Activation of autoreactive T-lymphocytes by cultured syngeneic glomerular mesangial cells

Abstract

The capacity of intrinsic, glomerular mesangial cells (MC) to cause an autoreactive response of syngeneic lymphocytes in vitro are presented. Initial experiments demonstrated the MHC class II dependent capacity of MC to present exogenous antigen to sensitized lymph node lymphocytes (LN) and to activate naive, allogeneic LN in the absence of a nominal antigen. However, the most striking finding of the present investigation was that mouse MC (C57BL/6 or DBA/2) augmented a significant activation of naive, syngeneic lymphocytes. The extent of the proliferative lymphocyte response was comparable to that observed after stimulation with allogeneic MC. Moreover, during syngeneic coculture substantial amounts of interferon bioactivity were generated. Equipotent concentrations of rm IFN-gamma were sufficient to induce class II MHC expression of mouse MC. In control experiments the macrophage cell line, IC-21 (C57BL/6), or freshly prepared DBA/2 mouse peritoneal macrophages did not elicit a syngeneic LN response. Using MC, which had not been pretreated, the MC-specific LN stimulation occurred after prolonged periods of coculture. The stimulation index (S.I.) was 9.77 after 144 hours compared with LN controls (S.I. = 1). However, a 48 hour pretreatment of MC with either rm IFN-gamma alone or in combination with rh TNF-alpha and/or the continuous presence of rm IL-1 alpha during coculture periods from 72 to 144 hours substantially enhanced the proliferative LN response. Analysis of non-adherent LN by flow cytometry (FACS) after 96 or 120 hours coculture with MC revealed an increased ratio of Thy1.2+ to B220+ cells with a predominant rise of L3T4+ T-helper cells compared to Lyt2+ cytotoxic T-cells. Furthermore, immune fluorescence microscopy showed that a fraction of Thy1.2+ lymphoblasts adhered to MC. FACS analysis of these adherent LN after detachment demonstrated that in comparison to cocultures with untreated MC, cocultures of LN with IFN-gamma/TNF-alpha pre-treated MC resulted in a 24.4% increase of Thy1.2+ cells, with 89% of these being L3T4+ T-helper lymphocytes. In conclusion, autoreactivity of preferentially T-helper cells to cocultured glomerular MC was shown, which may represent a useful model of T-lymphocyte dependent glomerulonephritis.

IFN-γ Production by Intrinsic Renal Cells and Bone Marrow-Derived Cells Is Required for Full Expression of Crescentic Glomerulonephritis in Mice

“…Up-regulation of MHC II allows murine mesangial cells to stimulate the proliferation of T cells (42) and to present Ag to T cells (43) in vitro. Transformed renal tubular epithelial cells can present Ag to MHC II in vitro (24).…”

Renal cell–expressed TNF receptor 2, not receptor 1, is essential for the development of glomerulonephritis

“…We propose that TNFR1-mediated differentiation and activation of APCs (40) might facilitate the rapid generation of sensitized T cells that are required for disease induction in our model. Apoptosis of T cells during presentation of antigen can be induced by APCs expressing Fas ligand (42,43), and we speculate that TNFR1 expressed on APCs such as glomerular mesangial and tubular epithelial cells may have a functional role in this process (15,44). Mesangial cells upregulate Fas ligand upon TNF stimulation in vitro (45).…”

The Hematopoietic Transcription Factor PU.1 Represses Gelatinase A Transcription in Glomerular Mesangial Cells

“…PU.1 expression is generally considered to be restricted to cells of hematopoietic lineage, including stem cells, macrophages, B-cells, and neutrophils (20,(27)(28)(29). Glomerular mesangial cells are multipotential pericytes that can execute macrophage-like functions, including phagocytosis, release of reactive oxygen species, and antigen presentation (30,31). These properties have given rise to speculation that mesangial cells derive from the bone marrow, a speculation that has been recently confirmed using transplanted green fluorescent protein-expressing transgenic bone marrow cells (32).…”