Biology subjects

van Dinther, M.

Publications and source records attributed to van Dinther, M..

4 recordsLinked to original sources

bioRxiv2026

Pro-domain-dependent folding and co-receptor-mediated targeting to optimize an antagonistic TGF-β monomer for gene-based delivery

Transforming growth factor-beta (TGF-{beta}), a potent promoter of extracellular matrix deposition and suppressor of infiltrating immunity, has arisen as an attractive target for improving outcomes in tissue fibrosis and cancer immune therapy. Despite the promise of TGF-{beta} inhibitors for attenuating the progression of fibrotic disorders or as adjuncts for cancer immunotherapy, current systemically administered inhibitors that target the ligand or receptors have significant on-target liabilities, including cardiotoxicity and development of pre-malignant cutaneous squamous lesions. Recently, an engineered mini monomer of TGF-{beta} (mmTGF-{beta}), which potently and specifically inhibits TGF-{beta} activity, was shown to strongly synergize with checkpoint inhibitors to suppress cancer progression in an aggressive model of melanoma when genetically delivered using an engineered form of vaccinia virus that preferentially infects cancer cells. Despite these promising results, however, a significant fraction of the mmTGF-{beta} was found to misfold, likely due to mispairing of the cysteines that comprise its cystine knot. Here, we demonstrate that inclusion of a modified form of the TGF-{beta} pro-domain that lacks its dimerization motif, the bowtie knot, dramatically improves both the folding and inhibitory activity upon secretion by mammalian cells, thus overcoming one of the major limitations of genetically delivering mmTGF-{beta}. Furthermore, we show that fusion of mmTGF-{beta} to a CD44 binding domain enhances the inhibitory potential of mmTGF-{beta} on immune cells, and on other cell types which express CD44, by more than 30-fold compared to cells negative for CD44. Together, these modifications provide a framework for further enhancing the efficacy and safety of mmTGF-{beta} for cancer immune therapy, and possibly also tissue fibrosis, when delivered genetically using vaccinia, or other related approaches.

bioengineering↗

bioRxiv2026

Decoding the Mechanism of Action of a Parasite TGFβAntagonist Inspires the Creation of Cell-type-specific TGFβ Modulators

Heligmosomoides polygyrus, a mouse parasite, modulates host immunity by secreting modular transforming growth factor-{beta} (TGF{beta}) mimics (TGMs). The agonist TGM1 interacts with TGFBR1, TGFBR2, and the co-receptor CD44 through domains D1/2, D3, and D4/5, respectively. In contrast, the antagonist TGM6, which lacks D1/2, but retains TGFBR2 binding through D3, targets different subsets of cells compared to TGM1. The TGM6 co-receptor is unknown. Using X-ray crystallography and binding studies, we show that TGM6 preferentially binds mouse TGFBR2 over human TGFBR2, and that this is essential for its antagonistic function. We identified low-density lipoprotein receptor-related protein 1 (LRP1) and betaglycan (TGFBR3) as co-receptors for TGM6. LRP1 enhances TGM6 efficacy and is vital for its specific antagonistic effects by promoting TGFBR2 degradation, while betaglycan counteracts TGM6 in a TGFBR2-dependent manner. The modular organization of TGMs enabled us to rationally design TGM1/6 chimeras or TGM-D3 fusion with an affibody that recognizes a specific cell-surface receptor, thereby altering cell-type specificity and functionality. Furthermore, we developed a TGFBR2 nanobody that, on its own, has no inhibitory effect but, when fused to a receptor antibody, antagonizes TGF{beta} signaling in a cell-selective manner. Thus, we designed programmable agents that modulate TGF{beta} signaling only in target co-receptor-expressing cells.

biochemistry↗

bioRxiv2023

TGM6, a helminth secretory product, mimics TGF-β binding to TβRII to antagonize TGF-β signaling in fibroblasts

The murine helminth parasite Heligmosomoides polygyrus expresses a family of proteins structurally related to TGF-{beta} Mimic 1 (TGM1), a secreted five domain protein that activates the TGF-{beta} pathway and converts naive T lymphocytes to immunosuppressive Tregs. TGM1 signals through the TGF-{beta} type I and type II receptors, T{beta}RI and T{beta}RII, with domains 1-2 and 3 binding T{beta}RI and T{beta}RII, respectively, and domains 4-5 binding CD44, a co-receptor abundant on T cells. TGM6 is a homologue of TGM1 that is co-expressed with TGM1, but lacks domains 1 and 2. Herein, we show that TGM6 binds T{beta}RII through domain 3, but does not bind T{beta}RI, or other type I or type II receptors of the TGF-{beta} family. In TGF-{beta} reporter assays in fibroblasts, TGM6, but not truncated TGM6 lacking domains 4 and 5, potently inhibits TGF-{beta}- and TGM1-induced signaling, consistent with its ability to bind T{beta}RII but not T{beta}RI or other receptors of the TGF-{beta} family. However, TGM6 does not bind CD44 and is unable to inhibit TGF-{beta} and TGM1 signaling in T cells. To understand how TGM6 binds T{beta}RII, the X-ray crystal structure of the TGM6 domain 3 bound to T{beta}RII was determined at 1.4 [A]. This showed that TGM6 domain 3 binds T{beta}RII through an interface remarkably similar to the TGF-{beta}:T{beta}RII interface. These results suggest that TGM6 has adapted its domain structure and sequence to mimic TGF-{beta} binding to T{beta}RII and function as a potent TGF-{beta} and TGM1 antagonist in fibroblasts. The coexpression of TGM6, along with the immunosuppressive TGMs that activate the TGF-{beta} pathway, may prevent tissue damage caused by the parasite as it progresses through its life cycle from the intestinal lumen to submucosal tissues and back again.

biochemistry↗

bioRxiv2020

TRAF4 inhibits bladder cancer progression by promoting BMP/SMAD signalling pathway

Bladder cancer is one of the most prevalent cancer types in the world, frequently exhibiting invasion and metastasis and therefore associated with poor prognosis. It is a progressive disease with high recurrence rates even after surgery, which calls for the urgent need for early intervention and diagnosis. The E3 ubiquitin ligase TNF Receptor Associated Factor 4 (TRAF4) has been largely implicated as a tumour-promoting element in a wide range of cancers. Over-expression and amplification of this gene product has been a common observation in breast and other metastatic tumours. In contrast, we observed that expression of TRAF4 negatively correlated with overall patient survival. Moreover, its expression was repressed at epigenetic levels in aggressive bladder cancer cells. We also describe an ERK kinase phosphorylation site on TRAF4 that inhibits its stability and localization to plasma membrane in such cells. Furthermore, knockdown of TRAF4 in epithelial bladder cancer cell lines leads to gain of mesenchymal genes and a loss of epithelial integrity. Reciprocally, stable over-expression of TRAF4 in mesenchymal cells leads to decreased migratory and invasive properties. Transcriptomic analysis upon TRAF4 mis-expression in bladder cancer cell lines revealed that higher TRAF4 expression enhanced BMP/SMAD and dampened NF-{kappa}B signalling pathways. Importantly, this notion was confirmed in bladder cancer patient material. Mechanistically, we showed that TRAF4 targets the E3 ubiquitin ligase SMURF1, a negative regulator of BMP/SMAD signalling, for proteasomal degradation in bladder cancer cells. We show that genetic and pharmacological inhibition of SMURF1 or its function inhibited migration of aggressive (mesenchymal) bladder cancer cells.

cancer biology↗