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.
Strickland
F M
FM
Department of Immunology, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA. fstrickl@notes.mdacc.tmc.edu
Darvill
A
A
Albersheim
P
P
Eberhard
S
S
Pauly
M
M
Pelley
R P
RP
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