This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Elder, J H Articles by Grant, C K Search for Related Content PubMed PubMed Citation Articles by Elder, J H Articles by Grant, C K

Localization of neutralizing regions of the envelope gene of feline leukemia virus by using anti-synthetic peptide antibodies.

ABSTRACT

We synthesized 27 synthetic peptides corresponding to approximately 80% of the sequences encoding gp70 and p15E of Gardner-Arnstein feline leukemia virus (FeLV) subtype B. The peptides were conjugated to keyhole limpet hemocyanin and injected into rabbits for preparation of antipeptide antisera. These sera were then tested for their ability to neutralize a broad range of FeLV isolates in vitro. Eight peptides elicited neutralizing responses against subtype B isolates. Five of these peptides corresponded to sequences of gp70 and three to p15E. The ability of these antipeptide antisera to neutralize FeLV subtypes A and C varied. In certain circumstances, failure to neutralize a particular isolate corresponded to sequence changes within the corresponding peptide region. However, four antibodies which preferentially neutralized the subtype B viruses were directed to epitopes in common with Sarma subtype C virus. These results suggest that distal changes in certain subtypes (possibly glycosylation differences) alter the availability of certain epitopes in one virus isolate relative to another. We prepared a "nest" of overlapping peptides corresponding to one of the neutralizing regions of gp70 and performed slot blot analyses with both antipeptide antibodies and a monoclonal antibody which recognized this epitope. We were able to define a five-amino-acid sequence required for reactivity. Comparisons were made between an anti-synthetic peptide antibody and a monoclonal antibody reactive to this epitope for the ability to bind both peptide and virus, as well as to neutralize virus in vitro. Both the anti-synthetic peptide and the monoclonal antibodies bound peptide and virus to high titers. However, the monoclonal antibody had a 4-fold-higher titer against virus and a 10-fold-higher neutralizing titer than did the anti-synthetic peptide antibody. Competition assays were performed with these two antibodies adjusted to equivalent antivirus titers against intact virions affixed to tissue culture plates. The monoclonal antibody had a greater ability to compete for virus binding, which suggested that differences in neutralizing titers may relate to the relative affinities of these antisera for the peptide conformation in the native structure.

This article has been cited by other articles:

• Farrell, K. B., Ting, Y.-T., Eiden, M. V. (2002). Fusion-Defective Gibbon Ape Leukemia Virus Vectors Can Be Rescued by Homologous but Not Heterologous Soluble Envelope Proteins. J. Virol. 76: 4267-4274 [Abstract] [Full Text]  
• Weimin Wu, B., Cannon, P. M., Gordon, E. M., Hall, F. L., Anderson, W. F. (1998). Characterization of the Proline-Rich Region of Murine Leukemia Virus Envelope Protein. J. Virol. 72: 5383-5391 [Abstract] [Full Text]  
• Ramsey, I. K., Spibey, N., Jarrett, O. (1998). The Receptor Binding Site of Feline Leukemia Virus Surface Glycoprotein Is Distinct from the Site Involved in Virus Neutralization. J. Virol. 72: 3268-3277 [Abstract] [Full Text]