Biology subjects

Bellio, M.

Publications and source records attributed to Bellio, M..

6 recordsLinked to original sources

bioRxiv2026

Zika virus oncolytic signaling reverts immunosuppressive and angiogenic glioblastoma microenvironment in vitro and in vivo

Glioblastoma (GBM), the most aggressive primary brain tumor, remains refractory to conventional therapies, characterized by high relapse rates and poor clinical prognosis. Oncolytic viruses represent a promising therapeutic frontier; specifically, Zika virus (ZIKV) has shown potent oncolytic activity against GBM in vitro and in vivo. However, its impact on the tumor microenvironment (TME) remains poorly understood. Here, we demonstrate that ZIKV modulates pivotal TME components, triggering paracrine anti-angiogenic signaling that impairs endothelial stabilization and reprogramming microglia toward an anti-tumoral phenotype. These findings were corroborated in vivo in GBM-bearing mice. Using unbiased RNA-Seq, we identified type III interferon (IFN) signaling as the primary mediator of this ZIKV-induced TME remodeling. Crucially, analysis of human glioma datasets revealed that the type III IFN receptor complex is highly expressed in patients, identifying a high-risk population equipped with the molecular machinery to respond to this axis. Exogenous treatment with type III IFN in vitro and in vivo successfully mimicked ZIKV's anti-tumoral effects, reducing angiogenesis and promoting immune activation. Our results demonstrate that ZIKV acts as an immunotherapeutic agent capable of shifting the TME toward an anti-tumoral state, highlighting the type III IFN pathway as an actionable vulnerability and a promising strategy for patients failing conventional therapies.

cancer biology↗

bioRxiv2025

Leishmania amazonensis infection induces IL1β-dependent hyperalgesia, while dampening mechanical allodynia in C57BL/6 mice

Leishmaniases are neglected diseases causing significant deaths and disabilities. In Brazil, the most prevalent form is cutaneous leishmaniasis, characterized by painless lesions despite intense inflammation and ulceration. While BALB/c mice models exhibit hypersensitization to inflammatory stimuli, C57BL/6 mice better mimic human-like lesion progression and nociceptive responses. This study aimed to investigate the mechanisms underlying nociceptive changes in cutaneous leishmaniasis using the C57BL/6 model. Following infection with L. amazonensis, behavioral and nociceptive tests revealed unaltered mechanical nociception and motor capacity, though thermal hypersensitivity emerged during the chronic phase. Elevated IL-1{beta} production in the lesions and upregulation of TRPV1 in dorsal root ganglia (DRG) neurons were detected via ELISA and qPCR. Mice deficient in IL-1{beta}-related proteins or receptors exhibited higher thermal nociception thresholds, highlighting IL-1{beta}s role in heat hypersensitization during late infection stages. Microscopy of chronic lesions revealed tissue deformities, indicating desensitization to mechanical and inflammatory stimuli due to nerve terminal alterations and fibroplasia from regenerative processes. Conversely, thermal hypersensitivity in chronic phases was driven by IL-1{beta} effects on thermal nociceptive neurons in the DRG. These findings suggest that IL-1{beta} and TRPV1 contribute to thermal hypersensitivity, while structural changes in lesions underlie mechanical desensitization. This model provides insights into the complex nociceptive mechanisms of cutaneous leishmaniasis.

pathology↗

bioRxiv2021

Zika virus infection during development impairs the formation of corpus callosum by disturbing axon guidance and growth of callosal neurons.

Congenital Zika Syndrome (CZS) is a set of birth defects caused by Zika virus (ZIKV) infection during pregnancy. Microcephaly is its main feature, but other brain abnormalities are found in CZS patients, such as ventriculomegaly, brain calcifications, and dysgenesis of the corpus callosum. Many studies have focused on microcephaly, but it remains unknown how ZIKV infection leads to callosal malformation. To tackle this issue, we infected mouse embryos in utero with a Brazilian ZIKV isolate and found that they are born with a reduction in callosal area and density of callosal neurons. ZIKV infection also causes a density reduction of PH3+ cells, intermediate progenitor cells and SATB2+ neurons. Moreover, axonal tracing revealed that callosal axons are reduced and misrouted. Also, ZIKV infected cultures show a reduction of callosal axon length. GFAP labelling showed that in utero infection compromises glial cells responsible for midline axon guidance. The RNA-Seq data from infected brains identified downregulation of axon guidance and axonogenesis related genes. In sum, we showed that ZIKV infection impairs critical steps of corpus callosum formation by disrupting not only neurogenesis but also axon guidance and growth across the midline. Summary StatementZika virus infection during development impairs the formation of corpus callosum by disturbing axon guidance and growth of callosal neurons.

neuroscience↗

bioRxiv2021

Cytotoxic CD4+ T cells driven by T-cell intrinsic IL-18R/MyD88 signaling predominantly infiltrate Trypanosoma cruzi-infected hearts

Increasing attention has been directed to cytotoxic CD4+ T cells (CD4CTLs) in different pathologies, both in humans and mice. The impact of CD4CTLs in immunity and the mechanisms controlling their generation, however, remain poorly understood. Here, we show that CD4CTLs abundantly differentiate during mouse infection with the intracellular parasite Trypanosoma cruzi. CD4CTLs display parallel kinetics to Th1 cells in the spleen, mediate specific cytotoxicity against cells presenting pathogen-derived antigens and express immunoregulatory and/or exhaustion markers. We demonstrate that CD4CTL absolute numbers and activity are severely reduced in both Myd88-/- and Il18ra-/- mice. Of note, the infection of mixed-bone marrow chimeras revealed that WT but not Myd88-/- cells transcribe the CD4CTL gene signature and that Il18ra-/- and Myd88-/- CD4+ T cells phenocopy each other. Moreover, adoptive transfer of WT CD4+GzB+ T cells to infected Il18ra-/- mice extended their survival. Importantly, cells expressing the CD4CTL phenotype predominate among CD4+ T cells infiltrating the infected mouse cardiac tissue and are increased in the blood of Chagas patients, in which the frequency of CD4CTLs correlates with the severity of cardiomyopathy. Our findings describe CD4CTLs as a major player in immunity to a relevant human pathogen and disclose T-cell intrinsic IL-18R/MyD88 signaling as a key pathway controlling the magnitude of the CD4CTL response.

immunology↗

bioRxiv2019

The cyanobacterial saxitoxin exacerbates neural cell death and brain malformations induced by Zika virus

The northeast (NE) region of Brazil commonly goes through drought periods, which favor cyanobacterial blooms, capable of producing neurotoxins with implications for human and animal health. The most severe dry spell in the history of Brazil occurred between 2012 and 2016. Coincidently, the highest incidence of microcephaly associated with the Zika virus (ZIKV) outbreak was described in the NE region of Brazil during the same years. In this work, we tested the hypothesis that saxitoxin (STX), a neurotoxin produced in South America by the freshwater cyanobacteria Raphidiopsis raciborskii, could have contributed to the most severe Congenital Zika Syndrome (CZS) profile described worldwide. Quality surveillance showed higher cyanobacteria amounts and STX occurrence in human drinking water supplies of NE compared to other regions of Brazil. Experimentally, we described that STX doubled the amount of ZIKV-induced neural cell death in progenitor areas of human brain organoids, while the chronic ingestion of water contaminated with STX before and during gestation caused brain abnormalities in offspring of ZIKV-infected immunocompetent C57BL/6J mice. Our data indicate that saxitoxin-producing cyanobacteria is overspread in water reservoirs of the NE and might have acted as a co-insult to ZIKV infection in Brazil. These results raise a public health concern regarding the consequences of arbovirus outbreaks happening in areas with droughts and/or frequent freshwater cyanobacterial blooms.\n\nAuthor summaryThe uncontrolled spreading of cyanobacteria in drinking water reservoirs has been the cause of serious public health problems worldwide. Toxin-producing cyanobacterial blooms commonly occur during drought periods in the northeast (NE) region of Brazil. During Zika Virus (ZIKV) outbreak in 2015-16, Brazilian NE showed disproportionately higher microcephaly incidence. Here, we test the hypothesis that the cyanotoxin saxitoxin (STX) may act as a co-insult for ZIKV. Water quality surveillance data showed increased cyanobacteria population and higher STX amount in NE region during 2014-2018. In vitro, we observed that neural progenitor cell death was doubled after STX exposure to ZIKV-infected brain organoids. In vivo, chronic ingestion of STX during gestational period potentiated ZIKV-derived brain abnormalities in newborn mice. Our study provides new insights that may explain the discrepancies among Brazilian regions regarding CZS severity. Moreover, the data highlight the importance of cyanobacteria and cyanotoxin freshwater monitoring for future arbovirus outbreaks.

neuroscience↗

bioRxiv2019

Mayaro virus replication restriction and induction of muscular inflammation in mice are dependent on age and type-I interferon response

Mayaro virus (MAYV) is an emergent Arbovirus belonging to the Alphavirus genus from the Togaviridae family which has been circulated in forest regions of American continent through small outbreaks. Recent studies warned for the risk of MAYV dispersion to new areas and for the potential establishment of an urban epidemic cycle. Similar to Chikungunya and other arthritogenic Alphavirus, MAYV-induced disease shows a high prevalence of arthralgia and myalgia that can persist for months. Despite this, knowledge regarding pathogenesis, characteristics of host immune response, and resolution of MAYV infections are still limited. Here we investigated the dependence of age, innate and adaptive immunity for the control of MAYV replication and induction of inflammation in mice. We observed that age and type I interferon response are related to restriction of MAYV infection and tissue inflammation in mice. Moreover, we showed that MAYV continues to replicate persistently in adult recombination activation gene-1 efficient mice (RAG1-/-), indicating that adaptive immunity is essential to MAYV clearance. Despite chronic replication, infected adult RAG1-/- mice did not develop an apparent signal of muscle damage at late infection. On the other hand, MAYV infection induces muscular and paw inflammation in young WT and adult Type I Interferon receptor deficient mice (IFNAR-/-). In addition, MAYV infection triggers an increase in the expression of pro-inflammatory mediators, such as TNF, IL-6, KC, IL-1{beta}, MCP-1, and RANTES, in muscle tissue, and decreases TGF-{beta} expression. Taken together, our study contributes to the comprehension of MAYV pathogenesis, and describes a translational mouse model for further studies of MAYV infection, as well for testing vaccine and therapeutic strategies against this virus.\n\nAuthor SummaryMAYV-induced disease presents a high prevalence of arthralgia and myalgia that potentially persist for months, which is characteristic of the arthritogenic Alphavirus group. However, information regarding MAYV infection and the molecular mechanism of pathogenesis is still scarce. Here we investigated the dependence of age, innate and adaptive immunity for the control of MAYV replication and induction of inflammation in mice. We observed that tissue inflammation and the restriction of MAYV replication in mice are affected by aging and type I interferon response. Besides, we also showed that adaptive immunity was important for MAYV clearance in adult mice. Histological analyses demonstrated that MAYV replication triggered muscular and paw inflammation in young WT and adult type-I interferon receptor deficient mice. In addition, the level of expression of several pro-inflammatory cytokines was increased in the muscle MAYV-infected mice. Our data provide an advance for understanding the molecular mechanism involved in MAYV pathogenesis, as well as describes an in vivo model for further investigations on MAYV infection and for antiviral compounds and vaccine testing.

microbiology↗