For instance, the time-dependent appearance of L. interrogans strain Lai co-localized with lysosomes significantly decreased in NADPH oxidase inhibitor apocynin pretreated J774A.1 cells after infection for 4, 12 and 24 h, but less significant changes in the co-localization of L. interrogans strain Lai with lysosomes were observed in apocynin pretreated THP-1 cells compared to THP-1 cells without apocynin pretreatment (Fig 4 and Fig 5). This evidence concerns the gene FMO5 and infection.