To what extent is stochastic noise responsible for phenotypic variability in biological systems? Feinerman et al. combine computer modeling with measurements of expression levels of multiple proteins required for signaling in populations of T cells, along with the response of the same cells to antigenic stimulation. Together these revealed how stochastic variation in expression of different components of antigen-induced signaling pathways had distinct effects on the response potential of T cells. For a clone of T cells responding to a given antigen, this could help by optimizing flexibility within the responding cell population while maintaining the overall uniformity required for reliable antigen discrimination.
O. Feinerman, J. Veiga, J. R. Dorfman, R. N. Germain, G. Altan-Bonnet, Variability and robustness in T cell activation from regulated heterogeneity in protein levels. Science 321, 1081-1084 (2008). [Abstract] [Full Text]