The critical window for host defense: macrophage trogocytosis eliminatesat the early establishment stage.

Abstract

INTRODUCTION: The ability ofto establish infection depends on evading host immune clearance during the early stages. This study investigated the mechanisms by which host macrophages eliminateduring this critical window. METHODS: We utilized a mouse infection model with fluorescently labeled protoscoleces to observe early immune dynamics. Histopathological analysis was performed to characterize lesion phenotypes. The mechanism of parasite killing was further explored usingco-culture experiments and scanning electron microscopy (SEM). RESULTS: Rapid immune cell infiltration and parasite clearance in the liver were observed within 24 hours post-infection. Histopathological analysis revealed two distinct lesion phenotypes: "Progressive Lesions," characterized by a failure of macrophage infiltration and parasite transformation into vesicles, and "Regressive Lesions," marked by high macrophage density and complete parasite elimination.experiments demonstrated that macrophages mediated protoscolex killing through complement-dependent trogocytosis, a process requiring active serum components. SEM confirmed direct macrophage-parasite contact and trogocytosis as the primary mode of elimination. DISCUSSION: These findings highlight the pivotal role of macrophage trogocytosis in early host defense againstinfection and provide new insights into the mechanisms of innate immunity in parasitic clearance.