The dual nature of TDC - bridging dendritic and T cells in immunity.

T_DC are hematopoietic cells with unique features that provide intriguing insights into the interplay between innate and adaptive immunity. They express a combination of conventional dendritic cell (DC) and T-cell markers and are found in secondary lymphoid organs (SLOs), lungs and liver of naïve mice, as well as in human blood. When analyzed ex vivo, T_DC can behave either as DCs or as T cells, depending on the provided stimuli. Notably, T_DC numbers and activation significantly increase in SLOs following viral infection, suggesting a potential role for T_DC in antiviral immune responses. In this review, we discuss the properties of these fascinating cells, which call for more investigation on their physiological role during immune responses to both pathogens and tumors.