Synthetic peptides of human CD4 enhance binding of Ig to monocyte/macrophage cells. I. Characterization and mapping studies

Petar Lenert; Ravindra L Mehta; Maurizio Zanetti

doi:10.4049/jimmunol.148.6.1759

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Synthetic peptides of human CD4 enhance binding of Ig to monocyte/macrophage cells. I. Characterization and mapping studies

Journal article

Peer reviewed

Synthetic peptides of human CD4 enhance binding of Ig to monocyte/macrophage cells. I. Characterization and mapping studies

Petar Lenert, Ravindra L Mehta and Maurizio Zanetti

The Journal of immunology (1950), Vol.148(6), pp.1759-1763

03/15/1992

DOI: 10.4049/jimmunol.148.6.1759

PMID: 1541816

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Abstract

Human T cell glycoprotein CD4 binds to class II MHC molecules and to HIV envelope protein gp120. We have shown that CD4 and synthetic peptides corresponding to amino acid residues 21-49 of the first extracellular domain of CD4, also bind Ig and, with greater avidity, antibody:Ag complex. We investigated the effect of CD4 synthetic peptides on the binding and uptake of human Ig by monocyte/macrophage U937 cells. We found that a synthetic peptide corresponding to amino acid residues 21-49 enhanced binding to U937 cells of both aggregated and nonaggregated Ig. The enhancement was concentration dependent, occurred both in normal and low ionic strength conditions, and varied with the time and the temperature of the preincubation step. The enhancement was maximal after preincubation for 3 h at 37 degrees C. A peptide concentration of 20 micrograms/ml was sufficient for optimal binding of both nonaggregated and aggregated Ig. CD4 peptide 21-49 also enhanced binding of Ig to Staphylococcus aureus protein A. These studies open a new perspective in the way monocyte/macrophage cells handle Ig, antibody:Ag or Id:anti-Id complex, in particular when present at threshold amounts in a nonprecipitating form.

Amino Acid Sequence

Peptide Fragments - metabolism

Temperature

Humans

Cells, Cultured

Models, Molecular

Molecular Sequence Data

Monocytes - metabolism

Structure-Activity Relationship

Immunoglobulins - metabolism

Macrophages - metabolism

Osmolar Concentration

Biological Transport

Time Factors

Protein Binding

Protein Conformation

Antigen-Antibody Complex - metabolism

In Vitro Techniques

Staphylococcal Protein A - metabolism

CD4 Antigens - metabolism

Details

Title: Subtitle: Synthetic peptides of human CD4 enhance binding of Ig to monocyte/macrophage cells. I. Characterization and mapping studies
Creators: Petar Lenert - Department of Medicine, University of California, San Diego 92103
Ravindra L Mehta
Maurizio Zanetti
Resource Type: Journal article
Publication Details: The Journal of immunology (1950), Vol.148(6), pp.1759-1763
DOI: 10.4049/jimmunol.148.6.1759
PMID: 1541816
ISSN: 0022-1767
eISSN: 1550-6606
Grant note: HD 25787 / NICHD NIH HHS
Language: English
Date published: 03/15/1992
Academic Unit: Immunology; Internal Medicine
Record Identifier: 9984094776502771

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