Detection of Acanthamoeba from Acanthamoeba Keratitis Mouse Model Using Acanthamoeba-Specific Antibodies

Although the prevalence of Acanthamoeba keratitis (AK) is rare, its incidence in contact lens wearers has increased. Acanthamoeba infections can lead to the loss of vision if the diagnosis and treatment are delayed. In this study, we investigated the diagnostic potential of two antibodies raised against the adenylyl cyclase-associated protein (ACAP) and periplasmic binding protein (PBP) of A. castellanii in the AK mouse model. The specificity of ACAP and PBP antibodies to Acanthamoeba was confirmed by immunocytochemistry. AK mouse models were produced by corneal infections with A. castellanii trophozoites for 7 days and 21 days. Enzyme-linked immunosorbent assay results revealed that both ACAP and PBP antibodies successfully detected Acanthamoeba antigens in the tears and eyeball lysates of the AK mouse model. The detection levels of Acanthamoeba antigens were similar at both infection time points. Anti-Acanthamoeba IgG, IgA, and IgM antibodies were evaluated from the sera of the AK mouse model. Notably, IgM and IgA antibody responses were highest and lowest at both time points, respectively. Our findings revealed that both ACAP and PBP antibodies could detect Acanthamoeba antigens in the tears and eyeball lysates of the AK mouse model. These results provide important information for understanding Acanthamoeba infections and developing a new diagnostic tool for AK.