Toxoplasma gondii protein fraction as a potent activator of dendritic cells (P4383)

Abstract

Abstract Dendritic cells (DCs) are professional antigen presenting cells that both initiate and modulate the immune responses. DCs activation leads to their maturation and production of cytokines such as IL-12. Therefore, their use in immunotherapy against cancers has been studied. We have investigated the potency of Toxoplasma gondii (TG) proteins for DC maturation to induce IL-12 production and mouse spleen cell proliferation. Methods: DCs were generated from Balb/c mouse bone marrow in the presence of GM-CSF and IL-4. Four protein fractions were obtained from sonically fragmented TG cells by precipitation with ammonium sulfate and were added as maturation factors on the last day of the DCs culture. The phenotype analysis was performed using anti-CD80, anti-CD86, anti-CD-40 and anti-MHC II monoclonal antibodies. IL-12p70 concentration in DCs supernatant was also determined. Ultimately, proliferation assay, phagocytic activity and cytokine production (IL-10 and IFNγ) in supernatants of DCs and T cells co-culture were done. Results: Total extract of TG and fraction 1 are more potent in activating DCs than other fractions and matured DCs (mDC) produced significantly higher levels IL-12p70. Expression of CD40 and CD86 was also significantly higher on these mDCs. Moreover, T cells co-cultured with these mDCs secreted higher level IL-10 and IFNγ. Conclusion: The selected fraction can be used in DC cell based immunotherapy approach to generate competent vaccines against tumor cells.