Structure of a TCR-Mimic Antibody with Target Predicts Pharmacogenetics

Ataie, Niloufar; Xiang, Jingyi; Cheng, Neal; Brea, Elliott J.; Lu, Wenhao; Scheinberg, David A.; Liu, Cheng Z.; Ng, Ho Leung

doi:10.1016/j.jmb.2015.12.002

Cited by 58 publications

(76 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The binding orientations of both mother clones were predicted to be diagonal across the peptide binding groove, but skewed towards the C-terminus of the peptide and the MHC α-chain when compared to crystal structures of TCRs with the same specificity (20). This agrees with results from studies showing that TCR-like antibodies generally bind diagonally, but can have more diverse orientations than TCRs (33)(34)(35)(36). Furthermore, it illustrates that other orientations for specific recognition of pMHC are possible than what is typically seen with naturally occuring TCRs, which may be restricted by co-receptor engagement and germline-imprinted MHC recognition motifs (37).…”

Section: Discussionsupporting

confidence: 88%

Affinity-engineered human antibodies detect celiac disease gluten pMHC complexes and inhibit T-cell activation

Frick

Høydahl

Hodnebrug

et al. 2019

Preprint

View full text Add to dashboard Cite

Antibodies specific for antigenic peptides bound to major histocompatibility complex (MHC) molecules are valuable tools for studies of antigen presentation. Such T-cell receptor (TCR)-like antibodies may also have therapeutic potential in human disease due to their ability to target disease-associated antigens with high specificity. We previously generated celiac disease (CeD) relevant TCR-like antibodies that recognize the prevalent gluten epitope DQ2.5-glia-α1a in complex with HLA-DQ2.5. Here, we report on second-generation high-affinity antibodies towards this epitope as well as a panel of novel TCR-like antibodies to another immunodominant gliadin epitope, DQ2.5-glia-α2. The strategy for affinity engineering was based on Rosetta modeling combined with pIX phage display and is applicable to similar protein engineering efforts. We isolated picomolar affinity binders and validated them in Fab and IgG format. Flow cytometry experiments with CeD biopsy material confirm the unique disease specificity of these TCR-like antibodies and reinforce the notion that B cells and plasma cells have a dominant role in gluten antigen presentation in the inflamed CeD gut. Further, the lead candidate 3.C11 potently inhibited CD4 + T-cell activation and proliferation in vitro in an HLA and epitope specific manner, pointing to a potential for targeted disease interception without compromising systemic immunity. Significance StatementConsumption of gluten-containing food drives celiac disease in genetically predisposed individuals. The underlying disease mechanism is not fully understood, but it is strictly dependent on activation of pathogenic T cells. We have engineered high-affinity human antibodies recognizing the T-cell target HLA-DQ2.5 in complex with gluten epitopes and studied cell-specific antigen presentation in patients, which shows that plasma cells and not dendritic cells dominate the inflamed tissue. The only available treatment is lifelong adherence to a gluten-free diet, which is difficult and not effective in all cases. We show that at least one of our antibodies can specifically inhibit activation of pathogenic T-cells in vitro and therefore shows promise for therapy.

show abstract

Section: Discussionsupporting

confidence: 88%

Affinity-engineered human antibodies detect celiac disease gluten pMHC complexes and inhibit T-cell activation

Frick

Høydahl

Hodnebrug

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…Given that the antibody that binds to WT1/HLA-A2, called ESK1, also bound to peptides that shared the same N-terminal residues as the WT1 peptide (22), the PIGQ (RMFPGEVAL) peptide was tested for activity against the D13.1.1 TCR. Tetramers of the PIGQ peptide/HLA-A2 did not bind to the D13.1.1 TCR (data not shown), nor did the PIGQ peptide stimulate CD8 T cells that expressed the D13.1.1 TCR (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…This antibody was tested for activity and toxicity in mice as a soluble Fc containing antibody, as a bi-specific molecule, and a CAR (19–21). However, recent crystallographic studies showed that the ESK1 antibody docked over the N-terminus of the WT1 peptide, with atomic interactions limited to the first four peptide residues, thus explaining why ESK1 cross-reacted with other human peptides that shared these residues such as the peptide PIGQ (22). Since the ESK1 antibody lacks specificity for WT1 peptide, it is unlikely to be applied in more sensitive therapeutic approaches, such as adoptive T cell therapies.…”

Section: Introductionmentioning

confidence: 99%

Comparison of T Cell Activities Mediated by Human TCRs and CARs That Use the Same Recognition Domains

Harris

Hager

Smith

et al. 2018

The Journal of Immunology

134

135

View full text Add to dashboard Cite

Adoptive T cell therapies have achieved significant clinical responses, especially in hematopoietic cancers. Two types of receptor systems have been used to redirect the activity of T cells, normal heterodimeric T-cell receptors (TCRs) or synthetic chimeric antigen receptors (CARs). TCRs recognize peptide-HLA complexes whereas CARs typically use an antibody-derived scFv (single-chain fragments variable) that recognizes cancer-associated cell-surface antigens. While both receptors mediate diverse effector functions, a quantitative comparison of the sensitivity and signaling capacity of TCRs and CARs has been limited due to their differences in affinities and ligands. Here we describe their direct comparison by using TCRs that could be formatted either as conventional αβ heterodimers, or as scFv constructs linked to CD3ζ and CD28 signaling domains or to CD3ζ only. Two high-affinity TCRs (KD values of approximately 50 and 250 nM) against MART1/HLA-A2 or WT1/HLA-A2 were used, allowing MART1 or WT1 peptide titrations to easily assess the impact of antigen density. Although CARs were expressed at higher surface levels than TCRs, they were 10 to 100-fold less sensitive, even in the absence of the CD8 co-receptor. Mathematical modeling demonstrated that lower CAR sensitivity could be attributed to less efficient signaling kinetics. Furthermore, reduced cytokine secretion observed at high antigen density for both TCRs and CARs suggested a role for negative regulators in both systems. Interestingly, at high antigen density, CARs also mediated greater maximal release of some cytokines, such as IL-2 and IL-6. These results have implications for next-generation design of receptors used in adoptive T cell therapies.

show abstract

“…For example, the therapeutic TCRm ESK1 binds to a composite antigen composed of HLA-A*02:01 amino acids in addition to three to five N-terminal residues of a WT1-derived peptide 9-mer. [10,16] Substitutions of the C-terminal amino acids of the target peptide still allows binding of the ESK1 TCRm. In addition, another TCRm (named 8F4) against the tumor-associated antigen PR1 has been shown to depend heavily on one residue of the PR1-peptide,[17] whereas a TCRm to the cancer-testis antigen PRAME[31] was shown to bind to the C-terminal end of the peptide sequence.…”

Section: Choosing the Right Antigenmentioning

confidence: 99%

“…Furthermore, HLA restriction selects small subsets of amino acid sequences for presentation, which means that an individual TCRm may work only for a subset of patients with particular HLA types. [10] Lastly, because the epitope consists of a linear peptide sequence within an MHC molecule (pMHC), there is also the possibility of cross-reactivity with other linear sequences that are homologous to the chosen epitope and may be presented on nontarget cells.…”

Section: Introductionmentioning

confidence: 99%

Opportunities and challenges for TCR mimic antibodies in cancer therapy

Chang

Gejman

Brea

et al. 2016

Expert Opinion on Biological Therapy

Self Cite

View full text Add to dashboard Cite

Introduction Monoclonal antibodies (mAbs) are potent cancer therapeutic agents, but exclusively recognize cell-surface targets whereas most cancer-associated proteins are found intracellularly. Hence, potential cancer therapy targets such as overexpressed self-proteins, activated oncogenes, mutated tumor suppressors, and translocated gene products are not accessible to traditional mAb therapy. An emerging approach to target these epitopes is the use of TCR mimic mAbs (TCRm) that recognize epitopes similar to those of T cell receptors (TCR). Areas covered TCRm antigens are comprised of a linear peptide sequence derived from degraded proteins and presented in the context of cell-surface MHC molecules. We discuss how the nature of the TCRm epitopes provides both advantages (absolute tumor specificity and access to a new universe of important targets) and disadvantages (low density, MHC restriction, MHC down-regulation, and cross-reactive linear epitopes) to conventional mAb therapy. We will also discuss potential solutions to these obstacles. Expert Opinion TCRm combine the specificity of TCR recognition with the potency, pharmacologic properties, and versatility of mAbs. The structure and presentation of a TCRm epitope has important consequences related to the choice of targets, mAb design, available peptides and MHC subtype restrictions, possible cross-reactivity, and therapeutic activity.

show abstract

Structure of a TCR-Mimic Antibody with Target Predicts Pharmacogenetics

Cited by 58 publications

References 53 publications

Affinity-engineered human antibodies detect celiac disease gluten pMHC complexes and inhibit T-cell activation

Affinity-engineered human antibodies detect celiac disease gluten pMHC complexes and inhibit T-cell activation

Comparison of T Cell Activities Mediated by Human TCRs and CARs That Use the Same Recognition Domains

Opportunities and challenges for TCR mimic antibodies in cancer therapy

Contact Info

Product

Resources

About