IMMUNE EFFECTOR-CELLS INDUCED BY COMPLETE FREUNDS-ADJUVANT EXERT AN INHIBITORY EFFECT ON ANTIGEN-SPECIFIC TYPE-2 T-HELPER RESPONSES

Background It has been well documented that environmental factors such as antigen-presenting cells and related cytokines could affect the de velopment of T helper cells. Objective The purpose of this study is to investigate the effect of different adjuvants on T cell development. Methods Ovalbumin (OVA) combined with aluminum hydroxide (Alum) plus p ertussis toxin (PT) or complete Freund's adjuvant (CFA) were used to s ensitize mice; the production of IgG and IgE anti-OVA antibodies was t hen followed. In addition, OVA-specific proliferative responses and cy tokine production by spleen cells were also investigated. Results The data showed that the adjuvants themselves could modify the pattern of immune response: (1) IgG(2a) anti-OVA antibody was higher in mice sens itized with OVA + CFA compared to that of mice sensitized with OVA + A lum + PT; (2) the ratio of IFN-gamma/IL-4 produced by OVA-stimulated s pleen cells was higher in mice sensitized with OVA + CFA than that of mice sensitized with OVA + Alum + PT; (3) increased percentage of gamm a delta T cells was noted in the peritoneal exudate cells of OVA + CFA immunized mice; and (4) the immune response of mice sensitized with O VA + Alum + PT was inhibited by the adoptively transferred ascitic cel ls from OVA + CFA immunized mice. Conclusion In general, the data sugg ested higher IgG(2a) and the ratio of IFN-gamma/IL-4 was noted in mice sensitized with OVA + CFA. Further elucidation of the regulatory mech anism of allergen-specific T helper cells development and exploration of possible agents for immunotherapy might shed light on the managemen t of atopic diseases.