Enhanced efficacy of glycoengineered rice cell-produced trastuzumab.

For several decades, a plant-based expression system has been proposed as an alternative platform for the production of biopharmaceuticals including therapeutic monoclonal antibodies (mAbs), but the immunogenicity concerns associated with plant-specific N-glycans attached in plant-based biopharmaceuticals has not been completely solved. To eliminate all plant-specific N-glycan structure, eight genes involved in plant-specific N-glycosylation were mutated in rice (Oryza sativa) using the CRISPR/Cas9 system. The glycoengineered cell lines, PhytoRice®, contained a predominant GnGn (G0) glycoform. The gene for codon-optimized trastuzumab (TMab) was then introduced into PhytoRice® through Agrobacterium co-cultivation. Selected cell lines were suspension cultured, and TMab secreted from cells was purified from the cultured media. The amino acid sequence of the TMab produced by PhytoRice® (P-TMab) was identical to that of TMab. The inhibitory effect of P-TMab on the proliferation of the BT-474 cancer cell line was significantly enhanced at concentrations above 1 µg/mL (****P < 0.0001). P-TMab bound to a FcγRIIIa variant, FcγRIIIa-F158, more than 2.7 times more effectively than TMab. The ADCC efficacy of P-TMab against Jurkat cells was 2.6 times higher than that of TMab in an in vitro ADCC assay. Furthermore, P-TMab demonstrated efficient tumour uptake with less liver uptake compared to TMab in a xenograft assay using the BT-474 mouse model. These results suggest that the glycoengineered PhytoRice® could be an alternative platform for mAb production compared to current CHO cells, and P-TMab has a novel and enhanced efficacy compared to TMab.

Production of Plant-Derived Japanese Encephalitis Virus Multi-Epitope Peptide in Nicotiana benthamiana and Immunological Response in Mice.

The current production of the Japanese encephalitis virus (JEV) vaccine is based on animal cells, where various risk factors for human health should be resolved. This study used a transient expression system to express the chimeric protein composed of antigenic epitopes from the JEV envelope (E) protein in Nicotiana benthamiana. JEV multi-epitope peptide (MEP) sequences fused with FLAG-tag or 6× His-tag at the C- or N-terminus for the purification were introduced into plant expression vectors and used for transient expression. Among the constructs, vector pSK480, which expresses MEP fused with a FLAG-tag at the C-terminus, showed the highest level of expression and yield in purification. Optimization of transient expression procedures further improved the target protein yield. The purified MEP protein was applied to an ICR mouse and successfully induced an antibody against JEV, which demonstrates the potential of the plant-produced JEV MEP as an alternative vaccine candidate.

Prognostic Significance of the Severity of Immune-Related Adverse Events in Advanced Cancer Patients Treated with PD-1/PD-L1 Inhibitors: A Real-World Data Analysis.

BACKGROUND: There is limited evidence regarding immune-related adverse events (irAEs) in Asian cancer patients treated with antibodies directed against programmed cell death-1 (PD-1) or programmed cell death-ligand 1 (PD-L1). OBJECTIVE: This study aimed to investigate the clinical patterns and prognostic significance of grade 1-2 and grade ≥ 3 irAEs by PD-1/PD-L1 inhibitors in cancer patients using real-world clinical data. PATIENTS AND METHODS: We conducted a retrospective study of cancer patients who received pembrolizumab, nivolumab, or atezolizumab at a tertiary hospital in South Korea. Incidence, time to onset, and grade 1-2 and grade ≥ 3 irAE risk factors were analyzed from medical records. The association of irAE severity with progression-free survival (PFS) and prognostic factors for PFS were evaluated. RESULTS: Among a total of 431 patients, irAEs occurred in 45.2%, and 9.5% were grade ≥ 3 irAEs. There were no significant differences in the median time to onset based on severity. Risk factors for the development of grade ≥ 3 irAEs were the presence of autoimmune disorders or diabetes mellitus. The median PFS was significantly different at 13.20, 9.00 and 4.17 months for the grade 1-2, grade ≥ 3, and no irAE groups, respectively. An increase in administration cycles was associated with a reduced risk of progression in patients with grade 1-2 and grade ≥ 3 irAEs. CONCLUSIONS: The development of grade ≥ 3 irAEs was affected by comorbidities and associated with improved PFS compared with those without irAEs. Our findings identified the real-world epidemiology, risk factors, and prognostic significance of irAEs, which may guide treatment decisions of PD-1/PD-L1 inhibitors.

The Moderating Role of COVID-19 Perceived Risk between Health Concern and Psychological Well-Being of Active Senior Campers Using PROCESS Macro Model.

This study attempts to contribute to improving the life of the elderly by empirically analyzing the factors affecting the psychological well-being of active seniors in the 'With COVID-19' era. To this end, the relationship between psychological well-being, health concern, and perceived risk of COVID-19 was verified for active seniors in Korea who enjoy camping. Two hundred and sixty-four valid questionnaires collected from active senior participants of "The Korea Camping Fair 2022" held in EXCO, Daegu, Korea, from 29 April to 1 May 2022, were analyzed. The main results were as follows. The health and psychological well-being of active seniors were higher than the normal level, and the perceived risk of COVID-19 was lower than the normal level. It was found that the health of active seniors had a positive effect on their psychological well-being. The perceived risk of COVID-19 was found to moderate the effect of health concern on psychological well-being. In conclusion, in order to improve the psychological well-being of active seniors, active leisure activities of the elderly are essential even in the COVID-19 situation, and various measures are needed to increase health. Not only this, but also, importantly, accurate information sharing on COVID-19 should be premised.

Will Perceived Risk of COVID-19 Move Exhibition Visitors from On-Site to Virtual? Focusing on Exhibition Quarantine Service Quality and Switching Intention.

COVID-19 has shifted people's activities from the real world to the virtual world in many fields, such as conferences, shopping, education, and more. In the field of MICE, however, exhibitions have been held steadily since the second half of 2020 in the form of on-site exhibitions. The exhibition organizers and related authorities have tried to attract exhibitors and visitors to the exhibition hall by providing exhibition quarantine services. Moreover, despite various perceived risks during the COVID-19 period, exhibition visitors continue to visit the exhibition. This study, therefore, paid attention to the psychological factors of visitors who consistently visit on-site exhibitions even during the pandemic. In addition to the perceived risks, this study tried to examine the quality of exhibition quarantine services and switching intention of visitors, and to analyze the relationships between them. A survey of 167 people who visited the camping exhibition and well-food exhibition held in June 2021 found that they would not visit the exhibition due to the functional and financial risk of the exhibition rather than the risk of the virus. On the other hand, it was found that visitors who felt the social risk of COVID-19 valued the quality of exhibition quarantine service. Furthermore, the study found that the quarantine service quality lowered switching intention. Therefore, the study suggests that exhibition organizers should think about ways to strengthen the most essential characteristics of on-site exhibitions along with appropriate quarantine measures to induce steady visits even during the pandemic.

How Will Video Conference Fatigue Affect Participants of MICE in the With-COVID-19 Era? Focusing on Video Conference Quality, Social Presence Theory, and Flow.

Is our mental health at risk due to spending a significant amount of time online due to the COVID-19 pandemic? In the new era that we are living in, where we live a life that coexists with the virus, we are participating in video conferences held online rather than on-site in order to slow the spread of the virus. Video conferencing has become our necessity since March 2020, and is becoming a new standard, especially in the MICE industry. Recently, however, people who have excessively used video conference platforms are complaining of video conference fatigue, which is a new negative emotion such as stress, anxiety, and worry as well as general work fatigue. Therefore, this study focused on the mechanism of video conferencing in MICE, which is rapidly digitally converted by the virus, and the digital psychological factors of the participants. This study derived the quality attributes of video conferencing in MICE and empirically analyzed the relationship with digital psychological factors of the video conference participants, such as video conference fatigue, social presence, and flow. One hundred and thirty-eight valid questionnaires collected from participants of several international academic conferences held in EXCO, Daegu, Korea, from 23 to 28 May 2021, were analyzed. The main results are as follows. First, unlike general video conference fatigue, MICE video conference fatigue was not found to be related to the preceding and following variables. This is due to the characteristics of the MICE video conference and the expertise of the participants. Second, social presence was identified as an important variable in MICE video conferencing. Although media-mediated, the feeling of being present with the presenter and participants was found to affect the participants' flow in the video conference. Third, in this study, the fun factor was identified as the most important video conference quality that can enhance the social presence of the video conference participants of MICEs.

Inactivation of the ß (1, 2)-xylosyltransferase and the α (1, 3)-fucosyltransferase gene in rice (Oryza sativa) by multiplex CRISPR/Cas9 strategy.

KEY MESSAGE: CRISPR/Cas9-mediated OsXylT and OsFucT mutation caused the elimination of plant-specific ß1,2-xylose and α1,3-fucose residues on glycoproteins in rice, which is the first report of OsXylT/OsFucT double KO mutation in rice. N-glycosylation pathway is the one of post-translational mechanism and is known as highly conserved in eukaryotes. However, the process for complex-N-glycan modification is different between mammals and plants. In plant-specific manner, ß1,2-xylose and α1,3-fucose residues are transferred to N-glycan core structure on glycoproteins by ß1,2-xylosyltransferase (ß1,2-XylT) and α1,3-fucosyltransferase (α1,3-FucT), respectively. As an effort to use plants as a platform to produce biopharmaceuticals, the plant-specific N-glycan genes of rice (Oryza sativa), ß1,2-xylT (OsXylT) and α1,3-FucT (OsFucT), were knocked out using multiplex CRISPR/Cas9 technology. The double knock-out lines were found to have frameshift mutations by INDELs. Both ß1,2-xylose and α1,3-fucose residues in the lines were not detected in Western blot analysis. Consistently, there was no peak corresponding to the N-glycans in MALDI-TOF/MS analysis. Although α1,3-fucose and ß1,2-xylose residues were not detected in the line, other plant-specific residues of ß1,3-galactose and α1,4-fucose were detected. Thus, we suggest that each enzymes working on the process for complex N-glycan biosynthesis might independently act in rice, hence the double knock-out of both OsXylT and OsFucT might be not enough to humanize N-glycan structure in rice.