Development of oral CTL vaccine using a CTP-integrated Sabin 1 poliovirus-based vector system

Mucosal COVID-19 vaccines: Risks, benefits and control of the pandemic

Based on mucosal immunization to promote both mucosal and systemic immune responses, next-generation coronavirus disease 2019 (COVID-19) vaccines would be administered intranasally or orally. The goal of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines is to provide adequate immune protection and avoid severe disease and death. Mucosal vaccine candidates for COVID-19 including vector vaccines, recombinant subunit vaccines and live attenuated vaccines are under development. Furthermore, subunit protein vac-cines and virus-vectored vaccines have made substantial progress in preclinical and clinical settings, resulting in SARS-CoV-2 intranasal vaccines based on the previously successfully used nasal vaccines. Additional to their ability to trigger stable, protective immune responses at the sites of pathogenic infection, the development of 'specific' mucosal vaccines targeting coronavirus antigens could be an excellent option for preventing future pandemics. However, their efficacy and safety should be confirmed.

COVID-19 Vaccines (Revisited) and Oral-Mucosal Vector System as a Potential Vaccine Platform

There are several emerging strategies for the vaccination of COVID-19 (SARS-CoV-2) however, only a few have yet shown promising effects. Thus, choosing the right pathway and the best prophylactic options in preventing COVID-19 is still challenging at best. Approximately, more than two-hundred vaccines are being tested in different countries, and more than fifty clinical trials are currently undergoing. In this review, we have summarized the immune-based strategies for the development of COVID-19 vaccines and the different vaccine candidate platforms that are in clinical stages of evaluation, and up to the recently licensed mRNA-based COVID-19 vaccines of Pfizer-BioNtech and Moderna's. Lastly, we have briefly included the potentials of using the 'RPS-CTP vector system' for the development of a safe and effective oral mucosal COVID-19 vaccine as another vaccine platform.

CTLs相关的免疫疗法在肝癌治疗中的新前景

癌细胞内多种蛋白加工处理所产生的异常多肽通过主要组织相容性复合物Ⅰ类分子递呈, 激发肿瘤细胞毒性T淋巴细胞(cytotoxic T lymphocytes, CTLs), 从而对肿瘤产生免疫作用. 但受多因素影响, 肝癌组织中的CTLs功能受抑制或呈无功能状态, 影响其抑癌作用. 近年来, 在肝癌重新活化和增强CTLs功能的研究方面, 已取得不同程度的成果. 现就其新进展, 从强化抗原提呈及直接诱导两条途径, 作一综述.

Mechanism for cytoplasmic transduction peptide-HBcAg18-27-Tapasin to induce HBV specific CTL response in C57BL/6 mice

AIM: To observe whether the fusion protein cytoplasmic transduction peptide (CTP) -HBcAg_18-27-Tapasin can induce HBV-specific cytotoxic T lymphocyte (CTL) response in C57BL/6 mice via the JAK / STAT pathway.

METHODS: C57BL/6 mice were randomly divided into four groups: CTP-HBcAg_18-27-Tapasin alone group, CTP-HBcAg_18-27-Tapasin + AG490 group, AG490 alone group, and PBS group. Mice were immunized with the fusion protein through intramuscular injection, and AG490 was administered through intraperitoneal injection. The proliferation of T lymphocytes was observed using CCK-8 assay. The levels of the cytokines secreted by T lymphocytes were detected by ELISA, and the levels of intracellular cytokines of proliferative T lymphocytes were detected by flow cytometry. Expression levels of molecules of the JAK/STAT signal pathway were detected by real-time PCR.

RESULTS: The percentage of CD8⁺IFN-γ⁺ T cells, T lymphocytes proliferative activity and the levels of Th1 cytokines in the CTP-HBcAg_18-27-Tapasin alone group were significantly increased compared with the CTP-HBcAg_18-27-Tapasin + AG490 group (P < 0.01), although there was no statistical significance between the other groups. The expression levels of Jak2 and STAT4 were significantly higher in the CTP-HBcAg_18-27-Tapasin alone group than the rest groups (P < 0.05), and the expression levels of Tyk2 and STAT1 were also dramatically increased in the CTP-HBcAg_18-27-Tapasin alone group compared to other groups (P < 0.01).

CONCLUSION: CTP-HBcAg_18-27-Tapasin fusion protein increases HBV-specific CTL response via the JAK/STAT signal pathway in C57BL/6 mice.