T cell determinants from autoantibodies to DNA can upregulate autoimmunity in murine systemic lupus erythematosus.

Abstract

Summary(NZB x NZW) F1 (BWF1) mice develop spontaneous T cell autoimmunity to VH region determinants of syngeneic anti-DNA before the onset of clinical disease. In this study, we characterized the immunogenicity, MHC binding, and lymphokine secretion patterns induced by T cell determinants from the VH region of one such anti-DNA mAb (A6.1) and examined their role in the regulation of autoimmunity. Determinants were identified by proliferation of syngeneic splenic T cells from young, unprimed BWF1 mice in response to overlapping 12-mer peptides representing the entire Vu region sequence. Immunization of young BWF1 mice with any of three determinants (A6H 34-45 [p34], A6H 58-69 [p58], and A6H 84-95 [p84]) elicited proliferative responses upon in vitro recall. Upon immunization with the whole A6.1 molecule, however, proliferative responses could be recalled only to the p58 peptide, defining this as immunodominant. The other two peptides (p34 and p84) elicited minimal or no proliferation and could be termed cryptic. Proliferative responses elicited by the cryptic determinants were restricted by a single class II (I-E d for p34 and I-A u for p84), whereas the immunodominant p58 determinant was restricted by both bE d and I-E u. The cryptic p34 and p84 bound strongly to I-E a and I-A u, respectively, whereas the immunodominant p58 peptide bound poorly to I-E a. A6H p84 elicited T cells that secreted lymphokines in a pattern consistent with a Thl-like phenotype, whereas p58 induced a Th2-1ike cytokine pattern. Immunization with p34 or p84, or adoptive transfer of a p84-reactive T cell line to young BWF1 mice significantly increased IgG anti-DNA levels, accelerated nephritis, and decreased survival. In conclusion, in BWF1 mice, autoreactive T cells recognizing both cryptic and dominant self-determinants on anti-DNA autoantibodies escape deletion or anergy induction. Furthermore, since these cells are spontaneously activated before the onset of clinical disease, they may be involved in the development of the autoimmune process.

Induction of Autoantibody Production Is Limited in Nonautoimmune Mice

“…Briefly, spleen cells were cultured with or without peptides for 5 days; supernatants were tested for IgG anti-dsDNA Ab, as described previously (3,4). Briefly, 96-well plates (Costar) were coated with dsDNA (100 g/ml; Sigma-Aldrich) overnight at 4°C.…”

“…Proteinuria and blood urea nitrogen were tested using Albustix and Azostix (range, 0 -4ϩ), respectively, and creatinine was estimated by reagents from Stanbio Laboratories (San Antonio, TX), as described previously (4,20).…”

“…The fractionated CD4 ϩ and CD8 ϩ T cells were cultured and periodically stimulated with syngeneic APCs (irradiated T cell-depleted spleen cells), A6H31-45 and Con A supernatant, as described previously (4).…”

Augmentation of natural immunity to a pro-inflammatory cytokine (TNF-alpha) by targeted DNA vaccine confers long-lasting resistance to experimental autoimmune encephalomyelitis

“…Following repeated immunization, even these engineered antibodies do trigger an apparently allotypic response. We have recently utilized the novel technology of naked DNA vaccination [53][54][55][56][57][58][59][60][61][62] to generate self-specific protective immunity against C-C chemokines and inhibit EAE. 63 Resistance could be transferred by C-C chemokine-specific neutralizing antibodies.…”

T Cell Studies in a Peptide-Induced Model of Systemic Lupus Erythematosus

“…Theories explaining the polyreactivity that is typical of the human disease include cross-reactivity of antiforeign and anti-self Abs (24), somatic mutation of the anti-foreign response to generate autoreactivity (25,26), and epitope spreading of the immune response to target self Ags (27)(28)(29)(30)(31)(32)(33). We have previously shown that cross-reactivity of the serum Abs accounts for much of the anti-self response in these mice (18).…”