Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1111/j.1365-2249.2007.03338.x
Title (Primary) Immunomodulation by mercuric chloride in vitro: application of different cell activation pathways
Author Hemdan, N.Y.A.; Lehmann, I.; Wichmann, G.; Lehmann, J.; Emmrich, F.; Sack, U.
Source Titel Clinical and Experimental Immunology
Year 2007
Department IMMU
Volume 148
Issue 2
Page From 325
Page To 337
Language englisch
Keywords cellular activation; helper T cells; immunotoxicity; inflammation; mercuric chloride
Abstract Evidence is emerging that exposure to mercury (Hg) may elicit many pathological manifestations, including immunomodulation. We tested whether changing cellular activation pathways may affect the immunomodulation by Hg. Human cell cultures were set up where isolated peripheral blood mononuclear cells, activated by monoclonal antibodies (MoAb: anti-CD3/-CD28/-CD40) or heat-killed Salmonella enterica serovar Enteritidis (hk-SE), exposed to mercuric chloride (HgCl2) for 24 h. Cell vitality was assessed by MTT assay, and modulation of cytokine profiles were monitored by enzyme-linked immunosorbent assay (ELISA), intracellular cytokine staining and reverse transcription-polymerase chain reaction (RT-PCR). Results show that Hg doses above 15 ng/ml significantly reduced cell vitality (P < 0·05). Lower doses elicited distinct effects on T helper 1 (Th1) and Th2 cytokine expression depending on cellular activation pathways. In MoAb-stimulated cells, interferon (IFN)-?, tumour necrosis factor (TNF)-a and interleukin (IL)-6 production was reduced. Doses up to 0·150 and 0·5 µg/ml increased IL-10 and IL-4 production, respectively, resulting in significantly reduced Th1/Th2 ratios. Stimulation by hk-SE, however, elevated Th1/Th2 ratios due to induction of IFN-? versus IL-10 production. Taken together, we conclude that low-level exposure to Hg, in the absence of inflammation, polarizes the immune response toward Th2, but not in the case of Th1-polarized responses elicited by Salmonella antigens that can be promoted instead. This demonstrates differential in vitro effects of Hg on the Th1/Th2 balance produced by different stimuli, which may have important experimental and scientific implications.
Persistent UFZ Identifier
Hemdan, N.Y.A., Lehmann, I., Wichmann, G., Lehmann, J., Emmrich, F., Sack, U. (2007):
Immunomodulation by mercuric chloride in vitro: application of different cell activation pathways
Clin. Exp. Immunol. 148 (2), 325 - 337 10.1111/j.1365-2249.2007.03338.x