A temporally dynamic autoregulatory transcriptional circuit controls the effector Treg programme.

Regulatory T cells (Treg) are negative regulators of the immune response; however, it is poorly understood whether and how transcription is induced and regulated in the periphery during T-cell responses. Using -Timer of cell kinetics and activity (Tocky) mice, which report real-time expression we show that the flux of new expressors and the rate of transcription are increased during inflammation. These persistent dynamics of transcription determine the effector Treg programme and are dependent on a Foxp3 autoregulatory transcriptional circuit.

A timer for analyzing temporally dynamic changes in transcription during differentiation in vivo.

Understanding the mechanisms of cellular differentiation is challenging because differentiation is initiated by signaling pathways that drive temporally dynamic processes, which are difficult to analyze in vivo. We establish a new tool, Timer of cell kinetics and activity (Tocky; or toki [time in Japanese]). Tocky uses the fluorescent Timer protein, which spontaneously shifts its emission spectrum from blue to red, in combination with computer algorithms to reveal the dynamics of differentiation in vivo.

Using multispectral imaging flow cytometry to assess an in vitro intracellular Burkholderia thailandensis infection model.

The use of in vitro models to understand the interaction of bacteria with host cells is well established. In vitro bacterial infection models are often used to quantify intracellular bacterial load by lysing cell populations and subsequently enumerating the bacteria. Modern established techniques employ the use of fluorescence technologies such as flow cytometry, fluorescent microscopy, and/or confocal microscopy.