Biology subjects

Rothenfusser, S.

Publications and source records attributed to Rothenfusser, S..

6 recordsLinked to original sources

bioRxiv2026

TRIM9 switches the morphological phenotype of melanoma cells

Melanoma is a highly plastic cancer characterized by distinct cellular phenotypes associated with broadly unique gene expression profiles. TRIM9 is a brain-enriched E3 ubiquitin ligase detected in melanoma, but how TRIM9 expression regulates melanoma phenotype is unknown. Using two metastatic human melanoma cell lines and a mouse melanoma model, we found that TRIM9 promoted melanoma proliferation and altered cell morphology. In cell lines, TRIM9 promoted cellular blebbing and negatively regulated adhesion, secretion, and mesenchymal motility. TRIM9 interacted with VASP in melanoma cells, altering VASP modification, localization, and dynamics. In the absence of TRIM9, cells had an altered actin organization and more focal adhesions, where VASP accumulated and exhibited rapid turnover. We find the alterations in actin architecture and adhesion associated with TRIM9 deletion were coincident with increased motile and contractile mesenchymal behavior in vitro. In vivo loss of TRIM9 in melanoma slowed tumor growth and altered metastasis frequency, size, and destination. Our findings indicate TRIM9 alters the proliferative and morphological phenotypes of metastatic melanoma cells to influence disease progression.

cancer biology↗

bioRxiv2025

RIG-I-like receptor-dependent type I Interferon regulates antigen dose and activation in yellow fever vaccine 17D-infected antigen presenting cells

The live-attenuated yellow fever vaccine 17D-204 (YF17D) activates robust innate immune responses followed by rapid induction of adaptive immunity resulting in long-lasting protection. YF17D triggers the production of type I interferons (IFNs) which have a dual role in antigen presenting cells regulating their infection and contributing to their activation. Infection with YF17D was detected in primary human blood monocytes and conventional dendritic cells (DCs) and in monocyte-derived DCs but was highly restricted by type I IFN. Blocking IFNAR signaling in YF17D-infected PBMC from vaccinated donors resulted in increased activation of YF17D-specific CD8+ T cells. Consistently, peak IFN-alpha plasma levels correlated inversely with the CD8+ T cells response in YF17D vaccinees. Loss of function experiments demonstrated a dominant role of retinoic acid inducible gene I (RIG-I)-like receptors (RLRs) and mitochondrial antiviral signaling protein (MAVS) for type I IFN induction and restriction of YF17D. The type I IFN response was mediated by 5 tri- or diphosphate dsRNA intermediates that are formed during YF17D infection. In vivo proximity labelling (IPL) of RIG-I and next-generation sequencing confirmed interaction of RIG-I with YF17D-dsRNA in infected cells. Thus, YF17D-triggered RLR-signaling restricts viral replication through type I IFN and thus limits the production of viral antigens that can be presented to T cells.

immunology↗

bioRxiv2024

Interferon-induced activation state of circulating dendritic cells and monocytes triggered by yellow fever vaccination correlates with early protective antibody responses

Yellow fever vaccination provides long-lasting protection and is a unique model for studying the immune response to an acute RNA virus infection in humans. To elucidate the early innate immune events preceding the rapid generation of protective immunity, we performed transcriptome analysis of human blood dendritic cell (DC) and monocyte subpopulations before and 3, 7, 14 and 28 days after vaccination. We detected temporary upregulation of IFN-stimulated genes (ISG) in all DC and monocyte subsets on day 3 and 7 after vaccination as well as cell type specific responses and temporal dynamics. Single cell RNA sequencing revealed rapid appearance of activated DC and monocyte clusters dominated by ISGs, inflammatory chemokines and genes involved in antigen processing and presentation. This was confirmed by flow cytometric analysis in a large cohort of vaccinees. We identified SIGLEC1/CD169 upregulation as a sensitive indicator of the transient IFN-induced activation state elicited in DCs and monocytes by YF17D vaccination correlating with early protective IgM antibody responses.

immunology↗

bioRxiv2023

Prior flavivirus immunity skews the yellow fever vaccine response to expand cross-reactive antibodies with increased risk of antibody dependent enhancement of Zika and dengue virus infection

Human pathogenic flaviviruses pose a significant health concern and vaccination is the most effective instrument to control their circulation. How pre-existing immunity to antigenically related viruses modulates immunization outcome remains poorly understood. In this study, we evaluated the effect of vaccination against tick-borne encephalitis virus (TBEV) on the epitope immunodominance and immunogenicity of the yellow fever 17D vaccine (YF17D) in a cohort of 250 human vaccinees. Following YF17D vaccination, all study participants seroconverted and generated protective neutralizing antibody titers. At day 28, TBEV pre-immunity did not affect the polyclonal neutralizing response which largely depended on the IgM fraction. We found that sera from TBEV-immunized individuals enhanced YF17D vaccine virus infection via antibody-dependent enhancement (ADE). Upon vaccination, individuals with TBEV pre-immunity had higher concentrations of cross-reactive IgG antibodies with limited neutralizing capacity against YF17D whereas vaccinees without prior flavivirus exposure showed a non-cross-reacting response. Using a set of recombinant YF17D envelope protein mutants displaying different epitopes, we identified quaternary epitopes as the primary target of neutralizing antibodies. Sequential immunizations redirected the IgG response towards the pan-flavivirus fusion loop epitope (FLE) with the potential to mediate enhancement of dengue and Zika virus infections whereas TBEV naive individuals elicited an IgG response directed towards neutralizing epitopes without an enhancing effect. We propose that the YF17D vaccine effectively conceals the FLE and primes a neutralizing IgG response in individuals with no prior flavivirus exposure. In contrast, the response in TBEV-experienced recipients favors weakly-neutralizing, cross-reactive epitopes potentially increasing the risk of severe dengue and Zika disease due to ADE.

immunology↗

bioRxiv2021

A high-throughput neutralization assay for yellow fever serodiagnostics

Quick and accurate detection of neutralizing antibodies (nAbs) against yellow fever is essential in serodiagnosis during outbreaks, for surveillance and to evaluate vaccine efficacy in population-wide studies. All this requires serological assays that can process a large number of samples in a highly standardized format. Albeit being laborious, time-consuming and limited in throughput, classical plaque reduction neutralization test (PRNT) is still considered gold standard for the detection and quantification of nAbs due to its sensitivity and specificity. Here we report the development of an alternative fluorescence-based serological assay (SNTFLUO) with an equally high sensitivity and specificity that is fit for high-throughput testing with the potential for automation. Finally, our novel SNTFLUO was cross-validated in several reference laboratories and against international WHO standards showing its potential to be implemented in clinical use. SNTFLUO assays with similar performance are available for the Japanese encephalitis, Zika and dengue viruses amenable for differential diagnostics. IMPORTANCEFast and accurate detection of neutralizing antibodies (nAbs) against yellow fever virus (YFV) is key in yellow fever serodiagnosis, outbreak surveillance and monitoring of vaccine efficacy. Although classical PRNT still remains gold standard for measuring YFV nAbs, this methodology suffers from inherent limitations such as a low throughput and an overall high labor intensity. We present a novel fluorescence-based serum neutralization test (SNTFLUO) with equally high sensitivity and specificity that is fit for processing large number of samples in a highly standardized manner and has the potential to be implemented in clinical use. In addition, we present SNTFLUO assays with similar performance for Japanese encephalitis, Zika and dengue viruses opening new avenues for differential diagnostics.

microbiology↗

bioRxiv2021

Impaired function and delayed regeneration of dendritic cells in COVID-19

Disease manifestations in COVID-19 range from mild to severe illness associated with a dysregulated innate immune response. Alterations in function and regeneration of dendritic cells (DC) and monocytes may contribute to immunopathology and influence adaptive immune responses in COVID-19 patients. We analyzed circulating DC and monocyte subsets in 65 hospitalized COVID-19 patients with mild/moderate or severe disease from acute disease to recovery and in healthy controls. Persisting reduction of all DC subpopulations was accompanied by an expansion of proliferating Lineage- HLADR+ cells lacking DC markers. Increased frequency of the recently discovered CD163+ CD14+ DC3 subpopulation in patients with more severe disease was associated with systemic inflammation, activated T follicular helper cells, and antibody-secreting cells. Persistent downregulation of CD86 and upregulation of PD-L1 in conventional DC (cDC2 and DC3) and classical monocytes associated with a reduced capacity to stimulate naive CD4+ T cells correlated with disease severity. Long-lasting depletion and functional impairment of DCs and monocytes may have consequences for susceptibility to secondary infections and therapy of COVID-19 patients.

immunology↗