Epitope DNA vaccines against tuberculosis: spacers and ubiquitin modulates cellular immune responses elicited by epitope DNA vaccine.
Cell-mediated immune responses are crucial in the protection against tuberculosis. In this study, we constructed epitope DNA vaccines (p3-M-38) encoding cytotoxic T lymphocyte (CTL) epitopes of MPT64 and 38 kDa proteins of Mycobacterium tuberculosis. In order to observe the influence of spacer sequence (Ala-Ala-Tyr) or ubiquitin (UbGR) on the efficacy of the two CTL epitopes, we also constructed DNA vaccines, p3-M-S(spacer)-38, p3-Ub (UbGR)-M-S-38 and p3-Ub-M-38. The immune responses elicited by the four DNA vaccines were tested in C57BL/6 (H-2b) mice. The cytotoxicity of T cells was detected by LDH-release method and by enzyme-linked immunospot assay for epitope-specific cells secreting interferon-gamma. The results showed that DNA immunization with p3-M-38 vaccine could induce epitope-specific CD8+ CTL response and that the spacer sequence (AAY) only enhanced M epitope presentation. The protein-targeting sequence (UbGR) enhanced the immunogenicity of the two epitopes. The finding that defined spacer sequences at C-terminus and protein-targeting degradation modulated the immune response of epitope string DNA vaccines will be of importance for the further development of multi-epitope DNA vaccines against tuberculosis.
Wang
Q-M
QM
Department of Medical Genetics, The Second Military Medical University, Shanghai, China.
Sun
S-H
SH
Hu
Z-L
ZL
Zhou
F-J
FJ
Yin
M
M
Xiao
C-J
CJ
Zhang
J-C
JC
D000818:Animals; D000939:Epitopes / Q000276:immunology*; D005260:Female; D007111:Immunity, Cellular / Q000276:immunology / Q000502:physiology; D007371:Interferon-gamma / Q000378:metabolism; D051379:Mice; D009169:Mycobacterium tuberculosis / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014162:Transfection; D014376:Tuberculosis / Q000276:immunology / Q000517:prevention & control*; D032581:Tuberculosis Vaccines / Q000276:immunology*; D025801:Ubiquitin / Q000276:immunology / Q000378:metabolism*; D019444:Vaccines, DNA / Q000276:immunology*
D000939:Epitopes; D032581:Tuberculosis Vaccines; D025801:Ubiquitin; D019444:Vaccines, DNA; D007371:Interferon-gamma