In the present invention parapox genomes were screened using a novel expression strategy to test genes for dendritic cell recruitment activity. One gene was identified, designated as B2WL, that induces dendritic cell accumulation when expressed in skin. In additional testing a second gene, PP30, was identified that exhibited adjuvant activity in the absence of stimulating dendritic cell accumulation at the site of inoculation. When co-inoculated with an antigen-encoding plasmid, both genes acted as adjuvants in stimulating an antibody response to antigens. Furthermore, nucleic acids encoding the identified B2WL peptide adjuvant enhanced the level of protection against viral infection provided by immunization with an HA-expression plasmid. Thus, novel adjuvants for genetic immunization are identified. The invention also demonstrates the application of the linear expression element (LEE) technology for screening genomes of pathogens that may contain genes that are useful when expressed and tested in a novel context.
