Vaccination with the repeat ?-hCG C-terminal peptide carried by heat shock protein-65 (HSP65) for inducing antitumor effects.

Vaccination with the repeat ?-hCG C-terminal peptide carried by heat shock protein-65 (HSP65) for inducing antitumor effects.

Tumour Biol. 2012 Jul 29;

Authors: Yang J, Zhang Y, Wang H, Gao Z, Wang Z, Liu B, Zhang X, Du M, Huang X, Xu M, Wu J, Li T, Liu J, Cao R

Abstract
The ?-subunit of human chorionic gonadotropin (?-hCG) is ectopically expressed in various types of cancer and has been utilized as an antigenic target in anti-cancer vaccines. In view of the low immunogenicity of this self-peptide, we designed a method based on the isocaudamer technique to generate 14 tandem repeats of the 10-residue sequence X of ?-hCG (109-118). These tandemly repeated copies were then combined with ?-hCG C-terminal 37 peptides (CTP37) and finally fused to mycobacterial heat-shock protein 65 (HSP65) to construct a fusion protein HSP65-X14-?hCGCTP37 as an immunogen. In this study, BALB/c female mice were immunized via subcutaneous injection of the designed protein. Humoral immune and cellular immune responses were effectively elicited. A high titer of anti-?-hCG antibody was detected in immunized mice sera by enzyme-linked immunosorbent assay and verified by Western blot analysis. The fusion protein, HSP65-X14-?-hCGCTP37, effectively inhibited the growth of Ehrlich ascites carcinoma in mice. These results suggest that HSP65-X14-?hCGCTP37 may be an effective tumor vaccine, and the use of multiple tandem repeats of a certain epitope is an effective method to overcome the low immunogenicity of self-peptide antigens.

PMID: 22843331 [PubMed - as supplied by publisher]

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