Upon inflammation, blood cells transfer genetic information to Purkinje neurons.
Although initially characterized as an organ with an immune privileged state, the brain does intimately interact with the immune system, particularly in response to systemic inflammation. Strong evidence for a direct transfer of functional RNA between blood and brain comes from transgenic mice expressing Cre recombinase specifically in the hematopoietic lineage displaying numerous recombined Purkinje neurons in response to inflammation. This transfer from blood to neurons is mediated by extracellular vesicles of hematopoietic origin containing Cre RNA leading to reporter gene expression in recipient cells. Recombined neurons show changes in their microRNA profile, further indicating a previously unrecognized RNA-based communication between the hematopoietic system and various organs, including the brain, in response to inflammation. See Ridder et al.
Image Credit: Kirsten Ridder