Immunobiological properties of a recombinant simian retrovirus-1 envelope protein and a neutralizing monoclonal antibody directed against it.
We previously reported that an area encompassing amino acids 147-162 of the envelope region of the simian (type D) retrovirus serotype 1 (SRV-1) constitutes an antigenic site for the binding of murine and rhesus neutralizing antibodies. Neutralizing antibodies to SRV-2 are directed to a different area, encompassing residues 96-102 of SRV-2. This paper presents data on the activity of an SRV-1 recombinant envelope protein (rEP) and of monoclonal hybridoma cell line, C11B8, produced from murine spleen cells immunized with SRV-1 rEP. Purified monoclonal antibodies from C11B8 bind to the SRV-1 rEP and to both SRV-1 and SRV-2. However, the monoclonal antibody exhibits strain specificity in the capacity to neutralize SRV-1 infection in vitro. Thus, C11B8 neutralizes SRV-1 infection but fails to neutralize four other known serotypes of the virus. C11B8 also binds to an SRV-1 synthetic peptide representing residues 142-167, which encompasses the previously defined antigenic site of recognition for neutralizing antibodies to SRV-1. This paper also contains evidence that the SRV-1 rEP construct binds the site for SRV-1 attachment to the cell receptor. This is indicated by the ability of SRV-1 rEP to compete with SRV-1 (but not with SRV-2) and inhibit its infectivity in vitro. In addition, SRV-1 rEP inhibits the neutralizing activity of C11B8 against SRV-1 infection in vitro. SRV-1 rEP has no inhibitory effect on rhesus neutralizing antibodies to SRV-2. Taken together, the above findings indicate that immunity conferred at the level of neutralizing antibodies during SRV infection is strain-specific and involves the recognition of envelope sequences unique to each strain.
Werner
L L
LL
University of California, School of Medicine, Department of Medical Microbiology and Immunology, Davis.
Torres
J V
JV
Leung
C Y
CY
Kwang
H S
HS
Malley
A
A
Benjamini
E
E
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D015153:Blotting, Western; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D015686:Gene Products, env / Q000235:genetics / Q000276:immunology*; D006825:Hybridomas / Q000276:immunology; D007132:Immunoglobulin Isotypes; D066298:In Vitro Techniques; D051379:Mice; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D011994:Recombinant Proteins / Q000276:immunology; D015301:Retroviruses, Simian / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D014764:Viral Proteins
D000911:Antibodies, Monoclonal; D000939:Epitopes; D015686:Gene Products, env; D007132:Immunoglobulin Isotypes; D011994:Recombinant Proteins; D014764:Viral Proteins; C070505:type D envelope protein, simian retrovirus