Figure 2.

Characterization of kinetic changes in immune cell infiltration in the transplanted lung grafts. A: Immunohistochemical staining for T cells (CD3) and macrophages (F4/80) in the allograft (B6D2F1/J to DBA/2J) model at various time points (days 7, 14, 28, and 40) after transplantation. T-cell and macrophage infiltration of the peribronchiolar area is noted along with perivascular and intraluminal infiltration. B: Immunophenotyping of infiltrating immune cell populations in allografts (B6D2F1/J to DBA/2J). Single-cell suspension of day 14 isografts (n = 3; black bars), day 14 allografts (n = 3; white bars), and day 28 allografts (n = 4; grey bars) were stained and analyzed by flow cytometric analysis to quantitate infiltrating CD45⁺ leukocytes, CD4⁺ T cells (CD4⁺), CD8⁺ T cells (CD8⁺), and B cells (CD19⁺). To identify myeloid cells, initial gates eliminated CD3⁺ and CD19⁺ lymphocytes and Ly-6G⁺ granulocytes. Subsequent gates identified CD11b⁺ dendritic cells (FSC^{moderate/high} nonautofluorescent CD11c⁺ CD11b⁺), monocyte-derived exudate macrophages (FSC^high autofluorescent CD11c⁺ CD11b⁺), and alveolar macrophages (FSC^high autofluorescent CD11c⁺ CD11b⁻). Total cell numbers were obtained by multiplying the cell frequency by the total number of CD45⁺ leukocytes for each lung. ^∗P < 0.05, ^∗∗P < 0.01. All comparisons were made with isografts other than when specified by the bar below the asterisk. Original magnification: ×200 (A).