The anthrax toxin is an AB toxin. The B component, protective antigen (PA) is known to directly target and disrupt host immune cells as part of its pathology. In particular, PA exhibits high affinity binding to capillary morphogenesis protein 2 (CMG2), a receptor expressed on dendritic cells, macrophages, and other antigen presenting cells. Dendritic cells are the most potent antigen presenting cells and can induce activation of T cells, crucial for a sustained immune response. Given the high affinity binding between PA and CMG2 and targeting of dendritic cells, we hypothesize that PA can be used as a vector for targeted delivery of conjugated antigens to dendritic cells. To test this hypothesis, we have generated a conjugate between PA and Spy0469, a putative 42 kDa surface protein of Streptococcus pyogenes. Since memory T-cell responses to Spy0469 are common in the human population, we surmise that activation of T-cells by the PA-Spy0469 conjugate would be stronger than Spy0469 or PA alone. To assess binding, we carried out the gel-shift assay and constructed binding curves using Prism software. Our results indicate that attachment of Spy0469 to domain 4 of PA, the receptor binding domain, does not disrupt the ability of PA to bind to the host cellular receptor CMG2. This suggests that vaccine antigens can conceivably be attached to domain 4 of PA and delivered to dendritic cells for development of immunity.