Delivery of TEM β-lactamase by gene-transformed Lactococcus lactis subsp. lactis through cervical cell monolayer

Lactococcus lactis subsp. lactis transformed with Plasmid ss80 (encoding the production and secretion of TEM β-lactamase) was used for the delivery of β-lactamase through the C-33A (cervix cell) monolayer. The viability of the cell monolayers co-cultured with L. lactis was examined by the trypan blue exclusion method. The integrity of the monolayers was monitored by measuring the transport of mannitol and propranolol as well as the transepithelial electrical resistance. The transport rate of β-lactamase through C-33A monolayer was increased by four- and nine-folds ( p < 0.05) at the first hour by the transformed L. lactis compared to the free solution with or without presence of the untransformed L. lactis, respectively. This increase was gradually diminished after the 1st hour: it became 30 and 50% ( p < 0.05) at 10 h. The presence of the untransformed L. lactis with free solution delivery also increased the transport rate by 100% at 1 h ( p < 0.05) and 15% at 10 h ( p > 0.05). The increase in transport rate by the transformed L. lactis is most probably due to the concentrate of β-lactamase on C-33A monolayer. When co-cultured with the L. lactis, the C-33A cell viability and the monolayer TEER remained steady for 10 h. The presence of L. lactis did not change the transport of propranolol and mannitol through the monolayers. In conclusion, the transformed L. lactis significantly ( p < 0.05) increased the transport of β-lactamase through the cervical monolayers, indicating probiotic bacteria delivery may be a promising approach for protein delivery through the vagina.