Differential effects of KLK1 and KLK6 on survival and proliferation of murine splenocytes.

<p>To differentiate between possible effects of KLK6 on cell survival versus proliferation, murine splenocytes were labeled with CFSE and cultured in defined media in the presence of 1 or 10 µg/ml of KLK1, KLK6, or vehicle alone (Control), for periods of 24 or 72 hr. At harvest dead cells were labeled using PI and samples were examined by flow cytometry. A, Stimulation of cultures with either 1 or 10 µg/ml of KLK6, but not KLK1, significantly reduced the number of dead (PI⁺) cells observed at either the 24 or 72 hr time points (72 hr shown, B). The intensity of CFSE labeling in PI^- cells was determined using the proliferation platform of the Flow Jo Program and labeling peaks observed after 24 hr are shown in (C). KLK1 (10 µg/ml), but not KLK6 promoted a significant increase in the percent of cells divided at the 24 hr time point (D); Data are expressed as mean ± SEM, One Way ANOVA with SNK post hoc test; P<0.001**, P<0.02*. (SSC, side scatter). Parallel observations have been made in a least three separate cell culture experiments.