The interaction between the viral envelope protein gp120 and the cellular surface antigen CD4 is a key event in HIV-1 infection. Reciprocal high affinity binding sites have been located in the first domain of CD4 and in the carboxy-terminal region of gp120, respectively. Upon infection, the membranes of the target cells fuse; sites of CD4 and gp120, distinct from their high affinity binding sites, play a role in the post-binding events leading to syncytia formation. We have studied the interactions of CD4 with gp120 and gp120-derived peptides using an in vitro assay based on immobilized recombinant soluble CD4 (sCD4). In this system CD4 binds to recombinant soluble gp120 and to anti-receptor peptides derived from the high affinity CD4-binding site of gp120, as well as to peptides corresponding to the principal neutralizing domain (PND) of the envelope protein, i.e., to the domain required for HIV-1-mediated syncytium formation. Competition experiments performed using epitope-specific mAbs and a variety of peptides indicated that PND-derived peptides are specifically recognized by a CD4 site adjacent to, but distinct from, the high affinity gp120-binding site of CD4. Synthetic peptides patterned on the PND of different viral isolates were retained onto sCD4-based affinity columns at different extent; some of the structural requirements for binding were analyzed. Studies performed on CD4+ T-cells showed that PND-derived peptides also interact with CD4 in its native membrane-bound conformation. These results indicate that a direct contact takes place between CD4 and the gp120 domain participating in HIV-induced syncytia formation.

Binding to CD4 of synthetic peptides patterned on the principal neutralizing domain of the HIV-1 envelope protein / M., Autiero; Abrescia, Paolo; M., Dettin; C., Dettin; C. DI BELLO AND J. G. U. A. R. D. I. O. L., A.. - In: VIROLOGY. - ISSN 0042-6822. - STAMPA. - 185:(1991), pp. 820-828.

Binding to CD4 of synthetic peptides patterned on the principal neutralizing domain of the HIV-1 envelope protein.

ABRESCIA, PAOLO;
1991

Abstract

The interaction between the viral envelope protein gp120 and the cellular surface antigen CD4 is a key event in HIV-1 infection. Reciprocal high affinity binding sites have been located in the first domain of CD4 and in the carboxy-terminal region of gp120, respectively. Upon infection, the membranes of the target cells fuse; sites of CD4 and gp120, distinct from their high affinity binding sites, play a role in the post-binding events leading to syncytia formation. We have studied the interactions of CD4 with gp120 and gp120-derived peptides using an in vitro assay based on immobilized recombinant soluble CD4 (sCD4). In this system CD4 binds to recombinant soluble gp120 and to anti-receptor peptides derived from the high affinity CD4-binding site of gp120, as well as to peptides corresponding to the principal neutralizing domain (PND) of the envelope protein, i.e., to the domain required for HIV-1-mediated syncytium formation. Competition experiments performed using epitope-specific mAbs and a variety of peptides indicated that PND-derived peptides are specifically recognized by a CD4 site adjacent to, but distinct from, the high affinity gp120-binding site of CD4. Synthetic peptides patterned on the PND of different viral isolates were retained onto sCD4-based affinity columns at different extent; some of the structural requirements for binding were analyzed. Studies performed on CD4+ T-cells showed that PND-derived peptides also interact with CD4 in its native membrane-bound conformation. These results indicate that a direct contact takes place between CD4 and the gp120 domain participating in HIV-induced syncytia formation.
1991
Binding to CD4 of synthetic peptides patterned on the principal neutralizing domain of the HIV-1 envelope protein / M., Autiero; Abrescia, Paolo; M., Dettin; C., Dettin; C. DI BELLO AND J. G. U. A. R. D. I. O. L., A.. - In: VIROLOGY. - ISSN 0042-6822. - STAMPA. - 185:(1991), pp. 820-828.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/132101
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