Assessing the antigenicity of different VP3 regions of infectious bursal disease virus in chickens from South Brazil

Abstract

Background Infectious bursal disease (IBD), also known as Gumboro disease, is a viral infection that causes mortality and immunosuppression in chickens (Gallus gallus). VP2 and VP3 are the major structural viral capsid components and are the most immunogenic proteins of IBD virus (IBDV). Reliable diagnostic tests using VP2 and VP3 produced in heterologous systems are important tools to control this infection. One advantage of an IBD diagnostic based on VP3, over those that use VP2, is that VP3 has linear epitopes, enabling its production in bacteria. Results We tested the suitability of recombinant VP3 (rVP3) as a diagnostic reagent in an enzyme-linked immunosorbent assay (ELISA). Compared with a commercial test, rVP3 ELISA showed high sensitivity and specificity as a diagnostic tool for vaccinated animals. In addition, rVP3, but not the commercial ELISA, was able to detect antibodies in nonvaccinated chickens, probably developed against circulating IBDV strains. It was possible the assessment of VP3 regions antigenicity using chicken antisera. Conclusions The full-length recombinant VP3 can be used to assess post vaccination immunological status of chickens and its production is feasible and inexpensive. The evaluation of VP3 regions as candidates for general use in the diagnosis of IBD in chickens should be conducted with caution. Our work was the first to identify several regions of VP3 recognized by chicken antibodies.

Oral Immunization with Recombinant Saccharomyces cerevisiae Expressing Viral Capsid Protein 2 of Infectious Bursal Disease Virus Induces Unique Specific Antibodies and Protective Immunity

“…This disease mainly occurs in 3–6 weeks chickens, characterized by the bursa of Fabricius (BF) atrophy. IBDV inhibits B cell response of acquired immunity through the destruction of lymphocytes in the BF, which increases susceptibility to other diseases and the probability of vaccination failure [ 2 , 3 ]. IBDV has strong resistance to many disinfectants.…”

Development of a Novel Assay Based on Plant-Produced Infectious Bursal Disease Virus VP3 for the Differentiation of Infected From Vaccinated Animals

“…VP3, the other major structural protein, is more conserved among strains and is immunogenic in chickens. However, the immunity induced by VP3 is not protective against clinical disease (Palka et al, 2021 ).…”

REPLICAID: replicon vaccines to combat avian infectious diseases

“…Wu et al, 2009). The typical adaptive immune response against IBDV targets the major antigenic determinant VP2 and to a lesser extent VP3 (Palka et al, 2021) (Figure 4). IBDV can be classified into two serogroups with serotype I, being pathogenic to chickens (species: Gallus gallus) whereas serotype II is non-pathogenic (Ismail et al, 1988).…”