3582 Scavenger Receptor Expression is Differentially Affected by DNAzyme-Gold Nanoparticle Conjugates

Abstract

OBJECTIVES/SPECIFIC AIMS: Scavenger receptor (SR) surface proteins are highly conserved motifs and are implicated in the uptake of nanotherapies. Gold nanoparticles functionalized with DNAzymes (DzNP) represent a promising novel nanotherapy for lung diseases such as asthma, particularly because they can be delivered directly to the lung. Our lab has been studying the therapeutic potential of a DzNP targeting GATA-3, a master transcription factor regulating Th2 inflammation. Although nanoparticle uptake through scavenger receptors has been described in macrophages in other models, the role of SRs in DzNP uptake in the lung is poorly understood. We hypothesize that scavenger receptors mediate DzNP uptake in alveolar macrophages. To begin examining this hypothesis, we examined whether DzNP exposure and uptake regulates gene expression of MARCO and MSR1, two class A scavenger receptors. METHODS/STUDY POPULATION: Using a silver stain, we measured dose dependent DzNP uptake in murine alveolar macrophages (MH-S). Using qRT-PCR, we measured gene expression of scavenger receptors MSR1 and MARCO in murine alveolar macrophages (MH-S) and after 24 hour exposure to 2251 DzNP, a DzNP targeting GATA-3, and dextran sulfate sodium (DSS), a known SR-A blocker. RESULTS/ANTICIPATED RESULTS: 2251 DzNP uptake in alveolar macrophages is dose dependent. MARCO gene expression levels significantly increase in murine alveolar macrophages when cultured with increasing concentrations of 2251 DzNP (10 pM-2 nM) or DSS 25-200 ug/ml) for 24 hours. However, MSR1 gene expression levels have minimal change when exposed to low concentrations of 2251 DzNP and DSS. At higher concentrations of 2251 DzNP and DSS, MSR1 expression levels are decreased. DISCUSSION/SIGNIFICANCE OF IMPACT: Alveolar macrophages exhibit a dose dependent increase in MARCO gene expression levels with increasing concentrations of 2251 DzNP and DSS, but MSR1 gene expression is not affected in a similar fashion. 2251 DzNP-induced increases in MARCO gene expression suggests that 2251 DzNP may facilitate its own uptake through MARCO. 2251 DzNP exposure negatively regulates MSR1 expression at higher doses and suggests that 2251 DzNP may inhibit its own uptake thought MSR1.