AEGiS-07IAC: Research for the effect of gp120/CD4 interactions in vivo.

7th International AIDS Conference


Florence, Italy — June 16-21, 1991

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Research for the effect of gp120/CD4 interactions in vivo.

Int Conf AIDS 1991 Jun 16-21; 7:26 (abstract no. M.A.18)
Amadori A, Zamarchi R, Veronese ML, DeSilvestro G, Salmaso L, Barelli A, Borri A, Chieco-Bianchi L; Institute of Oncology, Padova, ITALY

PREMISS: Much in vitro data indicate the effects of gp120/CD4 interactions, but no evidence that this phenomenon occurs in vivo has been provided so far.

METHODS: PBL were analyzed cytofluorographically with different mAb against CD4; CD4 expression and proliferative response to anti-CD3 was studied before and after in vitro pre-culture; the specificity of Ab recovered in culture supernatants (SN) of purified CD4+ cells was studied by Western blot.

RESULTS: PBL from most AIDS patients showed selective masking of the CD4 epitope recognized by Leu-3a mAb, which is closely associated with the gp120 binding site. This phenomenon was strictly associated with HIV infection; a good correlation with the number of circulating CD4+ cells and p24 antigen was seen. In vitro PBL culture for 24-36 h was associated with re-regulation of CD4 expression, as well as an increase in responsiveness to anti-CD3; Ab directed against env proteins were recovered in culture SN of purified CD4+ cells.

CONCLUSIONS: These data indicate that circulating CD4+ cells from AIDS patients are covered with gp120/anti-gp120 complexes, which down-regulate CD4 expression and cell function. The pathogenetic relevance of this phenomenon is thought-provoking, especially in light of the data on anti-CD4-mediated tolerance in murine models.

Keywords: AEGIS, Antigens, CD4, Antigens, CD3, Epitopes, Antibodies, Monoclonal, HIV Infections, Acquired Immunodeficiency Syndrome, In Vitro, Human, ICA7KWDaegis,antigens,cd4,antigens,cd3,epitopes,antibodies,monoclonal,hivinfections,acquiredimmunodeficiencysyndrome,invitro,human,ica7
910616
MA18

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