CBD May Reduce the Ability of Immune Cells to Kill Cancer That Displays a Specific Stress Protein | Research

The takeaway

CBD reduced the cancer-killing effectiveness of activated natural killer cells against tumors displaying high levels of the stress protein Hsp70, raising concerns about CBD use during certain immunotherapies.

Oncology researchers studying CBD-immune interactions; cancer patients using CBD alongside treatment.

CBD significantly reduced IFN-gamma and granzyme B release from tumor-targeting NK cells

What the researchers found

CBD treatment significantly reduced the release of interferon-gamma and granzyme B from activated NK cells, lowered Hsp70 expression on tumor surfaces, and decreased NK cell killing of high-Hsp70-expressing cancer cells. Low-Hsp70 tumors were unaffected.

Why it matters

Many cancer patients use CBD for symptom management during treatment. This study raises a specific, mechanistic concern: CBD might interfere with NK cell-based immune responses against tumors that display the stress protein Hsp70, potentially undermining certain immunotherapy approaches.

The numbers in context

CBD significantly reduced IFN-gamma and granzyme B release from activated NK cells. CBD decreased elevated mHsp70 expression on tumor cells but did not affect low baseline mHsp70. Killing of high-mHsp70 tumor cells by CBD-pretreated NK cells was reduced. Expression of NKp30, NKG2D, and CD69 receptors remained unchanged.

How the study worked

In vitro study examining CBD's effects on NK cells stimulated with TKD Hsp70 peptide and IL-2, and on HCT116 colorectal cancer cells with different levels of membrane Hsp70 expression. NK cell receptor expression, cytokine release, and cytotoxicity were measured.

What this study cannot tell us

In vitro study using cell lines, which may not reflect the complexity of CBD-immune interactions in living organisms. CBD concentrations used may not match what patients actually achieve in tissue. Only one type of cancer cell line was examined.

How to read the evidence

Preliminary: in vitro study with clear mechanistic findings, but not yet validated in animal models or human patients.

When this study was published

2024 preclinical study.

The bigger picture

As CBD becomes widely used alongside conventional cancer therapies, understanding where it helps and where it may hinder becomes critical. The Hsp70-NK cell axis is a target of emerging cancer immunotherapies, and CBD's interference with this specific pathway deserves attention in clinical settings.

Questions still open

Do these immunosuppressive effects of CBD occur at clinically relevant concentrations in cancer patients? Could timing CBD use around immunotherapy sessions mitigate potential interference?

Common questions

Does this mean CBD promotes cancer?

Not exactly. CBD specifically reduced NK cell effectiveness against tumors displaying high levels of a particular stress protein (Hsp70). It did not affect killing of tumors with low Hsp70. The concern is about potential interference with specific immune pathways, not cancer promotion broadly.

What is Hsp70 and why does it matter?

Hsp70 is a heat shock protein that appears on the surface of many tumor cells under stress. It serves as a target for activated NK cells. CBD reduced this surface marker on cancer cells, making them less visible to immune attack.

Read the original research

The immunomodulatory effects of cannabidiol on Hsp70-activated NK cells and tumor target cells.

Molecular immunology, 174, 1-10

View on PubMed ↗Publisher’s paper ↗

Citation

Wang, Fei; Bashiri Dezfouli, Ali; Multhoff, Gabriele. (2024). The immunomodulatory effects of cannabidiol on Hsp70-activated NK cells and tumor target cells.. Molecular immunology, 174, 1-10. https://doi.org/10.1016/j.molimm.2024.07.008