Identification of new cytotoxic T-cell epitopes on the 38-kilodalton lipoglycoprotein of Mycobacterium tuberculosis by using lipopeptides.
Induction of cytotoxic T lymphocytes (CTLs) by vaccination has been shown to protect against bacterial, viral, and tumoral challenge. The aim of this study was to identify CTL epitopes on the 38-kDa lipoglycoprotein from Mycobacterium tuberculosis. The identification of these CTL epitopes was based on synthesizing peptides designed from the 38-kDa lipoglycoprotein, with known major histocompatibility complex class I (MHC-I) binding motifs (H-2Db), and studying their ability to up-regulate and stabilize MHC-I molecules on the mouse lymphoma cell line RMA-S. To improve the capacity of the identified peptides to induce CTL responses in mice, palmitic acid with a cysteine-serine-serine spacer amino acid sequence was attached to the amino terminus of the peptide. Two of five peptides with H-2Db binding motifs and their corresponding lipopeptides up-regulated and stabilized the H-2Db molecules on RMA-S cells. Both lipopeptides, in combination with incomplete Freund's adjuvant, induced CTL responses in C57BL/6 (H-2(b)) mice. Moreover, the lipopeptide induced stronger CTL responses than the peptide. The capacity of the various lipopeptides to induce CTL displayed a good relationship with the ability of the (lipo)peptide to up-regulate and to stabilize H-2Db molecules. The capacity of the peptides and lipopeptides to up-regulate and stabilize MHC-I expression can therefore be used to predict their potential to function as a CTL epitope. The newly identified CTL epitopes and their lipid derivatives provide us with important information for future M. tuberculosis vaccine design.
da Fonseca
D P
DP
Eijkman-Winkler Institute for Microbiology, Infectious Diseases, and Inflammation, Section Vaccines, Academic Hospital Utrecht, Utrecht University, 3584 CX Utrecht, The Netherlands. D.Fonseca@lab.azu.nl
Joosten
D
D
van der Zee
R
R
Jue
D L
DL
Singh
M
M
Vordermeier
H M
HM
Snippe
H
H
Verheul
A F
AF
D000818:Animals; D018984:Epitopes, T-Lymphocyte; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D006183:H-2 Antigens / Q000096:biosynthesis; D064532:Histocompatibility Antigen H-2D; D008074:Lipoproteins / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014407:Tumor Cells, Cultured
D018984:Epitopes, T-Lymphocyte; D006023:Glycoproteins; D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D008074:Lipoproteins