T cell lines specific for a synthetic Heymann nephritis peptide derived from the receptor-associated protein

Depletion of gammadelta T cells exacerbates murine adriamycin nephropathy

It has been reported that the presence of gammadelta T cells in kidney is associated with kidney damage in human IgA nephropathy and in rat models of chronic renal injury, including Adriamycin nephropathy (AN), but the functional role of gammadelta T cells in this setting is unknown. This study examined the functional role of gammadelta T cells in tissue injury in a murine model of AN. Murine AN was induced in BALB/c mice by a single injection of Adriamycin. gammadelta T cells as a proportion of CD3(+) T cells were significantly increased in AN kidneys (16.8 +/- 3.9%) but not in lymph nodes (1.3 +/- 0.8%; P < 0.001). The proportion of gammadelta T cells in AN kidney correlated positively with serum creatinine and glomerular sclerosis. The Vgammadelta T cell receptor (TCR) repertoire in kidney showed expansion of a subset of cells that expressed Vgamma6/Vdelta1 genes and that used canonical TCR Vgamma6/Vdelta1 sequences in the CDR3 region of the TCR. gammadelta T cells that were sorted from the kidneys expressed TGF-beta but not IL-4, IL-10, or IFN-gamma. gammadelta T cells also expressed the activating receptor NKG2D and the NKG2D adaptor molecule DAP12. RAE-1, a ligand of NKG2D, was upregulated in AN kidney. Depletion of gammadelta T cells using anti-TCR gammadelta antibody resulted in worsening of serum creatinine, glomerulosclerosis, and interstitial inflammation. These studies indicate the involvement of the gammadelta T cell in innate recognition and regulation of inflammation in AN.

Glomerular T Cells Are of Restricted Clonality and Express Multiple CDR3 Motifs across Different Vβ T-Cell Receptor Families in Experimental Autoimmune Glomerulonephritis

Experimental autoimmune glomerulonephritis (EAG) is an animal model of Goodpasture's disease which can be induced in Wistar-Kyoto (WKY) rats by a single intramuscular injection of collagenase-digested rat glomerular basement membrane (GBM) in adjuvant. This model is characterised by anti-GBM antibody production, accompanied by focal necrotising glomerulonephritis with crescent formation and glomerular infiltration by T cells and macrophages. Previous work has shown that EAG is a T-cell-dependent disease. We proposed that intraglomerular T cells might be directly involved in pathogenesis and would be oligoclonal. In this study, EAG was induced by standard methods, the kidneys perfused with saline at week 2 and week 4, and the glomeruli separated by a sieving method. Glomerular RNA was extracted and reverse transcribed. RT-PCR showed overexpression of an average of two Vbeta families in each kidney analysed. However, no predominant single Vbeta family was overexpressed in any of the experimental animals. CDR3 spectratyping of Fam-labelled PCR products showed a marked restriction involving different Vbeta families. Sequencing demonstrated multiple CDR3 motifs, each expressed in association with different Vbeta gene segments. Our results show that glomerular T cells are of restricted clonality and suggest a role for antigen-specific effector T cells in the pathogenesis of EAG.

T cell receptor BV repertoires using real time PCR: a comparison of SYBR green and a dual-labelled HuTrec fluorescent probe

Real time PCR is a useful tool in immunological research but little has been published on the use of this technique in the measurement of T cell receptor (TCR) BV repertoires. We have compared the performance of SYBR green with that of a dual-labeled HuTrec (Human T cell receptor) fluorescent probe system. Serial dilutions of peripherals blood mononuclear cells were tested to compare the consistency of the two systems across multiple T cell receptor signal levels. Samples were diluted with non-TCR cDNA to simulate a low-level TCR signal within a tissue sample. The fluorogenic probe gave highly consistent results with a correlation coefficient of greater than 0.9 across a samples. SYBR green showed accurate results only when tested with high signal samples. Low-signal cDNA gave very poor results with SYBR green compared to the HuTrec fluorogenic probe with correlation coefficients as low as 0.65. Poorest performance occurred in the context of the simulated tissue sample with a high level of non-TCR DNA. Under these conditions, large amounts of nonspecific PCR product were generated which were detected by the SYBR green system and therefore distorted the results. SYBR green performed poorly when used with samples contaminated with significant quantities of non-target cDNA and samples with low target signal. It is therefore not an appropriate method for the measurement of TCR repertoires in small tissue samples. A dual-labeled HuTrec fluorescent probe produced a consistent TCR repertoire across a broad range of TCR signal levels and proved robust in the presence of contaminating non-TCR cDNA. We recommend the use of such a fluorescent probe in real time PCR for the assessment of TCR repertoires in small tissue samples. Where samples are assayed using SYBR green, agarose gel confirmation of PCR product specificity should be provided.

DNA Vaccination Against Specific Pathogenic TCRs Reduces Proteinuria in Active Heymann Nephritis by Inducing Specific Autoantibodies

We have previously identified potential pathogenic T cells within glomeruli that use TCR encoding Vbeta5, Vbeta7, and Vbeta13 in combination with Jbeta2.6 in Heymann nephritis (HN), a rat autoimmune disease model of human membranous nephritis. Vaccination of Lewis rats with naked DNA encoding these pathogenic TCRs significantly protected against HN. Proteinuria was reduced at 6, 8, 10, and 12 wk after immunization with Fx1A (p < 0.001). Glomerular infiltrates of macrophages and CD8(+) T cells (p < 0.005) and glomerular IFN-gamma mRNA expression (p < 0.01) were also significantly decreased. DNA vaccination (DV) causes a loss of clonality of T cells in the HN glomeruli. T lymphocytes with surface binding of Abs were found in DNA vaccinated rats. These CD3(+)/IgG(+) T cells expressed Vbeta5 and Vbeta13 that the DV encoded. Furthermore, FACS shows that these CD3(+)/IgG(+) cells were CD8(+) T cells. Analysis of cytokine mRNA expression showed that IL-10 and IFN-gamma mRNA were not detected in these CD3(+)/IgG(+) T cells. These results suggest that TCR DNA vaccination produces specific autoantibodies bound to the TCRs encoded by the vaccine, resulting in blocking activation of the specific T cells. In this study, we have shown that treatment with TCR-based DV, targeting previously identified pathogenic Vbeta families, protects against HN, and that the mechanism may involve the production of specific anti-TCR Abs.

Glomerular T cells in Heymann nephritis

Active Heymann nephritis (HN) is a rat model of human membranous nephropathy. The appearance of T cells within the glomeruli of HN rats suggests a role for these cells in the pathogenesis of the disease. The aims of this study were to investigate T cells infiltrating the glomerulus in HN in Lewis rats by polymerase chain reaction (PCR) of their Vbeta chains, CDR3 spectratyping and sequencing. HN was induced in Lewis rats by immunization with renal tubular antigen (Fx1A) in CFA. Kidneys were collected between 4 and 10 weeks. The glomeruli were separated, homogenized and RNA extracted. RT-PCR, CDR3 spectratyping and sequencing were used to further characterize the infiltrating T cells. Multiple Vbeta families showed restriction of their CDR3 spectratypes in each animal. Several TCR Vbeta families had identical-sized restricted spectratypes across several different animals. Four Vbeta families were sequenced. In three of those four families, the dominant clones showed identical sized CDR3 regions and a striking over-expression of Jbeta2.6. Further analysis of the CDR3 regions of the Jbeta2.6 clones showed a significant restriction of the amino acids at four of the six CDR3 positions. Glomerular T cells bearing similar CDR3 sequences, using Jbeta2.6 and expressing at least two, and possibly more, Vbeta genes are involved in the pathogenesis of HN.

Infiltration of canonical Vgamma4/Vdelta1 gammadelta T cells in an adriamycin-induced progressive renal failure model

We have previously reported an infiltration of renal interstitial gammadelta T cells in Adriamycin-induced progressive glomerulosclerosis in the rat kidney. The TCR repertoire and sequences used by these gammadelta T cells have now been studied. Two injections of Adriamycin 14 days apart caused segmental glomerulosclerosis, massive interstitial infiltration of mononuclear cells, and end-stage renal failure. Flow cytometry of lymphocyte subpopulations with Abs to CD3, the gammadelta TCR, and the alphabeta TCR showed that gammadelta T cells as a proportion of CD3(+) cells were increased in Adriamycin-treated kidneys (8.5 +/- 5.4%), but not in lymph nodes (1.3 +/- 0.4%). A semiquantitative score of glomerular damage (r = 0.65; p < 0.01) and creatinine (r = 0.62; p < 0.01) correlated significantly with the presence of gammadelta T cells. TCR Vgamma repertoire analysis by RT-PCR and Southern blotting showed that Vgamma2 was the dominant subfamily in lymph nodes, whereas Vgamma4 became the predominant subfamily in advanced stages of the rat Adriamycin-treated kidney. Sequencing of the Vgamma4-Jgamma junctional region showed an invariant sequence. The amino acid sequence of the junctional region of the Vgamma4 TCR was the same as the reported mouse canonical Vgamma4 TCR sequence. Analysis of the kidney Vdelta repertoire showed dominant expression of Vdelta1, and sequencing again revealed the selective expression of a canonical Vdelta1 gene. Semiquantitative RT-PCR for cytokine gene expression showed that gammadelta T cells from the kidneys expressed TGF-beta, but not IL-4, IL-10, or IFN-gamma. These results suggest that the predominant gammadelta T cells in the Adriamycin kidney use an invariant Vgamma4/Vdelta1 receptor.

T cell receptor BV gene usage in interstitial cellular infiltrates in active Heymann nephritis

BACKGROUND

Infiltration of the kidney by mononuclear cells is a prominent feature of active Heymann nephritis (HN). These cells could be present as a part of generalized inflammatory response, or could be proliferating in response to specific antigens. To examine these questions, we have analysed the T cell receptor (TCR) BV repertoire of T cells infiltrating the renal interstitium at regular time intervals throughout the course of the disease.

METHODS

HN was induced in Lewis rats by immunization with renal tubular antigen (Fx1A) in complete Freund's adjuvant (CFA). Kidneys were collected 8 and 12 weeks after immunization. Renal tissue was homogenized and RNA extracted. RT-PCR and sequencing were used to characterize expression of TCR BV genes.

RESULTS

Preferential expression of TCR BV2 and BV16 gene families was seen at 8 weeks. By 12 weeks the diversity of the TCR BV gene repertoire had increased and was highly heterogeneous. Sequence analysis of BV2, and BV16 RT-PCR products from 8 week HN kidneys revealed conserved usage of CDR3 regions, and an over-representation of arginine residues in the CDR3 regions at a frequency of between 60 and 100% of clones sequenced in most of BV2 and BV16 subfamilies.

CONCLUSION

The preferential usage of CDR3 region sequences in TCR BV2 and BV 16 families indicates clonal expansion of individual T cells in HN kidneys at 8 weeks. The conserved usage of arginine residues in the CDR3 regions may indicate recognition of select antigenic epitopes. By 12 weeks, the diverse TCR BV repertoire in the kidney may be due to epitope spreading or may represent a non-specific inflammatory response in the late phase of the disease.