Production of human growth hormone by Lactococcus lactis

TRAIL-expressing recombinant Lactococcus lactis induces apoptosis in human colon adenocarcinoma SW480 and HCT116 cells

AIMS

We investigated the ability of Lactococcus lactis, a species generally regarded as safe, to express tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) protein. The expressed protein was either cell wall anchored or secreted, and it was assessed whether this could induce apoptosis in human colon adenocarcinoma cell lines SW480 and HCT116.

METHODS AND RESULTS

Constructs were designed to produce either secreted or cell wall-anchored forms of human TRAIL cloned into pNZ7021 expression vector. The expression by L. lactis was confirmed by Western blotting and immunofluorescence. Induction of cell death was evaluated by coculturing transformants producing either form of TRAIL protein with the two cell lines followed by MTT assay. Gene expression of apoptosis genes, Bax and Bcl2, was assessed by qPCR. The viability of SW480 and HCT116 cells treated with recombinant L. lactis was significantly reduced. A significant change was observed in the ratio of Bax/Bcl2 expression in HCT116 cells only following treatment with the supernatant of recombinant L. lactis containing secreted TRAIL.

CONCLUSION

Recombinant L. lactis producing TRAIL protein can induce apoptosis in human colon adenocarcinoma cell lines SW480 and HCT116.

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of recombinant probiotics that produce anticancer compounds is a promising option for combating cancer cells.

CXCR4(+)-targeted protein nanoparticles produced in the food-grade bacterium Lactococcus lactis

AIM

Lactococcus lactis is a Gram-positive (endotoxin-free) food-grade bacteria exploited as alternative to Escherichia coli for recombinant protein production. We have explored here for the first time the ability of this platform as producer of complex, self-assembling protein materials.

MATERIALS & METHODS

Biophysical properties, cell penetrability and in vivo biodistribution upon systemic administration of tumor-targeted protein nanoparticles produced in L. lactis have been compared with the equivalent material produced in E. coli.

RESULTS

Protein nanoparticles have been efficiently produced in L. lactis, showing the desired size, internalization properties and biodistribution.

CONCLUSION

In vitro and in vivo data confirm the potential and robustness of the production platform, pointing out L. lactis as a fascinating cell factory for the biofabrication of protein materials intended for therapeutic applications.

Genome sequences of Lactococcus lactis MG1363 (revised) and NZ9000 and comparative physiological studies

Lactococcus lactis NZ9000 and its parent MG1363 are the most commonly used lactic acid bacteria for expression and physiological studies. We noted unexpected but significant differences in the growth behaviors of both strains. We sequenced the entire genomes of the original NZ9000 and MG1363 strains using an ultradeep sequencing strategy. The analysis of the L. lactis NZ9000 genome yielded 79 differences, mostly point mutations, with the annotated genome sequence of L. lactis MG1363. Resequencing of the MG1363 strain revealed that 73 out of the 79 differences were due to errors in the published sequence. Comparative transcriptomic studies revealed several differences in the regulation of genes involved in sugar fermentation, which can be explained by two specific mutations in a region of the ptcC promoter with a key role in the regulation of cellobiose and glucose uptake.