Biology subjects

Kalinke, U.

Publications and source records attributed to Kalinke, U..

8 recordsLinked to original sources

bioRxiv2025

Nipah virus Malaysia and Bangladesh strain-induced pathogenesis in mice lacking type I interferon receptor signaling

Nipah virus (NiV) is a zoonotic highly pathogenic Paramyxovirus inducing lethal outbreaks of encephalitis and severe acute respiratory syndrome (SARS) with an average case-fatality rate of 75%. Two viral strains, NiV-Malaysia (NiV-Mal) and NiV-Bangladesh (NiV-Ban), associated to distinct geographical distribution, route of transmission, symptoms and lethality have been described. Due to the permanent threat of these emerging infections and the lack of approved therapeutics, it is crucial to improve our understanding regarding NiV-associated pathogenesis. Mice represent a small and accessible animal model, provided with numerous biological tools for the functional assessment of different genes related to antiviral response. Here, we analyze the susceptibility of mice deficient for type I interferon receptor (IFNAR KO) to infection with either NiV-Mal or NiV-Ban through intraperitoneal or intranasal routes. Our results show that IFNAR KO mice are susceptible to NiV-Ban infection via intraperitoneal route, although to a lesser extent than NiV-Mal, and develop encephalitis and pulmonary syndrome with viral propagation to different organs and lethal outcome in 60% of infected animals. In addition, intranasal administration of both viral strains led to a subclinical infection with viral replication in brain and lungs and production of virus-specific neutralizing antibodies. These results indicate IFNAR KO mice as a small animal model permitting comparative studies of the immunopathogenesis perpetrated by both NiV-Mal and NiV-Ban infections. Author summaryAvailability of small animal models represents a major issue to characterize virus-associated pathogenesis to further implement therapeutic strategies. Previous studies performed with NiV-Mal and NiV-Ban strains in wild-type (WT) mice did not indicate signs of NiV disease. However, when challenged with NiV-Mal, IFNAR KO mice suffered fatal outcomes, thus providing useful information on viral immunopathogenesis. Surprisingly, while being the more frequently re-emerging virus strain, no infection studies with NiV-Ban have been performed in IFNAR KO mice so far. Here, we sought comparing pathogenesis after NiV-Mal- and NiV-Ban-infection following IP and IN inoculations in IFNAR KO mice. Indeed, our results highlighted that contrary to fatal IP challenge, IN inoculation lead to a subclinical infection with both NiV strains. Moreover, we determined that NiV-Mal is more pathogenic than NiV-Ban following IP infection. Finally, distinct histopathological manifestations and tropism were associated with each viral strain and specific route of infection. Overall, our study implies that IFNAR KO mice represent a useful animal model to study strain-specific NiV pathophysiology.

microbiology↗

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↗

bioRxiv2022

Innate immune response to SARS-1 CoV-2 infection contributes to neuronal damage in human iPSC-derived peripheral neurons

Severe acute respiratory coronavirus 2 (SARS-CoV-2) infection causes neurological disease in some patients suggesting that infection can affect both the peripheral and central nervous system (PNS and CNS, respectively). It is not clear whether the outcome of SARS-CoV-2 infection of PNS and CNS neurons is similar, and which are the key factors that cause neurological disease: SARS-CoV-2 infection or the subsequent immune response. Here, we addressed these questions by infecting human induced-pluripotent stem cell-derived CNS and PNS neurons with the {beta} strain of SARS-CoV-2. Our results show that SARS-CoV-2 infects PNS neurons more efficiently than CNS neurons, despite lower expression levels of angiotensin converting enzyme 2. Infected PNS neurons produced interferon {lambda}1, several interferon stimulated genes and proinflammatory cytokines. They also displayed neurodegenerative-like alterations, as indicated by increased levels of sterile alpha and Toll/interleukin receptor motif-containing protein 1, amyloid precursor protein and -synuclein and lower levels of nicotinamide mononucleotide adenylyltransferase 2 and {beta}-III-tubulin. Interestingly, blockade of the Janus kinase and signal transducer and activator of transcription pathway by Ruxolitinib did not increase SARS-CoV-2 infection, but reduced neurodegeneration, suggesting that an exacerbated neuronal innate immune response contributes to pathogenesis in the PNS.

microbiology↗

bioRxiv2022

The mycotoxin Beauvericin exhibits immunostimulatory effects on dendritic cells via activating the TLR4 signaling pathway

Beauvericin (BEA), a mycotoxin of the enniatin family produced by various toxigenic fungi, has been attributed multiple biological activities such as anti-cancer, anti-inflammatory, and anti-microbial functions. However, effects of BEA on dendritic cells remain unknown so far. Here, we identified effects of BEA on murine granulocyte-macrophage colony-stimulating factor (GM-CSF)-cultured bone marrow derived dendritic cells (BMDCs) and the underlying molecular mechanisms. BEA potently activates BMDCs as signified by elevated IL-12 and CD86 expression. Multiplex immunoassays performed on myeloid differentiation primary response 88 (MyD88) and toll/interleukin-1 receptor (TIR) domain containing adaptor inducing interferon beta (TRIF) single or double deficient BMDCs indicate that BEA induces inflammatory cytokine and chemokine production in a MyD88/TRIF dependent manner. Furthermore, we found that BEA was not able to induce IL-12 or IFN{beta} production in Toll-like receptor 4 (Tlr4)-deficient BMDCs, whereas induction of these cytokines was not compromised in Tlr3/7/9 deficient BMDCs. This suggests that TLR4 might be the functional target of BEA on BMDCs. Consistently, in luciferase reporter assays BEA stimulation significantly promotes NF-{kappa}B activation in mTLR4/CD14/MD2 overexpressing but not control HEK-293 cells. RNA-sequencing analyses further confirmed that BEA induces transcriptional changes associated with the TLR4 signaling pathway. Together, these results identify TLR4 as a cellular BEA sensor and define BEA as a potent activator of BMDCs, implying that this compound can be exploited as a promising candidate structure for vaccine adjuvants or cancer immunotherapies.

immunology↗

bioRxiv2020

Activation of cGAS/STING pathway upon paramyxovirus infection

During inflammatory diseases, cancer and infection, the cGAS/STING pathway is known to recognize foreign or self-DNA in the cytosol and activate an innate immune response. Here, we report that negative-strand RNA paramyxoviruses, Nipah virus (NiV) and Measles virus (MeV), can also trigger the cGAS/STING axis. While mice deficient for MyD88, TRIF and MAVS still moderately control NiV infection when compared to WT mice, additional STING deficiency resulted in 100% lethality, suggesting synergistic roles of these pathways in host protection. Moreover, deletion of cGAS or STING resulted in decreased type-I interferon production with enhanced paramyxoviral infection in both human and murine cells. Finally, the phosphorylation and ubiquitination of STING, observed during viral infections, confirmed the activation of cGAS/STING pathway by NiV and MeV. Our data suggest that cGAS/STING activation is critical in controlling paramyxovirus infection, and possibly represent attractive targets to develop countermeasures against severe disease induced by these pathogens.

immunology↗

bioRxiv2020

Sequential MAVS- and MyD88/TRIF-signaling triggers anti-viral responses of tick-borne encephalitis virus-infected murine astrocytes

Tick-borne encephalitis virus (TBEV), a member of the Flaviviridae family, is typically transmitted upon tick bite and can cause meningitis and encephalitis in humans. In TBEV infected mice, mitochondrial antiviral signaling protein (MAVS), the downstream adaptor of retinoic acid inducible gene I-like receptor (RLR)-signaling, is needed to induce early type I interferon (IFN) responses and to confer protection. To identify the brain resident cell subset that produces protective IFN-β in TBEV infected mice, we isolated neurons, astrocytes and microglia and exposed these cells to TBEV in vitro. Under such conditions, neurons showed the highest percentage of infected cells, whereas astrocytes and microglia were infected to a lesser extent. In the supernatant (SN) of infected neurons, IFN-β was not detectable, while infected astrocytes showed very high and microglia low IFN-β production. Transcriptome analyses of astrocytes implied that MAVS-signaling was needed early after TBEV infection. Accordingly, MAVS-deficient astrocytes showed enhanced TBEV infection and significantly reduced early IFN-β responses. At later time points, moderate amounts of IFN-β were detected in the SN of infected MAVS-deficient astrocytes. Transcriptome analyses indicated that MAVS-deficiency negatively affected the induction of early anti-viral responses, which resulted in significantly increased TBEV replication. Treatment with MyD88 and TRIF inhibiting peptides reduced late IFN-β responses of TBEV infected WT astrocytes and entirely blocked IFN-β responses of infected MAVS-deficient astrocytes. Thus, upon TBEV exposure of brain-resident cells, astrocytes are important IFN-β producers that show biphasic IFN-β induction that initially depends on MAVS- and later on MyD88/TRIF-signaling.Competing Interest StatementThe authors have declared no competing interest.View Full Text

immunology↗

bioRxiv2020

Notch and TLR signaling coordinate monocyte cell fate and inflammation

Conventional Ly6Chi monocytes have developmental plasticity for a spectrum of differentiated phagocytes. Here we show, using conditional deletion strategies in a mouse model of Toll-like receptor (TLR) 7-induced inflammation, that the spectrum of developmental cell fates of Ly6Chi monocytes, and the resultant inflammation, is coordinately regulated by TLR and Notch signaling. Cell-intrinsic Notch2 and TLR7-Myd88 pathways independently and synergistically promote Ly6Clo patrolling monocyte development from Ly6Chi monocytes under inflammatory conditions, while impairment in either signaling axis impairs Ly6Clo monocyte development. At the same time, TLR7 stimulation in the absence of functional Notch2 signaling promotes resident tissue macrophage gene expression signatures in monocytes and ectopic differentiation of Ly6Chi monocytes into macrophages and dendritic cells, which appear in the blood stream and infiltrate the spleen and major blood vessels, resulting in unrestrained systemic inflammation. Thus, Notch2 is a master regulator of Ly6Chi monocyte cell fate and inflammation in response to TLR signaling.

immunology↗

bioRxiv2019

Ifnar1 signaling breaks the hepatic urea cycle to regulate adaptive immunity

Infections induce complex host responses linked to antiviral defense, inflammation and tissue damage and repair. These processes are increasingly understood to involve systemic metabolic reprogramming. We hypothesized that the liver as a central metabolic hub may orchestrate many of these changes during infection. Thus, we investigated the systemic interplay between inflammation and metabolism in a mouse model of chronic viral infection and hepatitis. Here we show that virus-induced type I interferon (IFN-I) modulates wide-spread metabolic alterations of the liver in a hepatocyte-intrinsic Ifnar1-dependent way. Specifically, IFN-I repressed the transcription of numerous genes with metabolic function including Otc and Ass1, which encode enzymes of the urea cycle. This led to decreased arginine and increased ornithine concentrations in the circulation, resulting in suppressed virus-specific CD8 T cell responses and ameliorated liver pathology. These findings establish IFN-I-induced modulation of hepatic metabolism and the urea cycle as an endogenous mechanism of immunoregulation.

immunology↗