Identification and characterization of natural antibodies against tau protein in an intravenous immunoglobulin product

J Neuroimmunol. 2015 Dec 15:289:121-9. doi: 10.1016/j.jneuroim.2015.10.017. Epub 2015 Oct 28.

Abstract

The latest therapeutic approaches to Alzheimer disease are using intravenous immunoglobulin (IVIG) products. Therefore, the detailed characterization of target-specific antibodies naturally occurring in IVIG products is beneficial. We have focused on characterization of antibodies isolated against tau protein, a biomarker of Alzheimer's disease, from Flebogamma IVIG product. The analysis of IgG subclass distribution indicated skewing toward IgG3 in anti-tau-enriched IgG fraction. The evaluation of their reactivity and avidity with several recombinant tau forms was performed by ELISA and blotting techniques. Truncated non-phosphorylated tau protein (amino acids 155-421) demonstrated the highest reactivity and avidity index. We provide the first detailed insight into the reactivity of isolated natural antibodies against tau protein.

Keywords: Alzheimer disease; Avidity; Immunoreactivity; Intravenous immunoglobulins; Natural antibodies; Tau protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Epitopes / chemistry
  • Humans
  • Immunoglobulin G / immunology
  • Immunoglobulin G / isolation & purification*
  • Immunoglobulins, Intravenous / chemistry*
  • Immunoglobulins, Intravenous / immunology
  • Immunosorbent Techniques
  • Molecular Weight
  • Peptides / immunology
  • Protein Binding / immunology
  • Protein Structure, Tertiary
  • tau Proteins / immunology*

Substances

  • Epitopes
  • Immunoglobulin G
  • Immunoglobulins, Intravenous
  • Peptides
  • tau Proteins