Figure 4.

p21^Cip1 did not preferentially interact with cyclin-dependent kinases (cdk) in anergic T helper type 1 (Th1) cells. The Th1 cells were incubated in primary cultures with antigen ± n-butyrate. Following 6 days in primary cultures, viable Th1 cells were isolated and then restimulated with antigen for 36 hr. Following restimulation, whole cell lysates were prepared, and cdk2, cdk4 and cdk6 were immunoprecipitated from the lysates. The immunoprecipitated proteins (IP) and the proteins remaining in the lysate supernatant (SN) were separated by sodium dodecyl sulphate–polyacrylamide gel electrophoresis and then immunoblotted with antibodies specific for p21^Cip1 and the respective cdk.