Lck-deficient CTLs can polarize their centrosome toward antigen-presenting targets or anti-CD3 beads. (A) Cartoon defining distal and proximal positions of the centrosome relative to beads or targets. (B) Representative images of conjugates formed between rat anti-CD3 latex beads and F5 CTLs from WT, Lckoff, and Lckoff + PP2 labeled with antibodies to γ-tubulin (red) and anti–rat-FITC (green) in separate channels, viewed by differential interference contrast (DIC), and merged. (C) Quantitation of conjugates from F5 WT (n = 400), Lckoff (n = 400), or Lckoff + PP2 inhibitor (n = 300) CTL conjugates. A two-tailed Student’s t test for differences between WT and Lckoff samples + PP2 revealed a statistical significance (P = 0.01). (D) Quantitation of centrosome polarization from OT-I CTL-bead conjugates. Error bars show the standard deviation from the means from at least three independent experiments. n > 300 conjugates. Bars, 5 µm.
