Figure 2. T cell-specific P2RX7 promotes lung parenchymal CD4⁺ T cell accumulation and severe TB caused by hypervirulent mycobacteria.

WT (C57BL/6 or P2rx7^fl/fl), P2RX7-KO (P2rx7^−/−), or T cell-P2RX7-KO (CD4-Cre P2rx7^fl/fl) mice were infected with ~100 CFU of Mbv MP287. Non-infected mice were used as controls.

(A and I) Percentages of body weights in relation to day 0 of WT, P2RX7-KO, or T cell-P2RX7-KO mice.

(B and J) Lung weight values of WT, P2RX7-KO, or T cell-P2RX7-KO mice.

(C and K) CFU numbers per lung of WT, P2RX7-KO, or T cell-P2RX7-KO mice.

(D and L) Total lung cell numbers of WT, P2RX7-KO, or T cell-P2RX7-KO mice.

(E) Representative lung sections stained with H&E of WT or P2RX7-KO mice. Scale bars, 500 μm.

(F) Left: flow-cytometry plots of CD44 and CD45i.v. in lung CD4⁺ T cells. Right: average numbers of CD45i.v.⁺ and CD45i.v.⁻ CD44⁺CD4⁺ T cells/lung.

(G) Left: flow-cytometry plots of I-A^bESAT-6_4-17 and CD45i.v. expression in lung CD4⁺ T cells. Right: average numbers of CD45i.v.⁺ and CD45i.v.⁻ I-A^bESAT-6_4-17⁺CD44⁺CD4⁺ T cells/lung.

(H) Average numbers of medLN I-A^bESAT-6_4-17⁺CXCR3⁺CD4⁺ T cells.

(M) Macroscopic images of right upper lung lobes of WT and T cell-P2RX7-KO mice. Scale bars, 1 cm.

(N) Representative lung sections stained with H&E of WT and T cell-P2RX7-KO mice. Scale bars, 500 μm.

(O) Left: flow-cytometry plots of CD44 and CD45i.v. in lung CD4⁺ T cells of WT and T cell-P2RX7-KO mice. Right: average numbers of CD45i.v.⁺ and CD45i.v.⁻ CD44⁺CD4⁺T cells/lung.

Data from three independent experiments: n = 3–5/experimental group per experiment. Data shown as means ± SD. *p < 0.05, **p < 0.01, ***p < 0.001, one-way ANOVA (Tukey post tests) (B, D, F, G, J, L, and O) or unpaired t tests (A, C, H, I, and K).