Biology subjects

Lambooij, J. M.

Publications and source records attributed to Lambooij, J. M..

9 recordsLinked to original sources

bioRxiv2026

Label-Free Identification of Human Eosinophils Using 808 nm Side Scatter

Accurate identification and quantification of eosinophils is critical for the diagnosis and monitoring of eosinophil-associated disorders. While flow cytometry remains a powerful tool for leukocyte characterization, conventional instruments equipped with 405 nm or 488 nm side scatter (SSC) detectors offer limited resolution for eosinophil discrimination overlap in scatter with neutrophils. Using a spectral flow cytometer equipped with six distinct SSC detectors, we report a novel, label-free approach for eosinophil detection leveraging high 808 nm near-infrared SSC (IRSSC) uniquely observed in human eosinophils. This optical signature is independent of antibody labeling, activation fixation, or permeabilization, and shows strong concordance with conventional CD66b/CD16 gating strategies (R = 0.997). Notably, the high 808 nm SSC is absent in murine eosinophils, suggesting a species-specific structural feature such as in human eosinophils. These findings establish IRSSC as a robust, reagent-free biomarker for eosinophil detection, with broad implications for both clinical diagnostics and translational immunology.

immunology↗

bioRxiv2026

Increasing plasma bile salt levels with Bulevirtide alleviates DSS-induced colitis and LPS-induced inflammation

Background & AimsBulevirtide, a viral entry inhibitor used to treat chronic hepatitis delta virus (HDV) infection, targets the hepatic bile salt transporter Na+-Taurocholate Co-transporting Polypeptide (NTCP). As Bulevirtide displays preclinical potential to mitigate cholestatic liver injury, NTCP inhibition is currently explored as treatment for primary sclerosing cholangitis (PSC), a condition frequently associated with colitis. Here, we investigated the immunomodulatory effects of Bulevirtide in lipopolysaccharide (LPS)-induced inflammation and dextran sodium sulfate (DSS)-induced colitis in mice. MethodsThe immunomodulatory properties of the bile salt taurochenodeoxycholic acid (TCDC) were investigated in LPS-challenged mouse bone marrow-derived macrophages (BMDM) and human BLaER1 macrophages. The therapeutic efficacy of Bulevirtide against LPS-induced inflammation and DSS-induced colitis was evaluated in Slco1a/1b-/- FVB and C57BL/6J mice, which recapitulate human bile salt dynamics. ResultsIn BMDMs, TCDC reduced pro-inflammatory tumor necrosis factor alpha (TNF), increased anti-inflammatory interleukin (IL)-10, and suppressed inflammasome activation, as evidenced by reduced IL-1{beta}, IL-18 and cleaved-IL-1{beta} levels. Consistently, TCDC also reduced TNF and IL1B expression in human BLaER1 macrophages. In both FVB and C57BL/6J Slco1a/1b-/- mice, Bulevirtide increased plasma bile salt levels at least 30-fold. This systemic elevation of bile salts reduced plasma TNF and increased IL-10 in LPS-treated mice. Moreover, Bulevirtide attenuated DSS-induced colitis, evidenced by reduced disease scores and reduced intestinal Tnf expression. ConclusionThese findings highlight the anti-inflammatory effects of bile salts in preclinical models of colitis and support NTCP inhibition as a future therapeutic strategy to ameliorate both cholestasis and colitis in PSC. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=173 SRC="FIGDIR/small/719641v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@38efbeorg.highwire.dtl.DTLVardef@3e09borg.highwire.dtl.DTLVardef@8f1262org.highwire.dtl.DTLVardef@100179c_HPS_FORMAT_FIGEXP M_FIG C_FIG SynopsisInhibition of the Na+-Taurocholate Co-transporting Polypeptide using Bulevirtide induces systemic bile salt elevation and mitigates acute inflammation and colitis in mice. These findings support clinical evaluation of Bulevirtide in primary sclerosing cholangitis with protective effects against cholestasis and colitis.

immunology↗

bioRxiv2026

O-GlcNAcylation drives macrophage IL-4 responsiveness and tissue residency through metabolic and cell cycle calibration

The metabolic requirements for macrophage IL-4 polarization remain contentious, while immunometabolic studies of tissue resident macrophages are still sparse. Hexosamine biosynthesis has gained attention regarding its immune regulatory potential via downstream O-GlcNAcylation. Here we identify protein O-GlcNAcylation as a requirement for IL-4 polarization in vitro and proliferative expansion in vivo during cytokine challenge or infection. We further show that O-GlcNAcylation is critical for controlling tissue residency. By enforcing metabolic and cell cycle quiescence during differentiation, O-GlcNAcylation is needed for adult monocytes to establish a long-live residency program. In this context, its absence leads to perpetual DNA vulnerability and damage via reactive oxygen species, resulting in a senescent-like state poised for cell death. Conversely, long-lived populations instead require O-GlcNAcylation for self-renewal and inflammatory expansion. Our findings altogether suggest O-GlcNAcylation, fueled by hexosamine biosynthesis, serves as a central metabolic rheostat for resident macrophage formation and maintenance during homeostasis and disease.

immunology↗

bioRxiv2025

Totum-448, a polyphenol-rich plant extract, decreases hepatic steatosis and inflammation in diet-induced MASLD mice

The increasing prevalence of obesity-driven metabolic dysfunction-associated steatotic liver disease (MASLD) urges the development of new therapeutic strategies. Totum-448 is a unique patented combination of polyphenol-rich plant extracts designed to reduce hepatic steatosis, a risk factor for steatohepatitis and type 2 diabetes. In this study, we investigated the effects of Totum-448 on metabolic homeostasis and steatohepatitis in diet-induced MASLD mice. For this purpose, male C57Bl6/J mice were fed a high-fat diet in combination with sucrose-containing drinking water for 12 weeks, followed by diet supplementation with or without Totum-448 for 4 weeks. Body weight/composition, caloric intake, plasma parameters and whole-body glucose tolerance were measured throughout the study and fecal microbiota composition was determined by 16S sequencing. Hepatic steatosis, transcriptomic/lipidomic profiles and immune cell composition were assessed by histological/biochemical assays, RNA sequencing, MS-based lipidomics, and spectral flow cytometry. We found that Totum-448 significantly lowered hyperinsulinemia and systemic glucose intolerance in MASLD mice without affecting body weight, fat mass, calorie intake, feces production or fecal microbiota composition. Furthermore, a decrease in liver MASLD activity score and macrovesicular steatosis, hepatic triglycerides and cholesterol contents, and plasma alanine aminotransferase levels were observed. Totum-448 also reduced the liver inflammatory and pro-fibrotic transcriptomic signatures and decreased both MASLD-induced loss in tissue-resident Kupffer cells and recruitment of monocyte-derived pro-inflammatory macrophages. Altogether, Totum-448 reduces hepatic steatosis and inflammation in insulin-resistant, steatotic, obese mice, a dual effect that likely contributes to improved whole-body metabolic homeostasis. Supplementation with Totum-448 may therefore constitute a promising novel nutritional approach for MASLD patients.

physiology↗

bioRxiv2022

Early but not late exercise training in mice exacerbates hepatic inflammation in early NAFLD

Exercise effectively prevents obesity-related disorders, but it is unclear whether the beneficial health effects of exercise are restricted to unique circadian windows. Therefore, we aimed to study whether timing of exercise training differentially modulates the development and progression of non-alcoholic fatty liver disease (NAFLD), a disease currently estimated to affect over two billion people worldwide. We endurance-trained high fat-high cholesterol-fed NAFLD-prone male APOE*3-Leiden.CETP mice five times per week for eight weeks either in the early (ZT13) or in the late (ZT22) active phase and assessed the NAFLD score (histology) and hepatic inflammation compared to sedentary mice. Exercise training prevented an increase in body fat mass and fasting plasma glucose as expected, but neither early nor late training affected liver triglyceride or cholesterol content compared to sedentary mice, likely due to a very early stage of hepatic steatosis. In line, hepatic expression of de novo lipogenesis genes (e.g., Fasn, Srebp1c) was similarly downregulated by early and late training. However, exercise had a distinct time-dependent effect on hepatic inflammation, as only early training promoted an influx of pro-inflammtory cells into the liver paired with increased expression of the pro-inflammatory cytokines (e.g. Tnfa, Il1b). This data suggests that the timing of exercise is a critical factor for the effect on cardiometabolic disease development.

molecular biology↗

bioRxiv2022

Fasciola hepatica Fatty Acid Binding Protein 1 modulates T cell polarization by promoting dendritic cell thrombospondin-1 secretion without affecting metabolic homeostasis in obese mice

BackgroundThe parasitic trematode Fasciola hepatica evades host immune defenses through secretion of various immunomodulatory molecules. Fatty Acid Binding Proteins (fhFABPs) are among the main excreted/secreted proteins and have been shown to display anti-inflammatory properties. However, little is currently known regarding their impact on dendritic cells (DCs) and their subsequent capacity to prime specific CD4+ T cell subsets. Methodology/Principal FindingsThe immunomodulatory effects of both native F. hepatica extracts and recombinant fhFABPs were assessed on monocyte-derived human DCs (moDCs) and the underlying mechanism was next investigated using various approaches, including DC-allogenic T cell co-culture and DC phenotyping through transcriptomic, proteomic and FACS analyses. We mainly showed that fhFABP1 induced a tolerogenic-like phenotype in LPS-stimulated moDCs characterized by a dose-dependent increase in the cell-surface tolerogenic marker CD103 and IL-10 secretion, while DC co-stimulatory markers were not affected. A significant decrease in secretion of the pro-inflammatory cytokines IL-12p70 and IL-6 was also observed. In addition, these effects were associated with an increase in both Th2-on-Th1 ratio and IL-10 secretion by CD4+ T cells following DC-T cell co-culture. RNA sequencing and targeted proteomic analyses identified thrombospondin-1 (TSP-1) as a non-canonical factor highly expressed and secreted by fhFABP1-primed moDCs. The effect of fhFABP1 on T cell skewing was abolished when using a TSP-1 blocking antibody during DC-T cell co-culture. Immunomodulation by helminth molecules has been linked to improved metabolic homeostasis during obesity. Although fhFABP1 injection in high-fat diet-fed obese mice induced a potent Th2 immune response in adipose tissue, it did not improved insulin sensitivity or glucose homeostasis. Conclusions/SignificanceWe show that fhFABP1 modulates T cell polarization, notably by promoting DC TSP-1 secretion in vitro, without affecting metabolic homeostasis in a mouse model of type 2 diabetes.

immunology↗

bioRxiv2021

LKB1 signalling in dendritic cells controls whole-body metabolic homeostasis by limiting T helper 17 priming

Obesity-associated metaflammation drives the development of insulin resistance and type 2 diabetes, notably through modulating innate and adaptive immune cells in metabolic organs. The nutrient sensor liver kinase B1 (LKB1) has recently been shown to control cellular metabolism and T cell priming functions of dendritic cells (DCs). Here, we report that hepatic DCs from high-fat diet (HFD)-fed obese mice display increased LKB1 phosphorylation and that LKB1 deficiency in DCs (CD11c{Delta}LKB1) worsened HFD-driven hepatic steatosis, systemic insulin resistance and glucose intolerance. Loss of LKB1 in DCs was associated with increased cellular expression of Th17-polarizing cytokines and increased hepatic CD4+ IL-17A+ Th17 cells in HFD-fed mice. Importantly, IL-17A neutralization rescued metabolic perturbations in HFD-fed CD11c{Delta}LKB1 mice. Mechanistically, disrupted metabolic homeostasis was independent of the canonical LKB1-AMPK axis. Instead, we provide evidence for involvement of the AMPK-related salt-inducible kinase(s) in controlling Th17-polarizing cytokine expression in LKB1-deficient DCs. Altogether, our data reveal a key role for LKB1 signalling in DCs in protection against obesity-induced metabolic dysfunctions by limiting hepatic Th17 differentiation.

immunology↗

bioRxiv2020

Soluble mannose receptor induces pro-inflammatory macrophage activation andobesity-associated metaflammation

Pro-inflammatory activation of macrophages in metabolic tissues is critically important in induction of obesity-induced metaflammation. Here, we demonstrate that the soluble mannose receptor (sMR) plays a direct, functional role in both macrophage activation and metaflammation. We show that sMR binds CD45 on macrophages and inhibits its phosphatase activity, leading to a Src/Akt/NF-{kappa}B-mediated cellular reprogramming towards an inflammatory phenotype both in vitro and in vivo. Remarkably, increased serum sMR levels were observed in obese mice and humans and directly correlated with body weight. Additionally, MR deficiency lowers pro-inflammatory macrophages in metabolic tissues and protects against hepatic steatosis and whole-body metabolic dysfunctions in high-fat diet-induced obese mice. Conversely, administration of sMR in lean mice increases serum pro-inflammatory cytokines, activates tissue macrophages and promotes insulin resistance. Altogether, our results reveal sMR as novel regulator of pro-inflammatory macrophage activation which could constitute a new therapeutic target for metaflammation and other hyperinflammatory diseases.

immunology↗

bioRxiv2020

The helminth glycoprotein omega-1 improves metabolic homeostasis in obese mice through type-2 immunity-independent inhibition of food intake

Type 2 immunity plays an essential role in the maintenance of metabolic homeostasis and its disruption during obesity promotes meta-inflammation and insulin resistance. Infection with the helminth parasite Schistosoma mansoni and treatment with its soluble egg antigens (SEA) can induce a type 2 immune response in metabolic organs and improve insulin sensitivity and glucose tolerance in obese mice, yet a causal relationship remains unproven. Here, we investigated the effects and underlying mechanisms of the T2 ribonuclease omega-1 (ω1), one of the major S. mansoni immunomodulatory glycoproteins, on metabolic homeostasis. Male C57Bl6/J mice were fed a high-fat diet for 12 weeks followed by bi-weekly injection of SEA, ω1 or vehicle for 4 additional weeks. Whole-body metabolic homeostasis and energy expenditure were assessed by glucose/insulin tolerance tests and indirect calorimetry, respectively. Tissue-specific immune cell phenotypes were determined by flow cytometry. We show that treatment of obese mice with plant-produced recombinant ω1, harboring similar glycan motifs as present on the native molecule, decreased body fat mass and improved systemic insulin sensitivity and glucose tolerance in a time-and dose-dependent manner. This effect was associated with an increase in white adipose tissue (WAT) type 2 T helper cells, eosinophils and alternatively-activated macrophages, without affecting type 2 innate lymphoid cells. In contrast to SEA, the metabolic effects of ω1 were still observed in obese STAT6-deficient mice with impaired type 2 immunity, indicating that its metabolic effects are independent of the type 2 immune response. Instead, we found that ω1 inhibited food intake, without affecting locomotor activity, WAT thermogenic capacity or whole-body energy expenditure, an effect also occurring in leptin receptor-deficient obese and hyperphagic db/db mice. Altogether, we demonstrate that while the helminth glycoprotein ω1 can induce type 2 immunity, it improves whole-body metabolic homeostasis in obese mice by inhibiting food intake via a STAT6-independent mechanism.Author summary The obesity-induced chronic low-grade inflammation, notably in adipose tissue, contributes to insulin resistance and increased risk of type 2 diabetes. We have previously shown that infection with parasitic helminth worms was associated with protection against obesity-related metabolic dysfunctions both in mice and humans. We have also reported that treatment of obese mice with an extract of Schistosoma mansoni eggs (SEA) improves insulin sensitivity and glucose tolerance, a beneficial effect that was associated with a helminth-specific type 2 immune response in metabolic organs. Here, we studied the effects of omega-1 (ω1), a single immunomodulatory molecule from SEA, on metabolic health in obese mice, and investigated the role of the host immune response elicited. We found that ω1 induced a helminth-characteristic type 2 immune response in adipose tissue and improved both insulin sensitivity and glucose tolerance in obese mice. Yet, in contrast to SEA, ω1’s immunomodulatory properties were dispensable for its metabolic effects. Instead, we show that ω1 inhibited food intake, a feature accounting for most of the improvements in metabolic health. Together, our findings indicate that helminth molecules may improve metabolic health through multiple distinct mechanisms, and further characterization of such molecules could lead to new therapeutic strategies to combat obesity.List of abbreviationsAAMAlternatively activated macrophageALATAlanine aminotransferaseBATBrown adipose tissueDCDendritic cellEEEnergy expenditureGTTGlucose tolerance testHEKHuman embryonic kidneyHFDHigh-fat dietHOMA-IRHomeostatic model assessment of insulin resistanceIFN-γInterferon gammaILInterleukinILCInnate lymphoid cellITTInsulin tolerance testLBMLean body massLFDLow-fat dietNAFLDNon-alcoholic fatty liver diseaseNASHNon-alcoholic steatohepatitispLeX-ω1Recombinant omega-1 from LeX-glyco-engineered Nicotiana benthamiana plantsPMAPhorbol myristate acetatepWT-ω1Recombinant omega-1 from wild-type N. benthamiana plantsSEASchistosoma mansoni soluble egg antigensSTATSignal transducer and activator of transcriptionSVFStromal vascular fractionThT helperTNFTumor necrosis factorUCP1Uncoupling protein 1WATWhite adipose tissueWTWild-typeView Full Text

immunology↗