Pond Life Technologies Limited Liability Company — Department of Health and Human Services STTR Phase I: NIAID

Description

DESCRIPTION provided by applicant West Nile virus WNV has become endemic to the US with yearly infection peaks coinciding with the activity of its mosquito vector was the worst year for WNV since with deaths and estimates of non neuroinvasive cases There is no specific treatment or vaccine so mosquito control is the only approach available Fortunately controlling the vector also reduces the transmission of other diseases such as Dengue However the chemical pesticides that have played an important role in mosquito management are losing their effectiveness due to increasing resistance Moreover there are growing concerns over damage to non target organisms such as honeybees and possible links between pesticide exposure and neurogenerative diseases in people We are developing new products for mosquito control that are based on the simple idea of turning a larval food source the eukaryotic green alga Chlamydomonas into a safe and effective biolarvacide Chlamydomonas is an edible alga whose ability to swim and reproduce in aquatic habitats and its development as a genetic research model make it an attractive platform for mosquito control To this end we are expressing genes based on the Cry and Cyt genes of Bacillus thuringiensis israelensis Bti in the chloroplast of Chlamydomonas Bti is a safe biolarvacide that has not produced strong resistance in andgt yrs of use but it does not recycle in aquatic habitats In addition by using the chloroplast genome we avoid the use of bacterial antibiotic resistance genes and can restrict the possible transfer of Bti genes to other organisms Our ultimate goal is robust strains that express or Cry genes and Cyt Aa which inhibits the development of strong resistance Since we have demonstrated recently that Cry genes can be expressed in the organelle our priorities for Phase I are to express Cyt Aa in the chloroplast and to identify elements that increase Cry gene expression using Cry Aa as a model The Specific Aims for this proposal are to Synthesize a codon adapted Cyt Aa gene and express it in the chloroplast using an inducible system in order to optimize expression Use the gene from Aim to establish wild type strains that express the adapted Cyt Aa gene Wild type or constitutive Cyt Aa expression is necessary for it to be used for mosquito control Identify cis acting elements that increase the expression of Cry genes using Cry Aa as a model We will use our larvicidal strains that express Cry Aa in a wild type background as the starting point for optimization Implications of the specific aims for Phase II The successful chloroplast expression of Cyt Aa in the context of a stable wild type strain will justify the notion that we can create Chlamydomonas strains that do not engender strong resistance The increased expression of Cry Aa will strengthen our argument that we can generate strains that are highly lethal to many mosquito species including those that transmit WNV We anticipate that Phase the creation of strains that are lethal to larvae at cells mL or lower a mature culture of Chlamydomonas is cells mL can be completed for about $ Direct Validating the algal strains under field conditions safety testing and getting them registered with EPA would likely occur after Phase PUBLIC HEALTH RELEVANCE This project will increase public health by innovating a safe ecofriendly biological product for the control of mosquitoes that transmit West Nile virus dengue and encephalitis Since there are no vaccines or effective therapeutics for these diseases mosquito control is the only workable approach However there is growing concern over the chemical pesticides that make up most of the US market for mosquito control products and many groups have called for new safer products We are developing strains of Chlamydomonas a green alga that is normally a food source for mosquito larvae that produce their own versions of naturally occurring larvicidal proteins from Bacillus thuringiensis israelenss Bti These proteins are known to kill mosquito larvae with great specificity and formulations of them have been used around the world However they cannot recycle and become inactivated in aquatic environments Our algal strains will have the potential for safe sustained control of mosquitoes and should reduce the need for chemical pesticides