Identification of Antibody Glycosylation Structures That Predict Monoclonal Antibody Fc-effector Function

AIDS. 2014 Nov 13;28(17):2523-30. doi: 10.1097/QAD.0000000000000444.

Abstract

Objective: To determine monoclonal antibody (mAb) features that predict fragment crystalizable (Fc)-mediated effector functions against HIV.

Design: Monoclonal antibodies, derived from Chinese hamster ovary cells or Epstein-Barr virus-immortalized mouse heteromyelomas, with specificity to key regions of the HIV envelope including gp120-V2, gp120-V3 loop, gp120-CD4(+) binding site, and gp41-specific antibodies, were functionally profiled to determine the relative contribution of the variable and constant domain features of the antibodies in driving robust Fc-effector functions.

Methods: Each mAb was assayed for antibody-binding affinity to gp140(SR162), antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP) and for the ability to bind to FcγRIIa, FcγRIIb and FcγRIIIa receptors. Antibody glycan profiles were determined by HPLC.

Results: Neither the specificity nor the affinity of the mAbs determined the potency of Fc-effector function. FcγRIIIa binding strongly predicted ADCC and decreased galactose content inversely correlated with ADCP, whereas N-glycolylneuraminic acid-containing structures exhibited enhanced ADCP. Additionally, the bi-antenary glycan arm onto which galactose was added predicted enhanced binding to FcγRIIIa and ADCC activity, independent of the specificity of the mAb.

Conclusions: Our studies point to the specific Fc-glycan structures that can selectively promote Fc-effector functions independently of the antibody specificity. Furthermore, we demonstrated antibody glycan structures associated with enhanced ADCP activity, an emerging Fc-effector function that may aid in the control and clearance of HIV infection.

Publication types

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

MeSH terms

  • Animals
  • Antibodies, Monoclonal / chemistry
  • Antibodies, Monoclonal / immunology*
  • Antibodies, Monoclonal / isolation & purification
  • Antibody Affinity
  • Antibody-Dependent Cell Cytotoxicity
  • Chromatography, High Pressure Liquid
  • Cricetulus
  • Glycosylation
  • HIV / immunology*
  • HIV Antibodies / chemistry
  • HIV Antibodies / immunology*
  • HIV Antibodies / isolation & purification
  • Immunoglobulin Fc Fragments / chemistry
  • Immunoglobulin Fc Fragments / metabolism*
  • Mice
  • Phagocytosis
  • Protein Binding
  • Receptors, IgG / metabolism*
  • env Gene Products, Human Immunodeficiency Virus / immunology

Substances

  • Antibodies, Monoclonal
  • HIV Antibodies
  • Immunoglobulin Fc Fragments
  • Receptors, IgG
  • env Gene Products, Human Immunodeficiency Virus