New VIP Receptor-Blocking Peptides Boost T Cell Killing of Leukemia Cells in Mice and Human Samples | Research

The takeaway

From a combinatorial peptide library, researchers identified VIP receptor antagonists ANT308 and ANT195 that potently activate T cells and induce anti-leukemia responses in mouse AML models and patient samples — with computational binding predictions correlating with biological activity.

Computational binding correlated with anti-leukemia activity
predicted VIP receptor binding affinity of peptide variants positively correlated with both T cell activation and in vivo anti-leukemia responses — validating rational peptide drug design

What the researchers found

VIP receptor antagonists ANT308 and ANT195, identified through combinatorial library screening with computational binding prediction, potently activated T cells and induced anti-leukemia responses in mouse AML models and human AML patient samples.

Why it matters

Acute myeloid leukemia (AML) is an aggressive blood cancer with poor outcomes, especially after relapse. VIP receptor blockade represents a completely different immunotherapy approach than checkpoint inhibitors — unleashing T cells by removing a neuropeptide-mediated brake. ANT308's activity on patient-derived T cells suggests this could help AML patients who have failed other treatments.

The numbers in context

The combinatorial library screened multiple C-terminal sequence variations. Lead candidates showed improved receptor binding affinity and plasma stability over VIPhyb.

How the study worked

Created combinatorial library of VIPhyb C-terminal variants. In silico docking scored binding to VPAC1/VPAC2. Synthesized 15 top peptides. Tested T cell activation (mouse and human) in vitro. Evaluated anti-leukemia activity in C1498 myeloid leukemia mouse model (daily SC injections). Validated ANT308 mechanism in CD8+ T cells from AML patients.

Who was studied

Cell cultures and mouse leukemia models

What this study cannot tell us

Animal model (C1498 in C57Bl/6) — may not fully replicate human AML. Daily subcutaneous injections may limit patient compliance. In vitro human T cell activation doesn't guarantee in vivo anti-leukemia response. The peptide antagonists' pharmacokinetics and potential off-target effects (VIP has many physiological roles) need assessment. Small-scale patient sample testing.

How to read the evidence

Preliminary — animal study with human sample validation. Demonstrates proof-of-concept for VIP receptor antagonist immunotherapy in AML, but clinical trials are needed.

When this study was published

Published in 2024, advancing VIP receptor-targeted immunotherapy as a novel approach for acute myeloid leukemia.

The bigger picture

This study demonstrates that neuropeptide signaling can be therapeutically targeted in cancer immunotherapy. While checkpoint inhibitors (anti-PD-1/PD-L1) have transformed oncology, they don't work well in AML. VIP receptor antagonists activate T cells through an entirely different mechanism — removing a neuropeptide-mediated immunosuppressive signal. The correlation between computational predictions and biological activity validates rational peptide drug design for immunotherapy.

Questions still open

Would ANT308/ANT195 work synergistically with checkpoint inhibitors or CAR-T cells in AML?
What are the off-target effects of blocking VIP signaling systemically, given VIP's roles in gut, immune, and nervous system function?
Could longer-acting VIP receptor antagonists (pegylated or sustained-release) reduce the burden of daily injections?

Common questions

How does blocking a neuropeptide help fight leukemia?

VIP (vasoactive intestinal peptide) is a chemical messenger that tells immune cells to calm down. Tumors exploit this by producing VIP to suppress the T cells that would otherwise attack them. By blocking VIP receptors with antagonist peptides, the T cell 'brakes' are released, allowing them to recognize and kill leukemia cells. It's a different approach than checkpoint inhibitors but works toward the same goal — unleashing the immune system against cancer.

Why is this important for AML specifically?

AML is notoriously resistant to immunotherapy — checkpoint inhibitors like those used in lung cancer and melanoma haven't worked well in AML. VIP receptor blockade activates T cells through an entirely different pathway, potentially succeeding where other immunotherapies have failed. The fact that ANT308 activated T cells from actual AML patients to produce cancer-killing molecules (granzyme B, perforin) is particularly encouraging.

Read the original research

Identification and characterization of vasoactive intestinal peptide receptor antagonists with high-affinity and potent anti-leukemia activity.

bioRxiv : the preprint server for biology

View on PubMed ↗Publisher’s paper ↗

Citation

Wang, Yuou; Sen-Majumdar, Anish; Li, Jian-Ming; Sarkar, Srijon; Passang, Tenzin; Li, Yiwen; Cohen, Jamie; Chen, Zihan; Chaudagar, Kiranj; Das, Pankoj Kumar; Wang, Shuhua; Bruk, Nabute; Papadantonakis, Nikolaos; Giver, Cynthia R; Waller, Edmund K. (2024). Identification and characterization of vasoactive intestinal peptide receptor antagonists with high-affinity and potent anti-leukemia activity.. bioRxiv : the preprint server for biology. https://doi.org/10.1101/2024.11.08.622716