Expression, Tissue Localization and Serodiagnostic Potential of Echinococcus granulosus Leucine Aminopeptidase

Abstract

Echinococcus granulosus is the causative agent of cystic echinococcosis (CE), a widespread parasitic zoonosis. Leucine aminopeptidases (LAPs) of the M17 peptidase family have important functions in regulating the balance of catabolism and anabolism, cell maintenance, growth and defense. In this study, we presented a bioinformatic characterization and experimentally determined the tissue distribution characteristics of E. granulosus LAP (Eg-LAP), and explored its potential value for diagnosis of CE in sheep based on indirect ELISA. Through fluorescence immunohistochemistry, we found that Eg-LAP was present in the tegument and hooks of PSCs, the whole germinal layer and adult worm parenchymatous tissue. Western blotting results revealed that the recombinant protein could be identified using E. granulosus-infected sheep serum. The diagnostic value of this recombinant protein was assessed by indirect ELISA, and compared with indirect ELISA based on hydatid fluid antigen. The sensitivity and specificity rEgLAP-ELISA were 95.8% (23/24) and 79.09% (87/110), respectively, while using hydatid fluid as antigen showed the values 41.7% (10/24) and 65.45% (72/110). This is the first report concerning leucine aminopeptidase from E. granulosus, and the results showed that Eg-LAP belong to M17 peptidase families, and that it is involved in important biological function of E. granulosus. Furthermore, rEg-LAP is appropriate for diagnosing and monitoring CE in sheep in field. Development of a rapid test using rEg-LAP to diagnose sheep CE deserves further study.

Modelling diagnostics for Echinococcus granulosus surveillance in sheep using Latent Class Analysis: Argentina as a case study

“…At the individual level, sensitivity and specificity were estimated at 55% and 68% respectively (for an OD cut-off value of 0.378). It is well known that the diagnostic performance of E. granulosus ELISA assays is highly variable, with previously published sensitivity and specificity values ranging from 41% to 100% [ 25 , 26 , 28 ]. Variation in individual immune responses, cyst location, and antigen characteristics have been linked to variable ELISA sensitivity and specificity.…”

“…These techniques can be used to detect host antibodies specific to E. granulosus in serum samples, allowing for the detection of exposed/infected flocks without the need for necropsy. However, despite improvements to these approaches through the use of recombinant antigens, their diagnostic performance can be highly variable in the field, limiting their effectiveness as surveillance tools [ 23 , [25] , [26] , [27] , [28] ].…”

Ubenimex combined with Albendazole for the treatment of Echinococcus multilocularis-induced alveolar echinococcosis in mice

“…These studies suggest that EM-LAP could be a potential therapeutic target of E. multilocularis infection. LAP is a metalloprotease of the M17 family (14) and it plays a crucial role in many physiological processes including growth, nutrition and metabolism. It is especially important for the invasion of pathogenic parasites in the host (15).…”

Molecular and Functional Characterization of Inhibitor of Apoptosis Proteins (IAP, BIRP) in Echinococcus granulosus

“…It has been estimated that global burden of human CE averages 285,500 disability-adjusted life years (DALYs) (Wen et al, 2019). Besides, the estimated economic losses occurring due to animal echinococcosis are up to $1.2 billion annually, and these losses are linked to the decreased fur quality, hide value, milk production and fecundity in livestock (Wu et al, 2018). At present, the World Health Organization (WHO) has taken CE as one of the 17 neglected tropical diseases (NTDs) targeted for control or eradication by 2050 (Wen et al, 2019).…”