Dengue Viral RNA Levels in Peripheral Blood Mononuclear Cells are Associated with Disease Severity and Preexisting Dengue Immune Status

Background Infection with dengue viruses (DENV) causes a wide range of manifestations from asymptomatic infection to a febrile illness called dengue fever (DF), to dengue hemorrhagic fever (DHF). The in vivo targets of DENV and the relation between the viral burden in these cells and disease severity are not known. Method The levels of positive and negative strand viral RNA in peripheral blood monocytes, T/NK cells, and B cells and in plasma of DF and DHF cases were measured by quantitative RT-PCR. Results Positive strand viral RNA was detected in monocytes, T/NK cells and B cells with the highest amounts found in B cells. Viral RNA levels in CD14+ cells and plasma were significantly higher in DHF compared to DF, and in cases with a secondary infection compared to those undergoing a primary infection. The distribution of viral RNA among cell subpopulations was similar in DF and DHF cases. Small amounts of negative strand RNA were found in a few cases only. The severity of plasma leakage correlated with viral RNA levels in plasma and in CD14+ cells. Conclusions B cells were the principal cells containing DENV RNA in peripheral blood, but overall there was little active DENV RNA replication detectable in peripheral blood mononuclear cells (PBMC). Secondary infection and DHF were associated with higher viral burden in PBMC populations, especially CD14+ monocytes, suggesting that viral infection of these cells may be involved in disease pathogenesis

Evaluation of Cardiac Involvement in Children with Dengue by Serial Echocardiographic Studies

Background: Infection with dengue virus results in a wide range of clinical manifestations from dengue fever (DF), a self-limited febrile illness, to dengue hemorrhagic fever (DHF) which is characterized by plasma leakage and bleeding tendency. Although cardiac involvement has been reported in dengue, the incidence and the extent of cardiac involvement are not well defined. Methods and Principal Findings: We characterized the incidence and changes in cardiac function in a prospective in-patient cohort of suspected dengue cases by serial echocardiography. Plasma leakage was detected by serial chest and abdominal ultrasonography. Daily cardiac troponin-T levels were measured. One hundred and eighty one dengue cases were enrolled. On the day of enrollment, dengue cases that already developed plasma leakage had lower cardiac index (2695 (127) vs 3188 (75) (L/min/m2), p = .003) and higher left ventricular myocardial performance index (.413 (.021) vs .328 (.026), p = .021) and systemic vascular resistance (2478 (184) vs 1820 (133) (dynes·s/cm5), p = .005) compared to those without plasma leakage. Early diastolic wall motion of the left ventricle was decreased in dengue cases with plasma leakage compared to those without. Decreased left ventricular wall motility was more common in dengue patients compared to non-dengue cases particularly in cases with plasma leakage. Differences in cardiac function between DF and DHF were most pronounced around the time of plasma leakage. Cardiac dysfunction was transient and did not require treatment. Transient elevated troponin-T levels were more common in DHF cases compared to DF (14.5% vs 5%, p = 0.028). Conclusions: Transient left ventricular systolic and diastolic dysfunction was common in children hospitalized with dengue and related to severity of plasma leakage. The functional abnormality spontaneously resolved without specific treatment. Cardiac structural changes including myocarditis were uncommon. Author Summary: Dengue is a viral infection with a wide range of symptoms from a self-limiting fever called dengue fever (DF) to dengue hemorrhagic fever (DHF) which is characterized by leaky blood vessels and bleeding that can lead to shock in severe cases. Abnormal heart function has been reported but the frequencies and the progression of heart involvement are not well defined. In this study children with dengue had serial evaluation of their heart function during the course of the illness. Patients with DHF had comparatively low blood volume at the time of fever resolution and had decreased blood flow into the left lower heart chamber compared to DF cases. Relaxation and contraction of the left side of the heart were also relatively decreased in DHF. These abnormalities may contribute to the clinical response and complications of fluid replacement in dengue

Role of Cholesterol, SAMHD1 protein and Aedes aegypti saliva on Chikungunya virus infection in human skin fibroblasts

Le virus Chikungunya (CHIKV), arbovirus en pleine ré-émergence, a envahi rapidement de nombreuses zones géographiques du monde. La propagation mondiale de ce virus constitue une menace pour la santé humaine car il n'y a pas de vaccin ou d'agents antiviraux appropriés pour contrôler l'infection virale. La transmission du virus s’effectue lors de la piqure d’un moustique infecté du genre Aedes, qui injecte sa salive contenant le virus dans la peau de l’hôte humain. Afin de contrôler la dissémination du virus, il est primordial de développer des recherches sur l’identification de molécules antivirales et de comprendre les mécanismes moléculaires impliqués dans les interactions hôte-virus et/ou vecteur-virus-hôte. En utilisant différentes stratégies moléculaires et cellulaires, nous avons étudié le potentiel antiviral de l'Imipramine, une molécule déjà commercialisée et qui a la capacité de perturber le transport du cholestérol intracellulaire. Nous avons démontré que cette molécule est capable d'inhiber la réplication du CHIKV dans les fibroblastes cutanés humains. Nous avons mis en évidence que l'Imipramine affectait à la fois les étapes de fusion et de réplication pendant le cycle de réplication du virus. En outre, la molécule a également fortement inhibé la réplication de plusieurs Flavivirus comme le virus Zika (ZIKV), le virus du Nil occidental et le virus de la Dengue. Nous avons également déterminé le profil protéomique global des fibroblastes humains infectés par le CHIKV ou le ZIKV. Cela nous a permis de mettre en évidence les modulations significatives de plusieurs protéines stimulées par l'interféron et de protéines impliquées dans à la défense anti-virale dans les cellules infectées. Plus important encore, nos résultats montrent pour la première fois le rôle de la protéine SAMHD1 dans l'infection des fibroblastes cutanés par les arbovirus. Enfin, compte tenu des fortes interactions entre l’hôte, le vecteur et le CHIKV, l'effet de la salive du moustique Ae. Aegypti sur l'infection virale a été étudié. À notre connaissance, cette étude est la première à montrer l’importance de la salive d’Ae. aegypti sur la facilitation de l’infection du CHIKV, dans des fibroblastes cutanés, à travers la régulation des gènes impliqués dans la réponse interféron de type I.Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that has been spread worldwide. The dissemination of this virus is a threat to human health since there is no approved vaccine or appropriate antiviral agents to control viral infection. The global expansion of the virus is preceded by biting of infected Aedes mosquitos, which injects saliva containing the virus into the skin of the human host. Searching for effective antiviral compounds and understanding of the molecular mechanisms involved in host-virus or vector-virus-host interactions are crucial for controlling viral spread.Using different molecular and cellular strategies, we demonstrated that the FDA approved drug, imipramine, which has the capability to disturb intracellular cholesterol transport inhibits CHIKV replication in human skin fibroblasts. Imipramine was found to affect both the fusion and replication steps of the viral life cycle. Moreover, it also strongly inhibited the replication of several Flaviviridae family members, including Zika, West Nile and Dengue virus. We have also determined the global proteomic profile of Chikungunya and Zika virus infected human skin fibroblasts, and found that several interferon-stimulated proteins and antiviral response proteins are significantly up-regulated in the infected cells. More importantly, our results also provided for the first time a role of SAMHD1 in arbovirus infection of human skin fibroblasts. Finally, we demonstrated that Aedes aegypti saliva enhances CHIKV replication in human skin fibroblasts. To our knowledge, this is the first report showing the importance of Aedes aegypti saliva on promoting CHIKV infection via down regulation of the genes involving type I IFN secretion in the infected human cutaneous cells

Rôle du cholestérol, de la protéine SAMHD1 et de la salive d’Aedes aegypti dans l’infection des cellules cutanées par le virus Chikungunya

Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that has been spread worldwide. The dissemination of this virus is a threat to human health since there is no approved vaccine or appropriate antiviral agents to control viral infection. The global expansion of the virus is preceded by biting of infected Aedes mosquitos, which injects saliva containing the virus into the skin of the human host. Searching for effective antiviral compounds and understanding of the molecular mechanisms involved in host-virus or vector-virus-host interactions are crucial for controlling viral spread.Using different molecular and cellular strategies, we demonstrated that the FDA approved drug, imipramine, which has the capability to disturb intracellular cholesterol transport inhibits CHIKV replication in human skin fibroblasts. Imipramine was found to affect both the fusion and replication steps of the viral life cycle. Moreover, it also strongly inhibited the replication of several Flaviviridae family members, including Zika, West Nile and Dengue virus. We have also determined the global proteomic profile of Chikungunya and Zika virus infected human skin fibroblasts, and found that several interferon-stimulated proteins and antiviral response proteins are significantly up-regulated in the infected cells. More importantly, our results also provided for the first time a role of SAMHD1 in arbovirus infection of human skin fibroblasts. Finally, we demonstrated that Aedes aegypti saliva enhances CHIKV replication in human skin fibroblasts. To our knowledge, this is the first report showing the importance of Aedes aegypti saliva on promoting CHIKV infection via down regulation of the genes involving type I IFN secretion in the infected human cutaneous cells.Le virus Chikungunya (CHIKV), arbovirus en pleine réémergence, a envahi rapidement de nombreuses zones géographiques du monde. La propagation mondiale de ce virus constitue une menace pour la santé humaine car il n'y a pas de vaccin ou d'agents antiviraux appropriés pour contrôler l'infection virale. La transmission du virus s’effectue lors de la piqure d’un moustique infecté du genre Aedes, qui injecte sa salive contenant le virus dans la peau de l’hôte humain. Afin de contrôler la dissémination du virus, il est primordial de développer des recherches sur l’identification de molécules antivirales et de comprendre les mécanismes moléculaires impliqués dans les interactions hôte-virus et/ou vecteur-virus-hôte. En utilisant différentes stratégies moléculaires et cellulaires, nous avons étudié le potentiel antiviral de l'Imipramine, une molécule déjà commercialisée et qui a la capacité de perturber le transport du cholestérol intracellulaire. Nous avons démontré que cette molécule est capable d'inhiber la réplication du CHIKV dans les fibroblastes cutanés humains. Nous avons mis en évidence que l'Imipramine affectait à la fois les étapes de fusion et de réplication pendant le cycle de réplication du virus. En outre, la molécule a également fortement inhibé la réplication de plusieurs Flavivirus comme le virus Zika (ZIKV), le virus du Nil occidental et le virus de la Dengue. Nous avons également déterminé le profil protéomique global des fibroblastes humains infectés par le CHIKV ou le ZIKV. Cela nous a permis de mettre en évidence les modulations significatives de plusieurs protéines stimulées par l'interféron et de protéines impliquées dans à la défense antivirale dans les cellules infectées. Plus important encore, nos résultats montrent pour la première fois le rôle de la protéine SAMHD1 dans l'infection des fibroblastes cutanés par les arbovirus. Enfin, compte tenu des fortes interactions entre l’hôte, le vecteur et le CHIKV, l'effet de la salive du moustique Ae. Aegypti sur l'infection virale a été étudié. À notre connaissance, cette étude est la première à montrer l’importance de la salive d’Ae. aegypti sur la facilitation de l’infection du CHIKV, dans des fibroblastes cutanés, à travers la régulation des gènes impliqués dans la réponse interféron de type I

Rôle du cholestérol, de la protéine SAMHD1 et de la salive d’Aedes aegypti dans l’infection des cellules cutanées par le virus Chikungunya

Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that has been spread worldwide. The dissemination of this virus is a threat to human health since there is no approved vaccine or appropriate antiviral agents to control viral infection. The global expansion of the virus is preceded by biting of infected Aedes mosquitos, which injects saliva containing the virus into the skin of the human host. Searching for effective antiviral compounds and understanding of the molecular mechanisms involved in host-virus or vector-virus-host interactions are crucial for controlling viral spread.Using different molecular and cellular strategies, we demonstrated that the FDA approved drug, imipramine, which has the capability to disturb intracellular cholesterol transport inhibits CHIKV replication in human skin fibroblasts. Imipramine was found to affect both the fusion and replication steps of the viral life cycle. Moreover, it also strongly inhibited the replication of several Flaviviridae family members, including Zika, West Nile and Dengue virus. We have also determined the global proteomic profile of Chikungunya and Zika virus infected human skin fibroblasts, and found that several interferon-stimulated proteins and antiviral response proteins are significantly up-regulated in the infected cells. More importantly, our results also provided for the first time a role of SAMHD1 in arbovirus infection of human skin fibroblasts. Finally, we demonstrated that Aedes aegypti saliva enhances CHIKV replication in human skin fibroblasts. To our knowledge, this is the first report showing the importance of Aedes aegypti saliva on promoting CHIKV infection via down regulation of the genes involving type I IFN secretion in the infected human cutaneous cells.Le virus Chikungunya (CHIKV), arbovirus en pleine réémergence, a envahi rapidement de nombreuses zones géographiques du monde. La propagation mondiale de ce virus constitue une menace pour la santé humaine car il n'y a pas de vaccin ou d'agents antiviraux appropriés pour contrôler l'infection virale. La transmission du virus s’effectue lors de la piqure d’un moustique infecté du genre Aedes, qui injecte sa salive contenant le virus dans la peau de l’hôte humain. Afin de contrôler la dissémination du virus, il est primordial de développer des recherches sur l’identification de molécules antivirales et de comprendre les mécanismes moléculaires impliqués dans les interactions hôte-virus et/ou vecteur-virus-hôte. En utilisant différentes stratégies moléculaires et cellulaires, nous avons étudié le potentiel antiviral de l'Imipramine, une molécule déjà commercialisée et qui a la capacité de perturber le transport du cholestérol intracellulaire. Nous avons démontré que cette molécule est capable d'inhiber la réplication du CHIKV dans les fibroblastes cutanés humains. Nous avons mis en évidence que l'Imipramine affectait à la fois les étapes de fusion et de réplication pendant le cycle de réplication du virus. En outre, la molécule a également fortement inhibé la réplication de plusieurs Flavivirus comme le virus Zika (ZIKV), le virus du Nil occidental et le virus de la Dengue. Nous avons également déterminé le profil protéomique global des fibroblastes humains infectés par le CHIKV ou le ZIKV. Cela nous a permis de mettre en évidence les modulations significatives de plusieurs protéines stimulées par l'interféron et de protéines impliquées dans à la défense antivirale dans les cellules infectées. Plus important encore, nos résultats montrent pour la première fois le rôle de la protéine SAMHD1 dans l'infection des fibroblastes cutanés par les arbovirus. Enfin, compte tenu des fortes interactions entre l’hôte, le vecteur et le CHIKV, l'effet de la salive du moustique Ae. Aegypti sur l'infection virale a été étudié. À notre connaissance, cette étude est la première à montrer l’importance de la salive d’Ae. aegypti sur la facilitation de l’infection du CHIKV, dans des fibroblastes cutanés, à travers la régulation des gènes impliqués dans la réponse interféron de type I

The Effects of Essential Oils on the Nervous System: A Scoping Review

Essential oils are a mixture of natural aromatic volatile oils extracted from plants. The use of essential oils is ancient, and has prevailed in different cultures around the world, such as those of the Egyptians, Greeks, Persians, and Chinese. Today, essential oils are used in traditional and complimentary medicines, aromatherapy, massage therapies, cosmetics, perfumes and food industries. The screening effect of essential oils has been studied worldwide. They demonstrate a range of biological activities, such as antiparasitic, antifungal, antibacterial, antiviral, antioxidant, anti-inflammatory, anticancer, antiaging, and neuroprotective properties. In this scoping review, we provide a 10-year updated comprehensive assessment of volatile oils and their effects on the nervous system. MEDLINE, Scopus, and Google Scholar were systematically and strategically searched for original studies investigating these effects from 2012 to 2022. Approximately seventy studies were selected as included studies. Among these studies, several outcomes were reported, including antistress, antianxiety, analgesic, cognitive, and autonomic effects. Some essential oils showed developmental benefits, with the potential to induce neurite outgrowth. The neurotransmitter receptor level can also be modified by essential oil application. Physiological and pathophysiological outcome measures were reported. For physiological outcomes, arousal, cognitive performance, circadian eating behavior, emotional modulation, consumer acceptance, preferences, and willingness to buy were investigated. For pathophysiological conditions, pain, depression, anxiety, stress, sleep disorder, mental fatigue, agitated behavior, and quality of life were measured. In conclusion, essential oils showed promising effects on the nervous system, which can be further applied to their use in functional foods, drinks, and alternative therapy

Human host genetics and susceptibility to ZIKV infection

International audienceManaging emerging infectious diseases is a current challenge in the fields of microbiology and epidemiology. Indeed, among other environmental and human-related factors, climate change and global warming favor the emergence of new pathogens. The recent Zika virus (ZIKV) epidemic, of which the large and rapid spread surprised the scientific community, is a reminder of the importance to study viruses currently responsible for sporadic infections. Increasing our knowledge of key factors involved in emerging infections is essential to implement specific monitoring that can be oriented according to the pathogen, targeted population, or at-risk environment. Recent technological developments, such as high-throughput sequencing, genome-wide association studies and CRISPR screenings have allowed the identification of human single nucleotide polymorphisms (SNPs) involved in infectious disease outcome. This review focuses on the human genetic host factors that have been identified and shown to be associated with the pathogenesis of ZIKV infection and candidate SNP targets

The effects of mosquito saliva on dengue virus infectivity in humans.

International audienceArboviruses such as Dengue, Chikungunya, and Zika viruses represent a major public health problem due to globalization and propagation of susceptible vectors worldwide. Arthropod vector-derived salivary factors have the capacity to modulate human cells function by enhancing or suppressing viral replication and, therefore, modify the establishment of local and systemic viral infection. Here, we discuss how mosquito saliva may interfere with Dengue virus (DENV) infection in humans. Identification of saliva factors that enhance infectivity will allow the production of vector-based vaccines and therapeutics that would interfere with viral transmission by targeting arthropod saliva components. Understanding the role of salivary proteins in DENV transmission will provide tools to control not only Dengue but also other arboviral diseases transmitted by the same vectors

Engineering of Bifunctional Enzymes with Uricase and Peroxidase Activities for Simple and Rapid Quantification of Uric Acid in Biological Samples

Serum uric acid (SUA) is an important biomarker for prognosis and management of gout and other diseases. The development of a low-cost, simple, rapid and reliable assay for SUA detection is of great importance. In the present study, to save the cost of enzyme production and to shorten the reaction time for uric acid quantification, bifunctional proteins with uricase and peroxidase activities were engineered. In-frame fusion of Candida utilis uricase (CUOX) and Vitreoscilla hemoglobin (VHb) resulted in two versions of the bifunctional protein, CUOX-VHb (CV) and VHb-CUOX (VC). To our knowledge, this is the first report to describe the production of proteins with uricase and peroxidase activities. Based on the measurement of the initial rates of the coupled reaction (between uricase and peroxidase), CV was proven to be the most efficient enzyme followed by VC and native enzymes (CUOX+VHb), respectively. CV was further applied for the development of an assay for colorimetric detection of SUA, which was based on VHb-catalyzed oxidation of Amplex Red in the presence of hydrogen peroxide (H2O2). Under the optimized conditions, the assay exhibited a linear relationship between the absorbance and UA concentration over the range of 2.5 to 50 μM, with a detection limit of 1 μM. In addition, the assay can be performed at a single pH (8.0) so adjustment of the pH for peroxidase activity was not required. This advantage helped to further reduce costs and time. The developed assay was also successfully applied to detect UA in pooled human serum with the recoveries over 94.8%. These results suggest that the proposed assay holds great potential for clinical application

Chikungunya and Zika Viruses : Co-Circulation and the Interplay between Viral Proteins and Host Factors

International audienceChikungunya and Zika viruses, both transmitted by mosquito vectors, have globally re-emerged over for the last 60 years and resulted in crucial social and economic concerns. Presently, there is no specific antiviral agent or vaccine against these debilitating viruses. Understanding viral–host interactions is needed to develop targeted therapeutics. However, there is presently limited information in this area. In this review, we start with the updated virology and replication cycle of each virus. Transmission by similar mosquito vectors, frequent co-circulation, and occurrence of co-infection are summarized. Finally, the targeted host proteins/factors used by the viruses are discussed. There is an urgent need to better understand the virus–host interactions that will facilitate antiviral drug development and thus reduce the global burden of infections caused by arboviruses