The Schistosoma mansoni T2 ribonuclease omega-1 modulates inflammasome-dependent IL-1β secretion in macrophages

The T2 ribonuclease omega-1 is a powerful Th2-inducing factor secreted by the eggs of the blood fluke Schistosoma mansoni. Omega-1 can modulate pattern recognition receptor-induced inflammatory signatures and alter antigen presentation by dendritic cells:Recent findings have suggested that component(s) contained in or secreted by S. mansoni eggs (soluble egg antigen) can also enhance IL-1 beta secretion by dendritic cells stimulated with pattern recognition receptor ligands. Here we show that omega-1 enhances IL-1 beta secretion in macrophages stimulated with Toll-like receptor 2 ligand, and propose omega-1 as the factor in soluble egg antigen capable of regulating inflammasome activity. This effect is dependent on the C-type lectin receptor Dectin-1, caspase-8 and the ASC inflammasome adaptor protein, highlighting the ability of omega-1 to regulate multiple pattern recognition receptor signalling pathways. These mechanistic insights into manipulation of host immunity by a parasite product have implications for the design of anti-inflammatory therapeutic drugs. (C) 2015 Published by Elsevier Ltd. on behalf of Australian Society for Parasitology Inc.