FIG. 8.

Cytolytic activity of sorted recipient-derived and donor-derived CD8 T cells. (A) Pulmonary lymphocytes were isolated at the peak of infiltration, and CD8-positive cells were enriched by immunomagnetic selection. (Top) The efficacy of the positive selection was monitored for an aliquot of the cells by a two-color cytofluorometric analysis of CD8 (PE, FL-2) versus L^d (FITC, FL-1) expression performed for 20,000 cells with no preselection of gates. (Bottom) The majority of the CD8 T cells were labeled for L^d only and were then sorted into L^d-negative and L^d-positive sets. The efficacy of the sorting was monitored for 2,000 cells of each set by two-color cytofluorometric analysis of TCR α/β (PE, FL-2) and L^d (FITC, FL-1) expression performed with no preselection of gates. (B) The cytolytic activity of pulmonary CD8 T cells was determined by TCR α/β redirected lysis at the indicated effector-to-target (E/T) cell ratios. (Left) Cytolytic activity of the chimeric CD8 T-cell population after immunomagnetic purification but before the cytofluorometric sorting; (right) cytolytic activity of the sorted cells. For comparison, the presort activity is included for the part of the titration marked by dotted lines.