Generation of TGFβR2(-1) neoantigen specific HLA-DR4 restricted T cell receptors for cancer therapy - read online free

Sep 28, 2026

Adoptive transfer of patient T cells engineered to express a T cell receptor (TCR) with defined neoantigen specificity offers a practical approach to cancer therapy, yet CD4+ MHC II-restricted TCR development lags behind CD8+ MHC I systems. This study targets the TGFβR2(-1) frameshift neoantigen from recurrent microsatellite mutations in colorectal and gastric cancers. Methods used ABabDR4 mice to isolate TGFβR2(-1)-specific CD4+ TCRs and assess potency, processing, presentation, potency, and safety in vitro and in tumor cell line contexts.

LanguageEnglish

CategoryHealthcare

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Pages13

Reading Time33 min

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Open access Original research Generation of TGFβR2(-1) neoantigen specific HLA-DR4-restricted T cell receptors for cancer therapy Natalia Plewa , Lucia Poncette, Thomas Blankenstein To cite: Plewa N, Poncette L, Blankenstein T. Generation of TGFβR2(-1) neoantigen-specific HLA-DR4-restricted T cell receptors for cancer therapy. Journal for ImmunoTherapy of Cancer 2023;11:e006001 . doi:10.1136/jitc-2022-006001 ► Additional supplemental material is published online only. To view, please visit the journal online ([http://dx.doi.org/10](http://dx.doi.org/10) . 1136/jitc-2022-006001) . Accepted 06 February 2023 © Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. Max Delbruck Centre for Molecular Medicine, Berlin, Germany Correspondence to Professor Thomas Blankenstein; [tblanke@mdc-berlin.de](tblanke@mdc-berlin.de) ABSTRACT Background Adoptive transfer of patient’s T cells, engineered to express a T cell receptor (TCR) with defined novel antigen specificity, is a convenient form of cancer therapy. In most cases, major histocompatibility complex (MHC) I-restricted TCRs are expressed in CD8+ T cells and the development of CD4+ T cells engineered to express an MHC II-restricted TCR lacks behind. Critical is the choice of the target antigen, whether the epitope is efficiently processed and binds with high affinity to MHC molecules. A mutation in the transforming growth factor β receptor 2 (TGFβR2(-1)) gene creates a frameshift peptide caused by the deletion of one adenine (-1) within a microsatellite sequence. This somatic mutation is recurrent in microsatellite instable colorectal and gastric cancers and, therefore, is a truly tumor-specific antigen detected in many patients. Methods ABabDR4 mice, which express a diverse human TCR repertoire restricted to human MHC II molecule HLADRA/DRB1*0401 (HLA-DR4), were immunized with the TGFβR2(-1) peptide and TGFβR2(-1)-specific TCRs were isolated from responding CD4+ T cells. The TGFβR2(-1) -specific TCRs were expressed in human CD4+ T cells and their potency and safety profile were assessed by cocultures and other functional assays. Results We demonstrated that TGFβR2(-1) neoantigen is immunogenic and elicited CD4+ T cell responses in ABabDR4 mice. When expressed in human CD4+ T cells, the HLA-DR4 restricted TGFβR2(-1)-specific TCRs induced IFNy expression at low TGFβR2(-1) peptide amounts. The TGFβR2(-1)-specific TCRs recognized HLA-DR4+ lymphoblastoid cells, which endogenously processed and presented the neoantigen, and colorectal cancer cell lines SW48 and HCT116 naturally expressing the TGFβR2(-1) mutation. No MHC II alloreactivity or cross-reactivity to peptides with a similar TCR-recognition motif were observed, indicating the safety of the TCRs. Conclusions The data suggest that HLA-DR4-restricted TCRs specific for the TGFβR2(-1) recurrent neoantigen can be valuable candidates for adoptive T cell therapy of a sizeable number of patients with cancer. BACKGROUND Adoptive T cell therapy (ATT) with T cell receptor (TCR)-engineered T cells has become a promising option for cancer treatment. Clinical trials with TCR-engineered T cells showed objective responses1 but also WHAT IS ALREADY KNOWN ON THIS TOPIC | ⇒ Recurrent somatic mutations leading to targetable neoantigens are rare. The few described are presented by major histocompatibility complex (MHC) I molecules to CD8+ T cells. Case studies showed tumor regression with tumor-infiltrating lymphocytes containing neoantigen-specific CD4+ T cells. The TGFβR2(-1) mutation is recurrent in colorectal cancer (CRC) with microsatellite instability. CD8+ T cell responses specific for the TGFβR2(-1) neoantigen have been shown. No MHC II-restricted T cell receptor (TCRs) specific for TGFβR2(-1) have been described.
WHAT THIS STUDY ADDS | | --- | | ⇒ We demonstrated that TGFβR2(-1) neoantigen is immunogenic and processe

FAQs

Why is choosing the target antigen critical for engineered TCR-based cancer therapy?

The therapy depends on whether the epitope is efficiently processed and binds with high affinity to MHC molecules, ensuring reliable recognition by engineered T cells.

How was the TGFβR2(-1) neoantigen-specific CD4+ TCR generated and evaluated?

ABabDR4 mice expressing a diverse human TCR repertoire restricted to HLA-DR4 were immunized with the TGFβR2(-1) peptide, and TGFβR2(-1)-specific TCRs were isolated from responding CD4+ T cells. Their potency and safety were tested using cocultures and other functional assays.

What safety signals were reported for the HLA-DR4-restricted TGFβR2(-1)-specific TCRs?

The study reports no MHC II alloreactivity or cross-reactivity to peptides with a similar TCR-recognition motif, supporting a favorable safety profile.

Sep 28, 2026

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