Biology subjects

Stuecheli, S.

Publications and source records attributed to Stuecheli, S..

2 recordsLinked to original sources

bioRxiv2025

IGLV3-21-R110-directed bispecific antibodies activate T cells and promote killing in a high-risk subset of chronic lymphocytic leukemia

We previously used a disease-specific B cell receptor (BCR) point mutation (IGLV3-21R110) for selective targeting of a poor-risk subset of chronic lymphocytic leukemia (CLL) with chimeric antigen receptor (CAR) T cells. Since CLL is a disease of the elderly and a significant fraction of patients is not able to physically tolerate CAR T cell treatment, we explored bispecific antibodies as an alternative for precision targeting of this tumor mutation. Heterodimeric IgG1-based antibodies consisting of a fragment crystallizable region (Fc) attached to either an anti-IGLV3-21R110 Fab or an anti-CD3 (UCHT1) single chain variable fragment (R110-bsAb) selectively killed cell lines engineered to express high levels of the neoepitope as well as primary CLL cells using healthy donor and CLL patient-derived T cells as effectors. R110-bsAb spared polyclonal human B cells (as opposed to CD19-targeting Blinatumomab) as well as CD34+ human stem cells. Yet, R110-bsAb induced lower T cell activation than Blinatumomab with primary CLL cells likely due to lower expression of target antigen. In vivo, R110-bsAb specifically killed IGLV3-21R110-expressing cell lines and CLL cells while sparing peripheral blood mononuclear cells. These findings highlight bispecific antibodies as a promising, off-the-shelf immunotherapy for high-risk CLL patients, offering selective targeting while preserving healthy B cells.

cancer biology↗

bioRxiv2025

CAR T cell engineering impacts antigen-independent activation and co-inhibition

Viral vectors have successfully modified T cells to express chimeric antigen receptors (CAR), leading to clinical approvals. However, their high cost and regulatory challenges hinder rapid and broad clinical translation. Here, we demonstrate that our lentivirally (LV) manufactured R110-CAR T cells, targeting a leukemia neoepitope, can also be engineered using non-viral Sleeping Beauty (SB) transposition with minimal-sized DNA vectors. Flow cytometry and single-cell sequencing was used to compare the two production modes using healthy donor and CLL patient-derived T cells and a CD19-CAR T cell control. SB products were shifted towards CD8+ subsets with expression of activation/co-inhibition markers (CD69, LAG-3, TIM-3) despite their naive-like phenotype and lack of antigenic challenge. The CAR binding moiety modulated these patterns with R110-CAR T cells showing more aberrant phenotypes. Moreover, SB engineering resulted in inflammatory signatures along with RIG-I-like and TOLL-like nucleotide sensing potentially resulting from the transfection procedure. Patient-derived products showed significantly fewer CAR-expressing cells, reduced proliferation clusters, and lower T cell diversity, particularly with SB manufacturing, pointing at potential challenges with this method when engineering CLL T cells. Together, our data suggest that the engineering mode may substantially influence T cell properties and that these are further modulated by the CAR binding moiety and the type of T cell donor.

immunology↗