Targeting antigens to Dec-205 on dendritic cells induces a higher immune response in chickens: Hemagglutinin of avian influenza virus example

It is widely known that targeting a variety of antigens to the DEC-205 receptor on dendritic cells (DCs) significantly potentiate immunity. This communication reports the development of a new murine monoclonal antibody (mAb) against the chicken DEC-205, using as immunogen the carbohydrate recognition domain-2 (CRD-2) heterologously expressed. This mAb recognizes a protein band of 250 kDa by immunoprecipitation analysis and shows strong cross-reactivity with human and pig DEC-205. Furthermore, the hemagglutinin (HA) of avian influenza H5N2 virus was cloned and expressed using insect cell-baculovirus expression system. We chemically conjugated the anti-chicken DEC-205 antibody with the highly purified HA to direct the antigen to the dendritic cells and evaluate the immune response elicited in vivo by this conjugate. A single dose of chemical conjugate was sufficient to elicit a strong immune response in chickens as early as fourteen days after priming. In addition, the conjugate induced an earlier and higher response compared to unconjugated HA. These results suggest that the strategy described here has potential to be used in the future design and development of successful vaccines against different chicken infectious diseases with direct impact in biotechnology and veterinary fields.