Episode 12 - Immunogenic cell death in ECP-treated cutaneous T-cell lymphoma

In this episode of BJD Talks, Sam and Meera discuss the article ‘Evidence of immunogenic cell death (ICD) and ICD-dependent dendritic cell activation induced by extracorporeal photopheresis in patients with leukaemic forms of cutaneous T-cell lymphoma’ by Lackner et al. The full article can be accessed at https://doi.org/10.1093/bjd/ljaf102 

*This podcast was generated by an AI tool created by 67Bricks for the British Association of Dermatologists* 

Transcript

SPEAKER_01 0:00

Welcome to BJD Talks, the official podcast of the BJD. I'm Sam.

SPEAKER_00 0:04

And I'm Mira. In this episode, we will be discussing the article by Angelica Lachner et al. Evidence of Immunogenic Cell Death, ICD, an ICD-dependent dendritic cell activation induced by extracorporeal photophoresis in patients with leukemic forms of cutaneous T cell lymphoma from March 2025.

SPEAKER_01 0:26

Extracorporeal photophoresis or ECP is a key therapy for advanced cutaneous T cell lymphoma, particularly in its leukemic forms. While its safety and efficacy are well established, its underlying mechanisms have long been unclear. Until now.

SPEAKER_00 0:42

Exactly. This new study by Lackner and colleagues sheds light on the process, showing that ECP induces immunogenic cell death, or ICD, in malignant T cells. ICD is a particularly intriguing concept in cancer immunotherapy as it prompts the immune system to respond actively, turning dying cells into signals that recruit immune cells, such as dendritic cells.

SPEAKER_01 1:06

And dendritic cells are pivotal in initiating an adaptive immune response. They engulf and process these dying malignant cells, effectively teaching cytotoxic T lymphocytes to target tumor cells more effectively. It's as though the cancer cells provide the very blueprint for their destruction.

SPEAKER_00 1:24

Nicely put. Indeed, once these ICD markers emerged, dendritic cells began engaging with the malignant cells as shown through phagocytosis assays. Dendritic cells selectively engulfed ECP-treated CD4 positive T cells, not CD8 positive T cells. Crucially, blocking ICD signals like cowreticulin or extracellular ATP completely stopped this process, underlining their importance.

SPEAKER_01 2:34

These results could lead to refinements in ECP protocols and even broader applications beyond cutaneous T cell lymphoma. If validated in other cancers, it could reshape how ECP is used in immunotherapy.

SPEAKER_00 2:47

Absolutely. However, we should note some limitations. While ICD induction and dendritic cell activation are clear, the downstream effects, particularly whether cytotoxic T cells eliminate tumor cells, remain unexplored. More research is needed to connect these dots.

SPEAKER_01 3:04

Another consideration is the potential for off-target effects. ICD is generally beneficial in cancer, but its impact on healthy cells warrants attention. Reassuringly, ECP has not been linked to autoimmunity in practice, but it's an area worth investigating.

SPEAKER_00 3:20

Agreed. Understanding why ECP avoids off-target effects could be key, whether it's due to its delivery method or the nuances of ICD. Regardless, this study offers valuable insights into one of the most effective treatments for cutaneous T cell lymphoma.

SPEAKER_01 3:36

To summarize, ECP leverages ICD to activate dendritic cells, enhancing immune detection of malignant T cells. This helps to explain how it works and points to ways its effectiveness might be enhanced further.

SPEAKER_00 3:50

Precisely, and beyond ECP, it underscores ICD's broader potential as a target for cancer immunotherapy. It's an exciting time for dermatological oncology.

SPEAKER_01 4:00

On that note, we'll wrap up today's episode of BJD Talks. Thanks for listening and do join us next time for more insights into dermatology research.

SPEAKER_00 4:08

Until then, take care everyone.