Tieland, R. G. | bioRxiv Science

bioRxiv2024

Engineering BCMA CAR T cells for myeloma-targeted cargo delivery

Clinical responses with chimeric antigen receptor (CAR) T cells are encouraging, however, primary resistance and relapse after therapy prevent durable remission in a large fraction of cancer patients. One of the underlying causes comprises apoptosis resistance mechanisms in cancer cells that limit killing by CAR T cells. Therefore, we developed a technology that boosts tumor cell apoptosis induced by CAR T cells. We reveal that B cell maturation antigen (BCMA) CAR T cells equipped with a granzyme B-NOXA fusion construct improves killing of multiple myeloma (MM) cells, both in vitro and in a xenograft mouse model, by localizing NOXA to cytotoxic granules that are released into cancer cells upon contact. Since MM cells critically depend on MCL-1 expression, inhibition by its natural ligand NOXA effectively induces apoptosis. Overall, this strategy allows specific delivery of cargo into cancer cells and improves killing efficacy of CAR T cells in a tailor-made manner.

immunology↗

bioRxiv2021

Impaired LAIR-1-mediated immune control due to collagen degradation in fibrosis

Tissue repair is disturbed in fibrotic diseases like systemic sclerosis (SSc), where the deposition of large amounts of extracellular matrix components such as collagen interferes with organ function. LAIR-1 is an inhibitory collagen receptor highly expressed on tissue immune cells. We questioned whether in SSc, impaired LAIR-1-collagen interaction is contributing to the ongoing inflammation and fibrosis. We found that SSc patients do not have an intrinsic defect in LAIR-1 expression or function. Instead, fibroblasts from SSc patients deposit disorganized collagen products in vitro, which are dysfunctional LAIR-1 ligands. This can be mimicked in healthy fibroblasts stimulated by soluble factors that drive inflammation and fibrosis in SSc and is dependent of matrix metalloproteinases and platelet-derived growth factor receptor signaling. In support of a non-redundant role of LAIR-1 in the control of fibrosis, we found that LAIR-1-deficient mice have increased skin fibrosis in response to repeated injury and in the bleomycin mouse model for SSc. Thus, LAIR-1 represents an essential control mechanism for tissue repair. In fibrotic disease, excessive collagen degradation may lead to a disturbed feedback loop. The presence of functional LAIR-1 in patients provides a therapeutic opportunity to reactivate this intrinsic negative feedback mechanism in fibrotic diseases.

immunology↗