| dc.description.abstract | Targeting the CD40 receptor displayed by antigen-presenting cells to deliver a
specific immunogen has been successfully used to enhance immune responses,
specifically increasing antibody production and enhancing antibody affinity. When
tested in chickens, this platform induced specific IgG and IgA production within one
week post-immunization. However, proof of conferred protective efficacy using the
CD40-targeting vaccination method was still undetermined. Whole avian influenza
virus was loaded onto the guided complex and immunized birds were challenged with
highly pathogenic avian influenza (HPAI) to test efficacy. Furthermore, this research
addresses the application of guided complexes as an alternative method for epitope
mapping of microbial enzymes. Short peptide segments of the Clostridium perfringens
alpha toxin were loaded onto the antibody-guided complex and immunized into chickens
to induce antibody production for downstream use in neutralization assays to identify
specific regions able to block the toxin’s enzymatic functions. Lastly, to expand the
antibody-guided system repertoire, monoclonal antibodies against a new receptor,
specifically dendritic cell (DC) marker CD205, were developed for potential use to
further enhance immune response activation. Anti-CD205 monoclonal antibodies were
used to develop a new in vitro DC system obtained from peritoneal exudate cells.
In HPAI efficacy studies, functional antibody titers were detected up to six weeks
after a single subcutaneous administration. When boosted, the antibody-guided complex
conferred 100% protection in birds upon lethal H5N1 challenge. The guided system also proved useful for rapid polyclonal antibody production in chickens, which can be used in
epitope mapping studies. This system favors linear peptide targets for immunization in
order to maintain cost-effectiveness and short turnover time, but can still be used with
conformational epitopes. Monoclonal antibodies were successfully constructed against
chicken CD205 and used in a variety of immunoassays, as well as magnetic bead
isolation of DCs from peritoneal exudate cell populations. Overall, these data are the
first to report protective efficacy using the CD40-targeting system in chickens, the first
to propose the use of guided complexes in epitope mapping, and the first to isolate DCs
from peritoneal exudate using the anti-CD205 monoclonal antibodies. | en |
