More Related Content Similar to Human bacterial challenge experiments as an alternative (20) More from Meningitis Research Foundation (20) Human bacterial challenge experiments as an alternative3. Outline
•Previous studies of experimental pneumococcal carriage
–Jeff Weiser early work
–Our first experiments
•How we do our EHPC model
–Method, safety issues
•Results
–Challenge / re-challenge
–Humoral response
–Cellular response
•Where next?
–Vaccine testing
–Vaccine discovery
–Host immunity
–Microbial ecology
© The Liverpool School of Tropical Medicine
3
4. Previous studies of experimental carriage
•Jeff Weiser (U Penn, Philadelphia)
•JEM 2002 and I&I 2003
Type
cfu/naris
colonised
23F
5000
0 (4)
•Association noted with IgG to
22kD protein in serum
23F
7000
3 (6)
•Did not particularly comment
on dose dependency
23F
17000
3 (4)
•3 washes prior to inoculation
6B
2200039000
6 (8)
•Type 23F 6/14 colonised
•Type 6B 6/8 colonised
•F/up twice weekly and then weekly
J Expt Med 2002;195:359-362 and I&I 2003;71:5724-32
© The Liverpool School of Tropical Medicine
4
5. Experimental Human Pneumococcal Carriage
Early Studies
Study number
Description
Dates
n
Carriers
1
23F Bronchoscopy
Nov 09-Feb 10
9
1 =11%
2
23F No Bronchoscopy
Mar 10-Apr 10
6
0
3
6B No Bronchoscopy
Oct 2010
7
5= 71%
4
6B Bronchoscopy
Jan 11-Mar 11
9
0
5
6B No Bronchoscopy
Mar 11-Aug 11
9
2 =22%
6
6B Re-challenge
Jun 11-Sep 11
3
0
7
6B No Bronchoscopy-inocula test
Sep 2011
5
1=20%
8
23F No Bronchoscopy-inocula test
Sep 2011
4
2 =50%
9
Gates EHPC –
dose ranging 6B
Nov 11-Feb 12
50
21=42%
10
Gates EHPC –
dose ranging 23F
Feb 12-
60
3=6.0%
11
Gates EHPC - 6B re-challenge
Mar 12-May 12
7
0
© The Liverpool School of Tropical Medicine
5
6. Outline
•Previous studies of experimental pneumococcal carriage
–Jeff Weiser early work
–Our first experiments
•How we do our EHPC model
–Method, safety issues
•Results
–Challenge / re-challenge
–Humoral response
–Cellular response
•Where next?
–Vaccine testing
–Vaccine discovery
–Host immunity
–Microbial ecology
© The Liverpool School of Tropical Medicine
6
9. Outline
•Previous studies of experimental pneumococcal carriage
–Jeff Weiser early work
–Our first experiments
•How we do our EHPC model
–Method, safety issues
•Results
–Dose ranging and challenge / re-challenge
–Humoral response
–Cellular response
•Where next?
–Vaccine testing
–Vaccine discovery
–Host immunity
–Microbial ecology
© The Liverpool School of Tropical Medicine
9
10. Dose ranging study
1. Dose ranging studies: 6B and 23F
(Gritzfeld, J) in preparation
2. Reproducibility study: 42% carriage
Over 200 people inoculated with pneumococcus, no
SAE
© The Liverpool School of Tropical Medicine
10
11. Re-challenge: Carriage protects against acquisition of carriage
Subjects
PS
s1
s2
s3
s4
s5
s6
s7
s8
s9
s10
++
Proteins
Neither
+
=
+
=
+
++
++
+
++
+
+
+
Ferreira et al, AJRCCM 2013
© The Liverpool School of Tropical Medicine
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12. Response to carriage- cellular
Responses can be compared in non-carriage vs carriage
Note IL-17 response following colonisation
© The Liverpool School of Tropical Medicine
12
13. Macrophages activated with IL17 kill pneumococci
p = 0.004
p = 0.013
Percentage
change in cfu
recovered
compared to
media
Increased uptake
compared to
vehicle
Decreased uptake
compared to
vehicle
12.5ng/ml
125ng/ml
625ng/ml
rhIL-17 dose
Overall % increase in
uptake
© The Liverpool School of Tropical Medicine
-
26% ↑
37% ↑
13
14. Outline
•Previous studies of experimental pneumococcal carriage
–Jeff Weiser early work
–Our first experiments
•How we do our EHPC model
–Method, safety issues
•Results
–Challenge / re-challenge
–Humoral response
–Cellular response
•Where next?
–Vaccine testing
–Vaccine discovery
–Host immunity
–Microbial ecology
© The Liverpool School of Tropical Medicine
14
15. Carriage model to test vaccine efficacy (2010)
T=0
T=1
T=4
95%
Vaccine
29
N=58
Placebo
29
challenge
21
83%
1
1
12
10
*mock
challenge
8
challenge
21
*mock
challenge
8
*Mock challenge to control for natural acquisition
© The Liverpool School of Tropical Medicine
15
16. Vaccine (PCV vs Hep A): protection against carriage (2013)
© The Liverpool School of Tropical Medicine
16
17. Vaccine discovery – Me Vaccine
MRC/FAPESP Bilateral Agreement
LSTM/ Butantan Institute
Learning from acquired immunity (EHPC) how to design
better vaccines – Cross-reactive epitopes of PspA
Peptide Arrays: linear epitopes
Phage display: protective anti-PspA
monoclonal antibodies
Fragments (conformational epitopes)
-
IgG
CD4+ Th17
Me Vaccine to confer serotypeindependent protection
© The Liverpool School of Tropical Medicine
17
19. Host immunity – correlates of protection
© The Liverpool School of Tropical Medicine
19
21. Summary of Expt Human Pneumo Carriage project
•Safe inoculation of over 200 volunteers
–Strain differences in carriage
•First vaccine study ongoing
–Start with PCV
–Plan phase 2a in 2014
•Where next?
–Vaccine testing – in risk populations
–Vaccine discovery – by antigen knockout
–Host immunity – role of adjuvant
–Microbial ecology – effect of eradication
© The Liverpool School of Tropical Medicine
21
23. Acknowledgements
Home Team
• Daniela M. Ferreira, Adam Wright, Sarah
Glennie, Toni Banyard
• Andrea Collins, Sherouk El Batrawy, Jamie
Rylance, Dan Wootton, Ben Morton
• Jenna Gritzfeld, Mathieu Bangert, Kondwani
Jambo, Shaun Pennington
• Angela Wright, Carole Hancock, Dave
Shaw, Lorna Roche, Jane Ardrey
Collaborators
• Eddie Ades (CDC)
• Jerry Brown (UCL, London)
• Geoff Ginsberg (Duke)
• David Goldblatt (ICH, London)
• Peter Hermans, Amelieke Cremers, Aldert
Zomer (Nijmegen)
• Rob Heyderman (Malawi)
• Aras Kadioglu (Liverpool)
• Keith Klugman, Josh Shak (Emory)
• Rick Malley, Mark Lipsitch (Harvard)
• Eliane Miyaji, Adriane Moreno (Butantan)
Advisors
• Jeff Weiser (U Penn), Mark Alderson
(PATH)
Safety panel
• Rob Read, David Lalloo, Brian Faragher
...and our willing volunteers
© The Liverpool School of Tropical Medicine
Royal Liverpool and Broad
Green University Hospitals
NHS Trust
23
24. Summary of Expt Human Pneumo Carriage project
•Safe inoculation of over 200 volunteers
–Strain differences in carriage
•First vaccine study ongoing
–Start with PCV
–Plan phase 2a in 2014
•Where next?
–Vaccine testing – in risk populations
–Vaccine discovery – by antigen knockout
–Host immunity – role of adjuvant
–Microbial ecology – effect of eradication
Key Questions
Can we test the model in the elderly? HIV infected?
Can we use GMO in the model? Adjuvant?
© The Liverpool School of Tropical Medicine
24
25. Response to carriage - humoral
P=0.01*
PLoS Pathog. 2012 Apr;8(4):e1002622.
© The Liverpool School of Tropical Medicine
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26. Serum response to challenge by MSD
Anti-protein IgG - serum
*
**
*
* **
Pre-challenge samples
* * **
* *
*
***
**
*
Ab increased 20/27proteins
Post-challenge samples
(2 weeks post inoculation)
* P≤0.05 comparing pre vs post samples
© The Liverpool School of Tropical Medicine
26
27. Ab increased 14/27proteins
*
*
*
**
**
*
* * * ** *
Pre-challenge samples
Post-challenge samples
(2 weeks post inoculation)
Ab increased 14/27proteins
*
*
*
*
*
**
© The Liverpool School of Tropical Medicine
*
* * * *
*
*
P≤0.05 comparing pre vs
* post samples
27
28. Serum response to challenge by MSD
Mock challenge
No carriage found
Carriage found
Mock challenge shows lower post inoculation serum levels; carriage
alters response to many proteins
Ferreira et al. 2012 Unpub
© The Liverpool School of Tropical Medicine
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29. Response to carriage- cellular
We can detect Ag-specific responses in BAL but not NW
There are no naive mice in human studies of carriage
Wright et al. 2012 Unpub.
© The Liverpool School of Tropical Medicine
29
30. Colonization density- 6B culture
Relatively low dose recovery follows inoculation
A higher dose does not equal higher colonization density
© The Liverpool School of Tropical Medicine
30
31. A simple model of defence vs pneumococcal disease
© The Liverpool School of Tropical Medicine
31