Background:
Enterotoxigenic E.coli (ETEC), can be considered as the main cause of traveler’s diarrhea which is effecting children in developing countries. The bacterium has several virulence factors, including colonization factors (CFs), heat-labile (LT) and heat-stable (ST) toxins. World Health Organization has made this one of its priorities to produce a vaccine against ETEC due to its increased antibiotic resistance and growing limitations of access to clean drinking water sources.
Objective:
The objective of this study is to investigate oral immunogenicity of chitosan nanoparticles (CNPs) encapsulated CCL protein containing CfaB along with STa toxoid, CfaE and LtB.
Methods:
The E.coli BL21DE3 harboring pET-28a-ccl vector was used for protein expression. After purification and confirmation, the protein was encapsulated in CNPs and the particle size was measured. Immunogenicity was assessed by evaluating antibody titers after BALB/c mice vaccination. Finally, neutralization efficiency of immunized mice sera was evaluated by rabbit ileal loop test.
Results:
The purified protein (~57kDa) was confirmed by Western blotting and the size of CCL-CNPs was measured with average of 112.0nm with 98.8% of encapsulation efficiency. CCL-CNPs are able to stimulate immune system by providing suitable titers of antibody. The fluid accumulation in the rabbit’s intestine was significantly reduced.
Conclusion:
the CCL-CNPs can be considered as a candidate for producing oral nanovaccine.