Quantifying persistence in the T-cell signaling network using an optically controllable antigen receptor.

T cells discriminate between healthy and infected cells with remarkable sensitivity when mounting an immune response, which is hypothesized to depend on T cells combining stimuli from multiple antigen-presenting cell interactions into a more potent response. To quantify the capacity for T cells to accomplish this, we have developed an antigen receptor that is optically tunable within cell conjugates, providing control over the duration, and intensity of intracellular T-cell signaling. We observe limited persistence within the T-cell intracellular network on disruption of receptor input, with signals dissipating entirely in ~15 min, and directly show sustained proximal receptor signaling is required to maintain gene transcription. T cells thus primarily accumulate the outputs of gene expression rather than integrate discrete intracellular signals. Engineering optical control in a clinically relevant chimeric antigen receptor (CAR), we show that this limited signal persistence can be exploited to increase CAR-T cell activation threefold using pulsatile stimulation. Our results are likely to apply more generally to the signaling dynamics of other cellular networks.

Controlling the Potency of T Cell Activation Using an Optically Tunable Chimeric Antigen Receptor.

The ability of biological systems to convert inputs from their environment into information to guide future decisions is central to life and a matter of great importance. While we know the components of many of the signaling networks that make these decisions, our understanding of the dynamic flow of information between these parts remains far more limited. T cells are an essential white blood cell type of an adaptive immune response and can discriminate between healthy and infected cells with remarkable sensitivity. This chapter describes the use of a synthetic T-cell receptor (OptoCAR) that is optically tunable within cell conjugates, providing control over the duration, and intensity of intracellular T-cell signaling dynamics. Optical control can also provide control over signaling with high spatial precision, and the OptoCAR is likely to find application more generally when modulating T-cell function with imaging approaches.

Evaluation of α-amylase, lipase inhibition and in-vivo pharmacological activities of Eucalyptus camaladulensis Dehnh leaf extract.

In this present study, phytochemical screening, anti-ulcer assay, anti-diarrhea assay, anti-inflammatory assay, analgesic assay, lipase activity assay, amylase activity assay and the anti-bacterial activity of Eucalyptus camaladulensis Dehnh leaf extracted with methanol and 50% ethanol was analyzed for biological significance. Physical characterization of the non-volatile component revealed the higher yield of 16.92% in 50% ethanol expediting the use of 50% ethanol as a better alternative. Further use of crude extract revealed 33.89% (IC50 = 1.44 mg/ml) of α-amylase inhibition by methanol extract and 33.87% (IC50 = 3.21 mg/ml) lipase inhibition by 50% ethanol extract. Furthermore, 44.44% protective ratio towards ulcer was observed with the methanol extract, whereas 54.58% anti-inflammatory activity was shown by the 50% ethanol extract. The effectiveness of the extract was further enhanced by the presence of 62.54% motility and best analgesic property at 180 min of the exposure of the extract orally. The antioxidant activity of crude methanol extract revealed an IC50 value 601.8 µg/ml whereas, ethanol extract showed 1279.58 µg/ml in DPPH assay. Result revealed several health benefits of E. camaldulensis Dehnh leaf.