Figure 4. Flow cytometric analysis of graft-infiltrating lymphocyte populations. A, B: Allo-grafted cornea analyzed at day 7 post-op. A: Forward-sideward scatter morphology of graft infiltrating cells. B: Representative image of CD161^dull expression on LGL. No other cell type could be detected. Recorded events: 2–5×10³. C-H: FACS results of allo-rejecting corneas: Events acquired: 5×10³ to 3×10⁴ per sample. C: FSC-SSC morphology of GIL. D: Detection of T-lymphocytes. E: Measurement of CD8 and CD161 NK markers on GIL. F: Sub-characterization of CD4+ T-cells and MHC-2 detection. G: Expression pattern of CD3 from populations gated in E. H: Measurement of CD25 T-cell activation markers on populations gated in D. Cut-off or positive CD25 expression was determined by measuring isotype FMO samples on lymphocytes in draining LN from the same animal. For scaling reasons data are not shown in histogram. Bar diagram: Summary of all lymphocyte specimens identified in rejected corneas (left diagram) and appropriate sub-characterizations (right diagram) n=5.