Figure 4. CD47-SIRPα signaling in DCs controls the phagosomal PH and DNA degradation.

(A) MC38 tumor cells were co-cultured with bone marrow-derived DCs or macrophages in the presence of 30µg/ml rat Ig or anti-CD47 mAb. After one hour, CD11c⁺ DCs or F4/80⁺ macrophages were sorted. Phagosomal mtDNA was quantitated after different chase periods. (B) MC38 tumor cells were co-cultured with bone marrow-derived DCs or macrophages in the presence of 30µg/ml rat Ig or anti-CD47 mAb for one hour. Phagosomal acquisition of LAMP-1 was analyzed by flow organellocytometry. (C–D) BMDC and BMM were were cultured with MC38 tumor cells in the presence of rat Ig or anti-CD47 mAb. Phagosomal PH was measure on indicated time points. Data are represented as mean ± SEM. *p< 0.05, **p< 0.01. ns, not significant (Two-tailed student’s t test). Data are representative of two independent experiments. See also Figure S3.