M.Sc Thesis

M.Sc StudentFishma-Jacob Tali
SubjectInduction of Chickens Systemaic and Mucosal
Responses through Recombinant Components Produced
in E. coli and Tobacco
DepartmentDepartment of Biotechnology
Supervisors PROFESSOR EMERITUS Shimon Gepstein
DR. Eli Khayat


Infectious bursal disease virus (IBDV) is the causative agent of Gumboro disease, a major threat to the poultry industry. Recent immunological strategies for the delivery of antigens and immune modulators to the mucosal tissue include genetically modified microorganisms and plants. However, most vaccines require the use of a strong adjuvant and an effective delivery system. One of them is E.coli enterotoxin (LT), a powerful mucosal adjuvant. However, its use in humans is hampered by high toxicity. Recent advances generated non-toxic or reduced LT mutants. Our aim has been to generate an efficient recombinant vaccine against IBDV. Toward this goal, the Vp2 gene from the IBDV fused to β subunit of the LT mutant (LT(R192G)), and the entire viral genome fused to the enterotoxin molecules LT(R192G) were cloned.

The induction of systemic and mucosal immune system was tested by Western blot analysis and ELISA assays, using anti-Chicken antibodies. The treatments included the following: (i) feeding chickens with Vp2+ LTβ(R192G) chimeric protein expressed in transgenic plants (ii) intra muscular injection of protein extract from the transgenic plants and injection of recombinant proteins produced in E. coli.

The results presented in this work show that α and β subunits of LT(R192G) did contribute to immunization or protection.

We have shown that vaccination with the chimeric recombinant protein that combines the IBD virus structural proteins and the α and β subunits of LT and in particular the chimeric VP2 of IBD virus and the β subunit of LT are effective immunogens.