Figure 1.

CD3/CD28 Activation Induces PKM2 Expression and Nuclear Accumulation in Murine CD4⁺CD62L⁺ T Cells

Murine CD4⁺CD62⁺ T cells were stimulated in vitro for 3 days with CD3/CD28 antibodies and collected at different time points of activation.

(A) Quantification of Pkm2 mRNA in resting versus activated murine CD4⁺CD62L⁺ T cells by qRT-PCR (n = 5–6 from 4 independent experiments). ^∗p < 0.05 and ^∗∗∗∗p < 0.0001 compared to resting condition, by one-way ANOVA with Dunnett's post-hoc test.

(B) Left, western blot showing upregulation of PKM2 protein in CD4⁺CD62L⁺ T cells following activation. Right, quantification of PKM2 expression by densitometry analysis (n = 2–3 mice from 2 independent experiments).

For (A and B), data are the mean ± standard deviation (SD).

(C) Western blots showing time-dependent increase in PKM2 phosphorylation on tyrosine 105 (Tyr105) in activated murine CD4⁺ T cells. One representative experiment out of two is shown.

(D) Cells were collected at different time points of activation, crosslinked with DSS, and analyzed for PKM2 expression. A representative western blot displaying upregulation of monomeric/dimeric and tetrameric PKM2 in activated T cells is shown.

(E) Western blots showing time-dependent increase in PKM2 phosphorylation on serine 37 (Ser37) in activated murine CD4⁺ T cells.

(F) Cells were collected at different time points of activation. Nuclear and cytoplasmic fractions were isolated by cell fractionation and analyzed for PKM2 expression by western blot. A representative blot showing accumulation of PKM2 in the nucleus and its upregulation in the cytoplasm of activated murine CD4⁺CD62L⁺ T cells is presented.

For (D), (E), and (F), one representative experiment out of two-three is shown.