Killing of naive T cells by CD95L-transfected dendritic cells (DC): in vivo study using killer DC-DC hybrids and CD4(+) T cells from DO11.10 mice.
Dendritic cells (DC) play the dual task of initiating cellular immunity against potentially harmful foreign antigens (Ag), while maintaining immunological tolerance to self-Ag and environmental Ag. As an approach to induce Ag-specific suppression, we and others introduced CD95 ligand (L) cDNA into DC. The resulting "killer" DC delivered apoptotic signals, instead of activation signals, to primed CD4(+) T cells in vitro and induced Ag-specific immunosuppression in vivo. To study the impact of killer DC on naive T cells, the fate of Ag-reactive T cells and the extent of their depletion after killer DC treatment, we performed in vitro and in vivo reconstitution experiments using: (a) killer DC-DC hybrids created between CD95L-transduced XS106 DC clone (A/J origin) and splenic DC from BALB/c mice, (b) CD4(+) T cells isolated from DO11.10 transgenic mice (BALB/c background), and (c) OVA(323-339) peptide as relevant Ag. Ovalbumin (OVA)-pulsed killer DC-DC hybrids inhibited DO11.10 T cell activation triggered by conventional DC, instead of inducing their activation. Rapid apoptosis of T cells was observed after co-culture with OVA-pulsed killer DC-DC hybrids, but not with non-pulsed killer DC-DC hybrids or OVA-pulsed control DC-DC hybrids. For in vivo reconstitution, (BALB/cxA/J)F1 mice received subcutaneous administration of killer DC-DC hybrids, followed by intravenous inoculation of DO11.10 T cells. Killer DC-DC hybrids migrated preferentially to draining lymph nodes albeit with relatively low efficiency (0.5-1% recovery) and they induced significant, but incomplete (30-40%) killing of DO11.10 T cells in this location. These results document the abilities of CD95L-transduced DC to trigger apoptosis of naive T cells in an Ag-specific manner, to overrule T cell activation signals delivered by conventional DC, and to reduce local frequencies of Ag-reactive T cells in vivo. Our data also uncover two major limitations (relatively low homing efficiency and incomplete elimination of Ag-reactive T cells) that remain to be overcome for clinical application of CD95L-transduced DC strategy.
Kusuhara
Masahiro
M
Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, USA.
Matsue
Keiko
K
Edelbaum
Dale
D
Loftus
Julie
J
Takashima
Akira
A
Matsue
Hiroyuki
H
D000818:Animals; D017951:Antigen Presentation; D000941:Antigens / Q000276:immunology; D017209:Apoptosis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002465:Cell Movement; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000276:immunology* / Q000637:transplantation; D053222:Fas Ligand Protein; D005260:Female; D006183:H-2 Antigens / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006822:Hybrid Cells / Q000276:immunology / Q000637:transplantation; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000276:immunology*; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D010047:Ovalbumin / Q000276:immunology; D013047:Specific Pathogen-Free Organisms; D013601:T-Lymphocytes / Q000166:cytology*; D014612:Vaccines / Q000276:immunology
D000941:Antigens; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D006183:H-2 Antigens; D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen; D008562:Membrane Glycoproteins; D014612:Vaccines; D010047:Ovalbumin