An in-vivo brain-bacteria interface in the Xenopus brainless model reveals developmental brain as a key element of innate immunity

Over the past few years, interest in the field of neuroimmunology has expanded dramatically. While recent data and hypotheses suggest immunity as the 'seventh sense' to inform brain about microorganisms, the role of the brain to protect against infection is unknown. We demonstrate here that the brain signaling is an essential part of the innate immunity. In absence of a brain, survival rates of embryos injected with pathogenic E.coli decreased significantly. This effect was not due to actions of brain on immune cells or on early development of the immune system, but it is dynamically induced by the bacterial infection. Sub-network analysis revealed potential genes and signaling pathways mediating the protective effects of the brain. Taken together, these data identify a new protective role for the developmental brain and reveal revealed a number of regulated transcripts, including those pathways that represent novel targets for immune therapies Overall design: There were two biological replicates per treatment (brain intact, not infected; brain intact infected; brainless, not infected; brainless, infected).