Figure 3.

The TGF-β-Activating Integrin αvβ8 Is Preferentially Expressed on Effector Treg Cells

(A) RNA from non-activated or anti-CD3 and anti-CD28 antibody-activated naive (CD45RB^hiFoxp3⁻) or Treg (CD45RB^loFoxp3⁺) CD4⁺ T cell subsets isolated from the spleen of foxp3^GFP mice and analyzed for integrin β8 expression by qPCR. Integrin β8 levels were normalized to the housekeeping gene Hprt and presented relative to levels in naive T cells. Data (n = 4–8) are from three independent experiments.

(B) TGF-β activation by unstimulated or anti-CD3 and anti-28 antibody-activated splenic control (Itgb8^fl/flCre⁻) or Itgb8 KO (Itgb8^fl/flCd4-Cre⁺) Treg cells (CD4⁺CD45RB^loCD25^hi), detected by co-culture with an active TGF-β reporter cell line. Data (n = 4–8) are from four independent experiments.

(C) Integrin β8 levels were assessed by qPCR via RNA isolated from KLRG1⁺ or KLRG1⁻ Treg cells (CD45RB^loFoxp3⁺, isolated from foxp3^GFP mice) and values normalized to Hprt and displayed relative to naive CD4⁺ T cells in (A). Data (n = 4–8) are from three independent experiments.

(D) TGF-β activation levels from KLRG1⁺ or KLRG1⁻ Treg cell subsets (CD4⁺CD45RB^loCD25^hiKLRG1^+/− cells) either control or Itgb8 KO, assessed by co-culture with a TGF-β reporter cell line as described in (B). Data (n = 4–5) are from three independent experiments.

Error bars represent SEM. See also Figure S2.