Causes and Treatments of Dengue fever

Causes and Treatments of breakbone fever fever feverishness feverAbstractDengue fever is cause by positive-stranded RNA computer virus of the family Flaviviridae genusFlavivirus. Dengue virus is transmitted to humans by a mosquito sender Aedes aegypti belonging to genus Aedes of family Culicideae. 50 -100 million peoples are affected by dengue virus . Indian scientists induct develop a vaccine for the legal profession of the dengue fever. Dengue Virus Genome Contain 10 Viral Protein C,prM,E,NS1.NS2A,NS2B,NS3,NS4A,NS4B,NS5. vector race suppression ,replacement are elementtic approaches for maneuver of dengue. In the commonwealth suppression vector number is constraind to minimize ailment transmission and universe of discourse replacement of false- guinea pig vector was replaced with cistrontically modified vector unable(predicate) of transmitting the disease. Sterile Insect Technique ( model) is a particular type and environmentally benign modality to suppress the insect world, it is based on collective farming, and radiation-mediated sterilization, and large number of male insects are stop. The release of insects withstanding a dominant lethal (RIDL) offers a resolution to many of the weaknesses of traditional SIT which has narrow its practical application in mosquitoes while sustaining the efficacy ecologically friendly and particular types. RNA interference is a weapon of gene control sequence after placemental selectively. RNA viruses Interference (RNAi) pathway is one of the most small components of the innate immune system of insects that undersurface frustrate a variety of RNA virus much(prenominal) as flavivirus. From all the genetic based method RIDL proficiencys is most advance.IntroductionDengue fever is a viral disease transmitted by the rapid development of Aedes aegypti. (McCall and Kittayapong 2006) originally innate to watt Africa and spread in the whole world (Antonelli, Clayton et al.) 50 -100 million peoples are affected by dengue virus (Wilke and Marrelli 2012). Dengue virus belongs to the Flaviviridae family. Dengue virus has four major serotypes but antigenically distinct hotshot stranded RNA viruses . The four serotypes of dengue viruses cause disease. The severe variation of the disease, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DHF / DSS), can lead to internal bleeding and even death. (Malavige, Fernando et al. 2004 Olson, Alphey et al. 2006)There is no specific therapeutic drug available for dengue fever. Indian scientists have develop a vaccine for the proscribeion of the dengue fever animal footraces of this vaccine have yielded good wills but it is not yet commercialize. By Using yeast pastoris Pichia they have created a non-infectious dengue fever virus like particles made of and large DENV protein envelope to active virus-specific immunity. (Thisyakorn 2013).Dengue virus is 50-nm containing lipid membrane.180 identical copies of envelop protein is present a t the surface of viral membrane short transmembrane segment. The virus genome is of about 11000 bases that translates into a single large polyprotein that is cleaved into 3 geomorphological and 7 non-structural genes and short non-coding regions is also present on both the 5 and 3 ends The structural proteins are the capsid (C) protein, the envelope (E) glycoprotein and the membrane (M) protein. (Alcaraz-Estrada, Yocupicio-Monroy et al. 2010) (Nukui, Tajima et al. 2006)The increase of vectors in world is reason of emergence of diseases in new areas. therefore, there is emergency to control mosquito. Bed nets, space spraying are largely useless against this day biting mosquito. Therefore, there is a need to develop useful strategy to oercome dengue fever. Dengue control can be pull downd or elimination of the vector universe. The population vector can be cut down or eliminated based on genetic methods. There are both strategic objectives to control dengue by genetically modifie d mosquitoes.(McCall and Kittayapong 2006 Olson, Alphey et al. 2006)vector population suppressionpopulation replacement.In the population suppression vector number is reduced to minimize disease transmission and population replacement of wild-type vector was replaced with genetically modified vector incapable of transmitting the disease.(Antonelli, Clayton et al.) suppression techniques and replacement of population are not mutually exclusive and can be implemented in conjunction with new(prenominal) approaches. (Olson, Alphey et al. 2006 Organization 2009) For suppression of the vector population SIT (sterile insect technique) SIT is a specific control environment of the species method in which large numbers of sterile males are release these mate with wild effeminate reduces the reproductive capacity of mosquito. (Coleman and Alphey 2004 Helinski, El-Sayed et al. 2006) SIT mosquito control approaches have been tense and still planned .Reduction join competitiveness, and sterile female does not reduce the population ,fertility of irradiated males residual is the limitation of the approaches to mosquito control SIT. In SIT male mosquitoes are about liberation are not taking blood meals, and lethality performance so early larval death is density dependent reduction occur. (Yakob, Alphey et al. 2008 de Valdez, Nimmo et al. 2011 Lacroix, McKemey et al. 2012) RIDL (Release of Insects carrying a Dominant Lethal) strategy to reduce these limitations by recombinant DNA technology. In RIDL male n female mosquitoes are genetically modified approaches. (Coleman and Alphey 2004 Atkinson, Su et al. 2007 Phuc, Andreasen et al. 2007) OX513A RIDL bisex is a strain. The males are released to mate with wild females. The offspring of these mating die due to late larvae or pupae. and then the target population can be reduced. (Wallace 2013)In female transgenic mosquitoes OX3604C that genes are present to conduct flightless female-tetracycline-repressible phenotype. flightles s females can not mate with a male. (de Valdez, Nimmo et al. 2011 McGraw and ONeill 2013) And for substituting additional vector population or foreign genes are inserted to prevent the transmission vector of the disease. Foreign gene can be a gene Antipathogen, or a combination of transgenic approaches that will reduce or eliminate the transmission of disease from vectors to human.(Basu and Bhattacharya 2014)Genetic approaches leading to vector population suppressionGMV-based development of Sterile-Insect Technique (SIT)The sterile insect technique (SIT) is a specific method of species and environmentally benign control the insect population that relies on large number rearing and release of sterile insects.(Wilke and Marrelli 2012) These released insects compete for mates with wild females. Wild female pairing to a sterile male has no or fewer children, so that the population tends to decrease. If enough sterile insects are released for a sufficient period, the target population i s controlled or even eradicated topical anaestheticly(Wallace 2013). SIT has been used successfully for oer 50 years to control the entire area and / or elimination of several important bucolic pests and disease vectors, including the Mediterranean fruit go away, screwworm. (Coleman and Alphey 2004)Although conducted a series of tests in the 1970s, with some success, there is today no SIT programs on large-scale operation against mosquito species. (Yakob, Alphey et al. 2008 Lacroix, McKemey et al. 2012 Mwasunda October, 2012) Ae. aegypti is a, mosquito species fit for mass rearing. This species also appears to be reasonably coherent over large areas, without the problems of sub-species and barriers to mating.SIT has many advantages as compare to traditional strategiesit is species specific and to stay by from The harmful effects of pesticides on non-target species.The mating behavior of male insects is highly efficient as a substitute of relying on Human rights activists.wild i nsects Density are condensed thats why it works meliorate (Coleman and Alphey 2004)LIMITATION of SITThe main problem of SIT is the loss of competitiveness mating for the wild type due to sterilization of insects by irradiation.For mosquitoes, releasing only male is considered essential, since the sterile females bite and can and then transmit the disease, while male mosquitoes do not bite. So SIT including large-scale, gender-based separation . pupal coat can constantly give people male-only population for release.A secern difficulty for mosquito SIT is sterilization. pecker of pupae appear to harm insects irradiation as gravids is less harmful but operationally much harder. close to trials used sterilizing chemicals such as thiotepa, which was effective for sterilization, but led to trace contamination with this mutagenic chemical. other problem for mosquito SIT relates to the biology of the mosquito population. Unlike agricultural pests against which the main SIT programs a re directed at present, mosquito populations can be regulated primarily by density-dependent effects, in which a very fruitful population is maintained at a train stable for limited resource constraints,others problems of SIT is fitness be and operational difficulty of irradiation.(Coleman and Alphey 2004 Olson, Alphey et al. 2006 Wilke and Marrelli 2012)Release of Insects Carrying a Dominant Lethal GeneInsects are designed to carry a dominant lethal genetic system can be used to replace the need for radiation sterilization in a similar SIT program. In this RIDL is replaced engineered lethal dominant. At the aforementioned(prenominal) time RIDL and SIT, and some or all of the descendants of people die as a result of the release of inheriting one or more dominant lethal mutations, so that the population tends to decline. (Atkinson, Su et al. 2007 Yakob, Alphey et al. 2008 Massonnet-Bruneel, Corre-Catelin et al. 2013) machine Male mosquitoes have developed genetically modified to contain lethal gene, in order to armed combat the spread of dengue fever. LA513 is piggyBac transposon-based non-independent from 8.4 kilobytes. Insert LA513 transposon within aeydes mosquitoes by genetic engineering techniques to produce toxins in the larvae of mosquitoes stage down the stairs normal condition, and thus cause the death of the larva. Transposon LA513 mainly containing DsRed2 gene that is to drive in the modified identify genetically by red fluorescence due to the expression of that gene. and tTAV gene (tetracycline -repressible transcriptional activator) tTAV gene is under the control of its covert site, titO, and minimal promoter of Drosophila HSP70, and 3 UTR sequence of the fruit fly FS (1) K10. tTAV bind with its binding site titOs and gives a very high train of expression of tTAV which is toxic under normal conditions. In The presence of tetracycline tTAV connect with them. This model does not bind tTAV with titO and do not even lead to the expression of m ore tTAV therefore this construction gives a very high level expression of tTAV in the absence of tetracycline, but gives low expression in the presence of tetracycline. The high level expression of tTAV may be due to the interaction with the VP16 domain transcription factor that provides a key to the building of this deadly system. (Massonnet-Bruneel, Corre-Catelin et al. 2013) When genetically modified mosquitoes are released in the wild and mate with wild female offspring to inherit this trait lethality. The resulting offspring die before reaching the age of majority and the local mosquito swarms fall.(McGraw and ONeill 2013)Oxitec is a British company is working to find innovative solutions to control insects using biotechnology and genetics in advance (called RIDL) placed Egyptian genetically modified Aedes this product and is named as a OX513A bisex RIDL strain. (Massonnet-Bruneel, Corre-Catelin et al. 2013)Aeydes mosquito, one of the most important carrier of the dengue feve r,and decreased by 80% in the 2010 trial of these genetically modified mosquitoes in the Cayman Islands. Using genetically modified male aegypti we can reduce or eliminate the population of mosquitoes that specie, and thus we can control the transmission of dengue virus to humans, which causes dengue fever.Population replacement techniquesPopulation replacement techniques involve the insertion of additional or foreign genes to prevent the mosquitoes from transmitting the disease. The techniques may include inserting an antipathogen gene, an immune system upregulator, or a combination of transgenic approaches that will in the end result in the reduction or elimination of disease transmission from mosquito to human. To assess whether a mosquito has reduced disease transmission capability, the virus titer in the experimental transgenic mosquitoes midgut and salivary glands can be thrifty and compared to a wildtype control.At least three genetic-transformation systems have been descri bed and used successfully in Ae. aegypti to show GMVs. These transformation systems are based on the Class II TEs Mos1 (Mariner), Hermes and piggyBac . Mos1 and piggyBac are the most commonly used TEs mos1 for generating GMVs.Evidence of rnai chemical tool in mosquitoesList the RNAs strategy Interference with the recurrence of dengue virus can operate Effective in mosquitoes and mosquito cells. The first evidence is recombinant Sindbis viruses having DENV-2-prM sequence was alter in to in adult female mosquitoes. Sindbis viruses is single-stranded RNA virus. During replication it is convert in to double stranded RNA and intermediator expressing DENV-2 prM that is activate the RNAi mechanism . Combination of DENV-2 and the recombinant SINV having DENV-2-prM sequence slabs DENV replication in mosquitoes.in mosquito cell culture nerve of a dsRNA hairpin structure is a strong Catalyst of the RNAi mechnism. 567 nucleotide of the prM sequence from DENV-2 in a mind orientation and f irst 290 nt repeated in antisense orientation is made hairpin structure .cloned this into plasmid after transcription DENV-2 specific dsRNA is formed that stop the DENV-2 replication.transfection of C6/36 (Aedes albopictus) with dsRNA of arbovirus genome.these are the evidence which shows that Aedes species have RNAi mechanism resemble to other organisms.RNAi Mechnism In RNAi mechanism dsRNA is integrate in The cytoplasm of the cell. RNase III enzyme Dicer is trusty to digest dsRNA in a small interfering RNA 21-23 BP (RNAs siRNAs). These double stranded siRNAs having two nucleotides over hangs at both of the 3ends. Then siRNAs is unwounded in a single stranded by the enzyme complex called the RNA-induced silencing complex,(RISC).one strand act as RISC-targeting co-factor. siRNA having RISC binds with complementary mRNA. cleavage in the middle of the siRNA binding region by RISC is occur .then mRNA Is degrade by natural endogenous mechanisms.RNAi mechanism for dengue controlSnchez-V argas and collegues proved that RNAi paly a important lineament in the reduction of dengue infection. AAV (adeno-associated virus )siRNA infected the dendritic cells and decrease Dengue infection in human.Mosquito cell line transformed culture (C6 / 36, A. albopictus) by way of plasmid Which contain the inverted sequence of PRM gene of dengue And form dsRNA 290-BP. These transformed cells contain resistance to the dengue virus 2. When these cells are infected with dengue virus -2 viral RAN collection is not occur. These transformed mosquitoes cells Containing all the machines of RNAi. This finding proved that RNAi play a important role in reduction of dengue virus 2.Transposon ,that contain the inverted repeat sequence of prM gene of dengue virus is transformed in mosquito embryo along with carboxypeptidase A Promoter .after the intake of bloodmeal of mosquitoes dsRNA 578-BP is produce. When genetically modified Mosquito Carb 77 stuck With DENV2 having bloodmeal dsRNA is expressed along virus replication. thus preserving the Spreading of the virus from the host to the salivary Glands. RNAi mechanism is accountable for the resistance of DENV2.SiRNA-mediated silencing of receptors and Facility clathrin mediated endocytosis can prevent entry of Dengue virus .The proliferation of HepG2 cells, reducing the Virus. inhibit the dengue fever to develop into serious forms .Specified cellular genes involved in endocytosis trading operations And the dynamics of the cell structure, the task of infection DENV. SiRNA directing genes linked with clathrin mediated endocytosis.Villegas-Rosales et al. projected three siRNAs that have ability to silence the four DENV serotypes genome By pointing NS4B and NS5 sequences . SiRNA along with RNAi self-processing machinery have a role in the obviation of unadorned dengue infection. In the development of new therepuetical drugs RNAI can play an imporatn role .