Microbial and autoantibody immunogenic repertoires in TIF1? autoantibody positive dermatomyositis

Spyridon Megremis; Thomas Walker; Xiaotong He; James O'Sullivan; William E.R. Ollier; Hector Chinoy; Neil Pendleton; Antony Payton; Lynne Hampson; Ian Hampson; Janine Lamb

The identified microbial epitopes in both DM and healthy controls (HC) mapped to bacteria, viruses, fungi and archaea demonstrating the human capacity for building protection against a diverse group of species. The presence of a stably-enriched microbial component in DM was identified, characterised by a higher number of epitopes per species and against a wider microbial repertoire. The effect of sample size in our measurements suggests increased microbial exposure and interpersonal variability in the DM compared to the healthy group, leading to expansion of the identified DM-specific microbial signature upon screening additional samples. Even though our observations provide a static snapshot of the IgOme, the immune system has a memory and the accumulation of antibodies takes place from birth over the entire lifetime of the individual. Thus, our data suggest that DM as a clinical entity is characterised by diverse microbial exposure.