Killing of PHA-induced T-cell blasts. (A) Staining of PHA-induced T-cell blasts with various mAbs. Staining of PHA-induced T-cell blasts derived from patient A and from the healthy sister was performed with the F(ab′)2 fragments of anti-CD3, anti-CEACAM1, and anti–MHC class I mAb HP-1F7. (B) Staining of PHA-induced T-cell blasts and of the LnCap cell line with various fusion proteins. Staining was performed with the NKp46-Ig, NKp30-Ig, NKp44-Ig, and the control CD99-Ig fusion proteins. (C) NK clones derived from patients A, B, and C were assayed for cytotoxic activity against autologous PHA-induced T-cell blasts. The NK clones obtained from the healthy sister were assayed against PHA-induced T-cell blasts derived from patient A. NK clones were preincubated with or without F(ab′)2 fragments of polyclonal anti-CEACAM or the control polyclonal antiubiquitin antibodies. The targets, autologous PHA-induced T-cell blasts, were incubated with or without the F(ab′)2 fragments of HP-1F7 or the control 12E7 mAb. Assays were performed at an E/T ratio of 2:1. Shown are the mean results of several NK clones that were obtained from 3 independent experiments. The data represent the mean percentage of killing ± SD. (D) NK clones derived either from the healthy sister or from patients A, B, and C were assayed for killing of PHA-induced T-cell blasts derived from the healthy sister. NK clones and target PHA-induced T-cell blasts were pretreated as described for panel C. Assays were performed at an E/T ratio of 2:1. Shown are the mean results of several NK clones that were obtained from 3 independent experiments. All mAbs used were in the form of F(ab′)2. The data represent the mean percentage of killing ± SD.
