title: Depletion of suppressor T cells by 2'-deoxyguanosine abrogates tolerance in mice fed ovalbumin and permits the induction of intestinal delayed-type hypersensitivity.
abstract: We have re-examined the role of suppressor T cells (Ts) in regulating immune responses to fed proteins by investigating the effect of 2'-deoxyguanosine (dGuo) on systemic and intestinal immunity in mice fed ovalbumin (OVA). Administration of dGuo for 10 days abrogated the suppression of systemic delayed-type hypersensitivity (DTH) and antibody responses normally found after feeding OVA, and also prevented the generation of OVA-specific Ts. In parallel, mice given dGuo and fed OVA developed sensitization to OVA in the gut-associated lymphoid tissues (GALT) after oral challenge with OVA and had increased intraepithelial lymphocyte (IEL) counts and crypt cell production rates (CCPR) in the jejunal mucosa, indicating the presence of a local DTH response. These findings confirm the importance of Ts in preventing hypersensitivity to dietary protein antigens and suggest that enteropathies associated with food hypersensitivity are due to a defect in Ts activity.
mesh_terms: D000818:Animals; D003849:Deoxyguanosine / Q000494:pharmacology*; D004044:Dietary Proteins / Q000276:immunology; D005260:Female; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007108:Immune Tolerance; D007074:Immunoglobulin G / Q000096:biosynthesis; D007413:Intestinal Mucosa / Q000276:immunology*; D007958:Leukocyte Count; D008212:Lymphocyte Depletion; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*
chemical_list: D004044:Dietary Proteins; D007074:Immunoglobulin G; D010047:Ovalbumin; D003849:Deoxyguanosine