Figure 4.

Fate of transferred UL16 binding protein (ULBP) molecules. (a) Acquired ULBP3 is closely associated with NKG2D. NKG2D was immunoprecipitated from natural killer (NK) cells previously co-incubated with either Chinese hamster ovary (CHO) parental cells (CHO) or ULBP3 transfectants (CHO3) for 2 hr. After separation in SDS–PAGE, co-immunoprecipitated ULBP3 and NKG2D were detected by Western blot. The bands for the heavy and light chains of the antibody are indicated (HC and LC). (b) Stability of transferred ULBP on NK cells. After co-incubation for 1 hr with ULBP transfectants, NK cells were separated from the adherent cells by pipetting and maintained in culture for the indicated times (hr) and then analysed by flow cytometry. The percentage and mean fluorescence intensity (MFI) of ULBP⁺ NK cells are shown as the proportion of NK cells that remained positive for ULBP, relative to time 0. Results representative from three to six experiments are shown.