Horizontal gene transfer in pathogenic bacteria shapes progressive multiple sclerosis
Research identifies a specific strain of Tyzzerella nexilis enriched in secondary progressive MS that carries numerous mobile genetic elements and lacks defence mechanisms against them. In germ-free mice, colonisation with this strain increases susceptibility to experimental autoimmune encephalomyelitis through TLR5 stimulation by flagella and production of neuroactive reduced sulphur compounds, suggesting horizontal gene transfer may drive MS progression via gut microbiome alterations.