A contraceptive peptide vaccine targeting sulfated glycoprotein ZP2 of the mouse zona pellucida.

Abstract

In this study, we have mapped and characterized a B cell epitope of sulfated glycoprotein ZP2 (ZP2) as a step toward the development of a multi-epitope zona pellucida (ZP) vaccine. Recombinant polypeptides expressed by random deoxyribonuclease-digested fragments of ZP2 cDNA were screened for binding to IE-3, a monoclonal antibody to murine ZP2. Positive clones contained cDNA inserts encoding polypeptide corresponding to ZP2(103-134). When normal or ovariectomized female mice were immunized with three overlapping peptides that span this region of ZP2 (101-120, 111-130, 121-140), only ZP2(121-140) elicited IgG antibodies that reacted with mouse ovarian ZP, indicative of the presence of native B epitope and helper T cell epitope in ZP2(121-140). To more finely map the ZP2 B cell epitope, a random peptide display library was screened with the IE-3 antibody, and a consensus tetramer sequence VxYK that matched the ZP2(123-126) sequence VRYK was located. Competitive immunofluorescence analysis with single alanine-substituted VxYK peptides ranked the relative contribution of the three critical B cell epitope residues as Y > V > K. A chimeric peptide was constructed that contained the YRYK motif of ZP2 and a bovine RNase T cell epitope. Although (C57BL/6xA/J) F1 (B6AF1) female mice immunized with the chimeric peptide developed ZP antibody response, this peptide elicited antibody only in mice of the histocompatibility complex (MHC) H-2(k or b) haplotype. In contrast, ZP2(121-140) peptide elicited antibody in inbred mice with three additional mouse MHC haplotypes. Moreover, although ZP2(121-140) contained a T cell epitope, no oophoritis was observed after immunization of B6AF1 mice with ZP2(121-140) in complete Freund's adjuvant (CFA). In a preliminary trial, female B6AF1 mice immunized with ZP2(121-140) in CFA had reduced litter sizes as compared with mice injected with CFA alone.

• Authors: W Sun, Y H Lou, J Dean, K S Tung
• Journal: Biology of reproduction (Biol Reprod) Vol. 60 Issue 4 Pg. 900-7 (Apr 1999) ISSN: 0006-3363 [Print] United States
• PMID: 10084964 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Egg Proteins
• Epitopes
• Immunoglobulin G
• Membrane Glycoproteins
• Receptors, Cell Surface
• Recombinant Fusion Proteins
• Vaccines
• Zona Pellucida Glycoproteins
• Zp2 protein, mouse

Topics

• Amino Acid Sequence
• Animals
• Contraception, Immunologic
• Egg Proteins (chemistry, immunology)
• Epitope Mapping
• Epitopes (chemistry, immunology)
• Female
• Immunoglobulin G (immunology)
• Male
• Membrane Glycoproteins (chemistry, immunology)
• Mice
• Mice, Inbred BALB C
• Mice, Inbred C3H
• Mice, Inbred C57BL
• Mice, Inbred DBA
• Molecular Sequence Data
• Ovariectomy
• Receptors, Cell Surface
• Recombinant Fusion Proteins (immunology)
• T-Lymphocytes, Helper-Inducer (immunology)
• Vaccines
• Zona Pellucida (immunology)
• Zona Pellucida Glycoproteins