Edible Vaccines: eating our way to the eradication of disease
description
Transcript of Edible Vaccines: eating our way to the eradication of disease
Edible Vaccines:eating our way to the eradication of
disease
Vaccines
Eradication of small-pox Vaccine preventable diseases
– millions of deaths per year No vaccines
– HIV; ~2 million deaths per year
– malaria; 1.5 - 2.7 million deaths per year
There is a clear need for new vaccines, and vaccination strategies
Why is measles still killing children?
Failure to vaccinate:– fear
• safety and side effects
– misconceptions• prevalence and seriousness
– access/availability
Vaccine failure:– inactivation by heat– interference by maternal antibodies
A subunit based edible vaccine?
economical heat stable oral administration
– no more needles– mucosal immune response
sub-unit vaccine– unable to replicate– overcome maternal antibodies
Developing an edible vaccine for measles
Hemagglutinin (H) protein
• surface exposed protein
• targeted during the immune response
• sufficient to induce protective immunity
H F P
RNA + N L M
select an antigen
Tobacco expressing the MV-H protein
Western blot
50kDa
75kDa
100kDa
PNGase F - + - +
MV-H control
Transgenic tobacco
Feeding tobacco induces MV neutralising antibodies in mice
1
10
100
1000
0 49 78
days after initial feeding
MV
neu
tral
isat
ion
titre
MV-H control
Feeding tobacco may also induce a mucosal immune response
1
10
100
1000
10000
1 2 3 4 5 6 7 8 9
secr
eto
ry I
gA t
itre
MV-H Control Naive
titr
e
Treatment groups
Edible species
lettu
ce
toba
cco
con t
rol
MV-H75kDa
50kDa
From model system to practical vaccine
rice
con t
rol
Edible species – intraperitoneal experiment
From model system to practical vaccine
0
0.5
1
1.5
2
2.5
3
10 100 1,000 10,000
reciprocal serum dilution
abso
rban
ce (
655n
m)
MV-H tobacco
MV-H lettuce
control lettuce
MV-specific serum IgG titers
1
10
100
1000
10000
1 2 3 4 5 6 7
Edible species – intraperitoneal experiment
From model system to practical vaccine
MV-H lettuce control lettuce
MV-neutralisation titers
From model system to practical vaccine
an edible species delivery and dose issues
– quantity and number• higher antigen expression in plants
• targeting the antigen for better uptake
safety issues quality control and licensing GMO issues
Summary: tobacco, lettuce and rice can express the
MV-H protein
plant-derived MV-H protein is able to induce MV neutralising antibodies in mice
edible vaccines have the potential to address the limitations of the current measles vaccine
Acknowledgements
Viral Vaccine Unit,
(Monash University)
Steve Wesselingh
Jenny Martin
Diane Webster
Michelle Cooney
Zhongjun Huang
CSIRO, AdelaideIan Dry
Terri King
Steve Choimes
Melbourne UniversityRichard Strugnell