Synthetic peptide homologous to the envelope proteins of retroviruses shares a cross-reacting epitope with the CD4 receptor.
A synthetic peptide (CKS-17) homologous to a highly conserved region of the retroviral transmembrane protein p15E was tested for its effect on receptor expression on monocytes. The CKS-17 amino acid sequence is present in several retroviruses including human T-cell lymphotropic virus types I and II and human immunodeficiency virus. The CKS-17 peptide has been previously shown to inhibit monocyte superoxide production, natural killer cell activity, polyclonal B-cell activation, and monocyte-mediated killing by inactivation of interleukin-1. In this study, we demonstrated that the anti-CD4 monoclonal antibody OKT4 binds strongly in vitro to CKS-17-treated human blood monocytes, whereas other antibodies tested were not reactive. This observed binding was the result of direct interaction of OKT4 antibody with the CKS-17 peptide. Moreover, a partial homology was found in amino acid sequence analysis of the CD4 epitope and the CKS-17 peptide.
Rothmann
J
J
Division of Allergy-Immunology-Bone Marrow Transplantation, Children's Hospital of Philadelphia, Pennsylvania.
Hassan
N F
NF
Campbell
D E
DE
Kamani
N
N
Douglas
S D
SD
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D015704:CD4 Antigens / Q000276:immunology*; D002461:Cell Line, Transformed; D003429:Cross Reactions; D000939:Epitopes; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009000:Monocytes / Q000276:immunology; D010455:Peptides / Q000276:immunology*; D012191:Retroviridae Proteins / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D015704:CD4 Antigens; D000939:Epitopes; D010455:Peptides; D012191:Retroviridae Proteins; D014759:Viral Envelope Proteins