CD274 and infection: On the one hand, upregulation of PRR and TNF signaling pathways indicate that monocytes participate in the recognition of the infection and the initiation of the immune response, but on the other hand, expression of potent inhibitors of immunity such as IL-27, TIM-3 (75, 76), or PD-L1 (74) could also limit the stimulatory activity of these cells and promote an immunoregulatory environment.