FIG. 5.

Sera from inoculated GalT KO mice induce cytolysis of GalT⁺ target cells. LLCa cells were incubated with a 1:5 dilution of fresh sera for 60 min at 37°C and then assayed for viability by staining with 10 μg of PI/ml, followed by flow cytometric analysis of PI uptake as described in the text. (A and B) Media only and C57BL/6 sera used as negative controls. (C) Naive GalT KO sera. (D) NHS positive control. (E and F) Sera from immunized GalT KO mice. The percentage of dead (PI⁺) cells per sample is shown in the upper right histogram box. Sera from eight representative immunized GalT KO mice were assayed and yielded similar results.