(a-c) The memory phenotype of human T cells in the human lung implants of BLT-L mice (n=4 BLT-L mice, one lung implant per animal). (a) Percent of CD4+ (filled circles) and CD8+ (filled squares) human T cells expressing a memory phenotype (CD45RO+). (b) Percent of memory (CD45RO+) CD4+ (circles) and CD8+ (squares) human T cells expressing an effector memory (Tem, CCR7neg, closed symbols) or central memory (Tcm, CCR7+, open symbols) phenotype. (c) Percent of memory (CD45RO+) CD4+ (filled circles) and CD8+ (filled squares) T cells that are tissue-resident (TRM, CD69+). (d) Flow cytometry gating scheme. Regions identify the following human cell populations: RI (live cells), RII (human hematopoietic cells), RIII (T cells), RIV (CD8+ T cells), RV (CD4+ T cells), RVI (memory CD8+ T cells), RVII (CD8+ Tem), RVIII (CD8+ Tcm), RIX (CD8+ TRM), RX (memory CD4+ T cells), RXI (CD4+ Tem), RXII (CD4+ Tcm) and RXIII (CD4+ TRM). In a-c, horizontal lines represent mean ± s.e.m. (e) Human hematopoietic (hCD45) cells including dendritic cells (hCD11c), macrophages (hCD68), B cells (hCD20) and T cells (hCD3, hCD4 and hCD8) in lymphoid (spleen and lymph nodes) and non-lymphoid (liver and mouse lung) of BLT-L mice by immunohistochemical staining (positive cells: brown). Images shown are at 20X magnification and represent three BLT-L mice (scale bars: 100 µm).