Biology subjects

Zandhuis, N. D.

Publications and source records attributed to Zandhuis, N. D..

5 recordsLinked to original sources

bioRxiv2024

nsGSLs on tumors impair anti-tumor immune responses by OT-I T cells in vitro and support tumor growth in vivo

Tumors often evolve to engage numerous strategies to circumvent detection by the immune system. Our group recently discovered elevated neolacto-series glycosphingolipids (nsGSL) surface levels as a possible immune evasion mechanism of tumors. We demonstrated a direct disruption of both innate and adaptive anti-tumor immunity in vitro when expression of nsGSLs was upregulated on established target cells. It remains unclear however, whether in vivo nsGSLs play an active role in tumor development and can aid tumors in evading immune responses. To investigate whether nsGSLs facilitate tumor progression in vivo, we first established a murine model system using MC38-OVA cell lines with varying cell surface levels of nsGSLs. In vitro analysis revealed reduced MHC-I accessibility on tumor cells with elevated nsGSLs profiles, leading to diminished activation of OVA-specific OT-I T cells as evidenced by decreased expression of CD25, CD69, and production of IFN{gamma}, which subsequently resulted in decreased tumor cell death. Subsequent in vivo experiments investigating tumor outgrowth after engraftment of subcutaneously injected MC38-OVA cell lines with low or high cell surface levels of nsGSLs demonstrated better growth of nsGSL-rich tumor cells compared to nsGSL-poor tumors which could be controlled. Together these results suggest that nsGSLs expressed by tumors can facilitate immune evasion and subsequent tumor progression. These data pave the way to explore whether targeting of the GSL pathway with specific inhibitors could be advantageous as a therapy against tumors with high nsGSL levels.

immunology↗

bioRxiv2024

Tumor-expressed SPPL3 supports innate anti-tumor immune responses.

The development of an effective anti-tumor response relies on the synergistic actions of various immune cells that recognize tumor cells via distinct receptors. Tumors, however, often manipulate receptor-ligand interactions to evade recognition by the immune system. Recently, we highlighted the role of neolacto-series glycosphingolipids (nsGSLs), produced by the enzyme {beta}1,3-N-acetylglucosaminyltransferase 5 (B3GNT5), in tumor immune escape. We previously demonstrated that loss of signal peptidase like 3 (SPPL3), an inhibitor of B3GNT5, results in elevated levels of nsGSLs and impairs CD8 T cell activation. The impact of loss of SPPL3 and an elevated nsGSL profile in tumor cells on innate immune recognition remains to be elucidated. This study investigates the anti-tumor efficacy of neutrophils, NK cells, and {gamma}{delta} T cells on tumor cells lacking SPPL3. Our findings demonstrate that SPPL3-deficient target cells are less susceptible to trogocytosis by neutrophils and killing by NK cells and {gamma}{delta} T cells. Mechanistically, SPPL3 influences trogocytosis and {gamma}{delta} T cell instigated killing through modulation of nsGSL expression while SPPL3-mediated reduced killing by NK cells is nsGSL-independent. The nsGSL-dependent SPPL3 sensitivity depends on the proximity of surface receptor domains to the cell membrane and the affinity of receptor-ligand interactions as shown with various sets of defined antibodies. Thus, SPPL3 expression by tumor cells alters crosstalk with immune cells through the receptor-ligand interactome thereby driving escape not only from adaptive but also from innate immunity. These data underline the importance of investigating a potential synergism of GSL synthesis inhibitors with current immune cell activating immunotherapies.

immunology↗

bioRxiv2024

Regulation of IFNgamma production by ZFP36L2 in T cells is context-dependent

CD8+ T cells kill target cells by releasing cytotoxic molecules and pro-inflammatory cytokines, such as TNF and IFN{gamma}. The magnitude and duration of cytokine production is defined by post-transcriptional regulation, and a critical regulator herein are RNA-binding proteins (RBPs). Although the functional importance of RBPs in regulating cytokine production is established, the kinetics and mode of action through which RBPs control cytokine production is not well understood. Previously, we showed that the RBP ZFP36L2 blocks translation of pre-formed cytokine encoding mRNA in quiescent memory T cells. Here, we uncover that ZFP36L2 regulates cytokine production in a context-dependent manner. T cell-specific deletion of ZFP36L2 (CD4-cre) had no effect on T cell development, or on cytokine production during early time points (2-6h) of T cell activation. In contrast, ZFP36L2 specifically dampened the production of IFN{gamma} during prolonged T cell activation (20-48h). ZFP36L2 deficiency also resulted in increased production of IFN{gamma} production in tumour-infiltrating T cells that are chronically exposed to antigen. Mechanistically, ZFP36L2 regulates IFN{gamma} production at late time points of activation by destabilizing Ifng mRNA in an AU-rich element-dependent manner. Together, our results reveal that ZFP36L2 employs different regulatory nodules in effector and memory T cells to regulate cytokine production.

immunology↗

bioRxiv2022

The two enantiomers of 2-hydroxyglutarate differentially regulate cytotoxic T cell function

2-hydroxyglutarate (2HG) is a by-product of the TCA cycle, and is readily detected in the tissues of healthy individuals. 2HG is found in two enantiomeric forms: S-2HG and R-2HG. Here, we investigate the differential roles of these two enantiomers in CD8+ T cell biology, where we found they had highly divergent effects on proliferation, differentiation, and T cell function. We show here an analysis of structural determinants that likely underlie these differential effects on specific a-ketoglutarate (aKG)-dependent enzymes. Treatment of CD8+ T cells with exogenous S-2HG, but not R-2HG, increased CD8+ T cell fitness in vivo, and enhanced anti-tumour activity. These data show that S-2HG and R-2HG should be considered as two distinct and important actors in the regulation of T cell function.

immunology↗

bioRxiv2021

Mapping RNA-binding proteins in human B cells and Tcells upon differentiation

B cells and T cells are key players in the defence against infections and malignancies. To exert their function, B cells and T cells differentiate into effector and memory cells. Tight regulation of these differentiation processes is key to prevent their malfunction, which can result in life-threatening disease. Lymphocyte differentiation relies on the appropriate timing and dosage of regulatory molecules, and post-transcriptional gene regulation (PTR) is a key player herein. PTR includes the regulation through RNA-binding proteins (RBPs), which control the fate of RNA and its translation into proteins. To date, a comprehensive RBP expression map throughout lymphocyte differentiation is lacking. Using transcriptome and proteome analyses, we here provide an RBP expression map for human B cells and T cells. We observed that even though the overall RBP expression is conserved, the relative RBP expression is distinct between B cells and T cells. Differentiation into effector and memory cells alters the RBP expression, resulting into preferential expression of different classes of RBPs. For instance, whereas naive T cells express high levels of translation-regulating RBPs, effector T cells preferentially express RBPs that modulate mRNA stability. Lastly, we found that cytotoxic CD8+ and CD4+ T cells express a common RBP repertoire. Combined, our study reveals a cell type-specific and differentiation-dependent RBP expression landscape in human lymphocytes, which will help unravel the role of RBPs in lymphocyte function.

immunology↗