Heat-induced expression of MHC-linked HSP70 genes in lymphocytes varies at the single-cell level

Abstract

The expression of MHC-linked heat shock protein 70 (HSP70) genes HSP70-1 and HSP70-2 has been studied in human and rat lymphocytes and Concanavalin A (con A)-induced lymphoblasts by in situ hybridization and flow cytometry. In in vitro experiments transcripts of these genes were observed only after heat shock, and mitogen stimulation per se did not lead to induction. Heat shock-induced expression of HSP70-1 and HSP70-2 mRNA varied at the single-cell level. The fraction of HSP70-positive lymphocytes increased continuously with the severity of heat shock. However, 15-35% of the cells always remained HSP70 transcript negative. After fever induction in vivo similar variation of HSP70-1 and HSP70-2 mRNA expression could also be observed. Analysis of heat shocked lymphocytes by flow cytometry demonstrated that HSP70 induction varied also at the protein level, a fraction of cells always remaining unresponsive. Thus, HSP70 induction does not appear to occur in each cell and to a similar extent when a given cell population is exposed to the same stress.

Glutamine depletion impairs cellular stress response in human leucocytes

“…high fever, led to a 3-fold increase in HSP70 expression. A similar induction of HSP70 in heat stressed human lymphocytes was recently reported by others (Dressel & Gunther, 1999). We could show that this HSP70 induction is strongly impaired when the Gln concentration in the medium is reduced.…”

In vivoprediction of the nutrient status of individual microalgal cells using Raman microspectroscopy

“…The advantage of single-cell analysis is that population variability can be assessed. It has been shown that cell populations respond to the environment in ways often not predicted by measurement of the mean response, dispelling the myth of the 'average cell' (Zhao, 1997;Dressel & Gunther, 1999;Levsky & Singer, 2003). In vivo single-cell measurement allows one to probe fundamental questions about intercellular variability and what governs it.…”

INTERCOLONIAL VARIABILITY IN MACROMOLECULAR COMPOSITION IN P‐STARVED AND P‐REPLETE SCENEDESMUS POPULATIONS REVEALED BY INFRARED MICROSPECTROSCOPY1

“…The advantage of single coenobia or cell analysis over whole population analysis is that population variability can be assessed. This analysis is important because it has been shown that cell populations respond to the environment in ways often not predicted by measurement of the average response (Zhao 1997, Dressel and Gunther 1999, Levsky and Singer 2003).…”