The Effects Of Farnesyltransferase Inhibitor Abt-100 On Murine Helper T-Cell Differentiation And Cytokine Secretion

Farnesyltransferase Inhibitors (FTIs) are a class of drugs known to prevent the farnesylation and subsequent membrane attachment of a number of intracellular proteins. In various studies, the administration of FTIs has been found to play a role in the activation and development of T-cells in the immune system. FTIs have also been found to act as immunomodulators in delaying MHC-II mismatched skin allografts in mice. This study focuses on the effect of the FTI, ABT-100, on the differentiation and cytokine secretion of Th1 and Th2 helper T-cells in BALB/C mice to better understand which immune responses are targeted by FTIs. Splenocytes were isolated from BALB/C mice, skewed towards either a Th1 or a Th2 phenotype with the addition of cytokines, and treated with various concentrations of ABT-100. Splenocytes were also isolated and immediately cultured in the presence of ABT-100 to observe differentiation trends of helper T-cells. Cytokine production was measured using intracytoplasmic flow cytometry analysis. I found that ABT-100 treatment does not block Th1 or Th2 cell differentiation. Instead, ABT-100 treatment appears to affect cytokine production from effector T-cells. I found that ABT-100 causes a decrease in IFN-¿ production in mature Th1 cells yet does not affect IL-4 production in mature Th2 cells. This decrease in cytokine production as a result of ABT-100 treatments provides a potential mechanism for how ABT-100 works to delay MHC-II mismatched allograft rejection.

Performance Tuning Non-Uniform Sampling for Sensitivity Enhancement of Signal-Limited Biological NMR

Non-uniform sampling (NUS) has been established as a route to obtaining true sensitivity enhancements when recording indirect dimensions of decaying signals in the same total experimental time as traditional uniform incrementation of the indirect evolution period. Theory and experiments have shown that NUS can yield up to two-fold improvements in the intrinsic signal-to-noise ratio (SNR) of each dimension, while even conservative protocols can yield 20-40 % improvements in the intrinsic SNR of NMR data. Applications of biological NMR that can benefit from these improvements are emerging, and in this work we develop some practical aspects of applying NUS nD-NMR to studies that approach the traditional detection limit of nD-NMR spectroscopy. Conditions for obtaining high NUS sensitivity enhancements are considered here in the context of enabling H-1,N-15-HSQC experiments on natural abundance protein samples and H-1,C-13-HMBC experiments on a challenging natural product. Through systematic studies we arrive at more precise guidelines to contrast sensitivity enhancements with reduced line shape constraints, and report an alternative sampling density based on a quarter-wave sinusoidal distribution that returns the highest fidelity we have seen to date in line shapes obtained by maximum entropy processing of non-uniformly sampled data.