CUTTING EDGE - IMMUNOSTIMULATORY EFFECTS OF A PLASMID EXPRESSING CD40LIGAND (CD154) ON GENE IMMUNIZATION

Interaction of CD40 with its ligand (CD154) can induce CD40-bearing AP Cs to express immune stimulatory accessory molecules that facilitate i mmune recognition. We evaluated whether a plasmid vector encoding CD15 4 (pCD40L) could influence the immune response to a transgene protein encoded by coinjected plasmid DNA. We found that coinjection of pCD40L in BALB/c mice enhanced the Ab response to beta-galactosidase induced by i.m. or intradermal injection of placZ, a plasmid DNA vector encod ing beta-galactosidase. Furthermore, i.m. or intradermal coinjection o f pCD40L with placZ enhanced the generation of CTL specific for P815 c ells transfected with placZ. This study indicates that pCD40L can serv e as a genetic adjuvant capable of augmenting humoral and cellular imm une responses to Ags encoded by plasmid DNA expression vectors.