title: Role of 4-1BB in allograft rejection mediated by CD8+ T cells.
abstract: Blockade of traditional costimulatory molecules fails to inhibit rejection in many models where CD8+ T cells are sufficient to mediate rejection. This observation demonstrates that in many settings CD8+ T cells are not dependent upon CD28 or CD154 signals to mediate rejection. 4-1BB (CD137) has been shown to be an important regulatory molecule for CD8+ T cells in a variety of nontransplant models. Here we show that blocking the 4-1BB pathway significantly inhibited rejection of intestinal allografts by CD8+ but not CD4+ T cells. This effect was associated with significantly decreased expression of the genes encoding TNFalpha and secondary lymphoid chemokine (SLC) within the spleens of recipient mice. Disruption of the 4-1BB pathway also impaired the priming of alloantigen-specific CD8+ T cells and the accumulation of recipient dendritic cells within the spleen. These data directly demonstrate an important role for 4-1BB in allograft rejection; particularly rejection mediated by CD8+ T cells. Our data suggest that in addition to providing a direct costimulatory signal to T cells, the 4-1BB pathway may regulate other important steps in the immune response such as the migration of T cells and dendritic cells.
authors.affiliation: Emory Transplant Center and the Department of Surgery, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Zhong
authors.initials: Z
authors.lastname: Guo
authors.forename: Ying
authors.initials: Y
authors.lastname: Dong
authors.forename: Oliver
authors.initials: O
authors.lastname: Kim
authors.forename: John
authors.initials: J
authors.lastname: Hart
authors.forename: Andrew
authors.initials: A
authors.lastname: Adams
authors.forename: Christian P
authors.initials: CP
authors.lastname: Larsen
authors.forename: Robert S
authors.initials: RS
authors.lastname: Mittler
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Newell
mesh_terms: D000818:Animals; D015703:Antigens, CD; D018106:CD28 Antigens / Q000096:biosynthesis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D023201:CD40 Ligand / Q000096:biosynthesis; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002455:Cell Division; D005434:Flow Cytometry; D006084:Graft Rejection; D007422:Intestines / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000378:metabolism; D017475:Receptors, Nerve Growth Factor / Q000502:physiology*; D018124:Receptors, Tumor Necrosis Factor / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000378:metabolism; D013997:Time Factors; D014180:Transplantation / Q000379:methods; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9
chemical_list: D015703:Antigens, CD; D018106:CD28 Antigens; D012333:RNA, Messenger; D017475:Receptors, Nerve Growth Factor; D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins; C505715:Tnfrsf9 protein, mouse; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9; D023201:CD40 Ligand