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=<p>T cell responses play critical roles in host adaptive immunity against <italic>Pneumocystis</italic>. However, the dynamics and diversity of the T cell immune repertoire in human immunodeficiency virus (HIV)-negative <italic>Pneumocystis</italic> 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 <italic>Pneumocystis</italic>. Our findings demonstrated the clonal cells were mainly composed of CD4<sup>+</sup> T cells in response to <italic>Pneumocystis</italic>, which were marked by highly expressed genes associated with T cell activation. Mice infected with <italic>Pneumocystis</italic> showed reduced TCR diversity in CD4<sup>+</sup> T cells and increased diversity in CD8<sup>+</sup> T cells compared with uninfected controls. Furthermore, Th17 cells were mostly clonal CD4<sup>+</sup> T cells, which exhibited the phenotype of tissue-resident memory-like Th17 cells. In addition, <italic>Pneumocystis</italic>-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 <italic>Pneumocystis</italic> infection.</p>