Molecular characterization of a major nephritogenic domain in the autoantigen of anti-tubular basement membrane disease.

Abstract

Anti-tubular basement membrane (aTBM) disease is a form of primary interstitial nephritis mediated by autoimmune T cells and aTBM antibodies. In mice and humans the nephritogenic immune response is directed to a glycoprotein (3M-1) found along the proximal tubule of the kidney. We have isolated cDNAs from an expression library that encodes for the common framework domain of the 3M-1 antigen. This common domain was once related evolutionarily to a family of intermediate filament-associated proteins. Northern hybridization revealed that all isoforms of 3M-1 range between 1700 and 1900 base pairs and in situ hybridization studies indicate that transcripts are found in tubular epithelium. Candidate peptide fragments were deduced and synthesized from the sequence encoding this common framework domain, and one of the peptide residues was able to bind a monoclonal 3M-1-reactive aTBM antibody, stimulate the growth of 3M-1-reactive helper T cells, and induce nephritogenic effector T cells capable of producing interstitial nephritis.Our results indicate that a unique, immunodominant region of the 3M-1 antigen is an informative participant in the emergence of autoimmune inJury to certain basement membranes.Inflammatory interstitial nephritis, either as a primary or secondary process, plays a central role in the progressive development of nearly all forms of chronic renal failure (1). Very little, however, is known about the target antigens that focus injury toward parenchymal structures residing in the tubulointerstitium. Our laboratory has been studying this problem using a rodent model of human interstitial nephritis called anti-tubular basement membrane (aTBM) disease. aTBM disease develops in mice or rats following their immunization with renal tubular basement membranes in adjuvant (2,3). aTBM antibodies (aTBM-Abs/a3M-1-Abs) develop over 7-10 days, and extensive mononuclear infiltrates with tubular atrophy and fibrosis appear within several weeks.The target antigen of this disease, the 3M-1 glycoprotein (4), is expressed in mice on nearly all cortical tubular basement membranes and by cultured proximal tubular epithelium (MCT cells). It can be found intracellularly, on their cell surface, or in the culture supernatant as a secreted product of -30,000 Mr (5). Eventually some isoforms of 3M-1 are translocated to the lateral border of the proximal tubular basement membrane in vivo (4). The genes for 3M-1 map to the first (6) and fourth (7) linkage groups in rats and probably to chromosome VII in mice (6). The 3M-1 protein has been purified immunochemically from rabbits (4), mice (5), rats (8), and humans (9).The nephritogenic autoimmune response has also been characterized in mice, rats, and humans with polyclonal antisera (2, 8-11), by constructing monoclonal aTBM-Abs reactive to 3M-1 (Ma3M-1-Abs; refs 4, 10), and by establishing tubular antigen (3M-1)-specific CD4' helper (12,13) and CD8' effector T clones (14) that recognize 3M-1 on the surface of MCT cells (5, 15) or as a soluble moiety processed by tradition...

T cells reactive to an inducible heat shock protein induce disease in toxin-induced interstitial nephritis.

“…We next examined whether HSPl cells could recognize their target antigen in vivo after adoptive transfer into syngeneic mice. Previous work from our laboratory has shown that the technique of subcapsular adoptive transfer can specifically differentiate nephritogenic T cells from those which do not cause disease (18,23,25). T cells specific for irrelevant antigens do not infiltrate the kidney after adoptive transfer.…”

“…4 A demonstrates that HSP1 cells mediate a significant DTH response to the HSP peptide (HSP 180-196) to which they were generated. The specifidty of this response is demonstrated by the lack of a response to 3M-1(p1), a peptide sequence recognized by responding T ceils in the antitubular basement membrane model of interstitial nephritis (18).…”

“…24 h before testing (17). 8 h before receiving T cells, pretreated mice were injected in their footpads with 25/zl PBS (right side) or antigen (left side) (18). T cells at 8-10 d post passage were purified by centrifugation through Lympholyte, washed twice in PBS, and injected into the tail veins of the Fretreated mice (40-45 x 106 cells/mouse).…”

Revisiting Tolerance Induced by Autoantigen in Incomplete Freund’s Adjuvant

“…In an effort to address these issues, we revisited three models of EAE (mediated by injections of MBP, PLP, and MOG, respectively) and a related model of murine interstitial nephritis, antitubular basement membrane (␣TBM) disease (47)(48)(49). Like EAE, ␣TBM disease is elicited by immunization with a tissue-specific autoantigen (renal tubular Ag, RTA) in CFA, and injection of RTA with IFA has been reported to prevent the disease (50).…”

“…Disease scores for interstitial nephritis were defined as follows. Grade 0, normal kidney; grade 0.5, rare focal mononuclear cell infiltration; grade 1, mononuclear cell infiltration of the interstitium of Ͻ10% of the renal cortex; grade 2, mononuclear cell infiltration of the interstitium of Ͼ10% Ͻ50% of the renal cortex; grade 3, mononuclear cell infiltration of the interstitium of Ͼ50% of the renal cortex with tubular drop-out and interstitial fibrosis (47,48). Standard histologic scoring of brain inflammation in EAE was used (23,34).…”