Purinergic P2X4 receptors and mitochondrial ATP production regulate T cell migration
Carola Ledderose, … , Gary A. Visner, Wolfgang G. Junger
Carola Ledderose, … , Gary A. Visner, Wolfgang G. Junger
Published June 12, 2018
Citation Information: J Clin Invest. 2018;128(8):3583-3594. https://doi.org/10.1172/JCI120972.
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Research Article Cell biology

Purinergic P2X4 receptors and mitochondrial ATP production regulate T cell migration

Abstract

T cells must migrate in order to encounter antigen-presenting cells (APCs) and to execute their varied functions in immune defense and inflammation. ATP release and autocrine signaling through purinergic receptors contribute to T cell activation at the immune synapse that T cells form with APCs. Here, we show that T cells also require ATP release and purinergic signaling for their migration to APCs. We found that the chemokine stromal-derived factor-1α (SDF-1α) triggered mitochondrial ATP production, rapid bursts of ATP release, and increased migration of primary human CD4+ T cells. This process depended on pannexin-1 ATP release channels and autocrine stimulation of P2X4 receptors. SDF-1α stimulation caused localized accumulation of mitochondria with P2X4 receptors near the front of cells, resulting in a feed-forward signaling mechanism that promotes cellular Ca2+ influx and sustains mitochondrial ATP synthesis at levels needed for pseudopod protrusion, T cell polarization, and cell migration. Inhibition of P2X4 receptors blocked the activation and migration of T cells in vitro. In a mouse lung transplant model, P2X4 receptor antagonist treatment prevented the recruitment of T cells into allograft tissue and the rejection of lung transplants. Our findings suggest that P2X4 receptors are therapeutic targets for immunomodulation in transplantation and inflammatory diseases.

Authors

Carola Ledderose, Kaifeng Liu, Yutaka Kondo, Christian J. Slubowski, Thomas Dertnig, Sara Denicoló, Mona Arbab, Johannes Hubner, Kirstin Konrad, Mahtab Fakhari, James A. Lederer, Simon C. Robson, Gary A. Visner, Wolfgang G. Junger

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Figure 2

Mitochondria produce the ATP that is released from migrating T cells.

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Mitochondria produce the ATP that is released from migrating T cells. (A...
(A) ATP concentrations were measured in the supernatants of CD4+ T cells treated with CCCP (5 μM) for 10 minutes and stimulated with SDF-1α for 5 minutes (mean ± SD, n = 3; *P < 0.05 vs. control; 1-way ANOVA). (B and C) CD4+ T cells were treated with CCCP (5 μM), CBX (50 μM), apyrase (20 U/ml), suramin (100 μM), or cell culture medium (control) for 10 minutes, and polarization (B) and migration speed (C) in response to SDF-1α were analyzed. Data represent mean ± SD of 86 (no stimulation), 237 (control), 133 (CCCP), 110 (CBX), 87 (apyrase), and 49 (suramin) cells analyzed in 6 (control) or 3 separate experiments. *P < 0.05 vs. control (Kruskal-Wallis test). (D and E) CD4+ T cells were stained with the mitochondrial Ca2+ indicator Rhod-2 and the ATP probe 2-2Zn, stimulated with SDF-1α, and ATP release and mitochondrial Ca2+ influx were analyzed with fluorescence microscopy (see also Supplemental Video 4). Representative images of 6 individual experiments comprising a total of 55 cells are shown in D (scale bar, 5 μm; ×100 objective). The histogram shows the distribution of the 2-2Zn and Rhod-2 signal across the cell axis as indicated. (E) 2-2Zn and Rhod-2 fluorescence intensities were measured at the front of polarizing CD4+ T cells and normalized to the fluorescence intensities at the back of the same cell. Data are derived from 55 cells analyzed in 6 individual experiments.