Interleukin 10 pretreatment protects target cells from tumor- and allo-specific cytotoxic T cells and downregulates HLA class I expression.
Interleukin 10 (IL-10) is a cytokine with a variety of reported effects including inhibition of monocyte major histocompatibility complex (MHC) class II-dependent antigen presentation, type 1 helper T cell cytokine production, and inhibition of T cell proliferation. Herein we report the effect of IL-10 pretreatment on antigen presentation to tumor- and allo-specific CD8+ cytotoxic T lymphocytes (CTL). Prior incubation of human melanoma cells with recombinant IL-10 (rIL-10) for 48-72 h resulted in a dose-dependent, up to 100% inhibition, of autologous CTL-mediated, HLA-A2.1-restricted, tumor-specific lysis. Allo-specific CTL cytotoxicity against Epstein-Barr virus-transformed lymphoblastoid cell lines (LCL) was also inhibited, demonstrating a protective effect also on lymphoid cells. In contrast, IL-10 pretreatment of allogeneic LCL or K562 targets had either no effect or slightly enhanced cytotoxic activity mediated by freshly isolated or IL-2-activated natural killer cells. Flow cytometric analysis with monoclonal antibodies against HLA-A2, or nonpolymorphic determinants of MHC class I proteins, revealed a 20-50% reduction in cell-surface expression, whereas intercellular adhesion molecules 1, and 2, and lymphocyte function-associated antigen 3 levels were not affected. In addition, relative to untreated target cells, IL-10 pretreated tumor cells were unaltered in their capacity to affect CTL-mediated lysis by cold target inhibition, demonstrating that the effect of IL-10 is unrelated to the initial binding of CTL to their targets. These results are compatible with an effect of IL-10 on the MHC class I antigen presentation pathway, and suggest a novel mechanism of immune tolerance, based on escape from CTL-mediated tumor and allo-transplant rejection.
Matsuda
M
M
Microbiology and Tumor Biology Center, Karolinska Institute, Stockholm, Sweden.
Salazar
F
F
Petersson
M
M
Masucci
G
G
Hansson
J
J
Pisa
P
P
Zhang
Q J
QJ
Masucci
M G
MG
Kiessling
R
R
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis; D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D015789:HLA-A2 Antigen / Q000096:biosynthesis; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D016753:Interleukin-10 / Q000494:pharmacology*; D007700:Kinetics; D004915:Leukemia, Erythroblastic, Acute; D008198:Lymph Nodes / Q000276:immunology; D008207:Lymphatic Metastasis; D008545:Melanoma / Q000276:immunology*; D011994:Recombinant Proteins / Q000494:pharmacology; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015815:Cell Adhesion Molecules; D015789:HLA-A2 Antigen; D015395:Histocompatibility Antigens Class I; C065289:ICAM2 protein, human; D011994:Recombinant Proteins; D018799:Intercellular Adhesion Molecule-1; D016753:Interleukin-10