Th17 Lymphocytes in Children with Asthma: Do They Influence Control?

Evidence evaluated by European Food Safety Authority does not support lowering the temporary tolerable daily intake for bisphenol A

The European Food Safety Authority (EFSA) recently derived a tolerable daily intake (TDI) for bisphenol A (BPA) of 0.2 ng/kg bw/day. There are several issues with EFSA's hazard assessment review process, including that it was based on a limited subset of relevant studies. Multiple public commenters on EFSA's draft evaluation of BPA, including several European regulatory agencies, noted these issues, yet they were not adequately addressed by EFSA in the final evaluation. The TDI for BPA was based on an intermediate immunotoxicity endpoint in mice that has not been observed in other species; there is no evidence that it is a precursor event to any downstream pathological outcome. The TDI is several orders of magnitude lower than estimates of safe doses of BPA established by agencies worldwide, including EFSA's temporary TDI (t-TDI) for BPA established in 2015. Overall, the EFSA hazard assessment review process has led to a conclusion that there are low-dose effects of BPA based on very few, lower quality experimental animal studies. This conclusion is not supported by the totality of the available evidence, which includes multiple high-quality studies not considered by EFSA and indicates that the t-TDI established in 2015 is protective of human health.

Maternal antibiotic exposure enhances ILC2 activation in neonates via downregulation of IFN1 signaling

Microbiota have an important function in shaping and priming neonatal immunity, although the cellular and molecular mechanisms underlying these effects remain obscure. Here we report that prenatal antibiotic exposure causes significant elevation of group 2 innate lymphoid cells (ILC2s) in neonatal lungs, in both cell numbers and functionality. Downregulation of type 1 interferon signaling in ILC2s due to diminished production of microbiota-derived butyrate represents the underlying mechanism. Mice lacking butyrate receptor GPR41 (Gpr41-/-) or type 1 interferon receptor IFNAR1 (Ifnar1-/-) recapitulate the phenotype of neonatal ILC2s upon maternal antibiotic exposure. Furthermore, prenatal antibiotic exposure induces epigenetic changes in ILC2s and has a long-lasting deteriorative effect on allergic airway inflammation in adult offspring. Prenatal supplementation of butyrate ameliorates airway inflammation in adult mice born to antibiotic-exposed dams. These observations demonstrate an essential role for the microbiota in the control of type 2 innate immunity at the neonatal stage, which suggests a therapeutic window for treating asthma in early life.