AMRC

Background SARS-CoV-2 Omicron variants are highly resistant to vaccine-induced immunity and human monoclonal antibodies. Methods We previously reported that two nanobodies, P17 and P86, potently neutralize SARS-CoV-2 VOCs. In this study, we modified these nanobodies into trimers, called TP17 and TP86 and tested their neutralization activities against Omicron BA.1 and subvariant BA.2 using pseudovirus assays. Next, we used TP17 and TP86 nanobody cocktail to treat ACE2 transgenic mice infected with lethal dose of SARS-CoV-2 strains, original, Delta and Omicron BA.1.

Chromosomal translocation generates the MLL-AF4 fusion gene, which causes acute leukemia of multiple lineages. MLL-AF4 is a strong oncogenic driver that induces leukemia without additional mutations and is the most common cause of pediatric leukemia. However, establishment of a murine disease model via retroviral transduction has been difficult owning to a lack of understanding of its regulatory mechanisms.

We developed a diagnostic method for repeat expansion diseases using a long-read sequencer to improve currently available, low throughput diagnostic methods. We employed the real-time target enrichment system of the nanopore GridION sequencer using the adaptive sampling option, in which software-based target assignment is available without prior sample enrichment, and built an analysis pipeline that prioritized the disease-causing loci.

Significance Dendritic cells (DCs), essential for immune responses, originate from bone marrow hematopoietic stem cells via intermediate progenitors. In eukaryotic nuclei, DNA is packaged into 3D chromatin structures that have been implicated in gene regulation. However, the chromatin structure reorganization dynamics during DC differentiation remain unknown. Here, we analyzed 3D chromatin structures in DCs and their progenitors. In genomic regions at DC-specific genes, the 3D chromatin structures were reorganized upon DC differentiation. The transcription factor IRF8 promoted chromatin structure changes in DC progenitors, leading to DC-specific gene induction. Strikingly, the chromatin structures of infection-inducible genes were preestablished in unstimulated DCs. Our findings advance the understanding of DC biology and basic principles of gene regulation for cell differentiation and host defense.