The indoor air pollutant 2-ethyl-hexanol activates CD4 cells.

It has been reported that the numbers of people suffering from occupational asthma and skin rashes triggered by various chemicals in indoor air have increased markedly. Two-ethyl-hexanol (2-EH) is known to be an indoor air pollutant and its influence on health is of great concern. However, there are only a few reports regarding its effect on immune cells. Thus, we investigated the effects of 2-EH on immune responses in vitro with respect to effects on regulation of transcription factors as well as on 2-EH induced proliferation of spleen cells in vitro. The production of interleukin (IL)-6 and immunoglobulin were not induced by 2-EH. To characterize the effector cells of 2-EH, we prepared CD4-positive, CD8-positive, and peritoneal exudate cells (PEC). IL-2 was induced by 2-EH in CD4 cells, but not in CD8 cells. CD3-induced IL-2 expression was enhanced by 2-EH in CD4 cells, but not in CD8 cells. Moreover, IL-6 production was not induced by 2-EH in PEC. Nuclear factor-kappa B, nuclear factor of activated T, and signal transducer and activator of transcription-5 were activated by 2-EH in CD4 cells. Taken together, 2-EH activated CD4 cells, where this was accompanied by the activation of transcription factors. This suggested that the indoor pollutant 2-EH could function as a modulator of immune response.