIV-1 gp120 activates human basophils, AIDS, 14(8), 2000, pp. 931-938
Citations number
53
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Immunology
Journal title
AIDS
ISSN journal
0269-9370 → ACNP
Volume
14
Issue
8
Year of publication
2000
Pages
931 - 938
Database
ISI
SICI code
0269-9370(20000526)14:8<931:TISSOH>2.0.ZU;2-4
Abstract
Objective: To investigate the mechanism whereby HIV-1 envelope glycoprotein gp120 from four different isolates obtained in three different countries i nduces proinflammatory mediator release from normal human basophils. Methods: Histamine, cysteinyl leukotriene C-4 (LTC4) and interleukin 4 (IL- 4) release into the supernatant was measured in gp120-stimulated peripheral blood basophils from HIV-1 and HIV-2 negative subjects. Results: The HIV glycoprotein was a potent stimulus for release of these me diators in basophils purified from donors negative for HIV-1 and HIV-2. The re was also a correlation (r = 0.58; P < 0.01) between the maximum IL-4 rel ease from basophils induced by gp120 and by anti-IgE. Basophils from which IgE had been dissociated by brief exposure to lactic acid no longer release d histamine in response to gp120 and anti-IgE. Anti-IgE specifically desens itized basophils to a subsequent challenge with anti-IgE and gp120. Human m onoclonal IgM carrying the V(H)3 domain, but not that carrying the V(H)6 do main, inhibited gp120-induced secretion of histamine from basophils in a co ncentration-dependent manner. Synthetic peptides identical to regions dista nt from the N- and C-termini of gp120(MN) inhibited its activating capacity . Conclusions: gp120 acts as a viral superantigen interacting with the V(H) 3 domain of IgE to induce the release of preformed and de novo synthesized mediators from human cells carrying the Fc fragment Fc epsilon RI receptor. (C) 2000 Lippincott Williams & Wilkins.