Figure 4.

Depletion of γδT cells but not IL-17A/F or IL-22 protects the mouse brain from hypoxia-ischemia (HI)–induced preterm brain injury. A–H: γδT cell depletion as seen in the subcortical white matter volume by measuring the maltose-binding protein (MBP) immunohistochemical (IHC)–positive staining area (A, C, E, and F) and in the total tissue loss using microtubule associated protein (MAP)-2 IHC staining (B, D, G, and H) in Tcrd^−/− and wild-type (WT) mice at 7 days after HI. A: Total volume of the subcortical white matter. B: Total brain tissue loss in the WT versus Tcrd^−/− mouse brain. C and D: The total subcortical white matter area (C) and total brain tissue loss at the different brain levels (D). The x axis of C and B indicates the brain levels analyzed, where level 1 refers to the frontal part of the mouse brain and level 6 refers to the posterior part of the mouse brain. E–H: Representative images of the MBP (E and F) and MAP-2 (G and H) staining from the WT (E and G) and Tcrd^−/− (F and H) mouse brains at 7 days after HI. I–L: Brain injury after blocking IL-17A/F or in Il22^−/− mice at 7 days after HI. M and N: The Il17f and Il22 mRNA levels in WT, Tcrd^−/−, and Rag1^−/− mouse brains at 6 hours and 3 days after HI and in age-matched naïve control mice at postnatal day 5 (PND5) and postnatal day 8 (PND8), respectively. Data are expressed as means ± SEM (A–D, I–L) and as means ± SEM of the ratio of the target gene to the reference gene Gapdh (M and N). n = 29 Tcrd^−/− and 29 WT mice at 7 days after HI (A–H); n = 20 IL-17, 19 anti–IL-17, 15 WT, and 20 Il22^−/− mice (I–L); n = 7 to 10 control mice and 8 to 11 HI mice (M and N). ^∗P < 0.05, ^∗∗P < 0.01, and ^∗∗∗P < 0.001. TCR, T-cell receptor.