Coxsackievirus B3 infects and disrupts human induced-pluripotent stem cell derived brain-like endothelial cells

Innovative use of gram-positive enhancer matrix particles and affinity peptides in a vaccine against Coxsackievirus B3

Viral myocarditis (VM) is an inflammatory disease posing a serious threat to public health, with various viral pathogens contributing to its pathogenesis. Coxsackievirus B3 (CVB3) is the most frequently implicated causative agent and has been extensively studied because of its high prevalence and severity. No specific therapeutic interventions for VM exist, and vaccine development has encountered substantial challenges. Therefore, we aimed to develop a novel CVB3 mucosal vaccine as a preventive strategy against VM. Gram-positive enhancer matrice (GEM) particles serve as innovative mucosal vaccine adjuvants and antigen delivery systems that enhance antigen immunogenicity by facilitating effective mucosal immune responses. In this study, GEM particle display technology was used to develop two novel CVB3 vaccines: (1) a GEM particle-based vaccine displaying the CVB3 capsid protein VP1 via a PA anchor protein (GEM-PA-VP1), and (2) a GEM particle-based vaccine displaying VP1 via the FcSP peptide (GEM-Fc-VP1). Both GEM-PA-VP1 and GEM-Fc-VP1 vaacines significantly elevated levels of specific IgG, IgG1, IgG2a, sIgA and neutralizing antibodies in a mouse model, along with enhanced secretion of Th1- and Th2-associated cytokines, compared to controls. Notably, GEM-Fc-VP1 demonstrated superior immunogenicity compared with that of GEM-PA-VP1, evidenced by higher antibody titres and cytokine responses. In challenge protection experiments, both vaccines significantly improved survival rates, reduced myocardial enzyme levels, and decreased inflammatory cell infiltration in myocardial tissue, with GEM-Fc-VP1 exhibiting greater efficacy. These findings establish a foundation for the development of a safe and effective CVB3 candidate vaccine and provide novel insights into the potential of peptide-mediated subunit vaccine approaches.

Transcriptome of brain-like endothelial cells following coxsackievirus B3 infection

Coxsackievirus B3 is a leading cause of viral aseptic meningitis. To gain entry to the central nervous system, it must interact with and disrupt the brain endothelial cells of the blood-brain barrier. Here, we report the global transcriptome of stem-cell-derived brain-like endothelial cells during coxsackievirus B3 infection.

Transcriptomic analysis of coxsackievirus B3 infection in induced pluripotent stem cell-derived brain-like endothelial cells

Viral aseptic meningitis is a neuroinflammatory condition that occurs when viruses gain access to the central nervous system (CNS) and induce inflammation. The blood-brain barrier (BBB) is comprised of brain endothelial cells (BECs) that stringently regulate the passage of molecules, toxins, and pathogens from the circulation into the CNS. Through their unique properties, such as complex tight junctions, reduced rates of endocytosis, expression of efflux transporters, and restricted expression of leukocyte adhesion molecules, the BBB is often able to limit pathogen entry into the brain; however, certain neurotropic pathogens, such as coxsackievirus B3 (CVB3) are able to infect the CNS. We have previously demonstrated that CVB3 can infect and disrupt induced pluripotent stem cell-derived brain-like endothelial cells (iBECs), but the host response to this infection remains unknown. Here, we investigate global host transcriptional changes during CVB3 infection of iBECs using RNA sequencing. We validated our data set by exploring pathways altered by CVB3 using quantitative real-time PCR (qPCR) and enzyme-linked immunosorbent assay of upregulated cytokines and interferon signaling molecules.

IMPORTANCE

Coxsackievirus B3 (CVB3) is a leading cause of viral aseptic meningitis that can produce severe disease in susceptible individuals. To gain access to the central nervous system, CVB3 must cross central nervous system barriers, such as the blood-brain barrier. Previously, we have shown that CVB3 infects a human stem cell-derived brain-like endothelial cell model. Here, we report the global transcriptome of stem cell-derived brain-like endothelial cells to CVB3 infection and provide proof-of-concept validation of the dataset using molecular biology techniques. These data could inform novel mechanisms of CVB3-mediated blood-brain barrier dysfunction.

Common Chemical Plasticizer Di(2-Ethhylhexyl) Phthalate Exposure Exacerbates Coxsackievirus B3 Infection

Di(2-ethhylhexyl) phthalate (DEHP) is a common plastic rubberizer. DEHP leaches from plastic matrices and is under increasing scrutiny as numerous studies have linked it to negative human health manifestations. Coxsackievirus B3 (CVB) is a human pathogen that typically causes subclinical infections but can sometimes cause severe diseases such as pancreatitis, myocarditis, and meningoencephalitis. Though CVB infections are common, severe illness is relatively rare, and it is unclear what factors mediate disease severity. In this study, we sought to determine the effects that DEHP has on CVB infection in a variety of human cell types to evaluate whether this plastic-derived pollutant could represent a proviral environmental factor.

METHODS

HeLa cervical cancer cells, human induced pluripotent stem cell-derived brain-like endothelial cells (iBECs), and Caco-2 colon carcinoma cells were exposed to 40 µg/mL DEHP for 24 h prior to infecting with enhanced green fluorescent protein (EGFP)-expressing CVB. The severity of the infection was evaluated via fluorescence microscopy and flow cytometry-based viral EGFP detection, viral plaque assay on tissue culture media, and Western blotting to detect VP1 viral capsid protein. Interferon-associated proteins such as interferon regulatory factor (IRF) 3, IRF7, interferon-induced transmembrane (IFITM) 2, and IFITM3 were measured by Western blotting. The roles of IFITM2 and IFITM3 in the context of CVB infection were evaluated via siRNA silencing.

RESULTS

We found that DEHP drastically increased CVB infection in each of the cell types we tested, and, while the cellular processes underlying DEHP's proviral properties were not entirely clear, we observed that DEHP may subvert CVB-induced interferon signaling and elevate levels of IFITMs, which appeared to bolster CVB infection.

CONCLUSIONS

DEHP may represent a major environmental factor associated with the severity of CVB infection. Further understanding of how DEHP exacerbates infection may better elucidate its potential role as a proviral environmental factor.

Transient receptor potential channels in viral infectious diseases: Biological characteristics and regulatory mechanisms

BACKGROUND

Viral infectious diseases have long posed a challenge to humanity. In recent decades, transient receptor potential (TRP) channels have emerged as newly investigated cation channels. Increasing evidence suggests that TRP channel-mediated Ca2+ homeostasis disruptions, along with associated pathological changes, are critical factors in the onset and progression of viral infectious diseases. However, the precise roles and mechanisms of TRP channels in these diseases remain to be systematically elucidated.

AIM OF REVIEW

The aim of this review is to systematically summarize recent advances in understanding TRP channels in viral infections, and based on current progress and challenges, propose future directions for research.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review summarizes the classification and biological functions of the TRP family, explores the mechanisms by which TRP channels contribute to viral infections, and highlights specific mechanisms at three levels: virus, host, and outcome. These include the direct role in viral biology and replication, the indirect role in host immunity and inflammation, and the resulting pathological changes. Additionally, we discuss the potential applications of the TRP family in the treatment of viral infectious diseases and propose future research directions.

Enterovirus A71 crosses a human blood-brain barrier model through infected immune cells

Enterovirus A71 (EV-A71) is associated with neurological conditions such as acute meningitis and encephalitis. The virus is detected in the bloodstream, and high blood viral loads are associated with central nervous system (CNS) manifestations. We used an in vitro blood-brain barrier (BBB) model made up of human brain-like endothelial cells (hBLECs) and brain pericytes grown in transwell systems to investigate whether three genetically distinct EV-A71 strains (subgenogroups C1, C1-like, and C4) can cross the human BBB. EV-A71 poorly replicated in hBLECs, which released moderate amounts of infectious viruses from their luminal side and trace amounts of infectious viruses from their basolateral side. The barrier properties of hBLECs were not impaired by EV-A71 infection. We investigated the passage through hBLECs of EV-A71-infected white blood cells. EV-A71 strains efficiently replicated in immune cells, including monocytes, neutrophils, and NK/T cells. Attachment to hBLECs of immune cells infected with the C1-like virus was higher than attachment of cells infected with C1-06. EV-A71 infection did not impair the transmigration of immune cells through hBLECs. Overall, EV-A71 targets different white blood cell populations that have the potential to be used as a Trojan horse to cross hBLECs more efficiently than cell-free EV-A71 particles.IMPORTANCEEnterovirus A71 (EV-A71) was first reported in the USA, and numerous outbreaks have since occurred in Asia and Europe. EV-A71 re-emerged as a new multirecombinant strain in 2015 in Europe and is now widespread. The virus causes hand-foot-and-mouth disease in young children and is involved in nervous system infections. How the virus spreads to the nervous system is unclear. We investigated whether white blood cells could be infected by EV-A71 and transmit it across human endothelial cells mimicking the blood-brain barrier protecting the brain from adverse effects. We found that endothelial cells provide a strong roadblock to prevent the passage of free virus particles but allow the migration of infected immune cells, including monocytes, neutrophils, and NK/T cells. Our data are consistent with the potential role of immune cells in the pathogenesis of EV-A71 infections by spreading the virus in the blood and across the human blood-brain barrier.

Role of CARD9 in Cell- and Organ-Specific Immune Responses in Various Infections

The caspase recruitment domain-containing protein 9 (CARD9) is an intracellular adaptor protein that is abundantly expressed in cells of the myeloid lineage, such as neutrophils, macrophages, and dendritic cells. CARD9 plays a critical role in host immunity against infections caused by fungi, bacteria, and viruses. A CARD9 deficiency impairs the production of inflammatory cytokines and chemokines as well as migration and infiltration, thereby increasing susceptibility to infections. However, CARD9 signaling varies depending on the pathogen causing the infection. Furthermore, different studies have reported altered CARD9-mediated signaling even with the same pathogen. Therefore, this review focuses on and elucidates the current literature on varied CARD9 signaling in response to various infectious stimuli in humans and experimental mice models.

Host-microbe interactions at the blood-brain barrier through the lens of induced pluripotent stem cell-derived brain-like endothelial cells

Microbe-induced meningoencephalitis/meningitis is a life-threatening infection of the central nervous system (CNS) that occurs when pathogens are able to cross the blood-brain barrier (BBB) and gain access to the CNS. The BBB consists of highly specialized brain endothelial cells that exhibit specific properties to allow tight regulation of CNS homeostasis and prevent pathogen crossing. However, during meningoencephalitis/meningitis, the BBB fails to protect the CNS. Modeling the BBB remains a challenge due to the specialized characteristics of these cells. In this review, we cover the induced pluripotent stem cell-derived, brain-like endothelial cell model during host-pathogen interaction, highlighting the strengths and recent work on various pathogens known to interact with the BBB. As stem cell technologies are becoming more prominent, the stem cell-derived, brain-like endothelial cell model has been able to reveal new insights in vitro, which remain challenging with other in vitro cell-based models consisting of primary human brain endothelial cells and immortalized human brain endothelial cell lines.