Biology subjects

Lim, H. W.

Publications and source records attributed to Lim, H. W..

3 recordsLinked to original sources

bioRxiv2025

Rapid CAR Screening and circRNA-driven CAR-NK Cells for Persistent Shed-resistant Immunotherapy

Chimeric antigen receptor (CAR)-based immunotherapies against solid tumors face two major hurdles, the "decoy effect" of shedding antigens that sequester CARs, and the limited persistence of immune effectors within the immunosuppressive tumor microenvironment. Here, we present a mechanistic approach to overcome these barriers by integrating a physiologically relevant screening platform with circular RNA (circRNA) engineering. Unlike conventional screens using immortalized cell lines, we performed rapid functional screening directly in human primary natural killer (NK) cells to identify a novel scFv, CLMS10. Structural modeling revealed that CLMS10 targets a membrane-proximal epitope that overlaps the proteolytic cleavage site, thereby evading inhibition by soluble mesothelin (solMSLN). Furthermore, we demonstrated that circRNA-mediated CAR expression, when codelivered with interleukin-21 (IL-21), confers sufficient stability to withstand the continuous antigen shedding induced by cancer-associated fibroblasts (CAFs), resulting in reduced CAR downregulation. In an in vivo metastatic pancreatic cancer model, IL-21-augmented circCAR-MS10-NK cells exhibited potency comparable to that of lentivirally engineered CAR-NK cells while offering superior manufacturability. Overall, this study establishes a paradigm for generating shed-resistant CAR therapeutics through the strategic integration of epitope-specific functional selection and enhanced RNA stability.

bioengineering↗

bioRxiv2025

PRDM16 controls smooth muscle cell fate in atherosclerosis

Vascular smooth muscle cells (SMCs) normally exist in a contractile state but can undergo fate switching to produce various cell phenotypes in response to pathologic stimuli1-3. In atherosclerosis, these phenotypically modulated SMCs regulate plaque composition and influence the risk of major adverse cardiovascular events4,5. We found that PRDM16, a transcription factor that is genetically associated with cardiovascular disease, is highly expressed in arterial SMCs and downregulated during SMC fate switching in human and mouse atherosclerosis. Loss of Prdm16 in SMCs of mice activates a synthetic modulation program under homeostatic conditions. Single cell analyses show that loss of Prdm16 drives a synthetic program in all SMC populations. Upon exposure to atherogenic stimuli, SMC-selective Prdm16 deficient mice develop SMC-rich, fibroproliferative plaques that contain few foam cells. Acute loss of Prdm16 results in the formation of collagen-rich lesions with thick fibrous caps. Reciprocally, increasing PRDM16 expression in SMCs blocks synthetic processes, including migration, proliferation, and fibrosis. Mechanistically, PRDM16 binds to chromatin and decreases activating histone marks at synthetic genes. Altogether, these results define PRDM16 as a critical determinant of SMC identity and atherosclerotic lesion composition.

molecular biology↗

bioRxiv2017

Histone Deacetylase 7 Mediates Tissue-Specific Autoimmunity via Control of Innate Effector Function in Invariant Natural Killer T-Cells

We report that Histone Deacetylase 7 (HDAC7) controls the thymic effector programming of Natural Killer T (NKT) cells, and that interference with this function contributes to tissue-specific autoimmunity. Gain of HDAC7 function in thymocytes blocks both negative selection and NKT development, diverting these cells into a Tconv-like lineage. Conversely, HDAC7 deletion promotes thymocyte apoptosis and causes aberrant expansion of innate-effector cells. Investigating the mechanisms involved, we found that HDAC7 binds PLZF and modulates PLZF-dependent transcription. Moreover, HDAC7 and many of its transcriptional targets are human risk loci for IBD and PSC, autoimmune diseases that strikingly resemble the disease we observe in HDAC7 gain-of-function in mice. Importantly, reconstitution of iNKT cells in these mice abrogated their disease, suggesting that interaction between the defects in negative selection and iNKT cells caused by altered HDAC7 function can cause tissue-restricted autoimmunity, a finding that may explain the association between HDAC7 and hepatobiliary autoimmunity.

immunology↗