[Control of Opisthorchis viverrini infection for cholangiocarcinoma prevention]

Development of a subunit vaccine against the cholangiocarcinoma causing Opisthorchis viverrini: a computational approach

Opisthorchis viverrini is the etiological agent of the disease opisthorchiasis and related cholangiocarcinoma (CCA). It infects fish-eating mammals and more than 10 million people in Southeast Asia suffered from opisthorchiasis with a high fatality rate. The only effective drug against this parasite is Praziquantel, which has significant side effects. Due to the lack of appropriate treatment options and the high death rate, there is a dire need to develop novel therapies against this pathogen. In this study, we designed a multi-epitope chimeric vaccine design against O. viverrini by using immunoinformatics approaches. Non-allergenic and immunogenic MHC-1, MHC-2, and B cell epitopes of three candidate proteins thioredoxin peroxidase (Ov-TPx-1), cathepsin F1 (Ov-CF-1) and calreticulin (Ov-CALR) of O. viverrini, were predicted to construct a potent multiepitope vaccine. The coverage of the HLA-alleles of these selected epitopes was determined globally. Four vaccine constructs made by different adjuvants and linkers were evaluated in the context of their physicochemical properties, antigenicity, and allergenicity. Protein-protein docking and MD simulation found that vaccines 3 was more stable and had a higher binding affinity for TLR2 and TLR4 immune receptors. In-silico restriction cloning of vaccine model led to the formation of plasmid constructs for expression in a suitable host. Finally, the immune simulation showed strong immunological reactions to the engineered vaccine. These findings suggest that the final vaccine construct has the potential to be validated by in vivo and in vitro experiments to confirm its efficacy against the CCA causing O. viverrini.

Integrated One-Health approach for prevention and control of Opisthorchis viverrini infection in rural Thailand: a 3-year study

Opisthorchis viverrini infection is a pressing health issue in rural Southeast Asia and is associated with the risk of cholangiocarcinoma. Despite control efforts, high infection rates persist, including evidence of reinfection post-treatment. This study aimed to address this public health concern through an integrated One-Health approach in endemic areas in rural Thailand over a 3-year period. The study included data from 3600 participants from Udon Thani Province, Thailand, during the years 2020 to 2022 and involved integrated epidemiological data collection and risk factor analysis to understand the impact of various interventions on disease transmission in the community. The efficacy of interventions was assessed by monitoring the incidence of O. viverrini reinfection in 2021 and 2022. In 2020, 218 cases of O. viverrini infection (6.0%) were identified. Significant risk factors included proximity to water bodies and consumption of raw fish. Variables contributing to infection risk among participants (P < 0.001) were education level, engagement in traditional ceremonies, poor sanitation, absence of ducks in nearby water bodies, self-medication for parasitic conditions, and multiple infections within a household. Dogs, cats, and cyprinoid fish showed prevalence rates of 5.4%, 6.3%, and 11.5%, respectively. Geographic analysis revealed clusters of infected households around water bodies. Interventions, including in-depth interviews, focus-group discussions, health education, anthelminthic treatment, and biological control using local free-range ducks, were implemented, resulting in no human reinfections in the second year and a minimal 0.3% prevalence rate in the third year. This study offers valuable insights into the dynamic changes in infection prevalence, making a significant contribution to effective disease control and community health promotion. This integrated One-Health approach proved to be an effective strategy for the prevention and control of opisthorchiasis.

Molecular Biomarkers in Cholangiocarcinoma: Focus on Bile

Hepatobiliary system cancers have demonstrated an increasing incidence rate in the past years. Without the presence of early symptoms, the majority of such cancers manifest with a set of similar symptoms, such as cholestasis resulting in posthepatic icterus. Differential diagnosis of hepatobiliary cancers is required for the therapy selection, however, the similarity of the symptoms complicates diagnostics. Thus, the search for molecular markers is of high interest for such patients. Cholangiocarcinoma (CCA) is characterized by a poor prognosis due to a low resectability rate, which occurs because this disease is frequently beyond the limits of surgical therapy at the time of diagnosis. The CCA is diagnosed by the combination of clinical/biochemical features, radiological methods, and non-specific serum tumor biomarkers, although invasive examination is still needed. The main disadvantage is limited specificity and sensitivity, which complicates early diagnostics. Therefore, prognostic and predictive biomarkers are still lacking and urgently needed for early diagnosis. In contrast to serum, bile is more accessible to identify biliary disease due to its simpler composition. Moreover, bile can contain higher concentrations of tumor biomarkers due to its direct contact with the tumor. It is known that the composition of the main bile component - bile acids, may vary during different diseases of the biliary tract. This review summarizes the recent developments in the current research on the diagnostic biomarkers for CCA in serum and bile and provides an overview of the methods of bile acids analysis.

In silico prediction of secretory proteins of Opisthorchis viverrini, Clonorchis sinensis and Fasciola hepatica that target the host cell nucleus

Liver flukes Fasciola hepatica, Opisthorchis viverrini and Clonorchis sinensis are causing agents of liver and hepatobiliary diseases. A remarkable difference between such worms is the fact that O. viverrini and C. sinensis are carcinogenic organisms whereas F. hepatica is not carcinogenic. The release of secretory factors by carcinogenic flukes seems to contribute to cancer development however if some of these target the host cell nuclei is unknown. We investigated the existence of O. viverrini and C. sinensis secretory proteins that target the nucleus of host cells and compared these with the corresponding proteins predicted in F. hepatica. Here we applied an algorithm composed by in silico approaches that screened and analyzed the potential genes predicted from genomes of liver flukes. We found 31 and 22 secretory proteins that target the nucleus of host cells in O. viverrini and C. sinensis, respectively, and that have no homologs in F. hepatica. These polypeptides have enriched the transcription initiation process and nucleic acid binding in O. viverrini and C. sinensis, respectively. In addition, other 11 secretory proteins of O. viverrini and C. sinensis, that target the nucleus of host cells, had F. hepatica homologs, have enriched RNA processing function. In conclusion, O. viverrini and C. sinensis have 31 and 22 genes, respectively, that may be involved in their carcinogenic action through a direct targeting on the host cell nuclei.