Modulation of antigen immunogenicity by deleting epitopes recognized by NKT cells

Inventors

Saint-Remy, Jean-Marie

Assignees

Equaly SA

Abstract

The invention describes a method and compounds for the prevention of immune responses towards allofactors, towards viral vectors used for gene therapy and gene vaccination, towards proteins to which subjects are naturally exposed, towards genetically-modified organisms and towards undesirable effects related to vaccine administration for allergic or infectious diseases.

Core Innovation

The invention addresses an unexpected mechanism in which hydrophobic peptide or polypeptide segments containing CD1d-binding motifs are presented by CD1d to activate NKT cells. Such activation triggers cytokine release and, in some cases, cytolytic properties and suppression of adaptive CD4+ responses. The background problem is undesired immunogenicity arising from CD1d-dependent presentation of peptide or polypeptide segments carrying CD1d-binding motifs.

The invention provides preventing undesired immunogenicity by deleting or substituting key hydrophobic or anchoring residues in the CD1d-binding motif. Key positions are described as P1 and P7, where the [F/W/T/H/Y] amino acids of the motif are substituted by an amino acid different from [F/W/T/H/Y] to reduce binding to CD1d and reduce NKT-cell activation. The document also describes optionally disrupting the motif itself by adding or deleting within the CD1d-binding motif or substituting in a motif position P4.

The invention includes identifying CD1d-binding motifs in target proteins and testing CD1d-dependent NKT activation using CD1d-expressing cells and NKT cells, with readouts including cytokine production and CD1d tetramers. Engineered peptides or polypeptides are designed to show reduced CD1d binding and reduced capacity to activate NKT cells compared with the corresponding CD1d-binding peptides or polypeptides.

Examples described include FVIII, where functional CD1d-binding motifs activate NKT cells and are required for anti-FVIII antibody production, and motif-eliminating substitutions prevent NKT activation and anti-FVIII antibodies in hemophilia A mice. Another example is Ad5 hexon, where CD1d-binding motifs activate NKT cells and drive anti-Ad5 neutralizing antibodies, and substitution of P1 anchoring residues reduces NKT labeling and anti-Ad5 antibodies. Additional examples include modifications in Mal d 1, alpha-gliadin, and Der p 1 to reduce CD1d tetramer recognition and NKT activation, and described modulation in human IgG motifs to prevent NKT activation while leaving class II CD4+ activation.

Claims Coverage

The document provides two independent claims. The first covers an engineered peptide or polypeptide defined by SEQ ID NO:4 or SEQ ID NO:5, and the second covers a method that constructs an engineered peptide or polypeptide by specific motif substitutions at P1 and P7 and then measures reduced CD1d binding capacity and/or reduced capacity to activate NKT cells.

Across the independent claim set, the core claim coverage is (i) engineered peptides or polypeptides defined by SEQ ID NO:4 or SEQ ID NO:5 and (ii) motif-based engineering of CD1d-binding peptides or polypeptides by substituting the [F/W/T/H/Y] residues at P1 and P7 to reduce CD1d binding and reduce measured capacity to activate NKT cells, with optional measuring of reduced CD1d-binding capacity or activation capacity relative to a reference.

Stated Advantages

Documented Applications