Reversing interleukin‐2 inhibition mediated by anti–double‐stranded DNA autoantibody ameliorates glomerulonephritis in MRL‐lpr/lpr mice

Abstract

Objective. Our previous study demonstrated that anti-double-stranded DNA (anti-dsDNA) antibodies involved in lupus nephritis down-regulate the production of interleukin-2 (IL-2) in T cells, which in turn, contributes to the defective production of cytotoxic cells and to activation-induced cell death in vitro. To reveal novel molecular targets for lupus therapy, the molecular mechanisms of IL-2 down-regulation by anti-dsDNA were studied.Methods. Anti-dsDNA monoclonal antibody (mAb) 9D7 was used to study the molecular mechanisms of IL-2 production in vitro. Treatment with argininerich peptide, a penetration inhibitor, was used to verify the effect of internalization of anti-dsDNA on the production of IL-2. The signaling pathway for IL-2 expression induced by anti-dsDNA was analyzed by using kinase inhibitors. The therapeutic effects of these inhibitors were evaluated in MRL-lpr/lpr mice. Conclusion. These findings suggest that penetration of T cells by anti-dsDNA may inhibit IL-2 production by activating GSK-3. Moreover, blocking GSK-3 activation as well as inhibiting anti-dsDNA penetration is a potential therapeutic approach for lupus. Results. Inhibition of IL-2 production in activated Jurkat cells and human T cells pretreated with mAb

Transgenic overexpression of anti-double-stranded DNA autoantibody and activation of Toll-like receptor 4 in mice induce severe systemic lupus erythematosus syndromes

“…LPS can induce or accentuate polyclonal B cell activation, anti-DNA antibodies, and proliferative nephritis in susceptible mice [27]. In our study, although transgene-encoded scFv anti-dsDNA does not express the BCR on their surface, transgenic B cells may be anergic as judged by lower levels of serum anti-dsDNA (mean OD410 ¼ 0.3) than those of the MRL/lpr mice (mean OD410 ¼ 2.0) [17]. In addition, the anergic B cells of the 9D7 Tg mice could be stimulated by LPS to divide and differentiate into antibodysecreting cells in vitro (Fig.…”

“…In this study, we used a pathogenic 9D7 mAb to generate the transgenic mice. The 9D7 mAb was shown to penetrate cells via electrostatic interactions independent of its Fc portion [13,17], and stimulate secretions of IL-1b, IL-6, IL-8, IL-10, and TNF-a in immune cells [16]. Thus transgenic mice with scFv of 9D7 mAb may induce the polyclonal activation of B cells and inflammatory cells to elicit pathological changes in the kidneys (Figs.…”

“…In addition, the administration of anti-IL-10 neutralizing antibodies to humans [36] and mice [37] may induce significant clinical improvements for SLE. Even though the transgenic scFv anti-DNA antibodies can penetrate cells without the Fc portion and stimulate secretions of IL-1b, IL-6, IL-8, IL-10, and TNF-a [13,16,17], the anergic B cells of the 9D7 Tg mice could be further polyclonally activated by LPS to divide and differentiate into antibody-secreting cells and cause severe tissue damage (Fig. 4).…”

“…Our previous study demonstrated that the pathogenic functions of 9D7 mAb are dependent on their penetration ability, not on the Fc portion of the mAb [13,17]. To examine the effects of a pathogenic anti-dsDNA in normal mice, transgenic mice with a scFv transgene of 9D7 mAb were generated on the FVB background using the mouse immunoglobulin heavy chain promoter (pIgH) (Fig.…”

“…The 9D7 mAb also has been known to stimulate secretions of IL-1b, IL-6, IL-8, IL-10, and TNF-a from human mononuclear cells [16], while inhibiting IL-2 production in T cells [15]. Additionally, the reduction in IL-2 depends upon the penetration of 9D7 anti-dsDNA mAb, but is not dependent on the Fc receptor of T cells [17]. Therefore, 9D7 mAb may have great potential in inducing pathological changes in mice without the Fc portion.…”