Transcript HIPV3/EboGP aerosol HIPV3/EboGP IN/IT HPIV3 VRP

Aerosolized Ebola vaccine
protects primates and elicits
lung-resident T cell responses
Michelle Meyer, Tania Garron, Ndongala M. Lubaki, Chad E. Mire,
Karla A. Fenton, Curtis Klages, Gene G. Olinger, Thomas W.
Geisbert,Peter L. Collins and Alexander Bukreyev
Alexandra Scalvini & Émilien Gimaret
Ebola virus (EBOV)
Mononegavirales
Filoviridae
Ebolavirus
RNA (-) 19 kB
970 nm long
80 nm diameter
Target : human and NHP
(non human primate)
Severe hemorrhagic fever.
Fatality ranges from 50% to
90%.
Last outbreak (2014-2015 :
28601 cases, 11300 deaths
WHO)
Transmition : Aerosol, through mucosal surfaces, biological fluid droplets, fomites.
Background
• Vaccine strategy with aerosolized EBOV has never been tested.
• Aerosolized vaccines have many advantages : needle free, do not require
trained medical personal.
• Aerosolized vaccines create a different immune response that is poorly
studied in human.
Could aerosolized vaccine be protective against
EBOV?
The aerosolized vaccine
• Human Parainfluenza virus type 3-vectored vaccine that expresses the
glycoprotein (GP) of EBOV (HPIV3/EboGP)
• Delivered through nebulizer to the respiratory tract (site of replication of
HPIV3)
HPIV3
Nebulizer
Study 1
Immune responses induced
by the vaccination, in NHP
Experiment
*
*BAL = Broncho-Alveolar Lavage
•
•
2 injections  days 0 and 28
Lungs, blood and spleen samplings
Aims:
- Study of both mucosal and systemic antibody responses and cellmediated responses induced by aerosolized vaccine.
- Comparison to both liquid HPIV3/EbovGP and VRP vaccines.
Serum IgG, IgA and neutralizing antibody responses in NHP
Dose 1
Dose 2
Dose 1
Dose 2
Method:
EBOV-specific serum IgG and IgA analysed by ELISA
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
HPIV3
VRP
Serum IgG, IgA and neutralizing antibody responses in NHP
Dose 1
Dose 2
Dose 1
Dose 2
 Both aerosolized and liquid vaccines induce EBOVspecific serum IgG and IgA responses.
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
HPIV3
VRP
Serum IgG, IgA and neutralizing antibody responses in NHP
Ebola virus
Method:
Serum-neutralizing antibody responses against EBOV
determined by plaque-reduction assays.
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
HPIV3
VRP
Serum IgG, IgA and neutralizing antibody responses in NHP
Ebola virus
 Induction of a systemic antibody responses comparable
to those with liquid vaccine.
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
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VRP
Ability to cross-neutralize EBOV Bundibugyo (BDBV) and Sudan
(SUDV)
Ebola virus
Bundibugyo virus
Sudan virus
Method:
Serum-neutralizing antibody responses against EBOV,
BDBV and SUDV determined by plaque-reduction assays.
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
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VRP
Ability to cross-neutralize EBOV Bundibugyo (BDBV) and Sudan
(SUDV)
Ebola virus
Bundibugyo virus
Sudan virus
 Antibody cross-neutralization is stronger after the
second dose vaccine.
 Considerable animal-to-animal variability.
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
HPIV3
VRP
Mucosal antibody-responses in the respiratory tract
Method:
- EBOV-specific serum IgG and IgA
analysed by ELISA
- Serum-neutralizing antibody
responses against EBOV determined
by plaque-reduction assays.
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
HPIV3
VRP
Mucosal antibody-responses in the respiratory tract
 Both aerosolized and liquid
vaccines induce strong
mucosal antibody
responses in the respiratory
tract
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
HPIV3
VRP
Cell-mediated response
Non-mucosal CD8
CD4
% of cells
Mucosal CD8
MFI
Method:
- Flow cytometry
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
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VRP
Cell-mediated response
Mucosal CD8
Non-mucosal CD8
CD4
% of cells
 Strong T cell
responses
predominantly in
the respiratory
tract.
 Limited, but
detectable,
systemic spread.
MFI
 Mainly IFNγ- and
TNFα-secreting
T cells.
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
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VRP
Polyfunctional CD8 and CD4 T cell responses
Rhesus macaque
1 marker (IFN-γ or TNF-α or IL-2 or CD107a)
2 markers (e.g. 25% of the cells expresse
one marker and 75% expresse two markers).
3 markers
4 markers
Polyfunctional CD8 and CD4 T cell responses
1 marker
2 markers
CD8
3 markers
4 markers
CD4
-
Polyfunctional response higher in the lungs
Mainly polyfunctional for 3 or 4 markers
-
Polyfunctional response higher in the lungs
Mainly polyfunctional for 1 or 2 markers
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
HPIV3
VRP
Polyfunctional CD8 and CD4 T cell responses
1 marker
2 markers
CD8
3 markers
4 markers
CD4
-
Polyfunctional response higher in the lungs
Mainly polyfunctional for 3 or 4 markers
-
Polyfunctional response higher in the lungs
Mainly polyfunctional for 1 or 2 markers
HIPV3/EboGP aerosol
HIPV3/EboGP IN/IT
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VRP
Polyfunctional CD8 and CD4 T cell responses
1 marker
2 markers
CD8
3 markers
4 markers
CD4
 Both aerosolized and liquid vaccines induce a greater
activation of lung CD8 and CD4 T cells.
 Stronger activation of the CD8 T cells.
HIPV3/EboGP aerosol
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VRP
IFNγ expression in polyfunctional CD8 and CD4 T cells
CD8
 Greater level of
activation of CD8
T cells is
accompanied by
a greated level of
IFNγ secretion.
CD4
 Same trend for
CD4 T cells?
4markers
3markers
HIPV3/EboGP aerosol
2markers
HIPV3/EboGP IN/IT
1marker
HPIV3
VRP
STUDY 1: Conclusions
Aerosolized vaccine induce strong systemic and
mucosal antibody responses, comparable to those
obtained with liquid vaccine.
Induction of neutralizing antibodies able to crossneutralize different types of EBOV.
Greater activation of T cells in the lungs, by
aerosolized vaccine, may be the consequence of a
more efficient delivery to the pulmonary bronchiole.
Study 2
Protection conferred by
aerosolized vaccine
Experiment
•
•
•
•
2 injections  days 0 and 28
Or 1 injection at day 28 (purple)
EBOV infection at day 55
Blood sampling
Aims:
- Determine the protection that aerosolized vaccine could confer
against EBOV infection.
Serum and mucosal antibody responses
 Results similar
to the ones
obtain in the
study 1.
 Lower
responses with
only 1 injection
HIPV3/EboGP aerosol (2D)
HIPV3/EboGP aerosol (1D) HIPV3/EboGP IN/IT
HPIV3
Markers of EBOV infection, clinical sickness scores, survival and
viremia during EBOV infection
Liver, hemolysis,
kidney,
 A single
administration
of aerosolized
vaccine
completely
protects
against EBOV
infection.
HIPV3/EboGP aerosol (2D)
HIPV3/EboGP aerosol (1D) HIPV3/EboGP IN/IT
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Take home messages
Aerosolized vaccine induces strong systemic (high antibody and T
cell responses) and mucosal responses that can be accelerated
with a second dose.
Aerosolized vaccine confered cross-protection and can protect
against viral hemorrhagic fever.
Aerosolized vaccine can be easly implemented in case of an
outbreak, or during bioterrorism and warfare scenarios.
Perspectives:
• Application to other heamorrhagic fevers.
• Improve the cross-proctection efficiency.
• Phase I clinical study.
Thank you for your
attention !
Micrograph from F. A. Murphy, University of
Texas Medical Branch, Galveston, Texas.