Experimental model in rats for study on transmission dynamics and evaluation of Clonorchis sinensis infection immunologically, morphologically, and pathologically

Abstract

This study aims to gain a better insight into the transmission patterns and immunologic profile of Clonorchis sinensis infection and make a headway on the pathogenesis regarding cholangiocarcinoma and hepatic lesions. Experimental models orally infected by C . sinensis metacercariae were constructed in rats. Immunological assays were performed to measure serum level of IgA, IgE, IgG1, IgG2a, IFN-gamma, and IL-4. Infection parameters were assessed by worm recovery rate, eggs per gram faece and worm size. Pathological sections with livers were managed with immunofluorescence, hematoxylin, eosin, and Masson's trichrome staining to evaluate the hepatic pathological changes. Interestingly, rats infected with only one C . sinensis metacercariae even gained a high worm recovery rate of 83.3% compared with rats infected with more metacercariae. Serological changes according to different infection doses indicated that immune response presented a tendency to Th2 type by expressing transient high level of IgG1, IL-4, and IgE. Hepatic tissues appeared inflammatory and fibrotic, revealed by different stainings. Intrahepatic bile ducts displayed cholangiectasis and proliferation with excreted/secreted antigen histologically located. C . sinensis, as a fish-borne zoonosis, presented novel transmission patterns which explained high infection rate in endemic areas; infection rate of C . sinensis was frequency-dependent and dose-related. Humoral immunity played a prevalent role in resisting to C . sinensis based on the rat models. C . sinensis infection played an undoubted role in biliary and hepatic diseases.

Molecular characterization of cathepsin B from Clonorchis sinensis excretory/secretory products and assessment of its potential for serodiagnosis of clonorchiasis

“…Our results showed that Cs CB might be involved in the pathogenesis of C. sinensis -related hepatobiliary diseases as a component of ESP with antigenicity and immunogenicity. Indeed, C. sinensis adults dwell in the bile duct of host, persistently released ESP resulting in mechanical damage and chemical stimulus which must have brought on infiltration of inflammatory cells surrounding bile ducts and adenomatous hyperplasia of biliary epithelia [42-44]. However, there remains much to do to elucidate the mechanism of C. sinensis causing hepatobiliary diseases.…”

Low Divergence of Clonorchis sinensis in China Based on Multilocus Analysis

“…Two hundred and twenty-four C. sinensis -infected animals were collected in total (Table S1). Thirty-two metacercariae were isolated from fresh water fish in Guangdong and Guangxi provinces and were developed into adults in Sprague-Dawley rats using the standard method [15]. Genomic DNA from each adult worm was extracted using a commercial DNA extraction kit (Qiagen, Germany) according to the manufacturer's instructions.…”

Identification and Characterization of Paramyosin from Cyst Wall of Metacercariae Implicated Protective Efficacy against Clonorchis sinensis Infection

“…The previously described egg counting method [28] was employed to calculate eggs per gram feces (EPG) from weeks 4 post challenge infection. The experimental rats were sacrificed at week 6 post infection to recover adult worms from livers for worm burden evaluation.…”