The distribution of expression products of oral Ag85A DNA vaccine in spleen

Objective To detect the distribution of expression products of Ag85A DNA vaccine in spleen. Methods E. coil DH5α was transformed by pCDNA3. 1 +-Ag85A. After extraction and purification of the re-comhinant p]asmid with cndotoxin free kit, liposome encapsulated recombinant Ag85A DNA vaccine was pre-pared. C57BL/6 mice were randomly divided into two groups, test group and control group, respectively. The mice were immunized through intragastric administration once two weeks for three times. The mice were sacri-riced two weeks after the final administration of the vaccine. The expression products of Ag85A DNA vaccine in the spleen was detected by immunohistocbemistry and immunofluorescence methods. Results The expression products of Ag85A DNA vaccine in the spleen was scatted, including white pulp, marginal zone and red pulp cords. The intensity of Ag85A in the marginal zone and red pulp cords is higher than that in the white pulp. When comparing between the immunohisteehemistry results of the marginal zone and the white pulp, the value is t = 3. 039, P < 0. 05 ; between the red pulp cords and the white pulp, the value is t = 3. 068, P < 0. 05 ; be-tween the marginal zone and the red pulp cords, the value is t = 1. 750, P 0. 05. When comparing betweenthe immunofluoresccnce results of the marginal zone and the white pulp, the value is t = 3. 144, P < 0. 05; be-tween the red pulp cords and the white pulp, the value is t = 3. 098, P < 0. 05 ; between the marginal zone and red pulp cords, the value is t = 1. 3 6 9, P 0. 0 5. Conclusion While Liposome encapsulated recombinant Ag85A DNA vaccine administered orally, it could be absorbed. Its expression products distribute in the spleen and might induce systemic immune response. Key words: Ag85A;  DNA vaccine;  Spleen