Fig. 1: Adenosine accumulated during airway inflammation and ILC2 expresses adenosine receptor A2A.

a, b WT mice were treated with papain (20 μg/mouse/day) or PBS intranasally (i.n) for 5 consecutive days, the amount of adenosine in lung tissue or BALF were analyzed at different timepoint (n = 6). c The mRNA expression of adenosine receptors on the indicated mouse ILC subsets and other immune cells, including NK(CD3⁺NK1.1⁺NKP46⁺), ILC1(CD45⁺Lin⁻CD127⁺NK1.1⁺NKP46⁺), ILC2(CD45⁺Lin⁻CD90.2⁺CD25⁺ST2⁺), ILC3(CD45⁺Lin⁻CD127⁺CCR6⁺) as well as CD4⁺T(CD45⁺CD3⁺CD4⁺), CD8⁺T(CD45⁺CD3⁺CD8⁺) and B lymphocytes (CD45⁺B220⁺) determined by RT-PCR. d RT-PCR determined mRNA level of different adenosine receptors expressed on lung ILC2 (CD45⁺Lin⁻CD90.2⁺ CD25⁺ST2⁺). e Flow cytometry purified ILC2s (Gated on live CD45⁺Lin⁻ CD90.2⁺CD25⁺ST2⁺) from lung were cultured in the present of IL-2(20 ng/ml), IL-7(20 ng/ml) with or without IL-33(100 ng/ml) for 3 days, the mRNA expression of Il5, Il13 and adenosine receptors were analyzed by RT-PCR. f Immunofluorescence images of lung tissue from IL-5-Red5 reporter mice analyzed after papain challenge intranasally for 5 consecutive days, stained for DAPI (blue), A2A receptor (green), and IL-5 (red). Red arrows show the A2A⁺ ILC2, white arrow show the A2A⁺ non-ILC2 (bars, 20 µm). g Immunofluorescence images of A2B receptor expression on lung tissue, stained for DAPI (blue), A2B (green) and IL-5 (red). Red arrows show the A2B⁺ ILC2, white arrows show the A2B⁺ non-ILC2, blue arrows show the A2B⁻ ILC2 (bars, 20 µm). Data are representative of two independent experiments. Error bars show mean ± SEM; *P < 0.05; **P < 0.01; ***P < 0.001 by unpaired Student’s t test.