Tuning CAR-T cells by targeting cancer-associated glycan in pancreatic cancer - Accepted 30 October 2025

Sep 23, 2026

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Chimeric antigen receptor (CAR) T cell therapy improves cancer treatment, but efficacy in solid tumors is constrained by antigen heterogeneity, an immunosuppressive microenvironment, and the glycocalyx barrier. The glycocalyx, enriched in dense glycoproteins such as MUC1, can impede immune cell access and CAR engagement, while Tn antigen—often overexpressed as Tn-MUC1 in pancreatic cancer—provides a relevant target. The study integrates a non-signaling glyco-bridge binder that recognizes Tn-MUC1 into mesothelin-directed CAR-T cells, enhancing tumor recognition and cytotoxicity via density- and affinity-dependent CAR activation. A tandem HPA lectin-based bridge further broadens recognition across cancer types, improving killing in pancreatic cancer models.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages15

Reading Time38 min

AccessFree to download

Introduction

Solid tumor barriers to CAR-T efficacy

Target selection: Tn-MUC1 and the glycocalyx

Glyco-bridge CAR-T design

Tn-MUC1-specific bridge

Tandem HPA lectin-based bridge

Article [https://doi.org/10.1038/s41467-025-66102-2](https://doi.org/10.1038/s41467-025-66102-2) Tuning CAR-T cells by targeting cancerassociated glycan in pancreatic cancer Received: 22 August 2025 | Accepted: 30 October 2025 | | --- | | | | Check for updates | Sangwoo Park 1,2,3, Cassidy E. Ho1,2, Eli P. Darnell1,2,3, Alexandra N. Wolff1,2,3, Hana Takei 1,2, Filippo Birocchi 1,2,3, Amanda A. Bouffard1,2, Diego Salas-Benito1,2,3, Giulia Escobar 1,2,3, Mark B. Leick 1,2,3, Adele Mucci1,2, Trisha R. Berger1,2 & Marcela V. Maus 1,2,3 Chimeric antigen receptor (CAR) T cell therapy has transformed cancer treatment but its efﬁcacy remains limited in solid tumors due to antigen heterogeneity, an immunosuppressive microenvironment, and the glycocalyx barrier. The glycocalyx, composed of dense glycoproteins such as MUC1, is markedly expanded in cancers, where it impedes immune cell access and antigen engagement, thereby reducing efﬁcacy. In most adenocarcinomas, Tn antigen, comprising N-acetylgalactosamine linked to serine or threonine, is overexpressed. Tn-MUC1, a truncated form of MUC1 decorated with Tn antigen, is frequently overexpressed in pancreatic cancer. Here, we incorporate anon-signaling glyco-bridge binder recognizing Tn-MUC1 into mesothelindirected CAR-T cells. This bridge enhances tumor recognition and cytotoxicity by increasing avidity and facilitating CAR activation in a density-and afﬁnitydependent manner. To broaden its applicability, we design a tandem Helix pomatia agglutinin (HPA) lectin-based bridge that recognizes Tn antigens across cancer types. CAR-T cells with the HPA-bridge exhibit superior cytotoxicity in pancreatic cancer models. Chimeric antigen receptor T (CAR-T) cell therapy has revolutionized cancer immunotherapy by harnessing the body’s immune system to target and eliminate malignant cells. It has dramatically changed the treatment landscape for patients with relapsed and refractory B-cell malignancies, especially following FDA approval for diffuse large B-cell lymphoma, B-cell acute lymphoblastic leukemia, and multiple myeloma1–5. This success has sparked signiﬁcant interest in expanding the technology to solid tumors. CAR-T cell studies targeting various solid cancers, including pancreatic cancer and triple-negative breast cancer, have recently gained momentum, although challenges remain that can hinder CAR-T cell efﬁcacy and persistence6–11. These challenges include antigen heterogeneity, an immunosuppressive tumor microenvironment, and physical barriers such as the tumor stroma and cellular glycocalyx12–17. The physical barriers in solid tumors present signiﬁcant challenges to immune cells, including CAR-T cell therapy. In particular, the dense layer of heavily glycosylated proteins like mucins, which are often overexpressed in cancers, can modulate the tumor microenvironment that hinders immune cell inﬁltration and effective immune cell targeting8,17–22. The cancer-associated mucin MUC1, decorated with N-acetylgalactosamine (GalNAc) linked to serine orthreonine residues (known as the Tn antigen; Tn-MUC1), is frequently found in solid tumors such as pancreatic cancer and has become a target for several therapeutic strategies, including CAR-T cell therapy23–31. Speciﬁcally, CAR-T cells targeting Tn-MUC1 developed by Posey et al. were advanced to a clinical trial with patients with TnMUC1-overexpressing cancers, including pancreatic cancer and triplenegative breast cancer, and no signiﬁcant safety concerns or on-target/ off-tumor toxicity were reported (NCT04025216)23,32. However, glycoproteins and other large components of the glycocalyx are thought to sterically shield molecular epitopes, affecting the interactions between immune cells and tumor cells12. Aberrant N-glycosylation, 1Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA. 2Cellular Immunotherapy Program, Massachusetts General Hospital Cancer Center, Boston, MA, USA. 3Harvard Med

FAQs

Why is CAR-T cell efficacy limited in solid tumors?

Efficacy is limited by antigen heterogeneity, an immunosuppressive tumor microenvironment, and physical barriers including the glycocalyx.

What role does the glycocalyx and MUC1 play in CAR-T activity?

The glycocalyx, enriched with heavily glycosylated proteins like MUC1, can shield epitopes and hinder immune cell infiltration and CAR antigen engagement.

How does targeting Tn-MUC1 improve CAR-T function in pancreatic cancer?

Incorporating a glyco-bridge binder recognizing Tn-MUC1 increases tumor recognition and cytotoxicity by promoting CAR activation in a density- and affinity-dependent manner.

Sep 23, 2026

Uploaded by OmBimo