Lipoprotein antigens ofMycobacterium tuberculosis

BCG Vaccination Induces Robust CD4+ T Cell Responses to Mycobacterium tuberculosis Complex–Specific Lipopeptides in Guinea Pigs

“…The triacylated N terminus anchors the mature lipoprotein to the bacterial cell membrane but can be further processed: for some lipoproteins, cleavage sites have been described that allow for an enzymatic shedding of the protein, which leaves the lipidated N terminus tethered to the cell membrane (36,37). The immunogenicity of mycobacterial lipoproteins is long known (30), and a number of immunodominant epitopes from lipoproteins has been described. Although many of these epitopes were found in the middle or even carboxyl-terminal part of the proteins (38, 39), other reports indicated that the N-terminal part of lipoproteins, in particular of the 19-kDa lipoprotein, contains promiscuous T cell epitopes (40); and although lipoylation enhanced the immunogenicity of these N-terminal peptides, lipidation seemed not to be critically required for T cell recognition (41).…”

“…From an early report there was evidence that mycobacteria actively secrete lipopeptides (30). To investigate this possibility in the current context, we compared the reactogenicity of CME BCG and a total BCG cell lysate with a cell-free, filtered culture supernatant of an exponentially growing BCG culture.…”

Anti-tumor immunity induced by murine melanoma cells transduced with the Mycobacterium tuberculosis gene encoding the 38-kDa antigen

“…20 HSPs are also associated in vivo with the entire repertoire of peptides generated within the cell, and these noncovalent HSPpeptide complexes are particularly immunogenic. 21 In this article, we have shown that the expression of a Mycobacterium tuberculosis protein lacking chaperone activity 22 can enhance the immunogenicity of weakly antigenic tumor cells defective in costimulatory molecules and not expressing detectable levels of MHC antigens.…”

Host Responses and Antigens Involved in Protective Immunity to Mycobacterium tuberculosis

“…The L-alanine dehydrogenase (40 kDa). This enzyme catalyzes the reversible conversion of puruvate to L-alanine and may be involved in cell wall synthesis, as L-alanine is one of the four amino acids constituting the peptide moiety of the peptidoglycan layer [159]. No signal sequence was identified.…”

“…This molecule is mainly localized in the outer cell wall and only released to the surroundings in limited amounts. The protein is post-translationally modified by lipidation and is apparently anchored in the cell membrane by its lipid moiety [159]. The function of the 38 kDa protein is to bind and make phosphate available to the bacteria and the synthesis of this protein is highly up-regulated during phosphate starvation [160].…”