Trimannose-coupled antimiR-21 for macrophage-targeted inhalation treatment of acute inflammatory lung damage [scRNA-seq]

Recent studies of severe acute inflammatory lung disease including COVID-19 have identified macrophages to drive pulmonary hyperinflammation and long-term damage such as fibrosis. Here, we report on the development of a first-in-class, carbohydrate-coupled inhibitor of microRNA-21 (RCS-21), as a therapeutic means against pulmonary hyperinflammation and fibrosis. MicroRNA-21 was among the strongest upregulated microRNAs in COVID-19 and in mice with acute inflammatory lung damage and was the strongest expressed microRNA in pulmonary macrophages. Chemical linkage of an oligonucleotide inhibitor of microRNA-21 to trimannose achieved rapid and specific delivery to macrophages upon inhalation in mice. RCS-21 reversed pathological activation of macrophages and prevented pulmonary dysfunction and fibrosis after acute lung damage in mice. In human lung tissue infected with SARS-CoV-2 ex vivo, RCS-21 effectively prevented the exaggerated inflammatory response. Our data imply trimannose-coupling for effective and selective delivery of inhaled oligonucleotides to pulmonary macrophages and report on a first mannose-coupled candidate therapeutic for COVID-19. Overall design: Here, we carried out Single cell sequencing on primary lung cells isolated from RCS-21 and control-treated mice 14 days after bleomycin. Wild type mice were subjected to acute lung injury by bleomycin, and a single inhaled dose of RCS-21 or control oligo was administered using a nebulizer at 4 days after injury. 10 days later lungs were harvested, digested and the pulmonary cells were sorted into leukocytes and non-leukocytes using magnetic activated cell sorting. Cells were multiplexed from three different animals in each group and the proportion of CD45+ cells were reduced to 50% to avoid oversampling