Allergen-stimulated expression of CD154 (CD40 ligand) on CD3+ lymphocytes in atopic, but not in nonatopic individuals. Modulation by bacterial lipopolysaccharide.
The intention of this study was to mimic a naturally occurring stimulation by allergens and bacterial infection in order to determine whether specific allergen-induced, inflammatory responses may be changed or modified by bacterial products. Blood leukocytes from six atopic and six nonatopic individuals were examined for their surface expression of CD154, CD11a, and HLA-DR molecules and for secretion of IgE, eosinophil cationic protein (ECP), and the cytokines interleukin (IL)-4 and IL-5. Signals through CD154 are required for activation and proliferation of effector cells associated with the allergic, inflammatory response. HLA-DR and CD11a/CD18-mediated interactions are also involved in T- and B-cell functions. Birch-pollen (BP) allergens induced CD154 expression on CD3-positive lymphocytes only in atopic individuals. In nonatopics, the expression of CD154 could be induced only after exposure to BP and subsequent lipopolysaccharide (LPS) stimulation. Levels of CD154 expression were always higher in atopics than nonatopics. CD11a and HLA-DR expressions were upregulated, irrespective of atopic state, after BP and/or LPS stimulation. The increased secretion of IL-5 and total IgE in BP-supplemented cell cultures indicated that an allergic response had occurred. In conclusion, the results of this report do not support the hypothesis of a changed inflammatory response stimulated by the combined action of bacteria and allergens, as compared to allergen provocation alone.
Nakstad
B
B
Research Forum, Ullevål University Hospital, Oslo, Norway.
Kähler
H
H
Lyberg
T
T
D000328:Adult; D000485:Allergens / Q000276:immunology*; D017252:CD3 Complex / Q000097:blood*; D023201:CD40 Ligand; D005260:Female; D006684:HLA-DR Antigens / Q000097:blood; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D015847:Interleukin-4 / Q000378:metabolism; D015848:Interleukin-5 / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000097:blood; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood*; D008875:Middle Aged; D011058:Pollen / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014197:Trees / Q000276:immunology
D000485:Allergens; D017252:CD3 Complex; D006684:HLA-DR Antigens; D015848:Interleukin-5; D008070:Lipopolysaccharides; D016169:Lymphocyte Function-Associated Antigen-1; D008562:Membrane Glycoproteins; D023201:CD40 Ligand; D015847:Interleukin-4