Polymerisation of a T Cell Epitope with an Immunostimulatory C3d Peptide Sequence Enhances Antigen Specific T Cell Responses
- 192 Downloads
The complement protein C3d and C3d derived peptides that bind CD21 are known to enhance immunity to co-immunised antigens. In this study we have synthesised the minimal CD21 binding sequence of C3d (1227LYNVEA1232) as mono, di and tri tandem repeats and derivatised the N-terminus with an acryloyl moiety. These acryloyl-(C3d) n peptides were co-polymerised with a acryloyl-T cell epitope (PAS1K) from the Porphyromonas gingivalis antigen the RgpA–Kgp proteinase–adhesin complex. The ability of C3d containing polymers to enhance T cell immunity in vitro and in vivo was evaluated. When used to stimulate in vitro PAS1K-primed or RgpA–Kgp complex-primed T cells the C3d containing PAS1K polymers induced a mixed and significantly (p < 0.05) higher IL-4 and IFNγ T cell response compared to that induced by the PAS1K peptide or polymer. PAS1K polymers containing tandem repeats of C3d induced a significantly (p < 0.05) stronger maximal proliferative response, at the same antigenic dose, compared to that induced by the PAS1K peptide or polymer. When used as immunogens to prime T cells all of the C3d containing PAS1K polymers induced a dominant IFNγ T cell response and reduced the antigen dose required for maximal proliferation 150-fold compared to that required for the PAS1K-peptide or polymer primed T cells. In conclusion, the 6 residue sequence LYNVEA from C3d is sufficient to enhance immunity to an antigen and that the effect is more pronounced when C3d is part of the immunising antigen rather than an in vitro stimulating antigen.
KeywordsC3d complement Peptide synthesis Peptide polymers T cell immune responses
We also wish to thank Ms Jenny Davis for the animal welfare and handling. This work was supported by NHMRC Grants: APP1029878 and APP1008106.
- Frade R, Hermann J, Barel M (1992) A 16 amino acid synthetic peptide derived from human C3d triggers proliferation and specific tyrosine phosphorylation of transformed CR2-positive human lymphocytes and of normal resting B lymphocytes. Biochem Biophys Res Commun 188:833–842PubMedCrossRefGoogle Scholar
- Jung MC, Hartmann B, Gerlach JT, Diepolder H, Gruber R, Schraut W, Gruner N, Zachoval R, Hoffmann R, Santantonio T, Wachtler M, Pape GR (1999) Virus-specific lymphokine production differs quantitatively but not qualitatively in acute and chronic hepatitis B infection. Virology 261:165–172PubMedCrossRefGoogle Scholar
- Sandler SR, Karo W (1992) Polymer synthesis. Academic Press, BostonGoogle Scholar
- Suradhat S, Braun RP, Lewis PJ, Babiuk LA, van Drunen Littel-van den Hurk S, Griebel PJ, Baca-Estrada ME (2001) Fusion of C3d molecule with bovine rotavirus VP7 or bovine herpesvirus type 1 glycoprotein D inhibits immune responses following DNA immunization. Vet Immunol Immunopathol 83:79–92PubMedCrossRefGoogle Scholar
- Troye-Blomberg M, Romero P, Patarroyo ME, Bjorkman A, Perlmann P (1984) Regulation of the immune response in Plasmodium falciparum malaria. III. Proliferative response to antigen in vitro and subset composition of T cells from patients with acute infection or from immune donors. Clin Exp Immunol 58:380–387PubMedGoogle Scholar
- Zou Y, Lin J, Dai L, Pan R (1993) Group-transfer block copolymerization by bifunctional initiators. Gaodeng Xuexiao Huaxue Xuebao 14:294–295Google Scholar