Antigenic properties of peptide mimotopes of HIV-1-associated carbohydrate antigens

J Biol Chem. 2005 Aug 12;280(32):28959-65. doi: 10.1074/jbc.M502964200. Epub 2005 Jun 14.

Abstract

The glycan shield of the human immunodeficiency virus (HIV) envelope protein presents many potential epitopes for vaccine development. To augment immune responses to HIV, type 1 (HIV-1), envelope-associated carbohydrate antigens, we are defining peptide mimics of HIV-associated carbohydrate antigens that function as antigen mimotopes that upon immunization will induce antibodies cross-reactive with carbohydrate antigens. We have previously defined peptides with a putative sequence tract RYRY that mimic concanavalin A-binding glycans. To imitate the multivalent binding of carbohydrates, we compared the avidity of a linear (911) and cyclic peptide (D002) reactive with concanavalin A presented in a multiple antigen peptide (MAP) format. The affinity of the MAP-D002 peptide was higher than that of the peptide MAP-911, whereas the avidity of D002 peptide was lower than that of 911. Serum from mice immunized with MAP-911 had lower titer for oligomannose-9 than those elicited by MAP-D002 under the same conditions, but both immunogens elicited antibodies that can block the binding of GP120 to dendritic cells. Antibodies that bind to the studied MAPs were found in a preparation of normal human immunoglobulin for intravenous use. Those that were purified on 911 bound back to 911 and D002, whereas anti-D002 antibodies were specific only for D002. Human antibodies reactive with both mimotopes and with a mannosyl preparation were observed to bind to envelope protein. These results suggested the potential to fine-tune the antibody response to carbohydrate antigens by modifying structural features of peptide mimotope-based immunogens.

Publication types

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

MeSH terms

  • Animals
  • Autoantibodies / chemistry
  • Biosensing Techniques
  • Carbohydrates / chemistry*
  • Concanavalin A / chemistry
  • Dendritic Cells / cytology
  • Dendritic Cells / metabolism
  • Densitometry
  • Dose-Response Relationship, Drug
  • Enzyme-Linked Immunosorbent Assay
  • HIV Antigens / chemistry
  • HIV Envelope Protein gp120 / metabolism
  • HIV-1 / metabolism*
  • Humans
  • Immunoglobulins / chemistry
  • Kinetics
  • Mannose / chemistry
  • Mice
  • Mice, Inbred BALB C
  • Peptides / chemistry
  • Polysaccharides / chemistry
  • Protein Binding
  • Recombinant Proteins / chemistry
  • Surface Plasmon Resonance
  • Time Factors

Substances

  • Autoantibodies
  • Carbohydrates
  • HIV Antigens
  • HIV Envelope Protein gp120
  • Immunoglobulins
  • Peptides
  • Polysaccharides
  • Recombinant Proteins
  • Concanavalin A
  • Mannose