title: CD8+ T cells modulate late allergic airway responses in Brown Norway rats.
abstract: To test the hypothesis that CD8+ T cells may suppress the allergen-induced late airway response (LAR) and airway eosinophilia, we examined the effect of administration of Ag-primed CD8+ T cells on allergic airway responses, bronchoalveolar lavage (BAL) leukocytes, and mRNA expression for cytokines (IL-4, IL-5, and IFN-gamma) in OVA-sensitized Brown Norway rats. On day 12 postsensitization to OVA, test rats were administered 2 million CD8+ T cells i.p. isolated from either the cervical lymph nodes (LN group; n = 8) or the spleen (Spl group; n = 6) of sensitized donors. On day 14, test rats were challenged with aerosolized OVA. Control rats were administered PBS i.p. on day 12, and challenged with OVA (n = 10) or BSA (n = 6) on day 14. The lung resistance was measured for 8 h after challenge. BAL was performed at 8 h. Cytospin slides of BAL were analyzed for major basic protein by immunostaining and for cytokine mRNA by in situ hybridization. The LAR was significantly less in the LN group (1.8 +/- 0.5 U; p < 0.01) and BSA controls (1.4 +/- 0.7; p < 0.01), but not in the Spl group (6.7 +/- 2.2), compared with that in OVA controls (8.1 +/- 1.8). In BAL, the number of major basic protein-positive cells was lower in the LN and Spl groups compared with OVA controls (p < 0.05 and p < 0.01). IL-4- and IL-5-positive cells were decreased in the LN group compared with the OVA controls (p < 0.01). INF-gamma-positive cells were increased in the LN and Spl groups compared with the OVA controls (p < 0.01). Serum OVA-specific IgE levels were unaffected by CD8+ T cell transfers. These results indicate that Ag-primed CD8+ T cells have a potent suppressive effect on LAR.
authors.affiliation: Meakins-Christie Laboratories, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: R
authors.initials: R
authors.lastname: Taha
authors.forename: D
authors.initials: D
authors.lastname: Ihaku
authors.forename: Q
authors.initials: Q
authors.lastname: Hamid
authors.forename: J G
authors.initials: JG
authors.lastname: Martin
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D001985:Bronchial Provocation Tests; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000637:transplantation; D016207:Cytokines / Q000096:biosynthesis; D005434:Flow Cytometry; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000166:cytology / Q000276:immunology; D008297:Male; D010047:Ovalbumin / Q000097:blood / Q000276:immunology; D051381:Rats; D011914:Rats, Inbred BN; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D016207:Cytokines; D007073:Immunoglobulin E; D010047:Ovalbumin