i3S researchers develop a new strategy to create super CAR-T cells against solid tumors

A team from the Institute for Research and Innovation in Health at the University of Porto (i3S), led by Salomé Pinho, has discovered a new strategy to make (CAR-)T cell therapies more effective against solid tumors. The findings were published in Cancer Immunology Research, a journal of the American Association for Cancer Research (AACR).

The researchers showed that, in colorectal cancer, tumor-infiltrating T cells undergo significant changes in their surface sugars-chains (glycans) that hampers their ability to fight cancer. By using CRISPR/Cas9 gene editing to remove the MGAT5 gene, responsible for producing those deleterious glycans, the team restored T cell function, making them less exhausted and more resistant to better fight tumor cells.

Applying this approach to CAR-T therapy, which is already used in blood cancers but less effective in solid tumors, the team engineered the so-called “Glyco-CAR-T” cells. These glyco-modified super CAR-T cells demonstrated superior cytotoxic capacity and greater ability to control solid tumor growth in experimental models.

The study was led by first author Catarina Azevedo, supported by FCT, FLAD and Fulbright fellowships, in collaboration with Ângela Fernandes from i3S and Greg Delgoffe from the University of Pittsburgh.

Authors and Affiliations: 

Catarina M. Azevedo^1,2, Bingxian Xie^3,4, William G. Gunn^3,4, Ronal M. Peralta^3,4, Carolina S. Dantas^1,2, Henrique Fernandes-Mendes^2,9, Supriya Joshi^3,4, Victoria Dean^3,4, Pedro Almeida¹, Drew Wilfahrt^3,4, Nuno Mendes¹, Julian López Portero^5,6,7, Carmen Poves^7,8, María Jesús Fernández-Aceñero^5,6, Ricardo Marcos-Pinto^2,9, Ângela Fernandes¹*, Greg M. Delgoffe^3,4*, Salomé S. Pinho^1,2,10,11*

¹i3S – Institute for Research and Innovation in Health, University of Porto, Porto, Portugal

²ICBAS – School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal

³Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA

⁴Tumor Microenvironment Center, UPMC Hillman Cancer Center, Pittsburgh, PA, USA

⁵Department of Legal medicine, Psychiatry and Surgical Pathology, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain

⁶Department of Surgical Pathology, Hospital Clínico San Carlos, Madrid, Spain

⁷Instituto de Investigación del Hospital Clínico San Carlos (IdISSC), Madrid, Spain

⁸Gastroenterology Department, Endoscopy Unit Hospital Clínico San Carlos, Madrid, Spain

⁹Department of Gastroenterology, Santo António University Hospital Center, Porto, Portugal

¹⁰Faculty of Medicine, University of Porto, Porto, Portugal

*These authors contributed equally/Senior authors

¹¹Lead contact

Abstract:

T-cell therapies have transformed cancer treatment. While surface glycans have been shown to play critical roles in regulating T-cell development and function, whether and how the glycome influences T cell–mediated tumor immunity remains an area of active investigation. In this study, we show that the intratumoral T-cell glycome is altered early in human colorectal cancer, with substantial changes in branched N-glycans. We demonstrated that CD8⁺ T cells expressing β1,6-GlcNAc branched N-glycans adopted an exhausted phenotype, marked by increased PD1 and Tim3 expression. CRISPR/Cas9 deletion of key branching glycosyltransferase genes revealed that Mgat5 played a prominent role in T-cell exhaustion. In culture-based assays and tumor studies, Mgat5 deletion in CD8⁺ T cells resulted in improved cancer cell killing. These findings prompted assessment of whether MGAT5 deletion in anti-CD19 chimeric-antigen receptor (CAR) T cells could enable this therapeutic modality in a solid tumor setting. We showed that MGAT5 KO anti-CD19-CAR T cells inhibited the growth of CD19-transduced tumors. Together, these findings show that MGAT5-mediated branched N-glycans regulate CD8⁺ T-cell function in cancer and provide a strategy to enhance antitumor activity of native and CAR T cells.

Journal: Cancer Immunology Research journal

Link: https://doi.org/10.1158/2326-6066.CIR-25-0313