Culture filtrate specific H-2(b) restricted CD8+ T cells activated in vivo by Mycobacterium tuberculosis or bovis BCG recognize a restricted number of immunodominant peptides.
We previously demonstrated that Bacillus Calmette-Guerin (BCG) immunization activated D(b) restricted CD8+ cytolytic T lymphocyte (CTL) recognizing target cells incubated with mycobacterial culture filtrate. Here, we show that in vitro restimulation of spleen cells from BCG vaccinated or Mycobacterium tuberculosis infected mice with culture filtrate antigens leads to the appearance of a high percentage of D(b) restricted IFNgamma synthesizing CD8+ T cell blasts. Transporter associated protein-2 mutated RMA-S cells incubated with soluble culture filtrate proteins had their MHC class I D(b) but not K(b) molecules stabilized at the surface indicating that only D(b) ligands might be generated by antigen presenting cells. MHC class I bound peptides were acid eluted from the surface of RMA-S cells incubated with M. tuberculosis culture filtrate proteins. The crude peptide preparation was able to sensitize RMA-S cells for recognition by culture filtrate-specific cytolytic T cells. Peptides were subsequently fractionnated by reverse-phase high performance liquid chromatography and the main biological activity was identified in two fractions. These results provide a further evidence that the processing of exogenous culture filtrate proteins in vitro leads to the presentation of a restricted number or even a single immunodominant peptide to culture filtrate-specific CD8+ T cells.
Denis
Olivier
O
Laboratory of Mycobacterial Immunology, Pasteur Institute of Brussels, Engelandstraat 642, B-1180, Brussels, Belgium. odenis@ben.vub.ac.be
Stroobant
Vincent
V
Colau
Didier
D
D'Souza
Sushila
S
Huygen
Kris
K
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000276:immunology; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D017077:Culture Media, Conditioned; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D005260:Female; D006183:H-2 Antigens / Q000276:immunology*; D064532:Histocompatibility Antigen H-2D; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D016056:Immunodominant Epitopes / Q000276:immunology*; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D008285:Major Histocompatibility Complex / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009163:Mycobacterium bovis / Q000276:immunology*; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D010455:Peptides / Q000276:immunology
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D000942:Antigens, Bacterial; D017077:Culture Media, Conditioned; D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D015395:Histocompatibility Antigens Class I; D016056:Immunodominant Epitopes; D010455:Peptides; C489516:Tap2 protein, mouse; D007371:Interferon-gamma