Immune Cells Are DifferentiallyAffected by SARS-CoV-2 Viral Loads in K18-hACE2 Mice

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Laboratory information management system for COVID-19 non-clinical efficacy trial data / 한국실험동물학회지

Background@#As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research. @*Results@#In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research. @*Conclusions@#This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.

Combinatorial Antitumor Activity of Oxaliplatin with Epigenetic Modifying Agents, 5-Aza-CdR and FK228, in Human Gastric Cancer Cells

Epigenetic silencing is considered to be a major mechanism for loss of activity in tumor suppressors. Reversal of epigenetic silencing by using inhibitors of DNA methyltransferase (DNMT) or histone deacetylases (HDACs) such as 5-Aza-CdR and FK228 has shown to enhance cytotoxic activities of several anticancer agents. This study aims to assess the combinatorial effects of gene-silencing reversal agents (5-Aza-CdR and FK228) and oxaliplatin in gastric cancer cells, i.e., Epstein-Barr virus (EBV)-negative SNU-638 and EBV-positive SNU-719 cells. The doublet combinatorial treatment of 5-Aza-CdR and FK228 exhibited synergistic effects in both cell lines, and this was further corroborated by Zta expression induction in SNU-719 cells. Three drug combinations as 5-Aza-CdR/FK228 followed by oxaliplatin, however, resulted in antagonistic effects in both cell lines. Simultaneous treatment with FK228 and oxaliplatin induced synergistic and additive effects in SNU-638 and SNU-719 cells, respectively. Three drug combinations as 5-Aza-CdR prior to FK228/oxaliplatin, however, again resulted in antagonistic effects in both cell lines. This work demonstrated that efficacy of doublet synergistic combination using DNMT or HDACs inhibitors can be compromised by adding the third drug in pre- or post-treatment approach in gastric cancer cells. This implies that the development of clinical trial protocols for triplet combinations using gene-silencing reversal agents should be carefully evaluated in light of their potential antagonistic effects.

Lack of Association between Epstein-Barr Virus and Epithelial Malignancies Developed after Kidney Transplantation / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Organ transplant recipients are at high risk of developing malignancies due to immunosuppressive regimens. Unlike post-transplant lymphoproliferative diseases (PTLDs), where Epstein-Barr virus (EBV) plays an etiological role, there are conflicting data regarding the association of EBV with post-transplant epithelial malignancies. In order to clarify the role of EBV in carcinomas that develop after solid-organ transplantation, the presence of EBV infection in the carcinomas of post-kidney transplant patients was examined. MATERIALS AND METHODS: The presence of EBV infection in skin carcinoma (PTSC), gastric carcinoma (PTGC) and urothelial carcinoma (PTUC), which developed in the patients under an immune suppression regime following kidney transplantation, was examined. Tumors from the patients without organ transplantation were also used as a comparison in the study. The study group included five nasopharyngeal carcinomas (NPCs), one Hodgkin's disease (HD), one B-cell non-Hodgkin's malignant lymphoma (NHL) and one hypopharynx (HPC) tumor. RESULTS: Immunofluorescence assay and Western blot analysis, using sera from the same patients, confirmed that all of the tested patients were previously infected with EBV. From in situ hybridization, no EBER positive cells were detected in any of the tumor tissues obtained from the three kidney transplant recipients (PTSC, PTGC and PTUC) or in the NHL and HPC tissues. In contrast, all five of the NPC and HD tissues showed strong EBER positivity. CONCLUSION: These results suggest that there is a strong association of EBV with NPC and HD as previously reported, while no such strong association of EBV was found with epithelial malignancies that developed after kidney transplantation.