Human monoclonal anti-endothelial cell IgG-derived from a systemic lupus erythematosus patient binds and activates human endothelium in vitro


Yazici Z. A., RASCHI E., PATEL A., TESTONI C., BORGHI M., GRAHAM A., ...More

INTERNATIONAL IMMUNOLOGY, vol.13, no.3, pp.349-357, 2001 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 13 Issue: 3
  • Publication Date: 2001
  • Doi Number: 10.1093/intimm/13.3.349
  • Journal Name: INTERNATIONAL IMMUNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.349-357
  • Recep Tayyip Erdoğan University Affiliated: No

Abstract

Our objectives were to obtain monoclonal anti-endothelial cell antibodies (AECA) from systemic lupus erythematosus (SLE) patients, to characterize their antigen specificity, and their capability to induce a pro-inflammatory and pro-adhesive endothelial phenotype, and to investigate the mechanism of endothelial cell (EC) activation in vitro. Monoclonal IgG AECA were generated by hybridoma formation with human SLE B cells. Antigen specificity was characterized by immunoblotting with enriched cell membrane fractions, by cytofluorimetry and by cell solid-phase ELISA, Endothelial activation was evaluated by measuring increases in U937 cell adhesiveness, adhesion molecule (E-selectin and ICAM-1) expression and IL-6 production. In addition, mechanisms of endothelial activation were investigated by assessment of NF-kappaB by measuring the loss of its inhibitor I-kappaB. mAb E-3 bound live EC and recognized a 42 kDa EC membrane protein, it enhanced U937 adhesiveness, E-selectin and ICAM-1 expression and IL-6 production, and caused the loss of I-kappaB, We conclude this is the first in vitro demonstration that a human monoclonal AECA from a SLE patient reacts with a constitutive endothelial membrane antigen and induces a pro-inflammatory endothelial phenotype through NF-kappaB activation.