Single cell RNA-seq of CD4+ T cell subsets during LCMV-Armstrong infection

CD4+ memory T cells play a pivatol role in mediating long-term immunity and therefore are an important target in vaccine development. Multiple functionally distinct helper CD4+ T cell subsets can arise in response to a single invading pathogen, complicating the identification of rare memory CD4+ T cells. Here we found that expression of Id3, an inhibitor of E protein transcription factors, identified a population of cells within both the CD4+ Tfh and Th1 helper lineages that exhibited memory potential in response to secondary infection. Notably, a subset of Th1 memory cells expressing Id3 exhibited enhanced expansion upon response to pathogen, generating both Th1 and Tfh secondary effector cell populations, and displayed enrichment of key molecules associated with memory potential when compared to Id3lo Th1 cells. Thus, Id3 expression serves as an important marker of multipotent memory CD4+ T cells. Overall design: 3 samples, 2 replicates each, single cell rna-seq was performed on SMARTA T cells at D7, D21, and D44 of LCMV-Arm infection