Immunomodulatory effects of interferon-gamma on autoreactive nephritogenic T-cell clones.
BACKGROUND
We examined the immunomodulatory effects of interferon-gamma (IFN-gamma) on renal-derived CD4+ alpha/beta + T cells, called mouse renal (MR) cells, isolated from animals with murine chronic graft-versus-host disease, a model of autoimmune glomerulonephritis. MR T cells express a Th2 cytokine profile, although IFN-gamma expression is also detected in a subset of clones that adoptively transfers renal disease to naive recipients. In view of disparate patterns of IFN-gamma expression, we evaluated the effects of exogenous IFN-gamma on nephritogenic (MR1.3) and nonnephritogenic (MR1.6) clonal activity.


METHODS
These studies examined IFN-gamma-mediated effects on clonal proliferation, cytokine production, nephritogenic potential, and IFN-gamma receptor expression.


RESULTS
IFN-gamma mediated dose-dependent inhibition of MR1.3 and MR1.6 proliferation. This cytostatic effect was not mediated by inhibiting cytokine genes, as expression of interleukin (IL)-4, IL-10, IL-13, and IFN-gamma after IFN-gamma treatment was not markedly altered in either clone, although baseline IL-13 expression was enhanced in MR1.6. IFN-gamma markedly altered the functional phenotype of MR1.6, as pretreated recipients developed severe mononuclear cell infiltrates and tubular damage following adoptive transfer of MR1.6. Neutralizing anti-IFN-gamma antibodies did not inhibit MR1.3 nephritogenicity, but did block MR1.6-induced disease in IFN-gamma-treated mice. Although both clones constitutively expressed the IFN-gamma receptor beta chain, IFN-gamma exposure decreased its expression in MR1.3 cells, but did not markedly change its expression in MR1.6 cells.


CONCLUSIONS
These studies describe an unusual permissive role for IFN-gamma in modulating nephritogenic Th2 activity in vivo, which facilitates the initiation of cell-mediated autoimmune renal injury. Apparent differential effects of IFN-gamma on distinct T-cell clones may be mediated in part by alterations in cytokine receptor expression.
Meyers
C M
CM
University of Pennsylvania School of Medicine, Department of Medicine, Philadelphia, USA. meyersc@mail.med.upenn.edu
Zhang
Y
Y
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D019264:Adoptive Transfer; D000818:Animals; D000906:Antibodies / Q000378:metabolism / Q000494:pharmacology; D015551:Autoimmunity / Q000187:drug effects / Q000276:immunology*; D001667:Binding, Competitive; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002999:Clone Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis; D004195:Disease Models, Animal; D005921:Glomerulonephritis / Q000276:immunology*; D007371:Interferon-gamma / Q000378:metabolism / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D017471:Receptors, Interferon / Q000096:biosynthesis; D018418:Th2 Cells / Q000276:immunology; D000096743:Interferon gamma Receptor
D000276:Adjuvants, Immunologic; D000906:Antibodies; D016207:Cytokines; D007371:Interferon-gamma; D017471:Receptors, Interferon; D000096743:Interferon gamma Receptor