畜産物利用2

[V-16-25] Construction of Genetically Modified Lactic Acid Bacteria Secreting Recombinant Anti-CTLA-4 scFv

*野村 奈津実¹、生井 楓¹、重盛 駿¹、下里 剛士¹ (1. 信州大バイオメディカル研)

Lactic acid bacteria play a major role in the preservation and processing of milk. However, in recent years, genetically modified lactic acid bacteria (gmLAB) have attracted attention as inexpensive producers and carriers of recombinant proteins. Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) has been shown to suppress the anti-cancer immune response. In this study, we constructed a gmLAB strain that secretes an anti-mouse CTLA-4 single-chain fragment variable (CTLA4scFv) works for cancer treatment. An expression vector was introduced into Lactococcus lactis. The resulting gmLAB was grown in the presence of nisin, and the supernatants and cell pellets were analyzed. Purified CTLA4scFv was then added to wells coated with CTLA-4; binding to the target protein by enzyme-linked immunosorbent assay (ELISA). The results demonstrated the successful construction of a CTLA4scFv-secreting gmLAB, as demonstrated by the detection in the supernatant of a protein band of the expected size. In addition, the absorbance in ELISA increased when purified CTLA4scFv was added. In conclusion, we successfully constructed a gmLAB capable of secreting CTLA4scFv.