Macrophages subtype

Macrophage subtype 27E10, which has been shown to possess pro-inflammatory activity (ZwADLO et al. 1986, Bhardwaj et al. 1992), expressed IBl, 2E1, and 2B6/7 (Baron et al. 1998). on the other hand, in the anti-inflammatory macrophage subtype RM3/1, predominantly IBl and to some extent 2B6/7 were found. Treatment with cyclosporin A, phenobarbital, benzanthracene or ethanol resulted in induction of the expression of 3A3/4. Cyp IBl was the predominant isoenzyme in all monocytes and macrophages. In monocytes purified by adherence or induced by benzanthracene, U-popolysaccharide or 12-0-tetradecanoyl-phorbol-13-acetate, lAl was also expressed. 

In conclusion as for the role of A3 receptors in the inhibition of TNF-a production in macrophages discrepant results have been obtained and not only due to the different species considered. For example some studies attributed reduction of TNF-a to A3 receptors either in human and mouse species (Sajjadi et al. 1996 McWhinney et al. 1996), whilst other found this effect to be mediated essentially by A2A and in minor part by A2B without the involvement of the A3 receptors again in both human and mouse species (Zhang et al. 2005 Kreckler et al. 2006). Therefore it is difficult in this case to verify the relevance of the A3 receptor-induced cellular response when other adenosine subtypes like A2A and A2B are also activated. As for the effects exerted by the A3 subtype in human monocytes and macrophages it is possible to find support for an anti-inflammatory role for this receptor as attested by reduction of tissue factor, oxidative burst and perhaps TNF-a release. Also the recent discovery of an increase in MMP9 supports a role for A3 agonists in the therapy of myocardial infarction (Velot et al. 2008) (Fig. 12.4). 

Interferon gamma binds to different cell surface receptors than alpha and beta Specific effect of interferon gamma include enhancement of oxidative metabolism of macrophages, antibody-dependent cellular cytotoxicity, activation of natural killer cells, and expression of Fc and major histocompatibility antigens While all alpha interferon have similar biological effects, not all activities shared by each and in many cases the extent of activity various substantially for each interferon subtype... 

T cells are the principal source of IgE regulatory cytokines. CD4 T cells can be subdivided on the basis of the cytokines they secrete. These subsets have been termed T helper 1 (ThI) and T helper 2 (Th2) (Mos-mann etal., 1986 Mosmann, 1992) on the basis of the cytokines that they produce. ThI cells make IFN7, IL-2 and TNF 8 and effect cell-mediated immunity. In the mouse, ThI cells support IgG2a antibody production. Th2 cells make IL-4, IL-5, IL-6 and II IO, support IgE responses and cause eosinophilia. Some cytokines, e.g. IL-3, TNFa and granulocyte-macrophage colony stimulating fector (GM-CSF), are secreted in similar amounts by both subsets (Table 3.2). In addition to ThI and Th2 cells there are other subtypes such as ThO, which exhibit an unrestricted cytokine profile (Firestein et al., 1989), and there are probably others, such as a non-cytolytic vesicular stomatitis virus-specific 004" T cell clone which produces IL-6, TNFa and TNF/3 but not IL-2, IL-4 or IFN7 (Gao et al., 1993). 

This family includes two subtypes i. Short-chain (Sc subtype) interleukin (IL)-2, IL-3, IL-4, IL-5, IL-7, IL-9, IL-13, granulocyte-macrophage colony-stimulating factor (GM-CSF), monocyte/macrophage colony-stimulating factor (M-CSF), stem cell factor (SCF), IFNy... 

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