title: [Gene conjugation of molecular adjuvant C3d3 to hCGbeta enhanced the anti-hCGbeta humoral immune response via upregulation of CXCR4 expression on splenic B cells in DNA vaccination].
abstract: To investigate mechanism of the anti-hCGbeta humoral immune responsive enhancement by gene conjugation of the molecular adjuvant C3d3 to hCGbeta in DNA immunization, BALB/c mice were inoculated intramuscularly with pCMV4-hCGbeta-C3d3, pCMV4-hCGbeta and pCMV4, respectively. The titers of anti-hCGbeta IgG/IgA antibody in serum were determined by indirect ELISA. The IgG/IgA ASCs levels were evaluated by ELISPOT. The expressions of chemokine receptors on B cells were analyzed by RT-PCR, and CXCR4 expression was analyzed respectively by RT-PCR and FCM. The expression of CXCL12 in spleen was investigated respectively by RT-PCR and ELISA. We found that anti-hCGbeta IgG antibody titer in serum after pCMV4-hCGbeta-C3d3 immunization was significantly higher than that of pCMV4-hCGbeta immunization. But the anti-hCGbeta IgA antibody titers appeared no difference between the two immunized groups. The level of IgG ASCs in spleen of pCMV4-hCGbeta-C3d3 immunization was significantly higher than that of pCMV4-hCGbeta immunization,but the levels of IgA ASCs appeared no difference between the two groups. The expression of CXCR4 on B cell increased after pCMV4-hCGbeta-C3d3 immunization, and significantly higher than that of pCMV4-hCGbeta immunization. The rate of CXCR4+ cell was correlated to the numbers of the ASC (r = 0.966, P < 0.05). CXCL12 expression increased after pCMV4-hCGbeta and pCMV4-hCGbeta-C3d3 immunization, and appeared no difference between the two groups. These results above indicate that gene fusion of the molecular adjuvant C3d3 to hCGbeta can significantly enhance the antigen-specific antibody response, and the level of IgG ASCs in spleen via upregulation of CXCR4 expression on splenic B cells in DNA vaccination.
authors.affiliation: Laboratory for Reproductive Immunology, Hospital & Institute of Obstetrics and Gynecology, Shanghai Medical College, Fudan University, Shanghai 200011.
authors.forename: Xiao Ju
authors.initials: XJ
authors.lastname: He
authors.forename: Jin
authors.initials: J
authors.lastname: Da Li
authors.forename: Xiao Ying
authors.initials: XY
authors.lastname: Yao
authors.forename: Min Min
authors.initials: MM
authors.lastname: Yuan
mesh_terms: D000276:Adjuvants, Immunologic / Q000235:genetics; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000235:genetics*; D015933:Complement C3d / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D019718:Receptors, CXCR4 / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000166:cytology; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D018997:Chorionic Gonadotropin, beta Subunit, Human; D019718:Receptors, CXCR4; D011993:Recombinant Fusion Proteins; D019444:Vaccines, DNA; D015933:Complement C3d