In vitro and in vivo inhibition of the host TRPC4 channel attenuates Zika virus infection.

Zika virus (ZIKV) infection may lead to severe neurological consequences, including seizures, and early infancy death. However, the involved mechanisms are still largely unknown. TRPC channels play an important role in regulating nervous system excitability and are implicated in seizure development. We investigated whether TRPCs might be involved in the pathogenesis of ZIKV infection. We found that ZIKV infection increases TRPC4 expression in host cells via the interaction between the ZIKV-NS3 protein and CaMKII, enhancing TRPC4-mediated calcium influx. Pharmacological inhibition of CaMKII decreased both pCREB and TRPC4 protein levels, whereas the suppression of either TRPC4 or CaMKII improved the survival rate of ZIKV-infected cells and reduced viral protein production, likely by impeding the replication phase of the viral life cycle. TRPC4 or CaMKII inhibitors also reduced seizures and increased the survival of ZIKV-infected neonatal mice and blocked the spread of ZIKV in brain organoids derived from human-induced pluripotent stem cells. These findings suggest that targeting CaMKII or TRPC4 may offer a promising approach for developing novel anti-ZIKV therapies, capable of preventing ZIKV-associated seizures and death.

A Single-Dose mRNA Vaccine Employing Porous Silica Nanoparticles Induces Robust Immune Responses Against the Zika Virus.

Recently, lipid nanoparticles (LNPs)-based mRNA delivery has been approved by the FDA for SARS-CoV-2 vaccines. However, there are still considerable points for improvement in LNPs. Especially, local administration of LNPs-formulated mRNA can cause off-target translation of mRNA in distal organs which can induce unintended adverse effects. With the hypothesis that large and rigid nanoparticles can be applied to enhance retention of nanoparticles at the injection site, a polyethyleneimine (PEI)-coated porous silica nanoparticles (PPSNs)-based mRNA delivery platform is designed. PPSNs not only facilitate localized translation of mRNA at the site of injection but also prolonged protein expression. It is further demonstrated that the development of a highly efficacious Zika virus (ZIKV) vaccine using mRNA encoding full-length ZIKV pre-membrane (prM) and envelope (E) protein delivered by PPSNs. The ZIKV prME mRNA-loaded PPSNs vaccine elicits robust immune responses, including high levels of neutralizing antibodies and ZIKV E-specific T cell responses in C57BL/6 mice. Moreover, a single injection of prME-PPSNs vaccine provided complete protection against the ZIKV challenge in mice.

Pregnant women's perceptions on Information Sources on Zika Virus: a qualitative study.

The Zika virus (ZIKV) epidemic had a sanitary, psychosocial, and economic impact on individuals of reproductive age. The primary concern revolved around infection during pregnancy due to possible vertical transmission and its association with adverse fetal and infant outcomes, known as Congenital Zika Syndrome (CZS). This qualitative study employs phenomenology and grounded theory. This study includes interviews with 98 women, some pregnant during the ZIKV epidemic in Brazil, Colombia, and Puerto Rico, who had children with CZS or without diagnosed neurological impairment. Additionally, the study included a group of women who were pregnant during the COVID-19 pandemic in these same countries. In both groups, interviewees had varying levels of knowledge about ZIKV. The study found that messages conveyed through the media tended to be alarmist, in contrast to the information provided by healthcare professionals, which was considered more trustworthy. Pregnant women during the ZIKV epidemic reported receiving their ZIKV and CSZ infection diagnoses late, either during or after childbirth. The study underscores the needs of pregnant women in high-risk scenarios, the importance of health education processes, and the necessity to reinforce communication and continuing education.

A epidemia do vírus Zika (ZIKV) teve impacto sanitário, psicossocial e econômico sobre pessoas em idade reprodutiva. A principal preocupação foi a infecção durante a gravidez devido a possível transmissão vertical e sua associação com resultados fetais e infantis adversos, conhecida como síndrome congênita associada à infecção pelo Vírus Zika (SCZ). Este estudo qualitativo utiliza a fenomenologia e a teoria fundamentada. O estudo inclui entrevistas com 98 mulheres, parte grávida durante a epidemia de ZIKV no Brasil, Colômbia e Porto Rico e que tiveram filhos com SCZ ou sem comprometimento neurológico diagnosticado. Além disso, o estudo inclui um grupo de mulheres grávidas durante a pandemia de COVID-19 nos mesmos países. Em ambos os grupos, as entrevistadas tinham diferentes níveis de conhecimento sobre ZIKV. O estudo constatou que as mensagens veiculadas por meio da mídia eram alarmistas; em contraste com as informações fornecidas por profissionais de saúde, consideradas mais confiáveis. Mulheres gestantes durante a epidemia do ZIKV relataram ter recebido seu diagnóstico de infecção por ZIKV e SCZ tardiamente ou após o parto. O estudo destaca as necessidades das mulheres grávidas em cenários de alto risco, a importância de processos de educação em saúde e a necessidade de reforçar a comunicação e a educação continuada.

Serious Concern of Congenital Zika Syndrome (CZS) in India: A Narrative Review.

Congenital Zika syndrome (CZS) is a major concern in India and highlights the multifaceted challenges posed by the Zika virus (ZIKV). The alarming increase in CZS cases in India, a condition that has serious effects on both public health and newborns, has raised concerns. This review highlights the importance of raising concern and awareness and taking preventive measures by studying the epidemiology, clinical symptoms, and potential long-term consequences of CZS. The review also contributes to worldwide research and information sharing to improve the understanding and prevention of CZS. As India deals with the changing nature of CZS, this thorough review is an important tool for policymakers, health workers, and researchers to understand what is happening now, plan for what to do in the future, and work together as a team, using medical knowledge, community involvement, and study projects to protect newborns' health and reduce the public health impact of these syndromes.

Increased Angiotensin I-Converting Enzyme Activity in Zika Virus-Infected Mouse Brain: Implications for Therapy?

Congenital zika virus syndrome (CZS) has become a significant worldwide concern since the sudden rise of microcephaly related to zika virus (ZIKV) in Brazil. Primarily transmitted by Aedes mosquitoes, ZIKV shares serologic similarities with dengue virus (DENV), complicating the diagnosis and/or clinical management. The Angiotensin I-Converting Enzyme (ACE) was associated with either neuroprotective or anti-inflammatory properties in the central nervous system (CNS). The possible role(s) of ACE in these two flaviviruses infection remain largely unexplored. In this study, we evaluate ACE activity in the brain of ZIKV- or DENV-infected mice, both compared to MOCK, showing about 30% increased ACE activity only in ZIKV-infected mice (p = 0.024), while no change was noticed in brain from DENV-infected animals (p = 0.888). In addition, the treatment with interferon beta (IFNß), under conditions previously demonstrated to rescue the normal size of microcephalic brains determined by ZIKV infection, also restored ACE activity in ZIKV-infected animals to levels close to that of the MOCK control group. Although inflammatory responses expected for either ZIKV or DENV infections, only ZIKV was associated with microcephaly, as well as with increased ACE activity and reversion by treatment with IFNß. Furthermore, this increase in ACE activity was observed only after intracerebroventricular (ICV) injection (F (2, 16) = 7.907, p = 0.004), but not for intraperitoneal (IP) administration of ZIKV (F (2, 26) = 1.996, p = 0.156), suggesting that the observed central ACE activity modulation may be associated with the presence of this specific flavivirus in the brain.

Mosquito (Diptera: Culicidae) diversity and arbovirus detection across an urban and agricultural landscape.

Fragmented landscapes in Mexico, characterized by a mix of agricultural, urban, and native vegetation cover, presents unique ecological characteristics that shape the mosquito community composition and mosquito-borne diseases. The extent to which landscape influences mosquito populations and mosquito-borne diseases is still poorly understood. This work assessed the effect of landscape metrics -agriculture, urban, and native vegetation cover- on mosquito diversity and arbovirus presence in fragmented tropical deciduous forests in Central Mexico during 2021. Among the 21 mosquito species across six genera we identified, Culex quinquefasciatus was the most prevalent species, followed by Aedes aegypti, Ae. albopictus, and Ae. epactius. Notably, areas with denser native vegetation cover displayed higher mosquito species richness, which could have an impact on phenomena such as the dilution effect. Zika and dengue virus were detected in 85% of captured species, with first reports of DENV in several Aedes species and ZIKV in multiple Aedes and Culex species. These findings underscore the necessity of expanding arbovirus surveillance beyond Ae. aegypti and advocate for a deeper understanding of vector ecology in fragmented landscapes to adequately address public health strategies.

Immunogenicity and safety of a self-assembling ZIKV nanoparticle vaccine in mice.

Zika virus (ZIKV) is a mosquito-borne flavivirus that highly susceptibly causes Guillain-Barré syndrome and microcephaly in newborns. Vaccination is one of the most effective measures for preventing infectious diseases. However, there is currently no approved vaccine to prevent ZIKV infection. Here, we developed nanoparticle (NP) vaccines by covalently conjugating self-assembled 24-subunit ferritin to the envelope structural protein subunit of ZIKV to achieve antigen polyaggregation. The immunogenicityof the NP vaccine was evaluated in mice. Compared to monomer vaccines, the NP vaccine achieved effective antigen presentation, promoted the differentiation of follicular T helper cells in lymph nodes, and induced significantly greater antigen-specific humoral and cellular immune responses. Moreover, the NP vaccine enhanced high-affinity antigen-specific IgG antibody levels, increased secretion of the cytokines IL-4 and IFN-γ by splenocytes, significantly activated T/B lymphocytes, and improved the generation of memory T/B cells. In addition, no significant adverse reactions occurred when NP vaccine was combined with adjuvants. Overall, ferritin-based NP vaccines are safe and effective ZIKV vaccine candidates.

Zika virus infection in a cell culture model reflects the transcriptomic signatures in patients.

Zika virus (ZIKV), a re-emerging flavivirus, is associated with devasting developmental and neurological disease outcomes particularly in infants infected in utero. Towards understanding the molecular underpinnings of the unique ZIKV disease pathologies, numerous transcriptome-wide studies have been undertaken. Notably, these studies have overlooked the assimilation of RNA-seq analysis from ZIKV-infected patients with cell culture model systems. In this study we find that ZIKV-infection of human lung adenocarcinoma A549 cells, mirrored both the transcriptional and alternative splicing profiles from previously published RNA-seq data of peripheral blood mononuclear cells collected from pediatric patients during early acute, late acute, and convalescent phases of ZIKV infection. Our analyses show that ZIKV infection in cultured cells correlates with transcriptional changes in patients, while the overlap in alternative splicing profiles was not as extensive. Overall, our data indicate that cell culture model systems support dissection of select molecular changes detected in patients and establishes the groundwork for future studies elucidating the biological implications of alternative splicing during ZIKV infection.

Immunoinformatics-Based Design of Multi-epitope DNA and mRNA Vaccines Against Zika Virus.

In this study, we used an immunoinformatics approach to predict antigenic epitopes of Zika virus (ZIKV) proteins to assist in designing a vaccine antigen against ZIKV. We performed the prediction of CD8+ T-lymphocyte and antigenic B-cell epitopes of ZIKV proteins. The binding interactions of T-cell epitopes with major histocompatibility complex class I (MHC-I) proteins were assessed. We selected the antigenic, conserved, nontoxic, and immunogenic epitopes, which indicated significant interactions with the human leucocyte antigen (HLA-A and HLA-B) alleles and worldwide population coverage of 76.35%. The predicted epitopes were joined with the help of linkers and an adjuvant. The vaccine antigen was then analyzed through molecular docking with TLR3 and TLR8, and it was in silico cloned in the pVAX1 vector to be used as a DNA vaccine and designed as a mRNA vaccine.

Zika virus replication is impaired by a selective agonist of the TRPML2 ion channel.

The flavivirus genus includes human pathogenic viruses such as Dengue (DENV), West Nile (WNV) and Zika virus (ZIKV) posing a global health threat due to limited treatment options. Host ion channels are crucial for various viral life cycle stages, but their potential as targets for antivirals is often not fully realized due to the lack of selective modulators. Here, we observe that treatment with ML2-SA1, an agonist for the human endolysosomal cation channel TRPML2, impairs ZIKV replication. Upon ML2-SA1 treatment, levels of intracellular genomes and number of released virus particles of two different ZIKV isolates were significantly reduced and cells displayed enlarged vesicular structures and multivesicular bodies with ZIKV envelope protein accumulation. However, no increased ZIKV degradation in lysosomal compartments was observed. Rather, the antiviral effect of ML2-SA1 seemed to manifest by the compound's negative impact on genome replication. Moreover, ML2-SA1 treatment also led to intracellular cholesterol accumulation. ZIKV and many other viruses including the Orthohepevirus Hepatitis E virus (HEV) rely on the endolysosomal system and are affected by intracellular cholesterol levels to complete their life cycle. Since we observed that ML2-SA1 also negatively impacted HEV infections in vitro, this compound may harbor a broader antiviral potential through perturbing the intracellular cholesterol distribution. Besides indicating that TRPML2 may be a promising target for combatting viral infections, we uncover a tentative connection between this protein and cholesterol distribution within the context of infectious diseases.

Evaluation of the antiviral activity of new dermaseptin analogs against Zika virus.

Zika virus represents the primary cause of infection during pregnancy and can lead to various neurological disorders such as microcephaly and Guillain-Barré syndrome affecting both children and adults. This infection is also associated with urological and nephrological problems. So far, evidence of mosquito-borne Zika virus infection has been reported in a total of 89 countries and territories. However, surveillance efforts primarily concentrate on outbreaks that this virus can cause, yet the measures implemented are typically limited. Currently, there are no specific treatments or vaccines designed for the prevention or treatment of Zika virus infection or its associated disease. The development of effective therapeutic agents presents an urgent need. Importantly, an alternative for advancing the discovery of new molecules could be dermaseptins, a family of antimicrobial peptides known for their potential antiviral properties. In this study, we carried out the synthesis of dermaseptins and their analogs and subsequently assessed the bioactivity tests against Zika virus (ZIKV PF13) of dermaseptins B2 and S4 and their derivatives. The cytotoxicity of these peptides was investigated on HMC3 cell line and HeLa cells by CellTiter-Glo® Luminescent Cell Viability Assay. Thereafter, we evaluated the antiviral activity caused by the action of our dermaseptins on the viral envelope using the Fluorescence Activated Cell Sorting (FACS). The cytotoxicity of our molecules was concentration-dependent at microgram concentrations Expect for dermaseptin B2 and its derivative which present no toxicity against HeLa and HMC3 cell lines. It was observed that all tested analogs from S4 family exhibited antiviral activity with low concentrations ranging from 3 to 12.5 µg/ml , unlike the native B2 and its derivative which increased the infectivity. Pre-incubating of dermaseptins with ZIKV PF13 before infection revealed that these derivatives inhibit the initial stages of virus infection. In summary, these results suggest that dermaseptins could serve as novel lead structures for the development of potent antiviral agents against Zika virus infections.

Antiviral Potential of Fucoxanthin, an Edible Carotenoid Purified from Sargassum siliquastrum, against Zika Virus.

Considering the lack of antiviral drugs worldwide, we investigated the antiviral potential of fucoxanthin, an edible carotenoid purified from Sargassum siliquastrum, against zika virus (ZIKV) infection. The antiviral activity of fucoxanthin was assessed in ZIKV-infected Vero E6 cells, and the relevant structural characteristics were confirmed using molecular docking and molecular dynamics (MD) simulation. Fucoxanthin decreased the infectious viral particles and nonstructural protein (NS)1 mRNA expression levels at concentrations of 12.5, 25, and 50 µM in ZIKV-infected cells. Fucoxanthin also decreased the increased mRNA levels of interferon-induced proteins with tetratricopeptide repeat 1 and 2 in ZIKV-infected cells. Molecular docking simulations revealed that fucoxanthin binds to three main ZIKV proteins, including the envelope protein, NS3, and RNA-dependent RNA polymerase (RdRp), with binding energies of -151.449, -303.478, and -290.919 kcal/mol, respectively. The complex of fucoxanthin with RdRp was more stable than RdRp protein alone based on MD simulation. Further, fucoxanthin bonded to the three proteins via repeated formation and disappearance of hydrogen bonds. Overall, fucoxanthin exerts antiviral potential against ZIKV by affecting its three main proteins in a concentration-dependent manner. Thus, fucoxanthin isolated from S. siliquastrum is a potential candidate for treating zika virus infections.

Mapping the scientific output of organoids for animal and human modeling infectious diseases: a bibliometric assessment.

The escalation of antibiotic resistance, pandemics, and nosocomial infections underscores the importance of research in both animal and human infectious diseases. Recent advancements in three-dimensional tissue cultures, or "organoids", have revolutionized the development of in vitro models for infectious diseases. Our study conducts a bibliometric analysis on the use of organoids in modeling infectious diseases, offering an in-depth overview of this field's current landscape. We examined scientific contributions from 2009 onward that focused on organoids in host‒pathogen interactions using the Web of Science Core Collection and OpenAlex database. Our analysis included temporal trends, reference aging, author, and institutional productivity, collaborative networks, citation metrics, keyword cluster dynamics, and disruptiveness of organoid models. VOSviewer, CiteSpace, and Python facilitated this analytical assessment. The findings reveal significant growth and advancements in organoid-based infectious disease research. Analysis of keywords and impactful publications identified three distinct developmental phases in this area that were significantly influenced by outbreaks of Zika and SARS-CoV-2 viruses. The research also highlights the synergistic efforts between academia and publishers in tackling global pandemic challenges. Through mostly consolidating research efforts, organoids are proving to be a promising tool in infectious disease research for both human and animal infectious disease. Their integration into the field necessitates methodological refinements for better physiological emulation and the establishment of extensive organoid biobanks. These improvements are crucial for fully harnessing the potential of organoids in understanding infectious diseases and advancing the development of targeted treatments and vaccines.

Predicting Efficacy of a Purified Inactivated Zika Virus Vaccine in Flavivirus-Naïve Humans Using an Immunological Correlate of Protection in Non-Human Primates.

A traditional phase 3 clinical efficacy study for a Zika vaccine may be unfeasible because of the current low transmission of Zika virus (ZIKV). An alternative clinical development approach to evaluate Zika vaccine efficacy (VE) is therefore required, delineated in the US FDA's Accelerated Approval Program for licensure, which utilizes an anti-Zika neutralizing antibody (Zika NAb) titer correlated with non-human primate (NHP) protection as a surrogate endpoint. In this accelerated approval approach, the estimation of VE would be inferred from the percentage of phase 3 trial participants achieving the established surrogate endpoint. We provide a statistical framework to predict the probability of protection for human participants vaccinated with a purified inactivated ZIKV vaccine (TAK-426), in the absence of VE measurements, using NHP data under a single-correlate model. Based on a logistic regression (LR) with bias-reduction model, a probability of 90% protection in humans is expected with a ZIKV NAb geometric mean titer (GMT) ≥ 3.38 log10 half-maximal effective concentration (EC50). The predicted probability of protection of TAK-426 against ZIKV infection was determined using the two-parameter LR model that fit the calculated VE in rhesus macaques and the flavivirus-naïve phase 1 trial participants' ZIKV NAb GMTs log10 EC50, measured by a ZIKV reporter virus particle assay, at 1 month post dose 2. The TAK-426 10 µg dose predicted a probability of protection from infection of 98% among flavivirus-naïve phase 1 trial participants.

Exploring the role of brain-derived extracellular vesicles in viral infections: from pathological insights to biomarker potential.

Extracellular vesicles (EVs) are membrane-bound vesicles secreted by all cell types that play a central role in cell-to-cell communication. Since these vesicles serve as vehicles of cellular content (nucleic acids, proteins and lipids) with the potential to cross biological barriers, they represent a novel attractive window into an otherwise inaccessible organ, such as the brain. The composition of EVs is cell-type specific and mirrors the physiological condition of the cell-of-origin. Consequently, during viral infection, EVs undergo significant changes in their content and morphology, thereby reflecting alterations in the cellular state. Here, we briefly summarize the potential of brain-derived EVs as a lens into viral infection in the central nervous system, thereby: 1) uncovering underlying pathophysiological processes at play and 2) serving as liquid biopsies of the brain, representing a non-invasive source of biomarkers for monitoring disease activity. Although translating the potential of EVs from research to diagnosis poses complexities, characterizing brain-derived EVs in the context of viral infections holds promise to enhance diagnostic and therapeutic strategies, offering new avenues for managing infectious neurological diseases.

Novel quinoline substituted autophagy inhibitors attenuate Zika virus replication in ocular cells.

Zika virus (ZIKV) is a re-emerging RNA virus that is known to cause ocular and neurological abnormalities in infants. ZIKV exploits autophagic processes in infected cells to enhance its replication and spread. Thus, autophagy inhibitors have emerged as a potent therapeutic target to combat RNA viruses, with Hydroxychloroquine (HCQ) being one of the most promising candidates. In this study, we synthesized several novel small-molecule quinoline derivatives, assessed their antiviral activity, and determined the underlying molecular mechanisms. Among the nine synthesized analogs, two lead candidates, labeled GL-287 and GL-382, significantly attenuated ZIKV replication in human ocular cells, primarily by inhibiting autophagy. These two compounds surpassed the antiviral efficacy of HCQ and other existing autophagy inhibitors, such as ROC-325, DC661, and GNS561. Moreover, unlike HCQ, these novel analogs did not exhibit cytotoxicity in the ocular cells. Treatment with compounds GL-287 and GL-382 in ZIKV-infected cells increased the abundance of LC3 puncta, indicating the disruption of the autophagic process. Furthermore, compounds GL-287 and GL-382 effectively inhibited the ZIKV-induced innate inflammatory response in ocular cells. Collectively, our study demonstrates the safe and potent antiviral activity of novel autophagy inhibitors against ZIKV.

Wolbachia endosymbionts in Drosophila regulate the resistance to Zika virus infection in a sex dependent manner.

Drosophila melanogaster has been used extensively for dissecting the genetic and functional bases of host innate antiviral immunity and virus-induced pathology. Previous studies have shown that the presence of Wolbachia endosymbionts in D. melanogaster confers resistance to infection by certain viral pathogens. Zika virus is an important vector-borne pathogen that has recently expanded its range due to the wide geographical distribution of the mosquito vector. Here, we describe the effect of Wolbachia on the immune response of D. melanogaster adult flies following Zika virus infection. First, we show that the presence of Wolbachia endosymbionts promotes the longevity of uninfected D. melanogaster wild type adults and increases the survival response of flies following Zika virus injection. We find that the latter effect is more pronounced in females rather than in males. Then, we show that the presence of Wolbachia regulates Zika virus replication during Zika virus infection of female flies. In addition, we demonstrate that the antimicrobial peptide-encoding gene Drosocin and the sole Jun N-terminal kinase-specific MAPK phosphatase Puckered are upregulated in female adult flies, whereas the immune and stress response gene TotM is upregulated in male individuals. Finally, we find that the activity of RNA interference and Toll signaling remain unaffected in Zika virus-infected female and male adults containing Wolbachia compared to flies lacking the endosymbionts. Our results reveal that Wolbachia endosymbionts in D. melanogaster affect innate immune signaling activity in a sex-specific manner, which in turn influences host resistance to Zika virus infection. This information contributes to a better understanding of the complex interrelationship between insects, their endosymbiotic bacteria, and viral infection. Interpreting these processes will help us design more effective approaches for controlling insect vectors of infectious disease.

Generalized open-source workflows for atomistic molecular dynamics simulations of viral helicases.

Viral helicases are promising targets for the development of antiviral therapies. Given their vital function of unwinding double-stranded nucleic acids, inhibiting them blocks the viral replication cycle. Previous studies have elucidated key structural details of these helicases, including the location of substrate binding sites, flexible domains, and the discovery of potential inhibitors. Here we present a series of new Galaxy tools and workflows for performing and analyzing molecular dynamics simulations of viral helicases. We first validate them by demonstrating recapitulation of data from previous simulations of Zika (NS3) and SARS-CoV-2 (NSP13) helicases in apo and complex with inhibitors. We further demonstrate the utility and generalizability of these Galaxy workflows by applying them to new cases, proving their usefulness as a widely accessible method for exploring antiviral activity.

Evaluation of the effects of the Zika Virus-Immunoglobulin G+ complex on murine microglial cells.

After the Zika virus (ZIKV) epidemic in Brazil, ZIKV infections were linked to damage to the central nervous system (CNS) and congenital anomalies. Due to the virus's ability to cross the placenta and reach brain tissue, its effects become severe, leading to Congenital Zika Syndrome (CZS) and resulting in neuroinflammation, microglial activation, and secretion of neurotoxic factors. The presence of ZIKV triggers an inadequate fetal immune response, as the fetus only has the protection of maternal antibodies of the Immunoglobulin G (IgG) class, which are the only antibodies capable of crossing the placenta. Because of limited understanding regarding the long term consequences of ZIKV infection and the involvement of maternal antibodies, this study sought to assess the impact of the ZIKV + IgG⁺complex on murine microglial cells. The cells were exposed to ZIKV, IgG antibodies, and the ZIKV + IgG⁺complex for 24 and 72 h. Treatment-induced cytotoxic effects were evaluated using the cell viability assay, oxidative stress, and mitochondrial membrane potential. The findings indicated that IgG antibodies exhibit cytotoxic effects on microglia, whether alone or in the presence of ZIKV, leading to compromised cell viability, disrupted mitochondrial membrane potential, and heightened oxidative damage. Our conclusion is that IgG antibodies exert detrimental effects on microglia, triggering their activation and potentially disrupting the creation of a neurotoxic environment. Moreover, the presence of antibodies may correlate with an elevated risk of ZIKV-induced neuroinflammation, contributing to long-term CNS damage.

Aedes albopictus saliva contains a richer microbial community than the midgut.

BACKGROUND: Past findings demonstrate that arthropods can egest midgut microbiota into the host skin leading to dual colonization of the vertebrate host with pathogens and saliva microbiome. A knowledge gap exists on how the saliva microbiome interacts with the pathogen in the saliva. To fill this gap, we need to first define the microbial composition of mosquito saliva. METHODS: The current study aimed at analyzing and comparing the microbial profile of Aedes albopictus saliva and midgut as well as assessing the impact of Zika virus (ZIKV) infection on the midgut and saliva microbial composition. Colony-reared Ae. albopictus strains were either exposed to ZIKV infectious or noninfectious bloodmeal. At 14 ays postinfection, the 16S V3-V4 hypervariable rRNA region was amplified from midgut and saliva samples and sequenced on an Illumina MiSeq platform. The relative abundance and diversity of midgut and saliva microbial taxa were assessed. RESULTS: We observed a richer microbial community in the saliva compared with the midgut, yet some of the microbial taxa were common in the midgut and saliva. ZIKV infection did not impact the microbial diversity of midgut or saliva. Further, we identified Elizabethkingia spp. in the Ae. albopictus saliva. CONCLUSIONS: This study provides insights into the microbial community of the Ae. albopictus saliva as well as the influence of ZIKV infection on the microbial composition of its midgut and saliva. The identification of Elizabethkingia spp., an emerging pathogen of global health significance, in Ae. albopictus saliva is of medical importance. Future studies to assess the interactions between Ae. albopictus saliva microbiome and ZIKV could lead to novel strategies for developing transmission barrier tools.