Figure 2.

P2X7-dependent alteration of T cells can be prevented by blocking the activity of ARTC2.2. Freshly prepared spleen CD4⁺Foxp3⁺ Tregs and liver CD3⁺CD1d-tetramer⁺ NKT cells remain unaffected when kept at 4°C but rapidly shed CD27 when re-incubated at 37°C due to NAD⁺ release during cell preparation and ARTC2.2-mediated ADP-ribosylation of P2X7 (left panel). These cells also rapidly shed CD62L and expose phosphatidylserine at their cell surface (not illustrated here). Intravenous injection of an anti-ARTC2.2 blocking nanobody (s + 16a) before harvesting of the organs prevents ADP-ribosylation of P2X7 during cell manipulation and P2X7-dependent CD27 shedding when cells are re-incubated at 37°C (right panel).