Human dendritic cells process and present Listeria antigens for in vitro priming of autologous CD4+ T lymphocytes.
The role of human dendritic cells (DC) in the immune response toward intracellularly growing Listeria was analyzed under in vitro conditions using several morphological and functional methods. DC incubated with Listeria innocua and L. monocytogenes, respectively, readily phagocytosed the bacteria. Listeria did not impair viability and immunogenic potential of human DC. Listerial antigens were found to be processed within the lysosomal compartment of DC and colocalized with major histocompatibility complex (MHC) class II molecules, as shown by fluorescence and transmission electron microscopy. DC challenged with apathogenic L. innocua were highly effective in priming autologous naive T cells (mainly CD4+) in vitro. The T cells strongly proliferated in the presence of DC incubated with L. innocua, which could be significantly inhibited by anti-MHC II mAb. L. innocua-primed T cells were also successfully stimulated by DC harboring the pathogenic L. monocytogenes, either the wild-type strain EGD or the p60 reduced mutant strain RIII. From our results, we conclude that human DC infected with nonpathogenic intracellular bacteria are able to efficiently prime naive T cells, which are then suitable for recognition of antigens derived from related virulent bacterial species. This in vitro human model provides an interesting tool for basic research in infectious immunology and possibly for a new immunotherapy.
Eppler
Elisabeth
E
Division of Cell Biology, Institute of Anatomy, University of Zurich, Winterthurerstr. 190, Zurich 8057, Switzerland. eppler@anatom.unizh.ch
Walch
Michael
M
Latinovic-Golic
Sonja
S
Dumrese
Claudia
C
Filgueira
Luis
L
Groscurth
Peter
P
D000942:Antigens, Bacterial / Q000276:immunology*; D015703:Antigens, CD / Q000276:immunology; D051940:B7-2 Antigen; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D002470:Cell Survival / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology* / Q000382:microbiology / Q000648:ultrastructure; D005434:Flow Cytometry; D005839:Gentamicins / Q000494:pharmacology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D007136:Immunoglobulins / Q000276:immunology; D008087:Listeria / Q000187:drug effects / Q000276:immunology* / Q000648:ultrastructure; D008089:Listeria monocytogenes / Q000187:drug effects / Q000276:immunology / Q000648:ultrastructure; D008562:Membrane Glycoproteins / Q000276:immunology; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D000097802:CD83 Antigen
D000942:Antigens, Bacterial; D015703:Antigens, CD; D051940:B7-2 Antigen; D005839:Gentamicins; D000949:Histocompatibility Antigens Class II; D007136:Immunoglobulins; D008562:Membrane Glycoproteins; D000097802:CD83 Antigen; C497964:CD86 protein, human