Effects Of Uric Acid Sodium Salt Adjuvant On Humoral And Cellular Immune Responses Of BALB/c Mice

AIM:To investigate the effects of uric acid sodium salt (UANa) as an adjuvant on humoral and cellular immune responses of the BALB/c mice.METHODS:1. BALB/c mice were immunized with trichosanthin (TCS) as an antigen together with UANa suspension as an adjuvant. The antibody titers of IgG were detected by enzyme-linked immunosorbent assay.2. Dendritic cells (DC) were induced in vitro, the phenotypes of DC were analyzed by flow cytometry and the effect of UANa on DC maturity was evaluated.3. Delayed-type hypersensitivity (DTH) model was used to analyze the effect of UANa on cellular immune responses in vivo. The in vitro proliferation was determined by ConA stimulation.RESULTS:1. Freund's adjuvant could significantly enhance the serum IgG titer in mice against TCS, while UANa adjuvant failed to promote IgG titer but greatly restrain it. The results suggest that UANa adjuvant failed to promote the antibody response but significantly reduced antibody response when compared with TCS only.2. Bone marrow cells were isolated from mice's bone marrow and stimulated by rmGM-CSF and rmIL-4, DC characteristics were distincted by Optical Microscopy and Atomic Force Microscopy, suggesting that DC was induced successfully.Flow cytometry analysis showed that UANa has no effect on CD11c and CD83 expression on DC, but could significantly enhance the expression level of MHCâ…¡molecules, indicating that UANa has obviously promoted DC maturation.3. Abdomen with 0.5% DNFB sensitization, mouse DTH model was successfully established. ear tissue swelling and the thymus index and spleen index were promoted or enhanced by UANa suspension on DTH model; Biopsy of mouse ear were observed under optical microscope, implying that lymphocyte infiltration increased significantly; The lymphocytes proliferation capacity of lymph nodes and spleen from DTH mice was assayed by MTS colorimetry, the rusults showed that UANa Suspension could enhanced it notablely. In conclusion, UANa Suspension significantly increased DNFB-induced DTH inflammatory response in vitro.CONCLUSIONS:UANa suspension adjuvant could significantly enhance the cellular immune response but inhibit the humoral immune response to a certain degree, suggesting that UANa has potential application in enhancing the cellular immunity of a vaccine.