Signatures of murine PP Th17 derived Tfh cells
To determine the clinical relevance of the murine Th17-derived Tfh signatures in RA patients, we generated both splenic and PP murine Th17-derived Tfh cells signatures using bulk RNA-seq data. Overall design: To characterize the signature genes of Th17-derived Tfh cells, CD4+ T cells were enriched from the spleen and PP of K/BxN Th17 fate-mapping mice by negative selection kit (Stemcell) and sorted for ZsGreen+ Tfh (CD4+TCRß+CD25-ZsGreen+CXCR5+PD-1+) and ZsGreen- Tfh (CD4+TCRß+CD25-ZsGreen-CXCR5+PD-1+). Total RNA were then extracted by Trizol reagent. The signatures were defined as the genes that were upregulated in ZsGreen+ Tfh over ZsGreen– Tfh cells using 1.5 as the cut-off for fold change (p<0.05).  We then investigated these signatures in a cohort of HC and seropostive RA patients from a public scRNA-seq database.