A subset of mouse splenic macrophages can constitutively present alloantigen directly to CD8+ T cells.
About a third of mouse splenic macrophage (M phi) progenitors give rise to cloned progeny that constitutively induce the selective proliferation of naive allogeneic CD8+ T cells in a CD4+ helper cell-independent manner--a response that is inhibited by mAb to the MHC class I molecules present on the M phi. Colony-mixing experiments indicated that the failure of most M phi clones to present allo-Ag was not due to their suppression of the ability of CD8+ cells to respond, nor did the nonpresenting clones interfere with the activity of the allo-Ag presenting M phi. The allo-Ag presenting phenotypes were found to be a stable characteristic in a panel of cell lines derived from individual clones of M phi. Analysis of the cell lines revealed that the differential expression of allo-APC activity could not be attributed to the levels of MHC class I molecules; rather, the cell lines and the primary M phi clones differ in their expression of a cell-associated costimulator molecule that likely functions to induce the expression of the IL-2R on and the secretion of IL-2 from the T cells.
Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38101-0318.
J M
JM
McCormack
D
D
Sun
W S
WS
Walker
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens; D002478:Cells, Cultured; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000378:metabolism; D007519:Isoantigens / Q000276:immunology; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D015375:Receptors, Interleukin-2 / Q000502:physiology; D013154:Spleen / Q000166:cytology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D007376:Interleukin-2; D007519:Isoantigens; D015375:Receptors, Interleukin-2