Assessing the impact of mRNA vaccination in chronic inflammatory murine model.

The implications of administration of mRNA vaccines to individuals with chronic inflammatory diseases, including myocarditis, rheumatoid arthritis (RA), and inflammatory bowel disease (IBD), are unclear. We investigated mRNA vaccine effects in a chronic inflammation mouse model implanted with an LPS pump, focusing on toxicity and immunogenicity. Under chronic inflammation, mRNA vaccines exacerbated cardiac damage and myocarditis, inducing mild heart inflammation with heightened pro-inflammatory cytokine production and inflammatory cell infiltration in the heart. Concurrently, significant muscle damage occurred, with disturbances in mitochondrial fusion and fission factors signaling impaired muscle repair. However, chronic inflammation did not adversely affect muscles at the vaccination site or humoral immune responses; nevertheless, it partially reduced the cell-mediated immune response, particularly T-cell activation. These findings underscore the importance of addressing mRNA vaccine toxicity and immunogenicity in the context of chronic inflammation, ensuring their safe and effective utilization, particularly among vulnerable populations with immune-mediated inflammatory diseases.

Single-stranded DNA aptamer that specifically binds to the influenza virus NS1 protein suppresses interferon antagonism.

Non-structural protein 1 (NS1) of the influenza A virus (IAV) inhibits the host's innate immune response by suppressing the induction of interferons (IFNs). Therefore, blocking NS1 activity can be a potential strategy in the development of antiviral agents against IAV infection. In the present study, we selected a single-stranded DNA aptamer specific to the IAV NS1 protein after 15 cycles of systematic evolution of ligands by exponential enrichment (SELEX) procedure and examined the ability of the selected aptamer to inhibit the function of NS1. The selected aptamer binds to NS1 with a Kd of 18.91±3.95nM and RNA binding domain of NS1 is determined to be critical for the aptamer binding. The aptamer has a G-rich sequence in the random sequence region and forms a G-quadruplex structure. The localization of the aptamer bound to NS1 in cells was determined by confocal images, and flow cytometry analysis further demonstrated that the selected aptamer binds specifically to NS1. In addition, luciferase reporter gene assay, quantitative RT-PCR, and enzyme-linked immunosorbent assay (ELISA) experiments demonstrated that the selected aptamer had the ability to induce IFN-ß by suppressing the function of NS1. Importantly, we also found that the selected aptamer was able to inhibit the viral replication without affecting cell viability. These results indicate that the selected ssDNA aptamer has strong potential to be further developed as a therapeutic agent against IAV.

Novel system for detecting SARS coronavirus nucleocapsid protein using an ssDNA aptamer.

The outbreak of severe acute respiratory syndrome (SARS) in 2002 affected thousands of people and an efficient diagnostic system is needed for accurate detection of SARS coronavirus (SARS CoV) to prevent or limit future outbreaks. Of the several SARS CoV structural proteins, the nucleocapsid protein has been shown to be a good diagnostic marker. In this study, an ssDNA aptamer that specifically binds to SARS CoV nucleocapsid protein was isolated from a DNA library containing 45-nuceotide random sequences in the middle of an 88mer single-stranded DNA. After twelve cycles of systematic evolution of ligands by exponential enrichment (SELEX) procedure, 15 ssDNA aptamers were identified. Enzyme-linked immunosorbent assay (ELISA) analysis was then used to identify the aptamer with the highest binding affinity to the SARS CoV nucleocapsid protein. Using this approach, an ssDNA aptamer that binds to the nucleocapsid protein with a K(d) of 4.93±0.30nM was identified. Western blot analysis further demonstrated that this ssDNA aptamer could be used to efficiently detect the SARS CoV nucleocapsid protein when compared with a nucleocapsid antibody. Therefore, we believe that the selected ssDNA aptamer may be a good alternative detection probe for the rapid and sensitive detection of SARS.

Enhanced production of red blood cells in suspension by electrostatic interactions with culture plates.

Enucleation of erythroblasts, a critical step in the generation of red blood cells (RBCs), occurs at a low rate without cocultured stromal cells. Previously, the surface properties of the cell culture plate were not considered in the enucleation process, because the cells exist in suspension. Here, we show that a significantly higher rate of enucleation of erythroblasts occurred on the positively charged plates than on the negatively charged surfaces or the both negatively and positively charged plates. Also, the negatively and positively charged plate group showed a significantly higher enucleation than did the hydrophobic plates. Therefore, the plates fully coated with amine groups generated 1.88 times more enucleated RBCs than did the hydrophobic plates. This study suggests an important insight into the effect of surface characteristics of cell culture plates on suspension cell culture. Further, this simple and inexpensive procedure could contribute to a more efficient RBC production system, eliminating the need for robust and expensive coculture procedures.