BCR and Pneumocystis infectious disease: To assess the signatures of B-cell receptor diversity in B lymphocytes following Pneumocystis infection, we performed scRNA-seq and single-cell BCR sequencing on CD45+ immune cells from the lung tissue of uninfected mice (0 w) and mouse models at 1–4 weeks post-infection (1 w, 2 w, 3 w, and 4 w).