Immunization of sheep against Echinococcus granulosus with protoscolex tegumental surface antigens

Genotype Distribution of Enterobius vermicularis Isolates from Northwest Provinces of Iran

Background

Human infection with Enterobius vermicularis occurs worldwide. The most common clinical manifestation of a pinworm infection is an itchy anal region. This parasite is incidentally found in appendicitis. This study aims to characterize and genotype this parasite from different samples inferred by mt-DNA.

Methods

Forty appendectomies for acute clinical appendicitis, 40 positive scotch-tape samples, and 10 adult females worm isolated from patients. Genetic differentiation, haplotype differences, and isolates population structure were analyzed based on the cytochrome c oxidase subunit I (cox1) gene.

Results

It has been demonstrated that all isolations in the appendectomies specimens are similar, and the genetic difference divergence is seen in adult worm specimens. The neutral indices of the samples did not show a significant difference and show that there is no intra-specific and population distribution diversity.

Conclusion

Our results show different haplotypes in the B type of E. vermicularis population and add new information about genotyping of these parasites in Iran. In comparison with other studies, intra-specific variation of this parasite from Iran was observed.

Immunogenicity of peptide-based vaccine composed of epitopes from Echinococcus granulosus rEg.P29

Echinococcus granulosus is one of the main causes of economic loss in the livestock industry because of its food-borne transmission. Cutting off the transmission route is a valid prevention method, and vaccines are the most effective means of controlling and eliminating infectious diseases. However, no human-related vaccine has been yet marketed. As a genetic engineering vaccine, recombinant protein P29 of E. granulosus (rEg.P29) could provide protection against deadly challenges. In this study, we generated peptide vaccines (rEg.P29_T , rEg.P29_B , and rEg.P29_T+B ) based on rEg.P29 and an immunized model was established by subcutaneous immunization. Further evaluation showed that peptide vaccine immunization in mice induced T helper type 1 (Th1)-mediated cellular immune responses, leading to high levels of rEg.P29 or rEg.P29_B -specific antibodies. In addition, rEg.P29_T+B immunization can induce a higher antibody and cytokine production level than single-epitope vaccines, and immune memory is also longer. Collectively, these results suggest that rEg.P29_T+B has the potential to be developed as an efficient subunit vaccine for use in areas where E. granulosus is endemic.

The Immunization of Protoscolices P29 DNA Vaccine on Experimental Cystic Echinococosis in Balb/c Mice

PURPOSE

Cystic Echinococosis is one of the important parasitic diseases that is considered as a problem economics and health in many parts of the world. Many efforts have been performed for controlling the disease in the world. To reach a reliable vaccine against Cystic Echinococosis is one of the important duty of governments. Several antigen of hydatid cyst for vaccine candidate have been evaluated. In this study, P-29 antigen has been used for this purpose.

METHODS

E.g P29 antigen was cloned in Escherichia coli and transfected into the Chinese hamster ovary cell for antigen proliferation and used for vaccination in Balb/c mice. The recombinant antigen E.g-29 was shown using Western blot test. Two dilution of DNA vaccine (pCEgP-29) including 50 µg/100 µl and 100 µg/100 µl were prepared. Twenty four Balb/C male 6-8 week mouse were divided in 4 groups. The groups were included in 2 vaccination groups (pcEg.P29 50 µg/100 µl and 100 µg/100 µl dilution) as immunized groups and 2 groups of plasmid and PBS as control. The mice were injected intramuscularly 3 times with 2 weeks interval. After 3 weeks from last injection, all groups were challenged intraperitonealy with 2000 protoscolices. After 5 months, the mice were euthanized by ketamine/xylasine injection and number, size, and weight of cysts were recorded.

RESULTS

Immunization rate was up to 93% in vaccinated group when compared with the control group.

CONCLUSION

The results of this study showed that rEg.P29 could be considered as an effective vaccine for controlling of E. granulosus prevalence in intermediated host.

Sequence Analysis of Pvama-1 among Plasmodium Vivax Isolates in Sistan-Baluchistan

Background

Apical Membrane antigen 1 (AMA-1) is an important membrane protein that presents in all Plasmodium species and participates in critical phases in the attraction of cells. In human, it is one of the most immunodominant antigens with a protective immune response simulation role Apical Membrane antigen 1 (AMA-1) is an important membrane protein which presents in all Plasmodium species and is located on the surface of merozoite and sporozoites that participates in critical phases in attraction of human red blood cells by merozoites and hepatocytes by sporozoites, so in human, it is one of the most immunodominant antigens with a protective immune response simulation role. Since extra information is necessary to lighten of AMA-1 scope, we equaled genetic variation in P.vivax AMA-1 from 40 Iranian isolates with those reported from the other malarious countries.

Methods

Blood samples were collected from 40 patients' positive of P.vivax, and genomic DNA was extracted from the blood. The nucleotide sequence for 446 amino acid (AA) residues (42-488 of PvAMA-1) of AMA-1 gene was amplified via PCR and then sequenced.

Result

A total of 24 different haplotypes were recognized between samples. No new haplotype was determined in this research that was reported previously in other regions of Iran and the world. We detected 37-point mutations at the nucleotide level in their sequences and showed 43 amino acid variations, at 37 positions in which 6 sites demonstrate trimorphic polymorphism, and the others were dimorphic.

Conclusion

Sequence analysis of the major haplotype showed 95% similarity with P.vivax Sal-1 AMA-1 gene and high level of allelic diversity at the domain I of PvAMA-1 among P. vivax isolates of Iran. Because PvAMA-1 is noticeable as vaccine candidate antigen, these documents provide valuable information for the development of malaria vaccine.

Customizing the Protoscolicidal Activity by a Drug Delivery System: Application of Guar Gum in Electrospun Nanofibers

Background

The present study aimed to control mebendazole drug release from ethyl cellulose nanofibers containing guar gum produced by Electrospinning Method (ESM) on mortality of hydatid cyst protoscoleces under laboratory conditions.

Methods

The study was conducted in Arak Islamic Azad University, 2019. After preparation of ethyl cellulose nanofibers containing guar gum with concentrations 10, 250, 50 and 500 ppm with ESM, the uniformity and fineness of nanofibers were investigated by electron microscope. By determining the absorption of nanofibers during 312 h via spectrophotometry method, the amount of drug release was obtained. Then, the mortality of live protoscoleces in-vitro with nanofibers made with different concentrations was studied during 13 days.

Results

Guar gum nanofiber with four concentrations of 10, 50, 250 and 500 ppm had 0.78512, 0.83729, 1.0098 and 1.0633 absorption respectively and showed drug release 42.09%, 39.95%, 33.05% and 30.96% after 312 hours. Therefore, the survival of protoscoleces in the presence of guar gum with four concentrations was zero after 3, 6, 11 and 13 days (P<0.05).

Conclusion

To produce nanofibers carrying the drug for research related to the treatment of hydatid cysts, the electrospinning technique can be considered as a reliable method.

Use of Veterinary Vaccines for Livestock as a Strategy to Control Foodborne Parasitic Diseases

Foodborne diseases (FBDs) are a major concern worldwide since they are associated with high mortality and morbidity in the human population. Among the causative agents of FBDs, Taenia solium, Echinococcus granulosus, Toxoplasma gondii, Cryptosporidium spp., and Trichinella spiralis are listed in the top global risk ranking of foodborne parasites. One common feature between them is that they affect domestic livestock, encompassing an enormous risk to global food production and human health from farm to fork, infecting animals, and people either directly or indirectly. Several approaches have been employed to control FBDs caused by parasites, including veterinary vaccines for livestock. Veterinary vaccines against foodborne parasites not only improve the animal health by controlling animal infections but also contribute to increase public health by controlling an important source of FBDs. In the present review, we discuss the advances in the development of veterinary vaccines for domestic livestock as a strategy to control foodborne parasitic diseases.

Linking murine resistance to secondary cystic echinococcosis with antibody responses targeting Echinococcus granulosus tegumental antigens

Successful establishment of a parasite infection depends partially on the host intrinsic susceptibility to the pathogen. In cystic echinococcosis (CE), a zoonotic disease caused by the cestode parasite Echinococcus granulosus, the infection outcome in the murine model of secondary CE varies according to the mouse strain used. In this regard, intrinsic differences in susceptibility to the infection were previously reported for Balb/c and C57Bl/6 mice, being C57Bl/6 animals less permissive to secondary CE. Induction of parasite-specific antibodies has been suggested to play relevant roles in such susceptibility/resistance phenomena. Here, we report an in deep comparison of antibody responses induced in both mouse strains. Firstly, only C57Bl/6 mice were shown to induce specific-antibodies with efficient anti-parasite activities during early secondary CE. Then, through ImmunoTEM and Serological Proteome Analysis (SERPA), an evaluation of specific antibody responses targeting parasite tegumental antigens was performed. Both strategies showed that infected C57Bl/6 mice -unlike Balb/c animals- narrowed their IgG recognition repertoire against tegumental antigens, targeting fewer but potentially more relevant parasite components. In this sense, tegumental antigens recognition between Balb/c and C57Bl/6 mice, either by natural and/or induced antibodies, was analyzed through SERPA and MALDI-TOF/TOF studies. A total of 13 differentially recognized proteins (DRPs) uniquely targeted by antibodies from C57Bl/6 mice were successfully identified, wherein a subset of 7 DRPs were only recognized by infection-induced antibodies, suggesting their potential as natural protective antigens. In this regard, immunoinformatic analyses showed that such DRPs exhibited higher numbers of possible T cell epitopes towards the H-2-IA^b haplotype, which is present in C57Bl/6 mice but absent in Balb/c animals. In summary, our results showed that the genetic predisposition to generate better T-dependent antibody responses against particular tegumental antigens might be a key factor influencing host susceptibility in the murine model of secondary CE.

Designing a Recombinant Multi-Epitope Antigen of Echinococcus granulosus to Diagnose Human Cystic Echinococcosis

BACKGROUND

Cystic echinococcosis can cause severe disease and probable death in humans. Epitopes of its antigens play a key role in the sensitivity and specificity of immunodiagnostic tests.

METHODS

Epitope prediction software programs predict the most antigenic linear B-cell epitopes of AgB (8 kD), Ag5, and Ag95. Six such epitopes were predicted and connected by "Gly-Ser" linker and synthesized. The purity of the concentrated recombinant multi-epitope protein was assessed by 15% SDS-PAGE. Overall, 186 serum samples were collected from the Loghman Hakim Hospital and different laboratories, Tehran, Iran, from July 2016 to February 2017. Patients infected with hepatic hydatid cysts, patients infected by other parasites and viruses, and healthy individuals were used to detect the anti-CE IgG using recombinant multi-epitope protein.

RESULTS

Forty-one samples out of 43 cases of hydatidosis were diagnosed correctly as positive, and two were negative. In addition, six negative cases of healthy individual group were diagnosed as positive and negative with rMEP-ELISA and the commercial kit, respectively. Therefore, these six samples were considered as false positive using our method. In addition, a diagnostic sensitivity of 95.3% (95% CI, 84.19% to 99.43%) and a specificity of 95.0% (95% CI, 89.43% to 98.14%) were obtained using optimum cutoff value (0.20). The sensitivity and specificity of the commercial kit was 100%.

CONCLUSION

Our findings showed high diagnostic accuracy of the ELISA test using the developed recombinant protein, which encourages the use of this recombinant multi-epitope protein for rapid serological diagnosis of hydatidosis.

The Effect of Alpha-Tocopherol on the Expression of Epidermal Growth Factor Receptor and Transforming Growth Factor Beta Genes in Three Developmental Stages of Echinococcus granulosus

BACKGROUND

In recent decades platyhelminths have been used as model organisms to address some of the fundamental questions related to the growth and development of animal organisms. Epidermal Growth Factor Receptors (EGFR) and Transforming Growth Factor beta (TGF-beta) have a regulatory role in the growth and development of Echinococcus species. This study determined the effect of alpha-tocopherol on the expression of EGFR and TGF-beta genes in three in vitro developmental stages of E. granulosus.

METHODS

E. granulosus protoscoleces were cultured in diphasic medium containing bovine serum and CMRL 1066. Three developmental stages of E. granulosus, i.e. invaginated protoscoleces, evaginated protoscoleces and three-proglottid worms, were treated by alpha-tocopherol (250 μg/ml for 36 h) and the expression of EGFR and TGF-beta genes were evaluated by using qPCR analysis.

RESULTS

Intact protoscoleces were successfully developed to the segmented worms in diphasic culture media. Higher levels of both EGFR and TGF-beta gene expression were observed in the invaginated protoscoleces as well as the segmented worms in comparison to the non-treated controls.

CONCLUSION

Administration of alpha-tocopherol to different developmental stages of E. granulosus significantly enhanced EGFR and TGF-beta expression in the parasite. Both oxidant and non-oxidant activities of alpha-tocopherol could explain the study findings. Overexpression of the genes could in turn enhance growth factor effects and facilitates the viability of the parasite.

Cryopreservation of Echinococcus granulosus Protoscoleces

BACKGROUND

The main objective of the current study was to investigate on the cryopreservation of protoscoleces of Echinococcus granulosus, a causative agent of cystic hydatidosis in man.

METHODS

This study was conducted on isolated protoscoleces from hydatid cysts infected livers collected from slaughterhouse of Tehran, Iran in 2016. Viability of protoscoleces was evaluated by dye test. Cryopreservation of isolated protoscoleces in the presence of Dimethylsulfoxide (DMSO) and glycerol using a three-step cooling protocol involving an initial period at -20 °C, -80 °C and liquid nitrogen was performed.

RESULTS

The mean viability rate of 10% DMSO and 15% glycerol were 9% and 8% respectively. The protoscoleces of Echinococcus granulosus have been successfully thawed and recovered after 6 months storage in liquid nitrogen.

CONCLUSION

Cryopreservation method needs to be improved for each species of helminthes and can be useful for other immunological and laboratorial studies.

Combining proteomics and bioinformatics to explore novel tegumental antigens as vaccine candidates against Echinococcus granulosus infection

Echinococcus granulosus is the parasite responsible for cystic echinococcosis (CE), an important worldwide-distributed zoonosis. New effective vaccines against CE could potentially have great economic and health benefits. Here, we describe an innovative vaccine design scheme starting from an antigenic fraction enriched in tegumental antigens from the protoscolex stage (termed PSEx) already known to induce protection against CE. We first used mass spectrometry to characterize the protein composition of PSEx followed by Gene Ontology analysis to study the potential Biological Processes, Molecular Functions, and Cellular Localizations of the identified proteins. Following, antigenicity predictions and determination of conservancy degree against other organisms were determined. Thus, nine novel proteins were identified as potential vaccine candidates. Furthermore, linear B cell epitopes free of posttranslational modifications were predicted in the whole PSEx proteome through colocalization of in silico predicted epitopes within peptide fragments identified by matrix-assisted laser desorption/ionization-TOF/TOF. Resulting peptides were termed "clean linear B cell epitopes," and through BLASTp scanning against all nonhelminth proteins, those with 100% identity against any other protein were discarded. Then, the secondary structure was predicted for peptides and their corresponding proteins. Peptides with highly similar secondary structure respect to their parental protein were selected, and those potentially toxic and/or allergenic were discarded. Finally, the selected clean linear B cell epitopes were mapped within their corresponding 3D-modeled protein to analyze their possible antibody accessibilities, resulting in 14 putative peptide vaccine candidates. We propose nine novel proteins and 14 peptides to be further tested as vaccine candidates against CE.

Traumatic rupture of liver hydatid cysts into the peritoneal cavity of an 11-year-old boy: a case report from Iran

This is the first published case report of an 11-year-old patient with a rupture of a liver hydatid cyst (HC) into the peritoneal cavity after an abdominal trauma in Iran. The disease was diagnosed using focused abdominal sonography for trauma. To date, no cases of traumatic ruptures of liver HCs in children have been reported in Iran. In the endemic regions of the world, where patients suffer from a history of trauma and constant abdominal symptoms or anaphylactic shock, early diagnosis of HC is crucial as it may disseminate to other organs. The condition needs conservative surgery and follow-up.