Prof Luke O’Neill delivered the inaugural lecture at the RCSI Research Seminar Series

Prof Luke O’Neill delivered the inaugural lecture at the RCSI Research Seminar Series yesterday. Luke O’Neill is the professor of Biochemistry and Immunology at Trinity College Dublin. Luke is a world-renowned scientist known for his contributions to the field of Immunology, more specifically Toll-like receptors, innate immune signaling, cytokines and most recently Immunometabolism. He is one of Ireland’s most influential scientists having published >300 publications and is in the top 1% of the world’s most cited scientists in Immunology. He is the recipient of many prestigious awards including the Boyle Medal for Scientific Excellence and last year was elected a Fellow of the Royal Society.

Luke told us many exciting stories. The first highlighted how the inflammasome sensor NLRP3 is critical for the production of the pro-inflammatory cytokine IL-1. A cytokine essential for our fight against infection, but is elevated and extremely damaging in many diseases including Rheumatoid arthritis, colitis, Parkinson’s, Alzheimer’s, diabetes and hypertension. Luke’s team discovered a small molecule inhibitor against NLRP3 that has shown efficacy in 32 models of disease, as astounding effect never observed before. The inhibitor is now entering clinical trials and could excitingly pave the way as a radical treatment for many diseases.

The second story introduced the concept of Immunometabolism, a phenomenon where immune cells utilize metabolic pathways to generate inflammatory mediators. In response to infection, immune cells such as macrophages increase the production of glycolysis whilst at the same time cause a block in Kreb’s cycle. This block leads to the accumulation of intermediates such as succinate. Importantly, Luke has shown that succinate is critical for the production of IL-1 via the transcription factor HIF-1alpha. Inhibition of succinate ablates IL-1 production in response to infection, as well as in a number of disease models tested. Luke highlights that the manipulation of energy pathways could very likely provide an alternative mechanism for therapy in inflammatory disorders.

It was a real pleasure to hear Luke speak at RCSI. To learn more about the above stories, check out the following publications:

The circadian protein BMAL1 in myeloid cells is a negative regulator of allergic asthma

Asthma is of particular relevance to the area of circadian control of immunity, since it is a disease with very strong clinical evidence demonstrating regulation by circadian variation. Airway hypersensitivity and asthma attacks are more common at night in humans. The molecular basis for this is unknown and no model of asthma in animals with genetic distortion of the molecular clock exists.

Asthma is under strong circadian variation. Asthma symptoms worsen at night, particularly in the early hours of the morning. Lung function fluctuates in healthy individuals over 24 h period and these fluctuations are even more pronounced in asthmatics.

In this study, we showed that mice lacking the main clock transcription factor BMAL1 in myeloid cells have increased lung inflammation demonstrated by higher numbers of eosinophils and increased IL-5 (key pathogenic cytokine in asthma that recruits eosinophils).This suggests that Bmal1 is a potent negative regulator, in myeloid cells in the context of allergic asthma. Our findings might explain the increase in asthma incidents during the night in humans when BMAL1 expression is low.

Dr. Zbigniew Zaslona from TCD (pictured here) was the lead author on the study. Both Dr. Annie Curtis (MCT) and Prof. Luke O’Neill (TCD) were joint senior authors on the paper.

The circadian protein BMAL1 in myeloid cells is a negative regulator of allergic asthma.

Zaslona Z, Case S, Early JO, Lalor SJ, McLoughlin RM, Curtis AM*, O’Neill LA* – Both authors contributed equally to this study.

Am J Physiol Lung Cell Mol Physiol. 2017 Mar 23:ajplung.00072.2017. doi: 10.1152/ajplung.00072.2017. [Epub ahead of print]