The hinge region fragment of immunoglobulin G improves immunogenicity of recombinant gonadotrophin-releasing hormone conjugated to the T-helper epitope in designing peptide vaccines.
In our previous study, the hinge fragment (225-232/225'-232') of human immunoglobulin G1 (IgG1) was used as a space peptide linker for synthesizing the GnRH3-hinge-MVP chimeric peptide, whereby three repeated gonadotrophin-releasing hormone (GnRH) units and a T-cell epitope from measles virus fusion protein (MVP) were amide-bond-linked at the N and C terminus, respectively, to the hinge peptide for producing anti-GnRH antibody responses. To investigate whether or not the hinge region fragment can improve the immunogenicity of GnRH, we further synthesized and purified GnRH3-hinge-MVP, GnRH3-hinge and GnRH3-MVP using recombinant DNA technology. Under high pH conditions, GnRH3-hinge-MVP was capable of forming double-chain structures. Immunization of male mice with the immunogens of GnRH3-hinge-MVP resulted in the generation of high-titre antibodies specific for GnRH. The synthetic GnRH3-hinge and GnRH3-MVP induced a lower titre of anti-GnRH antibody than GnRH3-hinge-MVP. This was followed by a decrease in serum testosterone levels, which resulted in a low level of expression of the relaxin-like factor gene in the testis. Our data suggest that peptide and T-cell epitopes oriented at the N-terminus or C-terminus of hinge peptides simplify the antigenic peptide conjugates and may be considered as potential synthetic immunogens.
Xu
Jinshu
J
School of Pharmacy, Nanjing Medical University, Nanjing, China. jinshuuxu@yahoo.com
Wu
Jie
J
Wang
Xuejun
X
Zhang
Yin
Y
Li
Wenjia
W
Zhu
Zheng
Z
Zhu
Dongya
D
Hu
Zhuoyi
Z
Roque
Rouel S
RS
Liu
Jingjing
J
D000818:Animals; D000906:Antibodies / Q000097:blood; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D015870:Gene Expression / Q000276:immunology; D007987:Gonadotropin-Releasing Hormone / Q000276:immunology* / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors; D007074:Immunoglobulin G / Q000276:immunology; D007328:Insulin / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D010084:Oxidation-Reduction; D011506:Proteins / Q000276:immunology / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000378:metabolism; D013737:Testis / Q000276:immunology / Q000378:metabolism; D013739:Testosterone / Q000097:blood; D014157:Transcription Factors / Q000276:immunology / Q000378:metabolism; D022223:Vaccines, Subunit / Q000276:immunology*; D014764:Viral Proteins / Q000276:immunology* / Q000378:metabolism
D000906:Antibodies; D018984:Epitopes, T-Lymphocyte; C512006:GnRH3-hinge-MVP; D020662:Guanine Nucleotide Exchange Factors; D007074:Immunoglobulin G; D007328:Insulin; C084797:Leydig insulin-like protein; D011506:Proteins; C490805:Rgl2 protein, mouse; D014157:Transcription Factors; D022223:Vaccines, Subunit; D014764:Viral Proteins; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone