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

In the DM group, linear epitopes were identified for a total of 1,560 microbial species ( Figure S2A) compared to 1,498 in the HC group ( Figure S2B ). In both groups the highest level of richness (number of different species) was observed for bacteria, followed by viruses, fungi and archaea (Figure S2A & S2B) . We defined distinct epitopes as being any discrete epitope sequence retrieved from the DM and HC groups. Unique distinct epitopes represent any discrete epitope sequences which were observed exclusively in either DM or HC. Common distinct epitopes were discrete epitope sequences that were observed in both DM and HC groups by sequence and at a minimum of five-fold the NGS enrichment frequency in one group vs the other group. Unique distinct epitopes represented the vast majority of sequences observed (Fig 1) . Based on the distribution of the corresponding microbial species in the pools of 10 and 20 the majority of distinct species are shared between the P20 and P10 samples, whereas the majority of unique species are observed either in P20 or in P10, in both DM and HC ( Figure S2C & S2D, respectively). These data demonstrate the presence of a stably-enriched microbial component in DM ( Figure S2A ) and also in HC ( Figure S2B ).