MLR in the presence of SIRPα/β- or CD47-specific MoAbs or soluble SIRPα1ex.

Responding cells (1.5 × 10⁵) from allogeneic PB mononuclear cells were cultured with stimulator cells (DCs) in the presence of control (IgG1) antibody, antibody B1D5 specific for SIRPβ inhibitory antibodies specific for CD47 (CC2C6) and SIRPα/β (SE5A5), or soluble SIRPα1ex and SIRPβ1ex protein. Thymidine incorporation was measured on day 5 by a 16-hour pulse with³H-thymidine. The results show the means and SDs from a representative experiment in cpm (n = 6 replicates).