Modulation of HLA antigens in response to the binding of epidermal growth factor by A431 cells

AbstractIn a previous study [(1984) J. Cell Biol. 98, 725–731] we showed that the level of human MHC, HLA antigens on A431 carcinoma cells is reduced after these cells bind epidermal growth factor (EGF). Here we use flow cytometry to determine the effects of various doses and times of EGF treatment on HLA expression. We then show that the reduction in HLA expression is associated with a reduction in the level of phosphorylation of immunoprecipitable surface HLA antigens, although longer exposure of cells with EGF increased both surface HLA expression and their phosphorylation levels. Lateral diffusion of HLA antigens is lower in EGF-treated than in control cells. The lower diffusion coefficients measured may be causally related to the decreased phosphorylation of HLA antigens

Ginger extract inhibits LPS induced macrophage activation and function

<p>Abstract</p> <p>Background</p> <p>Macrophages play a dual role in host defence. They act as the first line of defence by mounting an inflammatory response to antigen exposure and also act as antigen presenting cells and initiate the adaptive immune response. They are also the primary infiltrating cells at the site of inflammation. Inhibition of macrophage activation is one of the possible approaches towards modulating inflammation. Both conventional and alternative approaches are being studied in this regard. Ginger, an herbal product with broad anti inflammatory actions, is used as an alternative medicine in a number of inflammatory conditions like rheumatic disorders. In the present study we examined the effect of ginger extract on macrophage activation in the presence of LPS stimulation.</p> <p>Methods</p> <p>Murine peritoneal macrophages were stimulated by LPS in presence or absence of ginger extract and production of proinflammatory cytokines and chemokines were observed. We also studied the effect of ginger extract on the LPS induced expression of MHC II, B7.1, B7.2 and CD40 molecules. We also studied the antigen presenting function of ginger extract treated macrophages by primary mixed lymphocyte reaction.</p> <p>Results</p> <p>We observed that ginger extract inhibited IL-12, TNF-α, IL-1β (pro inflammatory cytokines) and RANTES, MCP-1 (pro inflammatory chemokines) production in LPS stimulated macrophages. Ginger extract also down regulated the expression of B7.1, B7.2 and MHC class II molecules. In addition ginger extract negatively affected the antigen presenting function of macrophages and we observed a significant reduction in T cell proliferation in response to allostimulation, when ginger extract treated macrophages were used as APCs. A significant decrease in IFN-γ and IL-2 production by T cells in response to allostimulation was also observed.</p> <p>Conclusion</p> <p>In conclusion ginger extract inhibits macrophage activation and APC function and indirectly inhibits T cell activation.</p

Ginger extract inhibits LPS induced macrophage activation and function-1

<p><b>Copyright information:</b></p><p>Taken from "Ginger extract inhibits LPS induced macrophage activation and function"</p><p>http://www.biomedcentral.com/1472-6882/8/1</p><p>BMC Complementary and Alternative Medicine 2008;8():1-1.</p><p>Published online 3 Jan 2008</p><p>PMCID:PMC2234390.</p><p></p>with 100 ng/ml LPS in presence or absence of ginger extract for 24 h. The cells were harvested and stained with fluorophore conjugated mAb against B7.1 (), B7.2 () and CD40 () and analyzed in LSR II flow cytometer. Data are representative result of six replicates

Ginger extract inhibits LPS induced macrophage activation and function-2

<p><b>Copyright information:</b></p><p>Taken from "Ginger extract inhibits LPS induced macrophage activation and function"</p><p>http://www.biomedcentral.com/1472-6882/8/1</p><p>BMC Complementary and Alternative Medicine 2008;8():1-1.</p><p>Published online 3 Jan 2008</p><p>PMCID:PMC2234390.</p><p></p>with 100 ng/ml LPS in presence or absence of ginger extract for 24 h. The cells were harvested and stained with fluorophore conjugated mAb against MHC II and analyzed in LSR II flow cytometer. Data are representative result of six replicates

Ginger extract inhibits LPS induced macrophage activation and function-4

<p><b>Copyright information:</b></p><p>Taken from "Ginger extract inhibits LPS induced macrophage activation and function"</p><p>http://www.biomedcentral.com/1472-6882/8/1</p><p>BMC Complementary and Alternative Medicine 2008;8():1-1.</p><p>Published online 3 Jan 2008</p><p>PMCID:PMC2234390.</p><p></p>ce of ginger extract for 24 h. These pre-treated macrophages were used as the sole source of APCs along with syngeneic T cells as the responder cells in the presence of allostimulation. IL-2 and IFN-γ production was measured in the culture supernates after 72 h. incubation period. * ≤ 0.05 in comparison to Control. # ≤ 0.05 in comparison to LPS

Ginger extract inhibits LPS induced macrophage activation and function-3

<p><b>Copyright information:</b></p><p>Taken from "Ginger extract inhibits LPS induced macrophage activation and function"</p><p>http://www.biomedcentral.com/1472-6882/8/1</p><p>BMC Complementary and Alternative Medicine 2008;8():1-1.</p><p>Published online 3 Jan 2008</p><p>PMCID:PMC2234390.</p><p></p>ce of ginger extract for 24 h. These pre-treated macrophages were used as the sole source of APCs along with syngeneic T cells as the responder cells in the presence of allostimulation. T cell proliferation was measured by MTS assay after 72 h. incubation time. Results are presented as proliferation index equating the absorbance value (at 490 nm) of responder cells as 1. Responder cells only – no macrophages, Control- macrophages were not pre-treated, LPS- macrophages pre-treated with LPS only, LPS + G - macrophages pre-treated with LPS and ginger extract. Data represent mean ± S.D (n = 9). * ≤ 0.05 in comparison to Control. # ≤ 0.05 in comparison to LPS