Recombinant E.coli LLO/OVA Induces Murine BMDCs Maturation via TLR4 and NOD1 Receptor and Promotes Specific Cytotoxic T Cell Immunity

Key words: 
• Bone marrow-derived dendritic cells,BMDCs /
• Recombinant Escherichia coli /
• Toll-like receptor (TLR) /
• Nucleotide-binding oligomerization domain (NOD) /
• CD8+T cells

Abstract: Objective To explore the immune stimulation effect of recombinant E.coli LLO/OVA on mice bone marrow-derived dendritic cells (BMDCs) and T lymphocytes in vitro. Methods After BMDCs stimulated by E.coli LLO/OVA, their Toll-like receptor (TLR) and nucleotide-binding oligomerization domain (NOD) receptor signalling pathway were examined by superarray hybridization; and the priming effect of the vaccine activated BMDCs on CD43T and CD83T was determined by [3H]thymidine uptake and ELISA, the tumor cytotoxic effect of activated CD83F cells was determined by cytotoxic assay. Results After BMDCs were activated by E. coil LLO/OVA via TLR4, NOD1 receptor and NF-κB signalling pathway, the expression of their surface molecules including MHC class Ⅰ, MHC class Ⅱ, CD40, CD80 and CD86 significantly up-regulated; the secretion of IL-12 and IFN-γ, increased also. The mature BMDCs stimulated the allergic CD43T and CD83T cells proliferation and their IL-2 and IFN-γ secretion, and the activated CD83T cells effectively killed B16-OVA melanoma cells and RMA-S/OVA lymphoma cells in vitro. Conclusion E.coli LLO/OVA is effective in inducing BMDCs maturation via activating TLR4 and NOD1 receptor signalling pathway and promoting specific anti-tumor T cell immunity in vitro.