M16-Type Metallopeptidases Are Involved in Virulence for Invasiveness and Diffusion of Leptospira interrogans and Transmission of Leptospirosis

Abstract

Background Leptospirosis is a global zoonotic infectious disease caused by Leptospira interrogans. The pathogen rapidly invades into hosts and diffuses from bloodstream into internal organs and excretes from urine to cause transmission of leptospirosis. However, the mechanism of leptospiral invasiveness remains poorly understood. Methods Proteolytic activity of M16-type metallopeptidases (Lep-MP1/2/3) of L. interrogans was determined by spectrophotometry. Expression and secretion of Lep-MP1/2/3 during infection of cells were detected by quantitative reverse-transcription polymerase chain reaction, Western blot assay, and confocal microscopy. Deletion and complementation mutants of the genes encoding Lep-MP1/2/3 were generated to determine the roles of Lep-MP1/2/3 in invasiveness using transwell assay and virulence in hamsters. Results Leptospira interrogans but not saprophytic Leptospira biflexa strains were detectable for Lep-MP-1/2/3-encoding genes. rLep-MP1/2/3 hydrolyzed extracellular matrix proteins, but rLep-MP1/3 displayed stronger proteolysis than rLep-MP2, with 123.179/340.136 μmol/L Km and 0.154/0.159 s-1 Kcat values. Expression, secretion and translocation of Lep-MP1/2/3 during infection of cells were increased. ΔMP1/3 but not ΔMP2 mutant presented attenuated transmigration through cell monolayers, decreased leptospiral loading in the blood, lungs, liver, kidneys, and urine, and 10/13-fold decreased 50% lethal dose and milder histopathologic injury in hamsters. Conclusions Lep-MP1 and 3 are involved in virulence of L. interrogans in invasion into hosts and diffusion in vivo, and transmission of leptospirosis.

Internalization of Leptospira interrogans via diverse endocytosis mechanisms in human macrophages and vascular endothelial cells

“…Upon inhibition and genedepletion of ITGB1/CAV-1, the transcytosis efficiency of L. interrogans was reduced (Fig 6B and 6D). In human enteric, renal, and umbilical vein endothelial cell lines, L. interrogans was shown to use M16-Type metallopeptidases to hydrolyze extracellular matrix proteins and disassemble cell apical junctional complexes (AJCs), which may enhance transmigration through cell monolayers [61,62].…”

Estudio epidemiológico de leptospirosis en cobayos en la región interandina del sur del Ecuador

“…Esta enfermedad es considerada un problema emergente de salud pública afectando tanto a países en vías de desarrollo como a países desarrollados. Una extensa variedad de mamíferos puede actuar como reservorios de especies de Leptospira, dentro de estos las ratas se consideran el principal reservorio de transmisión de la enfermedad (Boey et al, 2019;Koizumi et al, 2022), ya que tras la colonización renal se pueden excretar cantidades importantes del patógeno al medio ambiente a través de la orina (Ge et al, 2020).…”

Leptolysin, a Leptospira secreted metalloprotease of the pappalysin family with broad-spectrum activity

“…An example is the thermolysin encoded by LIC13322 , which presents proteolytic activity against complement components C3 and C6 ( Amamura et al., 2017 ; Chura-Chambi et al., 2018 ). In addition, M16-type metallopeptidases are involved in Leptospira invasiveness and transmission ( Ge et al., 2020 ).…”