Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus belonging to the Togaviridae family, first isolated in Tanzania in 1952. The main vectors are mosquitoes from the Aedes species. Recently, the establishment of an envelope mutation increased infectivity for A. albopictus. CHIKV has recently re-emerged causing millions of infections in countries around the Indian Ocean characterized by climate conditions favourable to high vector density. Importation of human cases to European regions with high density of suitable arthropod vectors (such as A. albopictus) may trigger autochthonous outbreaks. The clinical signs of CHIKV infection include non-specific flu-like symptoms, and a characteristic rash accompanied by joint pain that may last for a long time after the resolution of the infection. The death rate is not particularly high, but excess mortality has been observed in concomitance with large CHIKV outbreaks. Deregulation of innate defense mechanisms, such as cytokine inflammatory response, may participate in the main clinical signs of CHIKV infection, and the establishment of persistent (chronic) disease. There is no specific therapy, and prevention is the main countermeasure. Prevention is based on insect control and in avoiding mosquito bites in endemic countries. Diagnosis is based on the detection of virus by molecular methods or by virus culture on the first days of infection, and by detection of an immune response in later stages. CHIKV infection must be suspected in patients with compatible clinical symptoms returning from epidemic/endemic areas. Differential diagnosis should take into account the cross-reactivity with other viruses from the same antigenic complex (i.e. O'nyong-nyong virus).

Chikungunya virus infection: an overview.

Antibodies can impact pathogens in the presence or in the absence of effector cells or effector molecules such as complement, and experiments can often sort out with precision the mechanisms by which an antibody inhibits a pathogen in vitro. In addition, in vivo models, particularly those engineered to knock in or knock out effector cells or effector molecules, are excellent tools for understanding antibody functions. However, it is highly likely that multiple antibody functions occur simultaneously or sequentially in the presence of an infecting organism in vivo. The most critical incentive for measuring antibody functions is to provide a basis for vaccine development and for the development of therapeutic antibodies. In this respect, some functions, such as virus neutralization, serve to inhibit the acquisition of a pathogen or limit its pathogenesis. However, antibodies can also enhance replication or contribute to pathogenesis. This review emphasizes those antibody functions that are potentially beneficial to the host. In addition, this review will focus on the effects of antibodies on organisms themselves, rather than on the toxins the organisms may produce.

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Functions of Antibodies

Prohibitin Ligands in Cell Death and Survival: Mode of Action and Therapeutic Potential

Sensors have been extensively used owing to multiple advantages, including exceptional sensing performance, user-friendly operation, fast response, high sensitivity and specificity, portability, and real-time analysis. In recent years, efforts in sensor realm have expanded promptly, and it has already presented a broad range of applications in the fields of medical, pharmaceutical and environmental applications, food safety, and homeland security. In particular, molecularly imprinted polymer based sensors have created a fascinating horizon for surface modification techniques by forming specific recognition cavities for template molecules in the polymeric matrix. This method ensures a broad range of versatility to imprint a variety of biomolecules with different size, three dimensional structure, physical and chemical features. In contrast to complex and time-consuming laboratory surface modification methods, molecular imprinting offers a rapid, sensitive, inexpensive, easy-to-use, and highly selective approaches for sensing, and especially for the applications of diagnosis, screening, and theranostics. Due to its physical and chemical robustness, high stability, low-cost, and reusability features, molecularly imprinted polymer based sensors have become very attractive modalities for such applications with a sensitivity of minute structural changes in the structure of biomolecules. This review aims at discussing the principle of molecular imprinting method, the integration of molecularly imprinted polymers with sensing tools, the recent advances and strategies in molecular imprinting methodologies, their applications in medical, and future outlook on this concept.

Molecularly Imprinted Polymer Based Sensors for Medical Applications.

Owing to their merits of simple, fast, sensitive, and low cost, electrochemical biosensors have been widely used for the diagnosis of infectious diseases. As a critical element, the receptor determines the selectivity, stability, and accuracy of the electrochemical biosensors. Molecularly imprinted polymers (MIPs) and surface imprinted polymers (SIPs) have great potential to be robust artificial receptors. Therefore, extensive studies have been reported to develop MIPs/SIPs for the detection of infectious diseases with high selectivity and reliability. In this review, we discuss mechanisms of recognition events between imprinted polymers with different biomarkers, such as signaling molecules, microbial toxins, viruses, and bacterial and fungal cells. Then, various preparation methods of MIPs/SIPs for electrochemical biosensors are summarized. Especially, the methods of electropolymerization and micro-contact imprinting are emphasized. Furthermore, applications of MIPs/SIPs based electrochemical biosensors for infectious disease detection are highlighted. At last, challenges and perspectives are discussed.

https://www.mdpi.com/1424-8220/20/4/996/pdf

Molecularly Imprinted Polymers and Surface Imprinted Polymers Based Electrochemical Biosensor for Infectious Diseases.

National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency,Pathumthani, ThailandChikungunya virus (CHIKV) has recently re-emerged causing millions of infections in coun-tries around the Indian Ocean. While CHIKV hasa broad host cell range and productively infectsa number of different cell types, macrophageshave been identiﬁed as a potential viral reser-voir serving to increase the duration of symp-toms. To date no CHIKV interacting protein hasbeen characterized and this study sought toidentify CHIKV binding proteins expressed ontarget cell membranes. Two-dimensional virusoverlay identiﬁed prohibitin (PHB) as a micro-glial cell expressed CHIKV binding protein. Co-localization, co-immunoprecipitation as well asantibody and siRNA mediated infection inhibi-tion studies all conﬁrmed a role for PHB in me-diating internalization of CHIKV into microglialcells. PHB is the ﬁrst identiﬁed CHIKV receptorprotein, and this study is evidence that PHBmay play a role in the internalization of multipleviruses. J. Med. Virol. 84:1757–1770,2012.

Identification of prohibitin as a Chikungunya virus receptor protein

Zika virus (ZIKV) is a flavivirus that was first identified in 1947. Initially, the virus was of little concern for health authorities given there were very few casualties among those suffering an infection. As such, only limited studies were performed on ZIKV. Recently, the viral infection has been linked to microcephaly in infants, which has prompted a dramatic increase in scientific interest in ZIKV research, including methods to allow for rapid virus identification. In this work we report the development of a new type of ZIKV electrochemical biosensor based on surface imprinted polymers and graphene oxide composites. The biosensor was used to detect ZIKV by measuring changes in the electrical signal with changing virus concentrations in buffer and serum using standard electrochemical techniques. The detection limit of our method is similar to the detection limit of the real-time quantitative reverse transcription PCR method.

Electrochemical Biosensor Based on Surface Imprinting for Zika Virus Detection in Serum

Duck tembusu virus (DTMUV) is an emerging duck pathogen in China and other Asian countries. It is unclear whether this emerging zoonotic infection poses a threat to humans. A previous study in 2012 showed surprisingly high rates of seropositivity and positive viral detection by RT-PCR in duck farm workers in China. To understand the nature of the threat of this emerging virus, we studied the neutralizing antibody response to a local isolate of DTMUV in an at-risk population, who were workers in duck farms and residents around farming areas in Central Thailand where DTMUV had been previously detected, and in a not-at-risk population, who were people living in the same or neighbouring province, but at a distance from the farms and who had no contact with ducks. The sera from the at-risk population showed higher anti-DTMUV neutralizing antibody titres as compared with those of the not-at-risk population. However, within the at-risk population, workers with direct contact with ducks did not show higher neutralizing titres than those without direct contact. Interestingly, some people in the not-at-risk group also displayed high neutralizing antibody titres to DTMUV. These sera were tested against other endemic Flaviviruses and showed no or low cross-reactivity suggesting the specificity of the neutralizing activity against DTMUV. These data raise a possibility of DTMUV as a potential zoonotic pathogen but the mode of transmission of the virus from ducks or other possible hosts to humans should be explored further.

Detection of antibodies to Duck Tembusu Virus in human population with or without the history of contact with ducks

An Asian Zika virus (ZIKV) isolated from a Thai patient that was serially passaged in Primary Dog Kidney (PDK) cells for attenuation displayed both big and small plaque-forming viruses by the 7th passage. Two small-plaque isolates were selected and purified for characterization as attenuated ZIKV candidates. In vitro growth kinetics showed significantly reduced titers for small-plaque isolates in Vero cells early post-infection compared to the parental ZIKV and a big-plaque isolate, but no significant difference was observed in C6/36 cells. Viral entry experiments elucidate that titer reduction likely occurred due to the diminished entry capabilities of a small-plaque isolate. Additionally, a small-plaque isolate displayed lowered neurovirulence in newborn mice compared to 100% lethality from infection with the parental ZIKV. Genomic analysis revealed the same three unique non-synonymous mutations for both small-plaque isolates: two on the envelope (E) protein at residues 310, alanine to glutamic acid (A310E), and 393, glutamic acid to lysine (E393K), and one on residue 355 of NS3, histidine to tyrosine (H355Y). Three-dimensional (3D) mapping suggests that the E protein mutations located on the receptor-binding and fusion domain III likely affect cell entry, tropism, and virulence. These ZIKV isolates and genotypic markers will be beneficial for vaccine development.

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Thitigun Jaimipuk

Papers

Identification of prohibitin as a Chikungunya virus receptor protein

Electrochemical Biosensor Based on Surface Imprinting for Zika Virus Detection in Serum

Detection of antibodies to Duck Tembusu Virus in human population with or without the history of contact with ducks

A Small-Plaque Isolate of the Zika Virus with Envelope Domain III Mutations Affect Viral Entry and Replication in Mammalian but Not Mosquito Cells