Scores of millions of people around the world are infected by
Schistosoma mansoni causing considerable morbidity, mortality and
loss of productivity. Safe chemotherapeutic agents have been used
though there are challenges of re-infection due to resistance. Both
epidemiological and experimental data suggest that acquired cell
mediated immunity play significant roles in regulating the intensity of
S. mansoni infection as well as its patho-physiologic sequelae.
Improved control of this trematode parasite may be obtained with
immunization to enhance the resistance of individuals to risk of
infection. This study investigated the cellular responses of mice
immunized with soluble proteins from foot and digestive gland of the
vector snail and challenged with S. mansoni. The proteins were used to
immunize the experimental groups then challenged with the S. mansoni.
The experimental groups were FT (immunized with foot protein) and DG
(immunized with digestive gland). The parameters, which were analyzed
to demonstrate protection, included; the worm counts and cellular
(IFN-γ, IL-5 cytokines) responses. It was observed that, the
experimental groups showed significant protection in terms of worm
reduction and immune responses. The group vaccinated with foot protein
showed higher protection (87.5%) as compared to the group vaccinated
with the digestive gland (50%) in terms of worm reduction. Cytokines
(IFN-γ and IL-5) production was present in different levels during
the assay time points which showed an aspect of protection. The Foot
protein of the vector showed more immunizing power than the digestive
gland. Research towards utilizing the two proteins as feasible vaccine
candidates is encouraged
