Fig. 3.
CD11c+ APCs in heavily infiltrated islets maintain the ability to trigger T cells. OT-I T cells were transferred into RIP-mOva recipients. Islets were isolated at different stages of infiltration: (−) no transfer control, (d4.5) early, (d7) late. CD11c+MHCIIhiDAPI– APCs sorted from the spleen or islets were incubated with in vitro-activated OT-I T cells labeled with Fura-2AM. Splenic APCs were antigen-pulsed. T cell–APC interactions and Fura fluorescence were imaged by time-lapse widefield microscopy. Data combined from two experiments. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. (A) Representative examples of calcium fluxes read out by Fura-2AM 340 nm/380 nm ratios. (B) Quantification of T cell–APC contacts and calcium-flux strength in T cells interacting with APCs. Statistics: Chi Square Test.