Viral Infection Triggers Rapid Differentiation of Human Blood Monocytes into Dendritic Cells (45.12)

Viruses post a constant threat of human existence. Although human immune system plays a central role in recognizing and eradicating pathogens, how it responds to virus infection remains unclear. Here we show that monocytes make up the majority of a wide variety of virus susceptible population in human peripheral blood mononuclear cells. Notably, infection with influenza virus, vesicular stomatitis virus and vaccinia virus promotes monocytes to differentiate within 18 hours into CD16-negative CD83-positive mature dendritic cells (DCs) with enhanced capacity to activate T cells. Virus-induced monocyte differentiation into DCs does not require cell division, and happens despite the synthesis of virus proteins, suggesting that monocytes thwart the capacity of these highly lytic viruses to hijack host cell biosynthesis pathway. Indeed, virus-induced DC differentiation from monocytes requires infectious virus and viral protein synthesis. Thus, our results demonstrate that monocytes are uniquely susceptible to virus infection among human peripheral blood mononuclear cells, with the likely purpose of differentiating into DCs with enhanced capacity to activate innate and acquired anti-virus immunity.