PDCD1 and bacterial infectious disease: Consistent with our data, a previous study showed high levels of IL-10 production in 24 h cultures of splenocytes exposed to PIC, a phenomenon that was associated with a limited expansion and function of effector CD8+ T cells in a bacterial infection mouse model.43 The immunomodulatory effects exerted by the combination of the E7 long peptide with PIC were enhanced by the systemic administration of anti-PD-1.