Acute B-Cell Inhibition by Soluble Antigen Arrays Is Valency-Dependent and Predicts Immunomodulation in Splenocytes

Biomacromolecules. 2019 May 13;20(5):2115-2122. doi: 10.1021/acs.biomac.9b00328. Epub 2019 May 2.

Abstract

Antigen valency plays a fundamental role in directing the nature of an immune response to be stimulatory or tolerogenic. Soluble antigen arrays (SAgAs) are an antigen-specific immunotherapy that combats autoimmunity through the multivalent display of autoantigen. Although mechanistic studies have shown SAgAs to induce T- and B-cell anergy, the effect of SAgA valency has never been experimentally tested. Here, SAgAs of discrete antigen valencies were synthesized by click chemistry and evaluated for acute B-cell signaling inhibition as well as downstream immunomodulatory effects in splenocytes. Initial studies using the Raji B-cell line demonstrated SAgA valency dictated the extent of calcium flux. Lower valency constructs elicited the largest reductions in B-cell activation. In splenocytes from mice with experimental autoimmune encephalomyelitis, the same valency-dependent effects were evident in the downregulation of the costimulatory marker CD86. The reduction of calcium flux observed in Raji B-cells correlated strongly with downregulation in splenocyte CD86 expression after 72 h. Here, a thorough analysis of SAgA antigenic valency illustrates that low, but not monovalent, presentation of autoantigen was ideal for eliciting the most potent immunomodulatory effects.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoantigens / chemistry*
  • Autoantigens / immunology
  • B-Lymphocytes / immunology*
  • B7-2 Antigen / immunology
  • Cell Line, Tumor
  • Cells, Cultured
  • Click Chemistry / methods
  • Encephalomyelitis, Autoimmune, Experimental / immunology
  • Encephalomyelitis, Autoimmune, Experimental / therapy
  • Humans
  • Immunoassay / methods
  • Immunomodulation*
  • Mice
  • Protein Array Analysis / methods
  • Spleen / cytology*
  • Spleen / immunology

Substances

  • Autoantigens
  • B7-2 Antigen