Establishment and Characterization of Patient-Derived Xenograft Models of Anaplastic Thyroid Carcinoma and Head and Neck Squamous Cell Carcinoma.

Patient-derived xenograft (PDX) models faithfully preserve the histological and genetic characteristics of the primary tumor and maintain its heterogeneity. Pharmacodynamic results based on PDX models are highly correlated with clinical practice. Anaplastic thyroid carcinoma (ATC) is the most malignant subtype of thyroid cancer, with strong invasiveness, poor prognosis, and limited treatment. Although the incidence rate of ATC accounts for only 2%-5% of thyroid cancer, its mortality rate is as high as 15%-50%. Head and neck squamous cell carcinoma (HNSCC) is one of the most common head and neck malignancies, with over 600,000 new cases worldwide each year. Herein, detailed protocols are presented to establish PDX models of ATC and HNSCC. In this work, the key factors influencing the success rate of model construction were analyzed, and the histopathological features were compared between the PDX model and the primary tumor. Furthermore, the clinical relevance of the model was validated by evaluating the in vivo therapeutic efficacy of representative clinically used drugs in the successfully constructed PDX models.

Preliminary Evaluation of Recombinant EPC1 and TPx for Serological Diagnosis of Animal Cystic Echinococcosis.

Animal cystic echinococcosis (CE) is one of the most important helminthic diseases and affects many mammalian intermediate hosts. Practical and effective diagnosis is crucial for animal CE control. Two different recombinant antigens derived from Echinococcus granulosus, Echinococcus protoscolex calcium binding protein 1 (rEg-EPC1) and thioredoxin peroxidase (rEg-TPx), were evaluated in this study to detect the specific immunoglobulin G (IgG) in sheep and goat with CE by the indirect enzyme-linked immunosorbent assays. The diagnostic effect of the above-listed proteins was determined to their sensitivity and specificity and compared with hydatid cyst fluid, two previously reported immunogenic recombinant proteins (dihydrofolate reductase and P29), and two commercial kits available in China. Of these, the best diagnostic results were obtained in the anti-TPx IgG ELISA, with 92.6% sensitivity, 98.8% specificity, and no cross-reactivity with anti-Eg95 IgG. Recombinant E. granulosus thioredoxin peroxidase shows good potential for serological diagnosis of animal cystic echinococcosis.

Echinococcus canadensis G8 Tapeworm Infection in a Sheep, China, 2018.

We report a sheep infected with Echinococcus canadensis G8 tapeworm in China in 2018. This pathogen was previously detected in moose, elk, muskox, and mule deer in Europe and North America; our findings suggest a wider host range and geographic distribution. Surveillance for the G8 tapeworm should be conducted in China.

Molecular Characterization of a Dirofilaria immitis Cysteine Protease Inhibitor (Cystatin) and Its Possible Role in Filarial Immune Evasion.

Infection with canine heartworm (Dirofilaria immitis), spread via mosquito vectors, causes coughing, asthma, pneumonia, and bronchitis in humans and other animals. The disease is especially severe and often fatal in dogs and represents a serious threat to public health worldwide. Cysteine protease inhibitors (CPIs), also known as cystatins, are major immunomodulators of the host immune response during nematode infections. Herein, we cloned and expressed the cystatin Di-CPI from D. immitis. Sequence analysis revealed two specific cystatin-like domains, a Q-x-V-x-G motif, and a SND motif. Phylogenetic analysis indicates that Di-CPI is a member of the second subgroup of nematode type II cystatins. Probing of D. immitis total proteins with anti-rDi-CPI polyclonal antibody revealed a weak signal, and immunofluorescence-based histochemical analysis showed that native Di-CPI is mainly localized in the cuticle of male and female worms and the gut of male worms. Treatment of canine peripheral blood mononuclear cells (PMBCs) with recombinant Di-CPI induced a Th2-type immune response characterized by high expression of the anti-inflammatory factor interleukin-10. Proliferation assays showed that Di-CPI inhibits the proliferation of canine PMBCs by 15%. Together, the results indicate that Di-CPI might be related to cellular hyporesponsiveness in dirofilariasis and may help D. immitis to evade the host immune system.

Molecular characterization of triosephosphate isomerase from Echinococcus granulosus.

Cystic echinococcosis (CE) is a zoonosis that can be caused by the larvae of Echinococcus granulosus; this disease occurs worldwide and is highly endemic in China. E. granulosus can produce energy by glycolysis as well as both aerobic and anaerobic respirations. Triosephosphate isomerase is a glycolytic enzyme present in a wide range of organisms and plays an important role in glycolysis. However, there has been little research on triosephosphate isomerase from E. granulosus (Eg-TIM). Here, we present a bioinformatic characterization and the experimentally determined tissue distribution characteristics of Eg-TIM. We also explored its potential value for diagnosing CE in sheep using indirect enzyme-linked immunosorbent assay (ELISA). Native Eg-TIM was located in the neck and hooks of protoscoleces (PSCs), as well as the tegument and parenchyma tissue of adult worms. The entire germinal layer was also Eg-TIM positive. Western blots showed that recombinant Eg-TIM (rEg-TIM) reacts with positive serum from sheep and had good immunogenicity. Indirect ELISA exhibited low specificity (53.6%) and low sensitivity (87.5%) and cross-reacted with both Taenia multiceps and Taenia hydatigena. Our results suggest that TIM may take part in the growth and development of E. granulosus. Furthermore, we determined that rEg-TIM is not a suitable serodiagnostic antigen for CE in sheep.

Serodiagnostic Potential of Alpha-Enolase From Sarcoptes scabiei and Its Possible Role in Host-Mite Interactions.

Infestation of the epidermis with the highly contagious ectoparasite, Sarcoptes scabiei, causes scabies, which is characterized by intense itching, pruritus, and secondary infection. This condition affects humans, livestock, and wildlife worldwide, incurring large economic losses and reducing the quality of human life. In the present study, we cloned the alpha-enolase, a key enzyme in the glycolytic and gluconeogenesis pathways, from S. scabiei var. cuniculi, characterized it and produced soluble recombinant enolase protein (rSsc-eno). We determined the localization of Ssc-eno in isolated mites and mites in lesioned skin. The results showed that native enolase was intensely localized in the tegument of the mouthparts, the entire legs, and the whole mites' body, as well as in the gut and reproduction system. Interestingly, we found that native enolase was widely distributed in mites in lesioned skin, with obvious high protein intensity compared with isolated mites. Building on good immunoreactivity, an indirect enzyme-linked immunosorbent assay (ELISA) based on rSsc-eno showed 92% sensitivity and 95.8% specificity, compared with other indirect ELISA in this study, rSsc-eno based ELISA is better in detecting scabies in rabbits. Besides, this method can detect S. scabiei infection as early as 1 week post infection. Compared with other detection methods, such as traditional microscopic examination and recently published universal conventional PCR, rSsc-eno ELISA was more effective to detect early infection in rabbits. Additionally, in vitro incubation experiments demonstrated the concentration-dependent acaricidal activity of rabbit anti-rSsc-eno sera against larval mites, suggested its potential as a vaccine candidate.

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

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.