Inhibition of UV-induced immune suppression and interleukin-10 production by plant oligosaccharides and polysaccharides.
Application of Aloe barbadensis poly/oligosaccharides to UV-irradiated skin prevents photosuppression of delayed-type hypersensitivity (DTH) responses in mice. We tested the hypothesis that these carbohydrates belong to a family of biologically active, plant-derived polysaccharides that can regulate responses to injury in animal tissues. C3H mice were exposed to 5 kJ/m2 UVB from unfiltered FS40 sunlamps and treated with between 1 pg and 10 micrograms tamarind xyloglucans or control polysaccharides methylcellulose or dextran in saline. The mice were sensitized 3 days later with Candida albicans. Tamarind xyloglucans and purified Aloe poly/oligosaccharides prevented suppression of DTH responses in vivo and reduced the amount of interleukin (IL)-10 observed in UV-irradiated murine epidermis. Tamarind xyloglucans were immunoprotective at low picogram doses. In contrast, the control polysaccharides methylcellulose and dextran had no effect on immune suppression or cutaneous IL-10 at any dose. Tamarind xyloglucans and Aloe poly/oligosaccharides also prevented suppression of immune responses to alloantigen in mice exposed to 30 kJ/m2 UVB radiation. To assess the effect of the carbohydrates on keratinocytes, murine Pam212 cells were exposed to 300 J/m2 UVB radiation and treated for 1 h with tamarind xyloglucans or Aloe poly/oligosaccharides. Treatment of keratinocytes with immunoprotective carbohydrates reduced IL-10 production by approximately 50% compared with the cells treated with UV radiation alone and completely blocked suppressive activity of the culture supernatants in vivo. The tamarind xyloglucans also blocked UV-activated phosphorylation of SAPK/JNK protein but had no effect on p38 phosphorylation. These results indicate that animals, like plants, may use carbohydrates to regulate responses to environmental stimuli.
Department of Immunology, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA. fstrickl@notes.mdacc.tmc.edu
F M
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Strickland
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Darvill
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Albersheim
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Eberhard
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Pauly
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Pelley
D000287:Administration, Topical; D000504:Aloe; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002240:Carbohydrate Sequence; D005260:Female; D005936:Glucans; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007375:Interleukin-1 / Q000096:biosynthesis*; D048031:JNK Mitogen-Activated Protein Kinases; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D020928:Mitogen-Activated Protein Kinases; D008969:Molecular Sequence Data; D010946:Plants, Medicinal; D011134:Polysaccharides / Q000494:pharmacology*; D012639:Seeds; D012867:Skin / Q000187:drug effects / Q000528:radiation effects; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000528:radiation effects; D014466:Ultraviolet Rays; D014990:Xylans; D048051:p38 Mitogen-Activated Protein Kinases
D005936:Glucans; D007375:Interleukin-1; D011134:Polysaccharides; D014990:Xylans; C029353:xyloglucan; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases