Proliferation of rat CD4⁺ T cells in response to CdtB in vitro.

<p>Values represent mean fluorescence intensity (MFI) of triplicate cultures of CFSE-labeled rat CD4⁺ T cells. (A) Cultures were terminated at days 2 and 4 (experiment 1). (B) Cultures were terminated at days 3 and 5 (experiment 2). The data are represented as means ± SEM. Increase in MFI of CFSE staining indicates inhibition of proliferation. Statistics were calculated by two-tailed t-test; *P<0.05, in comparisons to control cultures (0 ng/ml CdtB).</p