Increased efficacy of dendritic cells by protein components compared to total extract of Listeria monocytogenes in experimental tumor immunotherapy

Using dendritic cells (DCs) loaded with tumor antigens as a therapeutic strategy against tumors has been proposed. In order to increase the efficacy of DCs، a variety of factors such as TLR ligand molecules and bacterial products are used. In this study، the protein components of the bacteria Listeria monocytogeneses (LM) for induction of dendritic cell maturation were used. Bone marrow cells of Balb/c mice in the presence of IL-4 and GM-CSF were cultured for 5 days. On day 5، tumor lysate and then protein components or total extract of LM was added to immature DCs. In order to survey the maturation status of DCs، on day 7، the expression of CD80، CD86 AND MHC-II on the cell surface was evaluated. After induction of tumors in mice using WEHI-164 cell line، 106 mature dendritic cells subcutaneously injected. Tumor growth rate، survival rate and cytotoxic activity of spleen cells were evaluated in the studied groups. In mice vaccinated with protein components matured-DCs، delayed tumor growth rate and increased survival were seen. In addition، in these mice، the cytotoxic activity of spleen cells was higher compared to other groups. In all groups receiving protein components or total extract mature-DCs، increased cytotoxic activity and decreased tumor growth rate were seen compared to controls. Listeria monocytogenes protein components compared to total extract have higher ability to increase the efficacy of DCs for tumor immunotherapy in mouse model.