Difference between revisions of "Team:UNA Honduras"

Revision as of 21:25, 14 July 2015

                                               PROJECT DESCRIPTION

DECODING DENGUE DYNAMICS

Dengue fever is caused by the defensive reaction of the body to the invasion of a virus transmmited by mosquito bite. Its symptoms are skin rash, headache specially behind the eyes, muscle and joints aching, there is no cure, just tratment for the signs with analgesics. The only way to prevent the spreading of the disease is to control the population of the vector: the females of Aedes aegypti which also pread the virus of Chikungunyua causing an even more severe series of symptoms. Health authorities conduct public campaigns calling the population to keep gardens and backyars clean and free of objects accumulate water where mosquito eggs could be laid, to cover all water deposits, sweep away garbage in order to keep water running properly; they also spread and encourage the spreading of insecticides and larvicides. Even if the population had the education level to understand and follow these guidelines in their homes and backyards, nobody takes responsibility for common spaces like parks, streets or even their own roofs,so there is always plenty of room for the vector to thrive; health officers stress the need to follow the recommendations since there is no effective vaccine against dengue commercially available after more tan 70 years of trials using different approaches that were abandoned for diverse reasons, mainly contamination with murine tissues, overreaction on some patients or little effectiveness when balanced against the risks.

A fact that makes difficult for researchers to raise the effectiveness of vaccines is that the dengue virus has at least 4 different serotypes which prevalence shifts every year, in Honduras all these variants are found; not all patiens are equally susceptible to the virus, some are totally asymptomatic, others have minor ailments like those of the flu and need no medication at all, but some others present all signs and need hospital attention; any patient who has suffered one particular type of dengue becomes immunized for life regarding that particular type, nevertheless if the patient becomes infected by a second serotype, the crossed reaction could be so severe that classic dengue becomes hemorrhagic denge which is lethal most of the times, being the more susceptible groups: children and third age fellows.

Recently, a big pharmaceutical transnational enterprise developed a recombinant vaccine that uses attenuated live virus particles like yellow fever virus to carry a segment of the dengue virus envelope protein of each serotype, a cocktail of the 4 serotypes is given as a vaccine, needs 3 doses and in Phase III has proven an average effectivity of near 70% in trials conducted in several Latin American countries.

Our Project aims to produce a new protein able to produce an immunological response that could be the base for a different type of vacccine based in Sythetic Biology techniques. We have taken advantage of Bioinformatics using several databases featuring protein sequences and 3D structures in order to learn differences and similarities among the proteins of the 4 serotypes of the virus, to recognize the antigenic determinants called epitopes and search for them in the correspondent databases. We searched and identified epitopes for both L and T white cells and made consensus of those to modify suitable proteins. Next phase is to design an ideal protein containing epitopes fromo all 4 serotypes, and at least other one containing just one or two at the most of the 4 serotypes. For that we have searched in the databases for a suitable protein that bacteria normally exports from the cell, that has high levels of expression in our selected cell lineage, monomeric in order to take just one gene to be synthesized, big enough to contain from one to four epitopes and not to big or complicated so bacteria can synthetize it properly, with several hydrophilic loops where the epitopes can be inserted and flanked so they do not hide. We also took advantage of the abilities of programs and servers in order to check its 3D final structure and plan our construct including promoter, RBS the main new sequence and other factors like indicator sequences and terminators.

We are to order the sythesis of the respective coding gen taking advantage of the offer for all registered teams to make at least two bioparts, one containing the four serotypes and the other just one. Later in the summer with the bioparts sent back and the transforming kit from our sponsors transform our bacteria and check the expression of the designed protein. A new phase or second part of the Project will consist, after isolating the protein, in essays of effectivnes using first serum from patients recovered from dengue, then with lab animals and finally with human volunteers.