Construction of Attenuated Listeria monocytogenes (actA/inlB) and Preliminary Identification of Biological Activity
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
Attenuated Listeria monocytogenes (Lm) has the potential to become a live vaccine vector. It can also produce major histocompatibility complex (MHC)Ⅰ and MHC Ⅱ antigen presentation systems, and significantly stimulate immunity in cluster of differentiation (CD)8+ and CD4+ cells. The construction of avirulent gene deletion strains and the subsequent evaluation of their biological activity are crucial for the development of live vaccine vectors. Homologous recombination technology was used to construct Lm-?actA and Lm-?actA/?inlB strains, and the biological activities of attenuated strains were explored in terms of growth, virulence gene expression, and the capacity to invade HepG2 cells. The results showed that no difference in growth was found among the attenuated strains Lm-?actA, Lm-?actA/?inlB, and wild type Lm (EGD-e). Real time quantitative polymerase chain reaction (PCR) results showed that inlA expression was enhanced two-fold after the actA gene was deleted. The expression of plcB and hly genes was significantly elevated when actA and inlB genes were simultaneously deleted. The HepG2 cell invasion assay showed that the invasive capacity was enhanced after the actA gene was deleted and was weakened after deleting actA and inlB genes. Therefore, the construction of attenuated strains and study of their biological properties is not only important for understanding the pathogenesis of food-borne Lm, but also lays a foundation for the construction of vaccine vectors for the prevention of human and animal diseases.
