In contrast, despite a slight but not statistically significant tendency to reduce immune responses, rAAV2/1-PD-L1 co-injected with rAAV2/1-Ova failed to provide the same effect on immune priming (Figure 2C , left and middle panels). Also, treatment with rAAV2/1-PD-L1 did not allow the persistence of sOva in the serum in agreement with the significant amount of anti-Ova IgG detected in the serum of these animals ( Figure 2C ). This expected result confirmed that local transduction of muscle cells with rAAV2/1-PD-L1 can not interfere with the systemic immune priming against sOva since activation of the PD-1/PD-L1 pathway was anticipated to regulate T cells functions rather than their priming.