CRX-527 as a candidate adjuvant in a recombinant BCG-based malaria vaccine

Objective:To investigate the role of CRX-527,a Toll-like receptor 4 agonist,as the possible adjuvant for recombinant Mycobacterium bovis Bacillus Calmette-Guerin expressing merozoite surface protein 1C(BCG-MSP-1C).Methods:The mice were immunized with BCG and BCG-MSP-1C in the presence and absence of CRX-527.The untreated mice(injected with PBS-T80 only)were the negative control.The ability of CRX-527 to enhance IgG and its subclasses,as well as IL-4 and IFN-γproduction in the serum and spleen supernatant was evaluated using ELISA.Results:Mice immunized with BCG-MSP-1C exhibited the highest production of IgGs,IL-4 and IFN-γafter third immunization.In addition,CRX-527 further promoted the production of total IgG and IgG subclasses as well as IFN-γand IL-4 in the serum and splenocytes of immunized mice.Conclusions:CRX-527 has the potential as an adjuvant candidate for the candidate vaccines.Further study is needed to verify appropriate dosage for immunization and its efficacy.