SELF-REGULATION OF AUTOREACTIVE KIDNEY-INFILTRATING T-CELLS IN MRL-LPR NEPHRITIS

MRL-lpr kidney-infiltrating (KI) T cell clones (CD3+, TCR alpha/beta+, B220+, CD4-, CD8-) are autoreactive, exclusively proliferate to renal tissues, and secrete interferon-gamma (IFN-gamma). We now report that IFN-gamma treatment of tubular epithelial cells (TEC) decreases their ability to induce KI T cell proliferation. The decreased ability of IFN-gamma-treated TEC to induce T cell proliferation is evident by 24 hours and can be restored by re-exposure to TEC not treated with IFN-gamma. IFN-gamma-treated TEC supernatant does not diminish KI T cell proliferation and IFN-gamma-treated TEC fixed with glutaraldehyde remain less capable of inducing KI T cell proliferation. Although we have not identified the TEC surface molecule(s) modified by IFN-gamma, neither class I, class II, ICAM-1 nor IFN-gamma bound to the surface of TEC are responsible. In conclusion, IFN-gamma induces a surface alteration(s) on TEC capable of limiting their ability to induce KI T cell proliferation. The ability of autoreactive KI T cells to release IFN-gamma represents a self-regulatory mechanism for limiting T cell expansion.