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A7414 - Novel Oligonucleotide Therapy Alters the Lung Transcriptome in a House Dust Mite (HDM), Cyclic DiGMP Mouse Model of Severe, Corticosteroid-Resistant Asthma
Author Block: W. T. Gerthoffer1, S. C. Ramelli2, J. Bell3, R. Barrington4, J. Sparks5, M. Matar6; 1Pharmacology, Univ of Nevada, Reno, Reno, NV, United States, 2Critical Care Medicine, NIH, Bethesda, MD, United States, 3Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, United States, 4Microbiology, Univ of South Alabama, Mobile, AL, United States, 5Chemistry, Celsion Corporation, Hunstville, AL, United States, 6Chemistry, Celsion Corporation, Huntsville, AL, United States.
Rationale. Current antiinflammatory therapies of asthma effectively control signs of asthma in most patients with Type-2 inflammation. However, effective therapies have not been developed to control asthma signs in severe, steroid-resistant asthmatics, some of whom are Th2 low, Th17 high. Furthermore, no current therapies reverse airway remodeling in any asthma subtype. To address this lack of knowledge, novel oligonucleotide therapy was designed to inhibit translation of pro-inflammatory and pro-remodeling proteins in a mouse model of severe, corticosteroid-resistant asthma that combines house dust mite allergens plus the mucosal adjuvant, cyclic diGMP.
Methods. Allergic inflammation was elicited in female BALB/c mice by sensitization and repeated challenge with HDM extract plus cyclic di-GMP according to Raundahl et al., J. Clin. Invest. 2015; 125(8): 3037. At the end of a 38 day protocol whole lung RNA-seq analysis was conducted. Sequencing data were analyzed using a pipeline comprised of HISAT2 for mapping reads to the mouse genome, htseq-count and DESeq2 for differential expression. Gene Set Enrichment Analysis (GSEA, Broad Institute) was then used for pathway analysis of differentially expressed transcripts.
Results. HDM sensitized mice expressed elevated levels of Th2 high markers (Clca1, SerpinB2, Periostin and IL-13) when compared to nonsensitized mice. Mice sensitized with HDM plus cyclic di-GMP expressed elevated levels of Th17 high markers (IL17a, Rorc, Ccl20, IL23r) and somewhat lower levels of Th2 markers compared to HDM-sensitized mice. Dexamethasone (3 mg/kg, i.p. reduced lung inflammation in mice sensitized with HDM alone, but was less effective in mice sensitized with HDM plus cyclic di-GMP. Using the steroid-resistant HDM plus cyclic di-GMP model we also tested the efficacy of a miR-155-5p antisense oligonucleotide (a 15 nt LNA/DNA mixmer) delivered intravenously complexed with cationic lipid nanoparticles. In a rescue protocol antimiR-155 partially reversed inflammatory cell levels in bronchiolar lavage fluid and in lung tissue. Smooth muscle actin immunostaining was also reduced, suggesting a beneficial effect on remodeling. AntimiR-155 treatment reduced expression of gene sets that regulate immune cell differentiation, downregulated genes regulating translation and upregulated expression of DNA repair genes
Conclusion. Intravenously administered anitimiR-155 complexed to a lipid nanoparticle carrier partially reverses both lung inflammation and airway remodeling in a severe, corticosteroid-resistant asthma model. The impact of our studies derive from establishing the molecular targets of a new class of anti-inflammatory drugs that could become effective therapy for poorly controlled, steroid-resistant asthma.