Development of a next generation PZP vaccine

Harm HogenEsch, DVM, PhD

Ideal fertility control strategy(John W. Turner, Jr.)

• Highly effective• Multi-year duration• Reversible• No loss of basic social structure or sexual

behavior• No effect on existing pregnancy• No toxicity to recipient or applicator• Cannot pass through food chain• Can be delivered remotely• Cost effective

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Immunocontraception

• Induction of an immune response that inhibits fertility

• Potential targets:

– Hormones

• Gonadotropin releasing hormone (GnRH)

– Oocyte

• Zona pellucida proteins

– Sperm

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Porcine Zona Pellucida (PZP) vaccine

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Antibodies against ZP prevent binding of sperm and fertilization

Gupta et al., J Reprod Immunol 2009

PZP vaccine

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Oocyte

ZP2

ZP3

ZP4

ona pellucida

The immune responseto vaccines

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CD4+

B

lymph

dendritic cells

plasma cells

Types of vaccines

• Modified live vaccines - MMR

• Inactivated vaccines - polio

• Subunit vaccines:

– Viral proteins - hepatitis B

– Bacterial proteins - DTP

– Bacterial polysaccharides - Pneumococcus

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Subunit vaccines have two essential components

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Antigen*

Adjuvant

immuneresponse

protection

vaccine

Gaston Ramon

• 1886 – 1963

• 1906-1910 – l'Ecole NationaleVétérinaire d'Alfort

• Institut Pasteur – serum production in horses against diphtheria and tetanus

• Developed method to enhance antibody production.

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Adjuvants

Adjuvants

• Increase the magnitude of the immune response;

• Induce a specific type of immune response;

• Decrease the antigen dose and number of injections;

• Increase duration of immunity.

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PZP vaccines• Zonastat-H and Zonastat-D

– Protein extract from swine ovaries– 1st dose – modified complete Freund’s adjuvant

2nd dose – incomplete Freund’s adjuvant– Approved by the EPA for use in wildlife – Induces about 1 year of infertility

• PZP-22– Protein extract from swine ovaries– Slow release pellet (poly(lactide co-glycolide), PLGA)– QS-21 adjuvant– 2 years of infertility when combined with primer

• Spayvac®– Protein extract from swine ovaries– Liposome formulation

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Zonastat and PZP-22

• Porcine ovary proteins– poorly defined– immune response damages ovaries

• Adjuvants:– Freund’s adjuvant:

• Difficult to mix• Painful• Can cause abscesses• Not compatible with controlled release formulations

– QS-21• Unstable• Release profile from pellets is unknown

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Next generation PZP vaccine

• Effective long-lasting immune response after single injection;

• Easy to administer;

• Safe for the animals and environment;

• Well characterized and consistent among batches.

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Experimental approach

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Improved adjuvant• Potent• Safe• Compatible with

controlled release formulation

Recombinant PZP• Well characterized• Consistent

Controlled release

• Reproducible • Administered

in darts

Next generation PZP vaccine

Nano-11

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sweet corn variant – sugary-1

phytoglycogen

Nano-11

+ OSA and CHPTAC

Nano-11 enhances the antibody response

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Combination adjuvant

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Testing combination adjuvants in vitro

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PBMC + 5% serum

24 h

ELISA for IL-1β, TNF, CXCL10

Effect of combination adjuvants on cytokines production by equine PBMCs

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Recombinant PZP proteins

20http://www.amsbio.com/bacterial-protein-expression-services.aspx

Zona pellucida proteins

ZP1 ZP2 ZP3 ZP4

Human + + + +

Mouse + + + −

Horse + + + +

Pig − + + +

Cow − + + +

Dog − + + +

Cat − + + +

Hamster + + + +

Rat + + + +

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Acknowledgments

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Purdue University

Yung-Yi MosleyAnisa DunhamFangjia Lu

Laurent CouetilCarla Olave

Kinam Park

University of Toledo

John Turner

Bakers Trust

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Combination adjuvants

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Recent study – Joone et al. Equine Vet. J. 2015

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Group 1st dose Booster(5 weeks)

Pregnancy Abnormalovarian function

I 100 ugPZP/MFA

100 ugPZP/IFA

0/7 6/7

II 500 ugrPZP/MFA

500 ugrPZP/IFA

4/7 1/7

III MFA IFA 7/7 1/7

20/21 mares with local reactions, 3 with abscesses