Fine mapping of canine parvovirus B cell epitopes

Abstract

In this report we describe the topological mapping of neutralizing domains of canine parvovirus (CPV). We obtained 11 CPV-specific monoclonal antibodies (MAbs), six of which are neutralizing. The reactivities were as determined by ELISA and Western blot (immunoblot) analysis. VP2, the most abundant protein of the CPV capsid, seemed to contain all the neutralization sites. Also, an almost full-length genomic clone of CPV was constructed in the bacterial plasmid pUC18 to enable expression of CPV proteins. All the neutralizing MAbs recognized recombinant VP2 when it was expressed as a free protein in Escherichia coli but not when expressed as a fusion protein with glutathione-S-transferase. When two large fragments containing about 85 % and 67 % of the C terminus of VP2 were expressed, no neutralization sites were detected. When fusion proteins containing the N terminus were expressed, two linear determinants were mapped, one between residues 1 to 10 of VP2, and the other between amino acids 11 and 23. The peptide 11 GQPAVRNERATGS 23, recognized by MAb 3C9, was synthesized chemically and checked for immunogenicity, not being able to induce neutralizing activity. Although the antibody response in rabbits to all the fusion proteins was uniformly high, the anti-CPV response was very variable. Protein from pCPVExl 1, which contains a T cell epitope (peptide PKIFINLAKKKKAG) present in the VPl-specific region as well as the B cell epitopes, seemed to be the most effective in inducing virus neutralization.

Identification of Aleutian Mink Disease Parvovirus Capsid Sequences Mediating Antibody-Dependent Enhancement of Infection, Virus Neutralization, and Immune Complex Formation

“…This observation supports data from CPV that virus cross-linking is not sufficient for parvovirus neutralization (6,60,62). Other possible mechanisms for neutralization include occlusion of the receptor attachment site (6,38,40,55,60) and stabilization of capsids against genome uncoating (13,21,37,55). The modeled docking of Fab fragments over the exposed amino acids of VP2:428-446 (Fig.…”

Identification of Immunogenic Hot Spots within Plum Pox Potyvirus Capsid Protein for Efficient Antigen Presentation

“…To determine the ability of the specific mouse sera to neutralize CPV in vitro, a CRFK cell monolayer-protection assay was performed as described previously (26).…”

The structure of a neutralized virus: canine parvovirus complexed with neutralizing antibody fragment

“…Site B is on a ridge between the canyon and the depression at the two-fold axis. Epitopes corresponding roughly to sites A and B have also been identified by pepscan mapping [12][13][14]. Additional antigenic sites have been identified by peptide mapping.…”

“…Neutralizing antigenic sites have been determined on the CPV surface, using escape mutant analysis and peptide mapping [12][13][14][15] (Table 1, Fig. 1).…”