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We aimed to develop a reverse transcription loop-mediated isothermal amplification (RT-LAMP) platform for the rapid detection of chikungunya virus (CHIKV) in both patient and mosquito samples from Brazil. We optimized an RT-LAMP assay and then evaluated the specificity and sensitivity using visual detection. In comparison with the RT-qPCR reference method, we validated the utility of this assay as a molecular diagnostic test in a reference laboratory for arbovirus diagnostics using 100 serum samples collected from suspected CHIKV cases. Our RT-LAMP assay specifically detected CHIKV without cross-reactivity against other arboviruses. The limit of detection of our RT-LAMP was estimated in −1.18 PFU (confidence interval [CI] ranging from –2.08 to 0.45), resulting in a similar analytical sensitivity when directly compared with the reference standard RT-qPCR assay. Then, we demonstrate the ability of our RT-LAMP assay to detect the virus in different human specimens (serum, urine, and saliva), and crude lysate of Aedes aegypti mosquitoes in as little as 20–30 minutes and without a separate RNA isolation step. Lastly, we showed that our RT-LAMP assay could be lyophilized and reactivated by adding water, indicating potential for room-temperature storage. Our RT-LAMP had a clinical sensitivity of 100% (95% CI, 90.97–100.00%), clinical specificity of 96.72% (95% CI, 88.65–99.60%), and overall accuracy of 98.00% (95% CI, 92.96–99.76%). Taken together, these findings indicate that the RT-LAMP assay reported here solves important practical drawbacks to the deployment of molecular diagnostics in the field and can be used to improve testing capacity, particularly in low- and middle-income countries. [Display omitted] [ABSTRACT FROM AUTHOR]

Chikungunya virus (CHIKV) is responsible for the most endemic alphavirus infections called Chikungunya. The endemicity of Chikungunya has increased over the past two decades, and it is a pathogen with pandemic potential. There is currently no approved direct-acting antiviral to treat the disease. As part of our antiviral drug discovery program focused on alphaviruses and the non-structural protein 2 protease, we discovered that J12 and J13 can inhibit CHIKV nsP2 protease and block the replication of CHIKV in cell cultures. Both compounds are metabolically stable to human liver microsomal and S9 enzymes. J13 has excellent oral bioavailability in pharmacokinetics studies in mice and ameliorated Chikungunya symptoms in preliminary efficacy studies in mice. J13 exhibited an excellent safety profile in in vitro safety pharmacology and off-target screening assays, making J13 and its analogs good candidates for drug development against Chikungunya. [Display omitted] • NsP2 protease inhibitors with antiviral activity were investigated in this work. • Vinyl sulfone-based inhibitors were discovered to be active against Chikungunya virus. • The drug lead J13 has excellent oral bioavailability and off-target selectivity. • The drug lead, J13 , showed promising in vivo efficacy in mouse models. [ABSTRACT FROM AUTHOR]

The wild edible mushroom, Termitomyces has been employed in traditional medicine by various indigenous communities throughout Asia and Africa. In India, the Santal tribe used it to treat pox while the Mokokchung people used it for abdominal discomfort, cough and whooping cough. However, to date, the antiviral activity of Termitomyces has not been evaluated. Thus, the nutritional value, chemical composition and antiviral potential of Termitomyces clypeatus were investigated. Further, the in vivo oral toxicity of the mushroom extract was assessed in BALB/c mice. The proximate composition analysis indicated a high protein, crude fibre, carbohydrate and mineral content. Bioactive metabolites including Sphinganine, Burseran and Melleolide were also detected in the mushroom extract. For the first time, the anti-antiviral property of Termitomyces clypeatus (100μg/mL) with 95.74% ± 4.01% and 87.13% ± 3.61% inhibition in viral copy number of CHIKV and SARS-CoV-2, respectively was documented. The in vivo acute and sub-acute toxicity study using BALB/c mice revealed no clinical signs of toxicity on oral administration of the mushroom extract. These findings offer the scientific rationale for the possible safe use of Termitomyces clypeatus as a functional food in managing RNA viruses, CHIKV and SARS-CoV-2. [Display omitted] • Termitomyces clypeatus demonstrated anti-antiviral activity against CHIKV and SARS-CoV-2. • The proximate composition analysis revealed a high content of protein, crude fibre, carbohydrate and minerals. • Bioactive metabolites notably Sphinganine, Burseran and Melleolide were found in the mushroom extract. • Oral administration to BALB/c mice revealed no clinical signs of toxicity with respect to vital organs and hematology. [ABSTRACT FROM AUTHOR]

The spread of vector-borne infectious diseases is determined, among other things, by temperature. Thus, climate change will have an influence on their global distribution. In the future, Europe will approach the temperature optimum for the transmission of ZIKV and CHIKV. Climate scenarios and climate models can be used to depict future climatic changes and to draw conclusions about future risk areas for vector-borne infectious diseases. Based on the RCP 4.5 and RCP 8.5 climate scenarios, a geospatial analysis was carried out for the future temperature suitability of ZIKV and CHIKV in Europe. The results were presented in maps and the percentage of the affected areas calculated. Due to rising temperatures, the risk areas for transmission of ZIKV and CHIKV spread in both RCP scenarios. For CHIKV transmission, Spain, Portugal, the Mediterranean coast and areas near the Black Sea are mainly affected. Due to high temperatures, large areas throughout Europe are at risk for ZIKV and CHIKV transmission. Temperature is only one of many factors influencing the spread of vector-borne infectious diseases. Nevertheless, the representation of risk areas on the basis of climate scenarios allows an assessment of future risk development. Monitoring and adaptation strategies are indispensable for coping with and containing possible future autochthonous transmissions and epidemics in Europe. [ABSTRACT FROM AUTHOR]

Chikungunya virus (CHIKV) is a mosquito-borne virus transmitted by Aedes mosquitoes. While there are no antiviral therapies currently available to treat CHIKV infections, several licensed oral drugs have shown significant anti-CHIKV activity in cells and in mouse models. However, the efficacy in mosquitoes has not yet been assessed. Such cross-species antiviral activity could be favorable, since virus inhibition in the mosquito vector might prevent further transmission to vertebrate hosts. Here, we explored the antiviral effect of β-d-N4-hydroxycytidine (NHC, EIDD-1931), the active metabolite of molnupiravir, on CHIKV replication in Aedes aegypti mosquitoes. Antiviral assays in mosquito cells and in ex vivo cultured mosquito guts showed that NHC had significant antiviral activity against CHIKV. Exposure to a clinically relevant concentration of NHC did not affect Ae. aegypti lifespan when delivered via a bloodmeal, but it slightly reduced the number of eggs developed in the ovaries. When mosquitoes were exposed to a blood meal containing both CHIKV and NHC, the compound did not significantly reduce virus infection and dissemination in the mosquitoes. This was confirmed by modelling and could be explained by pharmacokinetic analysis, which revealed that by 6 h post-blood-feeding, 90% of NHC had been cleared from the mosquito bodies. Our data show that NHC inhibited CHIKV replication in mosquito cells and gut tissue, but not in vivo when mosquitoes were provided with a CHIKV-infectious bloodmeal spiked with NHC. The pipeline presented in this study offers a suitable approach to identify anti-arboviral drugs that may impede replication in mosquitoes. • The active metabolite of molnupiravir, β-d-N4-hydroxycytidine, inhibited CHIKV replication in mosquito cells and gut tissue. • β-d-N4-hydroxycytidine had no antiviral effect against CHIKV when provided to mosquitoes in a bloodmeal. • β-d-N4-hydroxycytidine was rapidly eliminated from mosquito bodies (<6 h) following a bloodmeal spiked with the drug. [ABSTRACT FROM AUTHOR]

Highlights • Developed CHIKV VLP immune phage display library of single domain antibodies. • Selected sdAb that bind to CHIKV VLPs and/or recombinant E1 with good affinity. • SdAb neutralized CHIKV in a plaque reduction neutralization test. • CC3 and CA6 yielded PRNT 50 values of 0.6 and 45.6 nM, respectively. • Alkaline phosphatase fusion to CC3 and CA6 improved affinity to CHIKV VLP and E1. Abstract Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that causes an arthralgia febrile illness that has affected millions of people on three continents. Previously, neutralizing monoclonal antibodies that have prophylactic and therapeutic activity were found to remove virus in joint tissues, thereby reducing the severity of symptoms in mice and non-human primates. In this study, we sought to develop thermostable small recombinant antibodies against CHIKV for future diagnostic, prophylactic and therapeutic applications. To develop these single domain antibodies (sdAb) a CHIKV immune library was constructed by displaying the consortium of variable heavy domains (VHH) amplified from peripheral white blood cells isolated from llamas immunized with CHIKV virus-like particles (VLPs). Five anti-CHIKV sdAb isolated using bio-panning were evaluated for their affinity and thermal stability. Their ability to detect CHIKV VLPs was demonstrated in both MagPlex- and ELISA- based assays. Finally, the ability of two sdAb, CC3 and CA6, to inhibit CHIKV infection were tested using a plaque reduction and neutralization test (PRNT), yielding PRNT 50 values of 0.6 and 45.6 nM, respectively. [ABSTRACT FROM AUTHOR]

Favipiravir (T-705) is a broad spectrum antiviral which has been approved in Japan for the treatment of severe influenza virus infections. We reported earlier that favipiravir inhibits the in vitro replication of CHIKV and protects against disease progression in CHIKV-infected immunodeficient mice. We here explored whether favipiravir is also able to inhibit CHIKV replication in the joints of mice either when treatment is initiated during the acute or during the chronic phase of the infection. To this end, C57BL/6J mice were infected with CHIKV in the left hind footpad and treatment with favipiravir (300 mg/kg/day, orally) was either given from day 0 to day 3 post-infection (p.i.) or from day 49 to day 55 p.i. In the untreated mice, viral RNA was still detectable in the joints up to 98 days p.i., yet no infectious viral particles were observed in these tissues. The 4 days treatment during the acute phase of the infection resulted in complete inhibition of systemic viral spread. As a consequence, no viral RNA was detected in the non-inoculated feet in contrast to the situation in the untreated control mice. When treatment was initiated at day 49 p.i., no significant reduction in viral RNA levels in joints were noted as compared to the untreated control. Interestingly, when attempting to amplify by RT-PCR material corresponding to virus genome from the chronic phase samples, some parts of the genome, such as the viral polymerase gene could not be amplified. Collectively, these results suggest that the viral RNA detected in the joints during the chronic phase is likely defective, which also explains the lack of effect of a viral replication inhibitor. [ABSTRACT FROM AUTHOR]

Emergence of new pathogenic viruses along with adaptive potential of RNA viruses has become a major public health concern. Therefore, it is increasingly crucial to investigate and assess the antiviral potential of nanocomposites, which is constantly advancing area of medical biology. In this study, two types of nanocomposites: Ag/NiO and Ag 2 O/NiO/ZnO with varying molar ratios of silver and silver oxide, respectively have been synthesised and characterised. Three metal/metal oxide (Ag/NiO) composites having different amounts of Ag nanoparticles (NPs) anchored on NiO octahedrons are AN-5 % (5 % Ag), AN-10 % (10 % Ag) and AN-15 % (15 % Ag)) and three ternary metal oxide nanocomposites (Ag 2 O/NiO/ZnO) i.e., A/N/Z-1, A/N/Z-2, and A/N/Z-3 with different molar ratios of silver oxide (10 %, 20 % and 30 %, respectively) were evaluated for their antiviral potential. Cellular uptake of nanocomposites was confirmed by ICP-MS. Intriguingly, molecular docking of metal oxides in the active site of nsP3 validated the binding of nanocomposites to chikungunya virus replication protein nsP3. In vitro antiviral potential of nanocomposites was tested by performing plaque reduction assay, cytopathic effect (CPE) analysis and qRT-PCR. The nanocomposites showed significant reduction in virus titre. Half-maximal inhibitory concentration (IC 50) for A/N/Z-3 and AN-5 % were determined to be 2.828 and 3.277 µg/mL, respectively. CPE observation and qRT-PCR results were consistent with the data obtained from plaque reduction assay for A/N/Z-3 and AN-5 %. These results have opened new avenues for development of nanocomposites based antiviral therapies. [Display omitted] • ICP-MS determined cellular uptake of nanocomposites observed in Vero cells. • Metal oxides molecular docking with nsP3 reveals binding of A/N/Z-3, inhibiting a chikungunya virus replication protein. • Antiviral efficacy of Ag/NiO and Ag 2 O/NiO/ZnO mixed metal oxide nanocomposites against CHIKV was evaluated by in vitro assays. • Nanocomposites offer high engineering potential for broad-spectrum antiviral activity against diverse pathogenic viruses [ABSTRACT FROM AUTHOR]

Summary Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that is emerging as a global threat because of the highly debilitating nature of the associated disease and unprecedented magnitude of its spread. Chikungunya originated in Africa and has since spread across the entire globe causing large numbers of epidemics that have infected millions of people in Asia, the Indian subcontinent, Europe, the Americas, and Pacific Islands. Phylogenetic analysis has identified four different genotypes of CHIKV: Asian, West African, East/Central/South African (ECSA), and Indian Ocean Lineage (IOL). In the absence of well-designed epidemiological studies, the aim of this review article was to summarize the global epidemiology of CHIKV and to provide baseline data for future research on the treatment, prevention, and control of this life-threatening disease. [ABSTRACT FROM AUTHOR]

Lentiviral vectors are gene delivery vehicles that integrate into the host genome of dividing and non-dividing mammalian cells facilitating long-term transgene expression. Lentiviral vector versatility is greatly increased by incorporating heterologous viral envelope proteins onto the vector particles instead of the native envelope, conferring on these pseudotyped vectors a modified tropism and host range specificity. We investigated the pseudotyping efficiency of HIV-1 based lentiviral vectors with alphaviral envelope proteins from the Chikungunya Virus (CHIKV-G) and Sindbis Virus (SINV-G). Following vector production optimisation, titres for the CHIKV-G pseudotype were comparable to the VSV-G pseudotype but those for the SINV-G pseudotype were significantly lower. High titre CHIKV-G pseudotyped vector efficiently transduced various human and mouse neural cell lines and normal human astrocytes (NHA) in vitro . Although transduction was broad, tropism for NHAs was observed. In vivo stereotaxic delivery in striatum, thalamus and hippocampus respectively in the adult rat brain revealed localised transduction restricted to striatal astrocytes and hippocampal dentate granule neurons. Transduction of different subtypes of granule neurons from precursor to post-mitotic stages of differentiation was evident in the sub-granular zone and dentate granule cell layer. No significant inflammatory response was observed, but comparable to that of VSV-G pseudotyped lentiviral vectors. Robust long-term expression followed for three months post-transduction along with absence of neuroinflammation, coupled to the selective and unique neuron/glial tropism indicates that these vectors could be useful for modelling and gene therapy studies in the CNS. [ABSTRACT FROM AUTHOR]

[Display omitted] Chikungunya fever is an acute infectious disease caused by Chikungunya virus (CHIKV) and transmitted by Aedes mosquito. It is characterized by fever, rash and arthralgia with no effective drugs. Lomerizine (Lom) is a new generation calcium antagonist, which is mainly used in the treatment of migraine. Certain antiviral function of Lom was shown by some research. In our study, a series of new derivatives of Lom were designed and synthesized, and their in-vitro anti-CHIKV activity was tested. The results showed that Lom and its derivatives had potent anti-CHIKV activity and low cytotoxicity. Among them, compounds B1 and B7 showed most potent antiviral activity. Besides, structure–activity relationships, in-silico ADMET properties were also analyzed. Molecular docking study was performed to rationalize the SAR and analyze the possible binding modes between B1 and amino acid residues in the active site of nsP3 protein to enhance the understanding of their action as antiviral agents. These finding provides research basis for the design and synthesis of effective anti-CHIKV drugs with Lom as the lead compound. [ABSTRACT FROM AUTHOR]

To effectively support the development of a Chikungunya (CHIKV) virus-like particle (VLP) vaccine, a sensitive and robust high-performance liquid chromatography (HPLC) method that can quantitate CHIKV VLPs and monitor product purity throughout the manufacturing process is needed. We developed a sensitive reversed-phase HPLC (RP-HPLC) method that separates capsid, E1, and E2 proteins in CHIKV VLP vaccine with good resolution. Each protein component was verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry (MS). The post-translational modifications on the viral glycoproteins E1 and E2 were further identified by intact protein mass measurements with liquid chromatography–mass spectrometry (LC–MS). The RP-HPLC method has a linear range of 0.51–12 μg protein, an accuracy of 96–106% and a precision of 12% RSD, suitable for vaccine product release testing. In addition, we demonstrated that the RP-HPLC method is useful for characterizing viral glycoprotein post-translational modifications, monitoring product purity during process development and assessing product stability during formulation development. [ABSTRACT FROM AUTHOR]

Yemen, which is located in the southwestern end of the Arabian Peninsula, is one of countries most affected by recurrent epidemics caused by emerging vector-borne viruses. Dengue virus (DENV) outbreaks have been reported with increasing frequency in several governorates since the year 2000, and the Chikungunya virus (CHIKV) has been also responsible of large outbreaks and it is now a major public health problem in Yemen. We report the results of the phylogenetic analysis of DENV-2 and CHIKV isolates (NS1 and E1 genes, respectively) detected in an outbreak occurred in Al-Hudayda in 2012. Estimates of the introduction date of CHIKV and DENV-2, and the phylogeographic analysis of DENV-2 are also presented. Phylogenetic analysis showed that the Yemen isolates of DENV belonged to the lineage 2 Cosmopolitan subtype, whereas CHIKV isolates from Yemen belonged to the ECSA genotype. All the CHIKV isolates from Yemen were statistically supported and dated back to the year 2010 (95% HPD: 2009–2011); these sequences showed an alanine in the aminoacid position 226 of the E1 protein. Phylogeographic analysis of DENV-2 virus showed that cluster 1, which included Yemen isolates, dated back to 2003 Burkina Faso strains (95% HPD 1999–2007). The Yemen, cluster dated back to 2011 (95% HPD 2009–2012). Our study sheds light on the global spatiotemporal dynamics of DENV-2 and CHIKV in Yemen. This study reinforces both the need to monitor the spread of CHIKV and DENV, and to apply significant measures for vector control. [ABSTRACT FROM AUTHOR]

Abstract: Chikungunya virus (CHIKV) is an Arbovirus that is transmitted to humans primarily by the mosquito species Aedes aegypti. Infection with this pathogen is often associated with fever, rash and arthralgia. Neither a vaccine nor an antiviral drug is available for the prevention or treatment of this disease. Albeit considered a tropical pathogen, adaptation of the virus to the mosquito species Aedes albopictus, which is also very common in temperate zones, has resulted in recent outbreaks in Europe and the US. In the present study, we report on the discovery of a novel series of compounds that inhibit CHIKV replication in the low μM range. In particular, we initially performed a virtual screening simulation of ∼5million compounds on the CHIKV nsP2, the viral protease, after which we investigated and explored the Structure–Activity Relationships of the hit identified in silico. Overall, a series of 26 compounds, including the original hit, was evaluated in a virus-cell-based CPE reduction assay. The study of such selective inhibitors will contribute to a better understanding of the CHIKV replication cycle and may represents a first step towards the development of a clinical candidate drug for the treatment of this disease. [Copyright &y& Elsevier]

Abstract: In October 2010, the Ministry of Public Health and Population reported an outbreak of dengue-like acute febrile illness in Al Hodayda governorate. By January 2011, a total of 1542 cases had been recorded from 19 of the 26 districts in the governorate with 104 purportedly associated deaths. In response this event, in January 2011 entomological investigations aimed at identifying the primary vector and the epidemic associated etiological agent were carried out. Based on the reported cases and the progress of the outbreak in the governorate, mosquito collection was undertaken in two of the most recent outbreak areas; Al Khokha district (130km south of Al Hodayda) and Al Muneera district (100km north). Mosquito adults were collected from houses using BG-sentinel™ traps, aspiration of resting mosquitoes and knock-down spraying. Indoor and outdoor containers adjacent to the houses were inspected for larvae. Subsequently mosquito pools were analyzed by RT-PCR for detection of the four dengue virus serotypes (DENV-1, DENV-2, DENV-3, DENV-4), and for Chikungunya virus (CHIKV). Aedes aegypti was the dominant mosquito species collected. Four pools represent 40% of the tested pools, all containing adult female Ae. aegypti, were positive for CHIKV. Three CHIKV isolates were obtained from the RNA positive mosquito pools and identified by rRT-PCR. This finding marks the first record of CHIKV isolated from Ae. aegypti in Yemen. The larval container and Breteau indices in the visited localities surveyed were estimated at 53.8 and 100, respectively. The emergence of this unprecedented CHIKV epidemic in Al Hodayda is adding up another arboviral burden to the already existing vector-borne diseases. Considering the governorate as one focal port in the Red Sea region, the spread of the disease to other areas in Yemen and in neighboring countries is anticipated. Public health education and simple measures to detect and prevent mosquito breeding in water storage containers could prevent and reduce the spread of mosquito-borne viruses like CHIKV and DENV in Yemen. [Copyright &y& Elsevier]

Abstract: Chikungunya virus (CHIKV) is an arthropod-borne virus of the Alphavirus genus, which is transmitted to humans by Aedes spp. mosquitoes and was firstly identified in Tanzania in the mid 1950s. In this article, the findings of a phylogenetic and phylogeographic analysis of the recent CHIKV pandemic are reported. We estimated time of origin of the ancestral virus, time and place of occurrence of A226V mutation, and the flow of viral strains from an area to the other. The Bayesian phylogenetic and phylogeographic analysis was performed on the whole dataset, which consisted of 195 E1 (envelope 1) CHIKV sequences, and on a subset (D2), including 146 of the 195 previous sequences. Using the relaxed clock model, we estimated a CHIKV E1 mean evolutionary rate (in the whole dataset) of 1.4×10−3 substitution/site/year (95% highest posterior density interval HPD 6.4×10−4–2.5×10−3), and of 2.2×10−3 (95% HPD 9.6×10−4–3.8×10−3) in the D2 subset, including only the strains involved in the recent Indian Ocean epidemic. The phylogeographical analysis suggested an African origin of CHIKV with a tMRCA of 146years corresponding to 1863 (95% HPD 1741–1941). Moreover D2 subset most probably originated in Kenya, with a tMRCA corresponding to the year 2002 (95% HPD 2000–2004), then spread following two distinct routes: one throughout the Indian Ocean (Reunion, Comoros) and the other moving from India then scattered in the South East Asia and reached Italy. In conclusion, we reconstructed the geographic spread of CHIKV during the last epidemic wave, which showed an eastward path from Africa to Indian Ocean island to India, and from there to other South East Asian countries. Whether A226V variants followed the same migration path remains undefined, since local independent mutations, followed by fixation due to selective advantage conferred by better adaptation to local vectors of infection, cannot be excluded. [Copyright &y& Elsevier]

Abstract: The chikungunya virus (CHIKV), an arbovirus of the genus Alphavirus, family Togaviridae, is mainly transmitted by Aedes mosquitoes. It causes an acute infection, characterized by high fever, polyarthralgia and rash and was responsible for a major outbreak which started in 2005 and spread over many islands of the south western Indian Ocean before it hit the Indian subcontinent. As nucleic acid amplification can be used only during the viremic period, serological tests are most widely used for the diagnosis of CHIKV infections. CHIKV IgM and IgG antibodies can be detected as soon as 3–6 days after clinical onset, respectively. Presently only in-house ELISA and immunofluorescence tests exist for analysing the CHIKV specific immune response. The first commercial indirect immunofluorescence test (IIFT) (EUROIMMUN AG, Lüebeck, Germany) was evaluated using two sera panels of patients from La Reunion and travellers returning with CHIKV infections from the Indian Ocean region. The IgM IIFT shows a specificity of 98.3% and a sensitivity of 96.9%. The specificity and sensitivity for the IgG IIFT are 100.0% and 95.4%, respectively. This commercial IIFT is a valuable tool for the diagnosis of CHIKV infections and antibody seroprevalence studies. [Copyright &y& Elsevier]

Chikungunya virus (CHIKV) is responsible for a self-limited illness that can evolve into long-lasting painful joint inflammation. In this study, we report a novel experimental CHIKV vaccine formulation of lipid nanoparticles loaded with a recombinant protein derived from the E2 structural protein. This antigen fragment, designated ∆E2.1, maintained the antigenicity of the native viral protein and was specifically recognized by antibodies induced in CHIKV-infected patients. The antigen has been formulated into nanoparticles consisting of nano-multilamellar vesicles (NMVs) combined with the adjuvant monophosphoryl lipid A (MPLA). The vaccine formulation demonstrated a depot effect, leading to controlled antigen release, and induced strong antibody responses significantly higher than in mice immunized with the purified protein combined with the adjuvant. More relevantly, E2-specific antibodies raised in mice immunized with ∆E2.1-loaded NMV-MPLA neutralized CHIKV under in vitro conditions. Taken together, the results demonstrated that the new nanoparticle-based vaccine formulation represents a promising approach for the development of effective anti-CHIKV vaccines. A vaccine composed of nano-multilamellar lipid vesicles (NMVs) carrying a new recombinant protein based on the Chikungunya virus (CHIKV) E2 protein, ∆E2.1, increases antibody titers in mice and is capable of generating antibodies that neutralize CHIKV in vitro, demonstrating the effectiveness of both the new antigen generated and the NMVs delivery system. [Display omitted] • A novel CHIKV antigen derived from the envelope protein (∆E2.1) was successfully expressed and easily purified from recombinant Escherichia coli cells. • The ∆E2.1 antigen maintained the antigenicity of the native virus protein and was efficiently recognized by antibodies present in CHIKV-infected convalescent patients. • The ∆E2.1 antigen was formulated in adjuvanted nano-multilamellar vesicles (NMV-MPLA) that promoted a depot effect with a controlled release of the antigen. • The ∆E2.1-NMV-MPLA vaccine formulation was highly immunogenic in mice and induced serum antibodies that were capable of neutralizing CHIKV under in vitro conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • An in silico analysis that predicts miRNAs of Chikungunya virus (CHIKV). • Genes targeted by miRNAs are associated with antiviral immune response and cellular proliferation. • Altered expression of genes that modulate cell cycle. Chikungunya virus (CHIKV) that causes chikungunya fever, is an alphavirus that belongs to the Togaviridae family containing a single-stranded RNA genome. Mosquitoes of the Aedes species act as the vectors for this virus and can be found in the blood, which can be passed from an infected person to a mosquito through mosquito bites. CHIKV has drawn much attention recently because of its potential of causing an epidemic. As the detailed mechanism of its pathogenesis inside the host system is still lacking, in this in silico research we have hypothesized that CHIKV might create miRNAs, which would target the genes associated with host cellular regulatory pathways, thereby providing the virus with prolonged refuge. Using bioinformatics approaches we found several putative miRNAs produced by CHIKV. Then we predicted the genes of the host targeted by these miRNAs. Functional enrichment analysis of these targeted genes shows the involvement of several biological pathways regulating antiviral immune stimulation, cellular proliferation, and cell cycle, thereby provide themselves with prolonged refuge and facilitate their pathogenesis, which in turn may lead to disease conditions. Finally, we analyzed a publicly available microarray dataset (GSE49985) to determine the altered expression levels of the targeted genes and found genes associated with pathways such as cell differentiation, phagocytosis, T-cell activation, response to cytokine, autophagy, Toll-like receptor signaling, RIG-I like receptor signaling and apoptosis. Our finding presents novel miRNAs and their targeted genes, which upon experimental validation could facilitate in developing new therapeutics to combat CHIKV infection and minimize CHIKV mediated diseases. [ABSTRACT FROM AUTHOR]

• Stearylamine, a cationic lipid shows strong inhibition against CHIKV. • Evaluation of Stearylamine on CHIKV replication in in vitro and in vivo system. • CHIKV replication in Vero cells is impeded by stearylamine treatment. • Stearylamine treatment minimized CHIKV infection in C57BL/6 infected mice. Chikungunya, a mosquito-borne disease that causes high fever and severe joint pain in humans, is a profound global threat because of its high rate of contagion and lack of antiviral interventions or vaccines for controlling the infection. The present study was aimed to investigate the antiviral activity of Stearylamine (SA) against Chikungunya virus (CHIKV) in both in vitro and in vivo. The antiviral activity of SA was determined by foci forming unit (FFU) assay, quantitative RT-PCR and cell-based immune-fluorescence assay (IFA). Further in vivo studies were carried out to see the effect of SA treatment in CHIKV infected C57BL/6 mice. The anti-CHIKV activity was evaluated using qRT-PCR in serum and muscle tissues at different time points and by histopathology. In vitro treatment with SA at a concentration of 50 μM showed a reduction of 1.23 ± 0.19 log10 FFU/mL at 16 h and 1.56 ± 0.12 log10 FFU/mL at 24 h posttreatment by FFU assay. qRT-PCR studies indicated that SA treatment at 50μM concentration showed a singnificant reduction of 1.6 ± 0.1 log10 and 1.27 ± 0.12 log10 RNA copies when compared with that of virus control at 16 and 24 h post incubation. Treatments in the C57BL/6 mice model revealed that SA at 20 mg/kg dose per day up to 3, 5 and 7 days, produced stronger inhibition against CHIKV indicating substantially decrease viral loads and inflammatory cell migration in comparison to a dose of 10 mg/kg. This first in vivo study clearly indicates that SA is effective by significantly reducing virus replication in serum and muscles. As a next-generation antiviral therapeutic, these promising results can be translated for the use of SA to rationalize and develop an ideal delivery system alone or in combination against CHIKV. [ABSTRACT FROM AUTHOR]

Chikungunya virus (CHIKV), a positive-sense, single-stranded RNA virus in the family Togaviridae, is transmitted by Aedes mosquitoes. Of three known CHIKV genotypes, the Asian genotype was introduced into the Caribbean islands and rapidly spread throughout Central and South Americas. We previously found patients with symptoms compatible with chikungunya fever in 2014–2015 in Aruba, a Caribbean island of 180 km2. We here describe the full genome sequences of eight CHIKV strains isolated from patient sera of the Aruban outbreak. Phylogenetic analysis revealed that two closely related but distinct lineages of Asian-genotype CHIKV circulated simultaneously during the epidemic in 2014–2015. These results suggested that CHIKV was introduced into Aruba more than once in a short period, reflecting the importance of Aruba as a travel hub within the region. • During the 2014-2015 Chikungunya virus (CHIKV) outbreak in a Caribbean island Aruba, we obtained 8 CHIKV isolates. • Phylogenetic analysis of these isolates revealed that two distinct lineages of Asian-genotype CHIKV cocirculated. • We confirmed Caribbean outbreak lineage specific duplication in the 3' untranslated region of these isolates. [ABSTRACT FROM AUTHOR]