Biology subjects

Krost, S.

Publications and source records attributed to Krost, S..

2 recordsLinked to original sources

bioRxiv2026

Pan-B-Lineage Targeting with Adapter CAR-T Cells Controls Antigen-Heterogeneous Lymphoma

Antigen heterogeneity and antigen-negative relapse represent major limitations to durable CAR-T cell efficacy in B-lineage malignancies. We previously developed the Adapter CAR-T cell (AdCAR-T) platform, which enables flexible redirection of engineered T cells to distinct surface antigens through biotinylated adapter molecules (AMs). In this study, AMs generated from an in-house-produced tafasitamab biosimilar (anti-CD19), commercial rituximab (anti-CD20), and an in-house-produced daratumumab biosimilar (anti-CD38) mediated potent, antigen-specific AdCAR-T cell cytotoxicity. While single-antigen targeting resulted in the selection of antigen-negative tumor populations, simultaneous targeting of CD19, CD20, and CD38 effectively controlled a defined heterogeneous Burkitt lymphoma model in vitro and induced sustained tumor control in vivo. Selective loss of the CD38+ AdCAR-T cell population after CD38-directed AM exposure was consistent with fratricide; however, the surviving CD38low population retained cytotoxic activity. These findings establish combinatorial AdCAR-T cell targeting as a flexible pan-B-lineage strategy for addressing pre-existing antigen heterogeneity and support further development of antibody-derived AM combinations for B-cell malignancies.

immunology↗

bioRxiv2025

Cysteine-Engineered CAR-T Cells to Counter Antigen Escape in B Cell Lymphoma

Chimeric Antigen Receptor (CAR-) T cell therapy represents a paradigm shift in immunotherapy of hematological cancers. However, selective pressure on cancer cells often leads to suppression of target antigens, eventually causing cancer relapse1,2. This so-called antigen escape renders CAR-T cells ineffective, posing a significant clinical challenge2-5. Therefore, identifying alternative targets less susceptible to antigen escape is crucial. Here, we describe a novel type of CAR-T cells utilizing cysteine-engineered antibody fragments that target altered redox states on the surface of B cell lymphoma (BCL)6. We demonstrate that cysteine-engineered CAR-T cells exhibit specific cytotoxicity in vitro against various BCL subtypes, including antigen escape models. Additionally, we show that cysteine engineering, achieved through single amino acid substitution in the state-of-the-art anti-CD19-CAR, enables co-targeting of both CD19-positive and -negative BCL. Our findings introduce a novel class of bifunctional CAR-T cells that target conventional antigens and altered redox states simultaneously, potentially reducing the risk of antigen escape. Abnormal redox states occur in several cancers, including breast and leukemia7-12, indicating a broad therapeutic scope.

cancer biology↗