Design of short peptides to block BTLA/HVEM interactions for promoting anticancer T-cell responses

PLoS One. 2017 Jun 8;12(6):e0179201. doi: 10.1371/journal.pone.0179201. eCollection 2017.

Abstract

Antibody based immune-checkpoint blockade therapy is a major breakthrough in oncology, leading to clinical benefit for cancer patients. Among the growing family of inhibitory receptors, the B and T lymphocyte attenuator (BTLA), which interacts with herpes virus entry mediator (HVEM), is a promising target for immunotherapy. Indeed, BTLA inhibits T-cell proliferation and cytokine production. The crystal structure of the BTLA/HVEM complex has shown that the HVEM(26-38) fragment is directly involved in protein binding. We designed and analyzed the capacity of several analogs of this fragment to block the ligation between BTLA and HVEM, using competitive ELISA and cellular assay. We found that the HVEM(23-39) peptide can block BTLA/HVEM ligation. However, the blocking ability was due to the Cys encompassed in this peptide and that even free cysteine targeted the BTLA protein and blocked its interaction with HVEM. These data highlight a Cys-related artefact in vitro, which should be taken in consideration for future development of BTLA/HVEM blocking compounds.

MeSH terms

  • Amino Acid Sequence
  • Cell Line
  • Cysteine / metabolism
  • Drug Design*
  • Humans
  • Neoplasms / drug therapy*
  • Neoplasms / immunology*
  • Neoplasms / pathology
  • Peptides / chemical synthesis*
  • Peptides / chemistry
  • Peptides / pharmacology
  • Peptides / therapeutic use*
  • Protein Binding / drug effects
  • Receptors, Immunologic / chemistry
  • Receptors, Immunologic / metabolism*
  • Receptors, Tumor Necrosis Factor, Member 14 / chemistry
  • Receptors, Tumor Necrosis Factor, Member 14 / metabolism*
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / immunology*

Substances

  • BTLA protein, human
  • Peptides
  • Receptors, Immunologic
  • Receptors, Tumor Necrosis Factor, Member 14
  • Cysteine

Grants and funding

This work was supported by Grant project no. PSPB-070/2010 “Design of BTLA inhibitors as new drugs against melanoma” financed by a grant from Switzerland through the Swiss Contribution to the enlarged European Union; and by the Interdisciplinary Fund from the Faculty of Biology and Medicine (FBM) of Lausanne.