Coxsackievirus B transmission and possible new roles for extracellular vesicles

2013 ◽  
Vol 41 (1) ◽  
pp. 299-302 ◽  
Author(s):  
Jameel M. Inal ◽  
Samireh Jorfi

Coxsackievirus B1, a member of the Picornaviridae family is a non-enveloped single-stranded RNA virus associated with human diseases including myocarditis and pancreatitis. Infection of the intestinal mucosa, lined by polarized epithelial cells, requires interaction of coxsackievirus with apically located DAF (decay-accelerating factor) before transport to the basolaterally located CAR (coxsackie and adenovirus receptor), where entry is mediated by endocytosis. As with many other non-enveloped viruses, coxsackievirus has to induce lysis of host cells in order to perpetuate infection. However, recent evidence indicates that virus spread to secondary sites is not only achieved by a lytic mechanism and a non-lytic cell–cell strategy has been suggested for coxsackievirus B3. A physical interaction between infected and non-infected cells has been shown to be an efficient mechanism for retroviral transmission and one type of extracellular vesicle, the exosome, has been implicated in HIV-1 transmission. HIV-1 also takes advantage of depolymerization of actin for spread between T-cells. Calpain-mediated depolymerization of the actin cytoskeleton, as a result of increases in intracellular calcium concentration during coxsackievirus infection, would result in a release of host cell-derived microvesicles. If so, we speculate that maybe such microvesicles, increasingly recognized as major vehicles mediating intercellular communication, could play a role in the intercellular transmission of non-enveloped viruses.

Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 543
Author(s):  
Annick Barre ◽  
Els J.M. Van Damme ◽  
Mathias Simplicien ◽  
Hervé Benoist ◽  
Pierre Rougé

Seaweed lectins, especially high-mannose-specific lectins from red algae, have been identified as potential antiviral agents that are capable of blocking the replication of various enveloped viruses like influenza virus, herpes virus, and HIV-1 in vitro. Their antiviral activity depends on the recognition of glycoprotein receptors on the surface of sensitive host cells—in particular, hemagglutinin for influenza virus or gp120 for HIV-1, which in turn triggers fusion events, allowing the entry of the viral genome into the cells and its subsequent replication. The diversity of glycans present on the S-glycoproteins forming the spikes covering the SARS-CoV-2 envelope, essentially complex type N-glycans and high-mannose type N-glycans, suggests that high-mannose-specific seaweed lectins are particularly well adapted as glycan probes for coronaviruses. This review presents a detailed study of the carbohydrate-binding specificity of high-mannose-specific seaweed lectins, demonstrating their potential to be used as specific glycan probes for coronaviruses, as well as the biomedical interest for both the detection and immobilization of SARS-CoV-2 to avoid shedding of the virus into the environment. The use of these seaweed lectins as replication blockers for SARS-CoV-2 is also discussed.


2016 ◽  
Author(s):  
Zhaohao Liao ◽  
Dillon C. Muth ◽  
Erez Eitan ◽  
Meghan Travers ◽  
Elin Lehrmann ◽  
...  

ABSTRACTExtracellular vesicles (EVs, including exosomes and microvesicles) are involved in intercellular communication in health and disease and affect processes including immune and antiviral responses. Ultracentrifuged serum is depleted of EVs and, when used in culture media, reduces growth and viability of some cell types. In this study, we examined the effects of serum EV depletion processes on HIV-1 replication in primary cells and cell lines, including two HIV-1 latency models. Increased HIV-1 production was observed in certain EV-depleted conditions, along with cell morphology changes and decreased cell viability. Add-back of ultracentrifuge pellets rescued baseline HIV-1 production. Primary cells appeared to be less sensitive to EV depletion. ACH-2 and U1 latency models produced more HIV-1 under EV-depleted conditions, while virus produced under processed serum conditions was more infectious. Finally, changes in cellular metabolism and gene expression were associated with EV-depleted culture. In conclusion, the EV environment of HIV-1 infected cells has a substantial effect on virus production and infectivity. EV-dependence of cell cultures should be examined carefully along with other experimental variables. However, EVs may not be the only particles depleted by ultracentrifugation or other processes. Effects of EVs may be accompanied by or confused with those of closely associated or physically similar particles.


2020 ◽  
Author(s):  
Keshan Zhang ◽  
Guowei Xu ◽  
Shouxing Xu ◽  
Xijuan Shi ◽  
Chaochao Shen ◽  
...  

ABSTRACTExosomes are cup-shaped vesicles that are secreted by cells and are involved in the intercellular transport of a variety of substances, including proteins, RNA, and liposomes. Studies have shown that pathogenic microorganisms are contained in exosomes extracted from pathogenic micro-infected cells. The Seneca Valley virus (SVV) is a non-encapsulated single-stranded positive-strand RNA virus that causes ulceration in the pig’s nose, the appearance of blisters, and other clinical symptoms similar to foot-and-mouth disease (FMD). Whether exosomes from SVV-infected cells can mediate SVV intercellular transmission is of great significance. There have been no studies showing whether exosomes can carry SVV in susceptible and non-susceptible cells. Here, we first extracted and identified exosomes from SVV-infected IBRS-2 cells. It was confirmed that replication of SVV can be inhibited when IBRS-2 cells treated with exosomes inbihitor GW4869. Furthermore, laser confocal microscopy and qRT-PCR experiments were performed to investigate whether exosomes can carry SVV and enable the virus to proliferate in susceptible and non-susceptible cells. Finally, exosome-mediated intercellular transmission can not be completely blocked by SVV-specific neutralizing antibodies. Taken together, this study showed that exosomes extracted from the SVV-infected IBRS-2 cells can carry SVV and transmit productive SVV infection between SVV susceptible and non-susceptible cells, this transmit infection is resistant to SVV specific neutralization antibody.IMPORTANCEExosomes participate in intercellular communnication between cells. Exosomes derived from virus-infected cells can mediate virus transmission or/and regulate immune response. However, the function of exosomes that from SVV-infected host cells during SVV transmission is unclear. Here, we demonstrate SVV can utilize host exosomes to establish productive infection in intercellular transmission. Furthermore, exosome-mediated SVV transmission is resistant to SVVV-specific neutralizing antibodies. This discovery sheds light on neutralizing antibodies resistant to SVVV transmission by exosomes as a potential immune evasion mechanism.


1996 ◽  
Vol 7 (4) ◽  
pp. 189-196 ◽  
Author(s):  
K. Hashimoto ◽  
E. Kodama ◽  
S. Mori ◽  
J. Watanabe ◽  
M. Baba ◽  
...  

A natural sulphated mucopolysaccharide (OKU40), extracted from a marine plant Dinoflagellata, and an artificial sulphated polysaccharide (OKU41), prepared from a marine Pseudomonas, displayed antiviral activities against several enveloped viruses. OKU40 and OKU41 were found to be homogenous in electrophoresis and sedimation velocity and had a molecular weight of 8.0 × 1065.0 × 105respectively. The sulphation rate of OKU40 and OKU41 was 8.9% and 5.4%, respectively. Each OKU40 and OKU41 inhibited the cytopathic effect of human immunodeficiency virus type 1 (HIV-1), type 2 (HIV-2) and zidovudineresistant HIV-1 in MT-4 cells at similar concentrations to those of dextran sulphate (molecular weight: 5000) (50% inhibitory concentrations: 0.86-1.95 μg mL−1), whereas these compounds did not affect the growth and viability of mock-infected MT-4 cells at concentrations up to 500 μg mL−1. These compounds proved inhibitory not only to HIV-1 and HIV-2 but also to other enveloped viruses, i.e. herpes simplex virus type 1, influenza virus A and B, respiratory syncytial virus and measles virus. OKU40 and OKU41 suppressed syncytium formation induced by cocultivation of MOLT-4/IIIb and MOLT-4 cells at concentrations higher than 20 μg mL−1. Although OKU41 inhibited the binding of HIV-1 to the host cells and the binding of anti-gp120 monoclonal antibody to HIV-1 gp120, OKU40 did not inhibit these bindings, suggesting that the mechanism of anti-HIV activity of OKU40 and OKU41 may be primarily due to the inhibition of virus-cell fusion and viral adsorption to the host cells, respectively. Furthermore, these compounds did not inhibit to the blood coagulation process at a concentration that was significantly inhibitory to HIV replication. The compounds appear to have an interesting potential as virucidal agents.


Retrovirology ◽  
2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Paola Miyazato ◽  
Misaki Matsuo ◽  
Benjy J. Y. Tan ◽  
Michiyo Tokunaga ◽  
Hiroo Katsuya ◽  
...  

Abstract Background Human T cell leukaemia virus type 1 (HTLV-1) is a retrovirus associated with human diseases such as adult T-cell leukaemia/lymphoma and HTLV-1 associated myelopathy/tropical spastic paraparesis. In contrast to another human retrovirus, human immunodeficiency virus type 1 (HIV-1), HTLV-1 persists in the host not via vigorous virus production but mainly via proliferation and/or long-term survival in the form of silent proviruses in infected host cells. As a result, HTLV-1-infected cells rarely produce virus particles in vivo even without anti-retroviral treatment. That should be an advantage for the virus to escape from the host immune surveillance by minimizing the expression of viral antigens in host cells. However, why HIV-1 and HTLV-1 behave so differently during natural infection is not fully understood. Results We performed cap analysis of gene expression (CAGE) using total RNAs and nascent, chromatin-associated, RNAs in the nucleus and found that HTLV-1 RNAs were processed post-transcriptionally in infected cells. RNA processing was evident for the sense viral transcripts but not the anti-sense ones. We also found a higher proportion of CG di-nucleotides in proviral sequences of HTLV-1-infected cells, when compared to the HIV-1 genomic sequence. It has been reported recently that CG dinucleotide content of viral sequence is associated with susceptibility to the antiviral ZC3HAV1 (ZAP), suggesting the involvement of this protein in the regulation of HTLV-1 transcripts. To analyse the effect of ZAP on HTLV-1 transcripts, we over-expressed it in HTLV-1-infected cells. We found there was a dose-dependent reduction in virus production with ZAP expression. We further knocked down endogenous ZAP with two independent targeting siRNAs and observed a significant increase in virus production in the culture supernatant. Other delta-type retroviruses such as simian T-cell leukaemia virus and bovine leukaemia virus, also contain high CG-dinucleotide contents in their viral genomes, suggesting that ZAP-mediated suppression of viral transcripts might be a common feature of delta-type retroviruses, which cause minimal viremia in their natural hosts. Conclusions The post-transcriptional regulatory mechanism involving ZAP might allow HTLV-1 to maintain a delicate balance required for prolonged survival in infected individuals.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 781
Author(s):  
Yuriy Kim ◽  
Gifty A. Mensah ◽  
Sarah Al Sharif ◽  
Daniel O. Pinto ◽  
Heather Branscome ◽  
...  

Here, we have attempted to address the timing of EV and virion release from virally infected cells. Uninfected (CEM), HIV-1-infected (J1.1), and human T cell leukemia virus-1 (HTLV-1)-infected (HUT102) cells were synchronized in G0. Viral latency was reversed by increasing gene expression with the addition of serum-rich media and inducers. Supernatants and cell pellets were collected post-induction at different timepoints and assayed for extracellular vesicle (EV) and autophagy markers; and for viral proteins and RNAs. Tetraspanins and autophagy-related proteins were found to be differentially secreted in HIV-1- and HTLV-1-infected cells when compared with uninfected controls. HIV-1 proteins were present at 6 h and their production increased up to 24 h. HTLV-1 proteins peaked at 6 h and plateaued. HIV-1 and HTLV-1 RNA production correlated with viral protein expression. Nanoparticle tracking analysis (NTA) showed increase of EV concentration over time in both uninfected and infected samples. Finally, the HIV-1 supernatant from the 6-h samples was found not to be infectious; however, the virus from the 24-h samples was successfully rescued and infectious. Overall, our data indicate that EV release may occur prior to viral release from infected cells, thereby implicating a potentially significant effect of EVs on uninfected recipient cells prior to subsequent viral infection and spread.


BIOMATH ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 2012297
Author(s):  
Debadatta Adak ◽  
Nandadulal Bairagi ◽  
Robert Hakl

Biological models inherently contain delay. Mathematical analysis of a delay-induced model is, however, more difficult compare to its non-delayed counterpart. Difficulties multiply if the model contains multiple delays. In this paper, we analyze a realistic HIV-1 infection model in the presence and absence of multiple delays. We consider self-proliferation of CD4+T cells, nonlinear saturated infection rate and recovery of infected cells due to incomplete reverse transcription in a basic HIV-1 in-host model and incorporate multiple delays to account for successful viral entry and subsequent virus reproduction from the infected cell. Both of delayed and non-delayed system becomes disease-free if the basic reproduction number is less than unity. In the absence of delays, the infected equilibrium is shown to be locally asymptotically stable under some parametric space and unstable otherwise. The system may show unstable oscillatory behaviour in the presence of either delay even when the non-delayed system is stable. The second delay further enhances the instability of the endemic equilibrium which is otherwise stable in the presence of a single delay. Numerical results are shown to be in agreement with the analytical results and reflect quite realistic dynamics observed in HIV-1 infected individuals.


2021 ◽  
Author(s):  
Jeffrey Kuniholm ◽  
Elise Armstrong ◽  
Brandy Bernabe ◽  
Carolyn Coote ◽  
Anna Berenson ◽  
...  

ABSTRACTHIV-establishes a persistent proviral reservoir by integrating into the genome of infected host cells. Current antiretroviral treatments do not target this persistent population of proviruses which include latently infected cells that upon treatment interruption can be reactivated to contribute to HIV-1 rebound. Deep sequencing of persistent HIV proviruses has revealed that greater than 90% of integrated HIV genomes are defective and unable to produce infectious virions. We hypothesized that intragenic elements in the HIV genome support transcription of aberrant HIV-1 RNAs from defective proviruses that lack long terminal repeats (LTRs). Using an intact provirus detection assay, we observed that resting CD4+ T cells and monocyte-derived macrophages (MDMs) are biased towards generating defective HIV-1 proviruses. Multiplex reverse transcription digital drop PCR identified Env and Nef transcripts which lacked 5’ untranslated regions (UTR) in acutely infected CD4+ T cells and MDMs indicating transcripts are generated that do not utilize the promoter within the LTR. 5’UTR-deficient Env transcripts were also identified in a cohort of people living with HIV (PLWH) on ART, suggesting that these aberrant RNAs are produced in vivo. Using 5’ rapid amplification of cDNA ends (RACE), we mapped the start site of these transcripts within the Env gene. This region bound several cellular transcription factors and functioned as a transcriptional regulatory element that could support transcription and translation of downstream HIV-1 RNAs. These studies provide mechanistic insights into how defective HIV-1 proviruses are persistently expressed to potentially drive inflammation in PLWH.Author SummaryPeople living with HIV establish a persistent reservoir which includes latently infected cells that fuel viral rebound upon treatment interruption. However, the majority of HIV-1 genomes in these persistently infected cells are defective. Whether these defective HIV genomes are expressed and whether they contribute to HIV associated diseases including accelerated aging, neurodegenerative symptoms, and cardiovascular diseases are still outstanding questions. In this paper, we demonstrate that acute infection of macrophages and resting T cells is biased towards generating defective viruses which are expressed by DNA regulatory elements in the HIV genome. These studies describe an alternative mechanism for chronic expression of HIV genomes.


2020 ◽  
Vol 2 (8) ◽  
Author(s):  
Onyeka S. Chukwudozie

Lassa virus (LASV) is a single-stranded RNA virus that has plagued the Sub-Saharan part of Africa, precisely Nigeria where various pathogenic strains with varied genomic isoforms have been identified. The human lysosomal-associated membrane protein 1 (LAMP1) is alternately required for the micropinocytosis of LASV. Therefore, it is of interest to understand the mechanism of action of the host LAMP1 with LASV protein during infection. The role of ST3 beta-galactoside alpha-2, 3-sialyltransferase 4 (ST3GAL4) in the interaction between LASV (glycoprotein) GP-C and the human LAMP1 is relevant in this context. Deposited curated protein sequences of both LAMP1 and LASV GP-C were retrieved for the study. The ST3GAL4 associated data was constructed and analysed from weighted network analysis to infer the function annotations and molecular mediators that characterize the LASV infection. The gene network shows that glycoprotein sialylation, sialyltransferase enzymatic activities and glycosphingolipid biosynthesis are linked with the ST3GAL4 function. However, the physical interaction of FAM 213A, CD8B molecule and proprotein convertase subtilisin/kexin type 1 inhibitor (PCSK1N) with ST3GAL4 is intriguing in this perspective. There are 11 glycosylated asparagine sequons of the human LAMP1 but only nine were assigned a sialylated glycan cap to mediate the LASV GP-C and LAMP1 interaction having exceeded a recommended glycosylation threshold of 0.5. Therefore, the sialylated glycans of the human LAMP1 are a total of nine and these sialylated glycans mediate the molecular recognition between LASV and LAMP1. This study therefore, predicts that there is a cellular interchange between N-linked glycosylation properties of the human LAMP1 and LASV glycoprotein, and sialylation functions of ST3GAL4 in LASV infectivity. Further studies and the clinical trial of this predictive model on the sialylated glycans of LAMP1 will facilitate the understanding of the LASV micropinocytosis process in host cells.


Retrovirology ◽  
2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Manojkumar Narayanan ◽  
Rutuja Kulkarni ◽  
Shuxian Jiang ◽  
Fatah Kashanchi ◽  
Anil Prasad

Abstract Background Extracellular Vesicles (EV) recently have been implicated in the pathogenesis of HIV-1 syndromes, including neuroinflammation and HIV-1 associated neurological disorder (HAND). Cocaine, an illicit stimulant drug used worldwide is known to exacerbate these HIV-1 associated neurological syndromes. However, the effects of cocaine on EV biogenesis and roles of EVs in enhancing HIV-1 pathogenesis are not yet well defined. Results Here, we investigated the effects of cocaine on EV biogenesis and release in HIV-1 infected immune cells and explored their roles in elicitation of neuroinflammation. We found that cocaine significantly augmented the release of EVs from uninfected and HIV-1 infected T-cells, DCs and macrophages. Further analysis of the molecular components of EVs revealed enhanced expression of adhesion molecules integrin β1 and LFA-1 in those EVs derived from cocaine treated cells. Intriguingly, in EVs derived from HIV-1 infected cells, cocaine treatment significantly increased the levels of viral genes in EVs released from macrophages and DCs, but not in T-cells. Exploring the molecular mechanism to account for this, we found that DCs and macrophages showed enhanced expression of the cocaine receptor Sigma 1-Receptor compared to T-cells. In addition, we found that cocaine significantly altered the integrity of the RNA-induced silencing complex (RISC) in HIV-1 infected macrophages and DCs compared to untreated HIV-1 infected cells. Characterizing further the molecular mechanisms involved in how cocaine increased EV release, we found that cocaine decreased the expression of the interferon-inducible protein BST-2; this resulted in altered trafficking of intracellular virus containing vesicles and EV biogenesis and release. We also observed EVs released from cocaine treated HIV-1 infected macrophages and DCs enhanced HIV-1 trans-infection to T-cells compared to those from untreated and HIV-1 infected cells. These EVs triggered release of proinflammatory cytokines in human brain microvascular endothelial cells (HBMECs) and altered monolayer integrity. Conclusions Taken together, our results provide a novel mechanism which helps to elucidate the enhanced prevalence of neurological disorders in cocaine using HIV-1 infected individuals and offers insights into developing novel therapeutic strategies against HAND in these hosts.


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