Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures on early gene expression for immune-related molecules by central nervous system mixed glial cell cultures

Abstract

Cytokines secreted within the central nervous system (CNS) are important in the development of multiple sclerosis (MS) lesions. The balance between Th1, monocyte/macrophage (M/M) and Th2 cytokines in the CNS may be pivotal in determining the outcome of lesion development. We examined the effects of mixtures of cytokines on gene expression by CNS glial cells, as mixtures of cytokines are present in MS lesions, which in turn contain mixtures of glial cells. In this initial analysis by gene array, we examined changes at 6 hours to identify early changes in gene expression that represent primary responses to the cytokines. Rat glial cells were incubated with mixtures of Th1, M/M and Th2 cytokines for 6 hours and examined for changes in early gene expression employing microarray gene chip technology. A minimum of 814 genes were differentially regulated by one or more of the cytokine mixtures in comparison to controls, including changes in expression in a large number of genes for immune system-related proteins. Expression of the proteins for these genes likely influences development and inhibition of MS lesions as well as protective and regenerative processes. Analysing gene expression for the effects of various combinations of exogenous cytokines on glial cells in the absence of the confounding effects of inflammatory cells themselves should increase our understanding of cytokine-induced pathways in the CNS.

Cytokines Reduce Toxic Effects of Ethanol on Oligodendroglia

“…Similar concentrations have been used in numerous in vitro studies, including ours [9][10][11]33], with effects on gene expression and cell function in many cell types. The physiologic relevance of the cytokine concentrations used in vitro can be debated.…”

“…We previously reported that these mixtures of cytokines induced a large number of changes in gene expression at 6 h in these mixed glial cultures, with each mixture giving a unique pattern of changes [9][10][11]. As expected, the Th1 and M/M cytokine mixtures upregulated a number of glial genes for cytokines, chemokines and their receptors considered to be pro-inflammatory, while the Th2 mixture downregulated many of these same genes [9]. In addition, Th2 cytokines upregulated the gene for the neurotrophin BDNF [10], a change subsequently confirmed at later time points by PCR (unpublished data).…”

“…The mixtures contained 10 ng/ml of each constituent cytokine as typically employed in a large number of in vitro systems, including our recent studies [9][10][11].…”

“…As one approach for identifying immunomodulatory mechanisms that affect oligodendroglia (OL) and white matter during ethanol exposure in early CNS development, we investigated the effects of ethanol on glial cultures, and asked whether proinflammatory or anti-inflammatory cytokines altered the glial responses. We used cytokine mixtures typical of those produced by Th1 or Th2 cells, or monocyte/macrophages (M/M) as used in our previous studies on effects of cytokines on gene expression in CNS glia [9][10][11]. In contrast to studies using a single cytokine and one glial population, we have examined the effects of these cytokine mixtures on glial cultures containing astroglia, microglia and OL to more closely model in vivo interactions.…”

Decreased inflammation and augmented expression of trophic factors correlate with MOG-induced neuroprotection of the injured nigrostriatal system in the murine MPTP model of Parkinson's disease

“…Cytokines produced by T cells strongly influence glial activation and induce various genes in glial cells, providing, for example in microglia, to present a pro-inflammatory or anti-inflammatory phenotype. [14,15]. The interaction between T cells and glial appears to mediate one of the main mechanisms of neuroprotective immunity.…”