Leptospira interrogans enters different host cells by binding to distinct molecules in the extracellular matrix

Abstract

Leptospirosis caused by Leptospira is a worldwide zoonotic disease. The 2 spirochete can efficiently invade host cells and spread from blood into internal organs, but the mechanisms of leptospiral internalization into different host cells remain poorly understood. Adhesion of leptospires to the ECM (extracellular matrix) initiated leptospire internalization in macrophage cell-lines THP-1, J774A.1, and in human umbilical epithelial cells (HUVEC). We assessed the distribution of ECM , including fibronectin (FN), laminin and collagens 1-4 (COL1-COL4) in different cells. FN was expressed in THP-1 and J774A.1 cells, and FN, LN, COL3 and COL4 were expressed in HUVEC. Then, we found leptospires adhered to FN, LN, COL3 and COL4. The most important intracellular leptospires in macrophages (THP-1 and J774A) significantly decreased when leptospires were pre-blocked with FN This indicates that FN has an important role in the adherence to and entry of leptospires in macrophages, while in HUVEC, FN, LN, COL3 and COL4 assume this role.

Keywords

• Leptospira interrogans
• extracellular matrix
• adhesion
• internalization