The role of costimulatory molecules (B7-1 and B7-2) on allergen-stimulated B cells in cedar pollinosis subjects.
BACKGROUND
B7-1 (CD80) and B7-2 (CD86), which are costimulatory molecules in T-cell activation, play important roles in the differentiation of TH1- or TH2-phenotypes. These molecules were also suggested to play important roles in sensitization to a cedar pollen antigen by blocking studies using neutralizing antibodies, but there have been very few studies concerning the effects following induction by antigen.


OBJECTIVE
In this study, we investigated the roles of B7-1 and B7-2 in the differentiation of TH1 and TH2 subsets after stimulation with the antigen in subjects with cedar pollinosis.


METHODS
Skin-prick test was performed in nine subjects with pollinosis and in nine normal controls. Peripheral blood mononuclear cells (PBMCs) were isolated and stimulated with Japanese cedar pollen extract. After in vitro stimulation, the expression of CD80 and CD86 on CD19+ cells was analysed by two-colour flow cytometry. Culture supernatants were collected for all subjects and the production of type 1 and type 2 cytokines was measured by ELISA.


RESULTS
After in vitro stimulation, the expression of CD80 (B7-1) was upregulated in both pollinosis and control subjects, but no significant difference was observed between the two groups. On the other hand, CD86 (B7-2) was significantly upregulated following stimulation in pollinosis subjects (P = 0.02). A significantly higher level of IL-5 (P = 0.04) was produced by PBMCs of pollinosis subjects than by those of normal controls. A significantly higher level of interferon (IFN)-gamma (P = 0.03) was produced by PBMCs of normal controls than by those of pollinosis subjects.


CONCLUSIONS
These results indicated that TH2 response was predominant in pollinosis subjects, and that CD19+ cells of pollinosis subjects expressed higher levels of B7-2 than those of control subjects after in vitro stimulation. In pollinosis subjects, B7-2 rather than B7-1 may be the costimulatory molecule involved in allergen-induced activation of PBMCs.
Morikawa
H
H
Department of Microbiology, Dokkyo University School of Medicine, Tochigi, Japan.
Nagashima
S
S
D000328:Adult; D000485:Allergens / Q000009:adverse effects*; D015703:Antigens, CD / Q000502:physiology*; D001402:B-Lymphocytes / Q000276:immunology*; D018122:B7-1 Antigen / Q000502:physiology*; D051940:B7-2 Antigen; D016207:Cytokines / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D008562:Membrane Glycoproteins / Q000502:physiology*; D008875:Middle Aged; D011058:Pollen / Q000009:adverse effects*; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014197:Trees; D015854:Up-Regulation
D000485:Allergens; D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497964:CD86 protein, human; D016207:Cytokines; D008562:Membrane Glycoproteins