Quantum dots and mouse strain influence house dust mite-induced allergic airway disease

Quantum dot nanoparticles (QDs) are engineered nanomaterials (ENMs) that have utility in many industries due to unique optical properties not available in small molecules or bulk materials. QD-induced acute lung inflammation and toxicity in rodent models raise concerns about potential human health risks. Recent studies have also shown that some ENMs can exacerbate allergic airway disease (AAD). In this study, C57BL/6J and A/J mice were exposed to saline, house dust mite (HDM), or a combination of HDM and QDs on day 1 of the sensitization protocol. Mice were then challenged on days 8, 9 and 10 with HDM or saline only. Significant differences in cellular and molecular markers of AAD induced by both HDM and HDM + QD were observed between C57BL/6J and A/J mice. Among A/J mice, HDM + QD co-exposure, but not HDM exposure alone, significantly increased levels of bronchoalveolar lavage fluid (BALF). IL-33 compared to saline controls. BALF total protein levels in both mouse strains were also only significantly increased by HDM + QD co-exposure. In addition, A/J mice had significantly more lung type 2 innate lymphoid cells (ILC2s) cells than C57BL/6J mice. A/J lung ILC2s were inversely correlated with lung glutathione and MHC-IIhigh resident macrophages, and positively correlated with MHC-IIlow resident macrophages. The results from this study suggest that 1) QDs influence HDM-induced AAD by potentiating and/or enhancing select cytokine production; 2) that genetic background modulates the impact of QDs on HDM sensitization; and 3) that potential ILC2 contributions to HDM induced AAD are also likely to be modulated by genetic background.