Workshop on Higher Education and Professional Responsibility in CBRN Applied Sciences and Technology across the Sub-Mediterranean Region 3-4 April 2012. Palazzo Zorzi, Venice Session 3. Inspiring Initiatives and Scientific Cooperation

1. Cooperation is Required for
Schistosomiasis Vaccine Production
and Implementation
Rashika El Ridi
Zoology Department, Faculty of Science,
Cairo University

2. What is Schistosomiasis? Also named Snail
Fever, Bilharzia or Bilharziasis
A disease, very often of
children, caused by the platyhelminth
parasite of the genus Schistosoma

3. The Infective Stage: The Cercaria
Coming out of an Infected Snail

4. Adult Schistosomes

6. In the Host Vasculature, Schistosome Pairs
Deposit Hundreds of Eggs Daily

7. The Granuloma

8. Geographical Distribution of Schistosomiasis
blue: S. mansoni; green: S. haematobium; red: S. japonicum
orange: S. mansoni and S. haematobium

10. Besides affecting 500 million people and 800
million, mostly children, at risk of the
infection, schistosomiasis deviates the host
immune system towards a polarized T helper
(Th) 2 environment, thus rendering the affected
human highly susceptible to cancer development
and to infection with acquired immuno-
deficiency (HIV) and hepatic (namely HCV)
virus, Mycobacterium tuberculosis, and
malaria, afflictions all requiring a strong Th1
immune environment for control and resistance.

11. The Only Drug Available:
Praziquantel

12. The disease may be
eradicated via elimination of
transmission if an effective
vaccine is available. Many
roadblocks hindered the
development of such vaccine.

13. We needed to identify the correct
parasite antigen (s) for use in
vaccination.
We needed to identify the
mechanism(s) by which the
immune system of the host may
attack the parasite.

14. A- Parasite Antigen(s) Selection
We have identified the correct parasite
vaccine candidate antigens, the larval
excretory-secretory products
(ESP), namely glutathione-S-
transferase (GST), enolase, triose-
phosphate-isomerase
(TPI), glyceraldehyde 3-phosphate
dehydrogenase, and 2 cys-
peroxyredoxin (thioredoxin peroxidase)

15. B- The Most Plausible
Mechanism(s) of Protective
Immunity
The Hunt in the Pulmonary
Capillaries

16. How would then the Host Immune
Effectors Attack the Parasite?
• They do not directly kill it. They
PURSUE, HUNT it in the tight capillaries of
the lung vasculature.

17. The Most Plausible Mechanism(s) of
Protective Immunity
The Hunt of Larvae in the Pulmonary Capillaries
by the Host Immune Effectors:
IFN-g-activated macrophage release of NO and H2O2
IL-17-mediated neutrophils recruitment and the efficiency of
neutrophils extracellular trap
IL-4-and IL-13-and ESP/Antibody-activated basophils release of
histamine and its effects of the capillary endothelium
permeability
IL-4-and IL-5-and ESP/Antibody-activated eosinophils release of
toxic basic proteins, the most powerful effectors of parasite
attrition.

21. We have been
able to render the
hunt as effective
as possible, via
using the correct
adjuvant

23. 50
45
40
Individual mouse total worm burden
35
30
25
20
15
10
5
0
Inf/Controls IL-25/Mix IL-33/Mix IL-25 IL-33/Controls
Mean + SE 37.5 + 2.3 12.1 + 1.2 8.5 + 0.9 27.2 + 2.7 20.5 + 2.9
P and reduction <0.0001 <0.0001 0.0145 0.0007
(versus Inf/Controls) 67.63% 77.33% 27.46% 45.33%
P and reduction <0.0001 0.0033
(versus cytokine Controls) 55.51% 58.53%

24. We are further improving the selection of larval
excretory-secretory candidate vaccine
antigens, singly or in a mixture,
and the immunization regimen, namely antigen and
Type-2 adjuvant dose, injection site and schedule,
And we may likely reach a sterilizing vaccine for
schistosomiasis in a near future.
Cooperation is required for independent
experiments, pre- and clinical
studies, and production and
implementation of the vaccine

25. Collaborators
Dr. Hatem Tallima
(Ph. D.)
and
Mr. Abdel Badih Foda
And the Theodore
Bilharz
Research Institute Team
at the Schistosome
Biological Supply
THANK YOU Program