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

Abstract

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.

Evaluating the Diagnostic Potential of Chorismate Mutase Poly-Clonal Peptide Antibody for the Acanthamoeba Keratitis in an Animal Model

“…Previously, we reported that Acanthamoeba antigens in tears and eyeball lysates of the AK mouse model were detected by adenylyl cyclase-associated protein (ACAP) and periplasmic binding protein (PBP) antibodies [28]. Interestingly, Acanthamoeba antigens in the AK mice samples were detected to a greater extent by the CM antibody in comparison to the ACAP and PBP reported in our previous study.…”

“…To address this limitation, we recently reported the diagnostic potential of Acanthamoeba-specific adenylyl cyclase-associated protein (ACAP) and periplasmic binding protein (PBP) antibodies using the tears and eyeball lysates acquired from the AK mouse model [28]. While this study demonstrated that non-invasive diagnosis of AK via antibodybased methods is feasible, both ACAP and PBP antibodies weakly interacted with the murine samples.…”

New Frontiers in Acanthamoeba Keratitis Diagnosis and Management

“…Several studies have reported on target structures in Acanthamoeba spp. These potential targets for antibodies may aid in diagnosis in the future: inosine-uridine preferring nucleoside hydrolase (IPNH), chorismite mutase (CM), carboxylesterase, adenylyl cyclaseassociated protein (ACAP), and periplasmic binding protein (PBP) [65][66][67][68][69]. Additional studies have demonstrated the utility of CM and ACAP/PBP antibodies in AK diagnosis in mouse and rabbit animal models, respectively [69,70].…”

“…These potential targets for antibodies may aid in diagnosis in the future: inosine-uridine preferring nucleoside hydrolase (IPNH), chorismite mutase (CM), carboxylesterase, adenylyl cyclaseassociated protein (ACAP), and periplasmic binding protein (PBP) [65][66][67][68][69]. Additional studies have demonstrated the utility of CM and ACAP/PBP antibodies in AK diagnosis in mouse and rabbit animal models, respectively [69,70]. Antibody-based tests hold potential in the diagnosis of AK but still require further investigation and development prior to their widespread use.…”