AUTHOR=Yang Hu-Qin , Wang Yi-Shan , Zhai Kan , Tong Zhao-Hui TITLE=Single-Cell TCR Sequencing Reveals the Dynamics of T Cell Repertoire Profiling During Pneumocystis Infection JOURNAL=Frontiers in Microbiology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.637500 DOI=10.3389/fmicb.2021.637500 ISSN=1664-302X ABSTRACT=

T cell responses play critical roles in host adaptive immunity against Pneumocystis. However, the dynamics and diversity of the T cell immune repertoire in human immunodeficiency virus (HIV)-negative Pneumocystis pneumonia (PCP) remains unclear. In this study, single-cell RNA and single-cell T cell receptor (TCR) sequencing were applied to cells sorted from lung tissues of mice infected with Pneumocystis. Our findings demonstrated the clonal cells were mainly composed of CD4+ T cells in response to Pneumocystis, which were marked by highly expressed genes associated with T cell activation. Mice infected with Pneumocystis showed reduced TCR diversity in CD4+ T cells and increased diversity in CD8+ T cells compared with uninfected controls. Furthermore, Th17 cells were mostly clonal CD4+ T cells, which exhibited the phenotype of tissue-resident memory-like Th17 cells. In addition, Pneumocystis-infected mice showed biased usage of TCRβ VDJ genes. Taken together, we characterized the transcriptome and TCR immune repertoires profiles of expanded T cell clones, which demonstrate a skewed TCR repertoire after Pneumocystis infection.