title: Hemokinin-1 as an adjuvant molecule enhancing humoral and memory responses to HBsAg DNA vaccination.
abstract: Incorporation of molecular adjuvants into DNA vaccines is often used to improve the induction of immune responses, but few approaches aim to specifically activate B cells for an enhanced humoral response only. Hemokinin-1 (HK-1) is a factor that activates B cells for proliferation, survival, differentiation into plasma cells, and Ab production. Therefore, we investigated if it may be used as a molecular adjuvant for DNA vaccines to elicit strong humoral and memory responses. The HK-1 coding sequence was sub-cloned as single or triple copies in-frame downstream of S2 HBsAg in the proVAX/S2 construct. Compared to mice immunized with proVAX/S2 or proVAX/S2-HK-1, proVAX/S2-3HK-1 induced a higher level of IgG production, a higher percentage of differentiated antibody-secreting plasma cells, and a higher level of T-cell proliferation. Furthermore, a higher proportion of B cells had the B220(+)CD27(+) phenotype in these groups, and specific antigen re-challenge induced a higher level of total IgG production 60 d after the last immunization, suggesting that the use of HK-1 as an adjuvant promoted immunological memory. Taken together, these results suggest that using HK-1 as an adjuvant molecule could enhance the immunogenicity of HBsAg DNA vaccines, and result in stronger humoral and memory responses. Therefore, HK-1 may lead to the development of a novel humoral-biased molecular adjuvant for an HBsAg DNA vaccine against hepatitis B infection.
authors.affiliation: State Key Laboratory for Agro-Biotechnology, Department of Microbiology and Immunology, College of Biological Science, China Agricultural University, Beijing, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Chen
authors.forename: Wang
authors.initials: W
authors.lastname: Zhang
authors.forename: Wenqing
authors.initials: W
authors.lastname: Gao
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zou
authors.forename: Congcong
authors.initials: C
authors.lastname: Feng
authors.forename: Hu
authors.initials: H
authors.lastname: Liu
authors.forename: Chenliang
authors.initials: C
authors.lastname: Zhou
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D005260:Female; D006509:Hepatitis B / Q000276:immunology / Q000517:prevention & control / Q000821:virology; D006510:Hepatitis B Antibodies / Q000097:blood*; D006514:Hepatitis B Surface Antigens / Q000235:genetics / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007156:Immunologic Memory; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D041681:NIH 3T3 Cells; D015320:Tachykinins / Q000235:genetics / Q000276:immunology*; D014611:Vaccination; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D015320:Tachykinins; D019444:Vaccines, DNA; C507968:hemokinin-1