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Objective: Our previous studies have demonstrated that Plasmodium immunotherapy (infection) has antitumor effects in mice. However, as a new form of immunotherapy, this therapy has a weakness: its specific killing effect on tumor cells is relatively weak. Therefore, we tested whether Plasmodium immunotherapy combined with gemcitabine (Gem), a representative chemotherapy drug, has synergistic antitumor effects. Methods: We designed subcutaneously and intravenously implanted murine Lewis lung cancer (LLC) models to test the antitumor effect of Plasmodium chabaudi ASS (Pc) infection in combination with Gem treatment and explored its underlying mechanisms. Results: We found that both Pc infection alone and Gem treatment alone significantly inhibited tumor growth in the subcutaneous model, and combination therapy was more effective than either monotherapy. Monotherapy only tended to prolong the survival of tumor-bearing mice, while the combination therapy significantly extended the survival of mice, indicating a significant synergistic effect of the combination. In the mechanistic experiments, we found that the combination therapy significantly upregulated E-cadherin and downregulated Snail protein expression levels, thus inhibiting epithelial-mesenchymal transition (EMT) of tumor cells, which may be due to the blockade of CXCR2/TGF-ß-mediated PI3K/Akt/GSK-3ß signaling pathway. Conclusion: The combination of Pc and Gem plays a synergistic role in inhibiting tumor growth and metastasis, and prolonging mice survival in murine lung cancer models. These effects are partially attributed to the inhibition of EMT of tumor cells, which is potentially due to the blockade of CXCR2/TGF-ß-mediated PI3K/Akt/GSK-3ß/Snail signaling pathway. The clinical transformation of Plasmodium immunotherapy combined with Gem for lung cancer is worthy of expectation.

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Biotechnological approaches have always sought to utilize novel and efficient methods in the prevention, diagnosis, and treatment of diseases. This science has consistently tried to revolutionize medical science by employing state-of-the-art technologies in genomic and proteomic engineering. CRISPR-Cas system is one of the emerging techniques in the field of biotechnology. To date, the CRISPR-Cas system has been extensively applied in gene editing, targeting genomic sequences for diagnosis, treatment of diseases through genomic manipulation, and in creating animal models for preclinical researches. With the emergence of the COVID-19 pandemic in 2019, there is need for the development and modification of novel tools such as the CRISPR-Cas system for use in diagnostic emergencies. This system can compete with other existing biotechnological methods in accuracy, precision, and wide performance that could guarantee its future in these conditions. In this article, we review the various platforms of the CRISPR-Cas system meant for SARS-CoV-2 diagnosis, anti-viral therapeutic procedures, producing animal models for preclinical studies, and genome-wide screening studies toward drug and vaccine development.

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Postoperative recurrence causes a high mortality rate among patients with hepatocellular carcinoma (HCC). The current study aimed to determine the effects of Plasmodium infection on HCC metastasis and recurrence. The antitumor effects of Plasmodium infection were determined using two murine orthotopic HCC models: The non­resection model and the resection model. Tumour tissues derived from tumour­bearing mice treated with or without Plasmodium infection were harvested 15 days post­tumour inoculation. The expression levels of biomarkers related to epithelial­mesenchymal transition (EMT) and molecules associated with CC­chemokine receptor 10 (CCR10)­mediated PI3K/Akt/GSK­3ß/Snail signalling were identified using reverse transcription­quantitative PCR and western blotting. The results demonstrated that Plasmodium infection significantly suppressed the progression, recurrence and metastasis of HCC in the two mouse models. The expression levels of E­cadherin were significantly higher in the Plasmodium­treated group compared with that in the control group, whereas the expression levels of Vimentin and Snail were significantly lower in the Plasmodium­treated group. Furthermore, Plasmodium infection inhibited the activation of Akt and GSK­3ß in the tumour tissues by downregulating the expression levels of CCR10 and subsequently suppressing the accumulation of Snail, which may contribute to the suppression of EMT and the prevention of tumour recurrence and metastasis. In conclusion, the results of the present study demonstrated that Plasmodium infection inhibited the recurrence and metastasis and improved the prognosis of HCC by suppressing CCR10­mediated PI3K/Akt/GSK­3ß/Snail signalling and preventing the EMT. These results may be important for the development of novel therapies for HCC recurrence and metastasis, especially for patients in the perioperative period.

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BACKGROUND: The Salsola kali (S. kali) pollen is one of the most important causes of allergic rhinitis in the deserts and semi-desert areas. Immunotherapy with allergen extracts remains the only available treatment addressing the underlying mechanism of allergy. However, given the low efficacy of this method, it is necessary to find more effective and alternative therapeutic interventions using molecular biology and bioinformatics tools. In this study, a hypoallergenic vaccine was designed on the basis of B-cell epitope approach for S. kali immunotherapy. METHODS: Using the Immune Epitope Database (IEDB), a 35-mer peptide was selected and chemically conjugated to a keyhole limpet hemocyanin (KLH) molecule. Specific IgG and IgE from immunized BALB/c mice sera against the vaccine (Sal k 1-KLH), S. kali extract and the recombinant protein, rSal k 1, were measured using ELISA. Also, inhibition of IgE by mouse IgG was evaluated using an inhibitory ELISA. Finally, the IgE reactivity and T-cell reactivity of the designed vaccine were evaluated by dot blot assay and MTT assay. RESULTS: Vaccination with the vaccine produced high levels of protective IgG in mice, which inhibited the binding of patients IgE to recombinant proteins. The result showed that the designed vaccine, unlike the recombinant protein and extract, did not induce T-cell lymphocytes response and also exhibited decreased IgE reactivity. CONCLUSION: The designed vaccine can be considered as a promising candidate for therapeutic allergen-specific immunotherapy.

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AIM: House dust mite (HDM) allergens are important elicitors of IgE-mediated allergies. This study was aimed at constructing and characterizing a recombinant fusion protein, DpTTDp, which was based on carrier-bound Der p 1-derived peptides for HDM allergen immunotherapy. METHODS: Using the Immune Epitope Database (IEDB), we identified from Der p 1, a 34-mer hypoallergenic peptide. Two copies of the hypoallergen were then fused to a partial fragment of a tetanus toxoid molecule's N-and C terminus and expressed in Escherichia coli. After purification to homogeneity, the protein was evaluated for allergenicity and its ability to induce blocking antibodies upon immunization. RESULTS: Upon immunization of mice, DpTTDp induced high levels of protective IgG-antibodies that blocked allergic patients' IgE reactivity to HDM. In addition, DpTTDp lacked relevant IgE-reactivity, induced low T-cell proliferation and IFN-γ in peripheral blood mononuclear cells of HDM-allergic patients' sera. CONCLUSION: The protein represents a promising HDM-allergy immunotherapy candidate vaccine.

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House dust mite (HDM) allergy is the leading cause of IgE-mediated hypersensitivity. Therefore identifying potential epitopes in the Dermatophagoide pteronyssinus 23 (Der p 23), a major house dust mite allergen will aid in the development of therapeutic vaccines and diagnostic kits for HDM allergy. Experimental methods of epitope discovery have been widely exploited for the mapping of potential allergens. This study sought to use immunoinformatic methods to analyze the structure of Der p 23 for potential immunoreactive B and T-cell epitopes that could be useful for AIT and allergy diagnosis. We retrieved a Der p 23 allergen sequence from Genbank database and then analyzed it using a combination of web-based sequence analysis tools including the Immune Epitope Database (IEDB), Protparam, BCPREDS, ABCpred, BepiPred, Bcepred among others to predict the physiochemical properties and epitope spectra of the Der p 23 allergen. We then built 3D models of the predicted B-cell epitopes, T cell epitopes and Der p 23 for sequence structure homology analysis. Our results identified peptides 'TRWNEDE', 'TVHPTTTEQPDDK', and 'NDDDPTT' as immunogenic linear B-cell epitopes while 'CPSRFGYFADPKDPH' and 'CPGNTRWNEDEETCT' were found to be the most suitable T-cell epitopes that interacted well with a large number of MHC II alleles. Both epitopes had high population coverage as well as showing a 100% conservancy. These five Der p 23 epitopes are useful for AIT vaccines and HDM allergy diagnosis development.

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More than 25% of the global population has IgE mediated allergic diseases. Allergen immunotherapy (AIT) is the only available form of treatment that alters the underlying mechanism of IgE-mediated allergic diseases. AIT is aimed at desensitizing allergic individuals by repeatedly administering disease-causing allergens over a long period of time. Despite its proven efficacy in numerous clinical trials, the effectiveness of AIT still suffers some drawbacks due to the quality of allergens used and in particular the unavailability of efficient allergen delivery systems. Several studies have demonstrated that bacterial ghosts (BG) systems can be used to display and deliver antigens to their targets for the management of diseases. However, there is no report documenting the use of BG systems for immunotherapy of IgE-mediated diseases so far. Thus, in this review, we intend to discuss the potentialities of BG systems for displaying and delivering allergens for future management of IgE-mediated diseases.

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