Comparison of the phagocytosis and inflammatory response of murine macrophages infected by Leptospira strains 56606v and 56606a / 上海交通大学学报（医学版）

ABSTRACT

Objective: To compare the response and consequence of mouse macrophages infected by Leptospira interrogans 56606v and 56606a, and explore the mechanisms of pathogenic Leptospira to cause disease. Methods: Peritoneal macrophages of C57BL/6 mice were infected by pathogenic Leptospira 56606v and non-pathogenic Leptospira 56606a respectively. Immunofluorescence staining was performed to observe phagocytosis and clearance of Leptospira after infection, and realtime-PCR was used to determine cytokine production of macrophages. Results: After 72-hour infection, strain 56606v exhibited a lower phagocytic rate but survived after incubation with peritoneal macrophages compared with strain 56606a, which showed a higher phagocytic rate but was cleared at that time point. Additionally, cytokine production of macrophages incubated with 56606v was lower than that with 56606a. Conclusion: Leptospira interrogans strain 56606v can survive in macrophages, which may contribute to evasion from phagocytic clearance and lead to disease, while strain 56606a can be cleared, which implicates a lower pathogenicity.