Figure 5.

rDPPIV inhibits the proliferation of D. discoideum cells. Buffer, rDPPIV, rAprA, or rCfaD were added to wild‐type D. discoideum cells and the cell density was measured 18 h later. The inhibition of proliferation was then measured in comparison to the proliferation of the buffer control cells. All 3 proteins significantly inhibited proliferation (P < 0.05, t tests). (B) The indicated concentrations of rDPPIV were added to D. discoideum cells and the proliferation inhibition was assayed as in A. rDPPIV concentrations from 1 to 1000 ng/mL significantly inhibited proliferation (P < 0.05, t tests). (C) 300 ng/mL rDPPIV was added to wild‐type, aprA⁻, and cfaD⁻ cells and proliferation inhibition was measures as in A. rDPPIV significantly inhibited the proliferation of all three cell lines (P < 0.05, t test). Values are mean ± SEM, n = 3.