A peptide that ameliorates lupus up-regulates the diminished expression of early growth response factors 2 and 3

J Immunol. 2008 Feb 1;180(3):1584-91. doi: 10.4049/jimmunol.180.3.1584.

Abstract

Expansion of autoreactive T cells and their resistance to anergy was demonstrated in systemic lupus erythematosus (SLE). A pair of transcription factors, early growth response 2 (Egr-2) and 3 (Egr-3), are negative regulators of T cell activation that were shown to be important in anergy. A peptide (designated hCDR1 for human CDR1) based on the CDR-1 of an anti-DNA Ab ameliorated SLE in both induced and spontaneous lupus models. Our objectives were to determine the expression levels of Egr-2 and Egr-3 in autoreactive T cells following immunization with the lupus-inducing anti-DNA Ab that bears a common Id designated 16/6Id and also in a full-blown SLE and to determine the effect of hCDR1 on these transcription factors. We demonstrated diminished expression levels of Egr-2 and Egr-3 mRNA both early after immunization with the 16/6Id and in SLE-afflicted (NZB x NZW)F1 (New Zealand Black and New Zealand White) mice. Furthermore, by down-regulating Akt phosphorylation and up-regulating TGFbeta secretion, treatment with hCDR1 significantly up-regulated Egr-2 and Egr-3 expression. This was associated with an increased expression of the E3 ligase Cbl-b. Inhibition of Akt in T cells of immunized mice decreased, whereas silencing of the Egr-2 and Egr-3 in T cells of hCDR1-treated mice increased IFN-gamma secretion. Thus, hCDR1 down-regulates Akt phosphorylation, which leads to up-regulated expression of T cell Egr-2 and Egr-3, resulting in the inhibition of IFN-gamma secretion that is required for the maintenance of SLE.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / pharmacology*
  • Clonal Anergy / drug effects*
  • Early Growth Response Protein 2 / antagonists & inhibitors*
  • Early Growth Response Protein 2 / genetics
  • Early Growth Response Protein 2 / metabolism
  • Early Growth Response Protein 3 / antagonists & inhibitors*
  • Early Growth Response Protein 3 / genetics
  • Early Growth Response Protein 3 / metabolism
  • Humans
  • Interferon-gamma / metabolism
  • Interleukin-2 / pharmacology
  • Lupus Erythematosus, Systemic / immunology*
  • Mice
  • Mice, Inbred Strains
  • Peptide Fragments / pharmacology*
  • Phosphoinositide-3 Kinase Inhibitors
  • Phosphorylation / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism
  • Proto-Oncogene Proteins c-cbl / metabolism
  • RNA, Messenger / metabolism
  • Recombinant Proteins / pharmacology
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / immunology
  • Transforming Growth Factor beta1 / metabolism
  • Up-Regulation

Substances

  • Antibodies, Monoclonal
  • Early Growth Response Protein 2
  • Interleukin-2
  • Peptide Fragments
  • Phosphoinositide-3 Kinase Inhibitors
  • RNA, Messenger
  • Recombinant Proteins
  • Transforming Growth Factor beta1
  • Early Growth Response Protein 3
  • edratide
  • Interferon-gamma
  • Proto-Oncogene Proteins c-cbl
  • Proto-Oncogene Proteins c-akt