Immunocontraception, or contraception mediated by the immune system, is being
widely studied as an alternative, humane form of population control. The induction of
an immune response against a specific component of the mammalian oocyte, termed
zona pellucida (ZP) has been shown to be an effective immunocontraceptive in several
species. Comparatively little work has been done investigating the use of ZP antigens
in the domestic cat. This study aimed to investigate porcine ZP(B+C) and feline ZPA,
B and C as immunogens in the domestic cat, and further to elucidate their effects on
reproduction. Immunisation of female cats with porcine ZP(B+C) failed to elicit a
detectable antibody response as assessed by ELISA, immunoblotting and
immunohistochemistry. Additionally, there was no effect on the structure of the ovaries
nor on breeding performance. Feline ZPA, B and C were cloned into the
pkCMVint.polyli mammalian expression vector and used to immunise female cats.
ELISA revealed that immunisation with either pkCMVint.fZP(B+C) or pkCMVint.fZPA
DNA (Treated) resulted in a low-level circulating antibody response, which was
apparently short-lived. Immunoblotting did not reveal any common pattern of
recognition of antigenic polypeptides between responding animals. Ovaries from fZP
Treated animals, however, showed antibody binding specifically on the ZP of follicles
from late primary / early secondary, through to antral stages. Despite the antibody
binding, the overall structure of the ovaries remained unaffected in all but two of the
fZP Treated cats. Two fZPA immunised cats exhibited ovaries that had no
recognisable follicular structures, however, the observed abnormalities could not be
conclusively linked to fZPA immunisation. Overall, a significant lymphoproliferative
response was shown in fZP Treated cats when compared with Controls. Fertility was
not significantly affected in fZP Treated cats, although there was a tendency towards
increased incidence of unsuccessful matings or pregnancies. The fZP DNA
preparations studied here exhibit potential as an immunocontraceptive, with the ability
to generate a lymphoproliferative response against fZP and elicit antibodies
specifically recognizing fZP in situ. Further studies should continue to investigate the
immunogenicity of, and characterise the immune response against, such fZP DNA
preparations.
| Identifer | oai:union.ndltd.org:ADTP/221853 |
| Date | January 2007 |
| Creators | joyceand@iinet.net.au, Jocye A Eade |
| Publisher | Murdoch University |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://www.murdoch.edu.au/goto/CopyrightNotice, Copyright Jocye A Eade |
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