Correction: mRNA-Mediated Gene Supplementation of Toll-Like Receptors as Treatment Strategy for Asthma In Vivo.

[This corrects the article DOI: 10.1371/journal.pone.0154001.]

Inflammatory cells in BALF and lung tissue.

<p>(A) Mice were treated according to the injection schedule for the HDM-induced asthma model. (B) BALF was centrifuged and cells were analyzed via differential cell count. Differences remained non-significant. Data are presented as mean ± SEM; n = 3. (C) Representative micrographs of BALF cellspin preparations are shown (scale 100 μm, magnification x200). (D) Levels of neutrophils and eosinophils in lung tissue were measured via flow cytometry. Differences remained non-significant. Data are presented as mean ± SEM; n = 3.</p

mRNA-Mediated Gene Supplementation of Toll-Like Receptors as Treatment Strategy for Asthma <i>In Vivo</i>

<div><p>Asthma is the most common chronic disease in childhood. Although several therapeutic options are currently available to control the symptoms, many drugs have significant side effects and asthma remains an incurable disease. Microbial exposure in early life reduces the risk of asthma and several studies have suggested protective effects of Toll-like receptor (TLR) activation. We showed previously that modified mRNA provides a safe and efficient therapeutic tool for <i>in vivo</i> gene supplementation. Since current asthma drugs do not take patient specific immune and TLR backgrounds into consideration, treatment with tailored mRNA could be an attractive approach to account for the patient’s individual asthma phenotype. Therefore, we investigated the effect of a preventative treatment with combinations of <i>Tlr1</i>, <i>Tlr2</i> and <i>Tlr6</i> mRNA in a House Dust Mite-induced mouse model of asthma. We used chemically modified mRNA which is–in contrast to conventional viral vectors–non-integrating and highly efficient in gene transfer. In our study, we found that treatment with either <i>Tlr1/2</i> mRNA or <i>Tlr2/6</i> mRNA, but not <i>Tlr2</i> mRNA alone, resulted in better lung function as well as reduced airway inflammation <i>in vivo</i>. The present results point to a potentially protective effect of TLR heterodimers in asthma pathogenesis.</p></div

Groups of mice and their respective treatment following the injection schedule of Fig 1A.

<p>Groups of mice and their respective treatment following the injection schedule of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154001#pone.0154001.g001" target="_blank">Fig 1A</a>.</p

Tissue reaction and lung function after <i>Tlr</i> mRNA treatment.

<p>(A) Tissue inflammation and goblet cell metaplasia were analyzed on H&E- and PAS-stained lung sections. Representative micrographs are shown (original magnification of H&E sections: x200, scale 100 μm, PAS sections: x400). (B) PAS stained lung sections were analyzed to quantify PAS⁺ cells. Data are represented as individual mice, horizontal lines state means; n = 9. (C) Airway resistance was measured in response to rising concentrations of methacholine (MCh) using the isolated, perfused and ventilated lung (IPL). Statistical analysis was separately performed for each MCh concentration, * and # are PBS vs. the respective group, § is <i>Tlr1/2</i> vs. <i>Tlr2</i>. *<i>P</i> ≤ 0.05, **<i>P</i> ≤ 0.01, and ***<i>P</i> ≤ 0.001. Statistical results for each concentration can be found in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154001#pone.0154001.s001" target="_blank">S1 Table</a>. (D) Data at 10 μM MCh are presented as Box and Whiskers blot. Medians are shown as +. Tukey’s Multiple Comparison Test **<i>P</i> < 0.01. Data are represented as means; data at 10 μM MCh are additionally stated as means ± SEM; n = 6 (<i>Tlr2</i> n = 5, <i>Tlr2/6</i> n = 4). Tabular values at 10 μM MCh (cmH2O/ml/s), values stated as “0” were excluded due to damage of the lungs.</p

mRNA-Mediated Gene Supplementation of Toll-Like Receptors as Treatment Strategy for Asthma In Vivo.

Asthma is the most common chronic disease in childhood. Although several therapeutic options are currently available to control the symptoms, many drugs have significant side effects and asthma remains an incurable disease. Microbial exposure in early life reduces the risk of asthma and several studies have suggested protective effects of Toll-like receptor (TLR) activation. We showed previously that modified mRNA provides a safe and efficient therapeutic tool for in vivo gene supplementation. Since current asthma drugs do not take patient specific immune and TLR backgrounds into consideration, treatment with tailored mRNA could be an attractive approach to account for the patient's individual asthma phenotype. Therefore, we investigated the effect of a preventative treatment with combinations of Tlr1, Tlr2 and Tlr6 mRNA in a House Dust Mite-induced mouse model of asthma. We used chemically modified mRNA which is-in contrast to conventional viral vectors-non-integrating and highly efficient in gene transfer. In our study, we found that treatment with either Tlr1/2 mRNA or Tlr2/6 mRNA, but not Tlr2 mRNA alone, resulted in better lung function as well as reduced airway inflammation in vivo. The present results point to a potentially protective effect of TLR heterodimers in asthma pathogenesis