SBIR-STTR Award

This Small Business Innovation Research (SBIR) Phase I project aims to develop recombinant monoclonal antibodies using "mosaic" antigens derived from Leptospira spp proteins identified in the urine of clinical patients. The mosaic antigens are designed to artificially combine important antigenic epitopes in order to maximize the coverage of potential epitopes in one structure and to provide broader coverage than those afforded by multiple synthetic peptides. Our approach involves the use of computational biology and bioinformatics to create, score, and select "mosaic" antigens from Leptospira spp. Antigenic properties of the mosaic antigens are evaluated by indirect ELISA using a panel of well-characterized human sera from clinical patients and apparently healthy individuals. We will then use recombinant DNA and protein engineering techniques to derive cognate chimeric proteins, followed by the generation of recombinant epitope-specific monoclonal antibodies that target potential epitopes (rather than a few dominant epitopes) generated from the "mosaic" protein. The diagnostic potential of the recombinant antibody is evaluated by immunoblotting and ELISA using leptospirosis specimens from early and convalescent phases of the illness. The broader impact/commercial potential of this project, if successful, will be the development of a rapid, non-invasive, one-step, multiplex test that will have general applicability in the timely diagnosis of a complement of febrile illnesses, including leptospirosis. This is aimed at tropical and subtropical countries where the disease incidences are higher and where current tools are mostly inadequate. Early leptospira diagnosis is essential because antibiotic treatment is most effective when initiated early in the course of the disease. Current diagnostic tools are unsuitable for use in resource-limited settings especially in the tropical regions where other similar acute febrile illnesses are common. It expands the multiplex diagnostic test panel we are presently developing by iterative expansion.

This Small Business Innovation Research (SBIR) Phase II project proposes to develop and validate a non-invasive, multiplex urine dipstick for clinical diagnosis of Acute Febrile Illness (AFI) caused by polymicrobial infections. The target diseases include leptospirosis, typhoid fever, dengue, as well as Plasmodium falciparum and P. vivax malaria, responsible for ~229M AFI's and >800,000 deaths a year worldwide. Current diagnostic tools are invasive, technically complex, and thus not suitable in tropical and subtropical countries where these diseases are most prevalent, especially in rural and point-of-care settings where blood testing is impractical. The Phase I project successfully developed and validated pathogen-specific recombinant antibody reagents that demonstrated diagnostic potential in urine. This Phase II project envisages two broad objectives: (i) detailed characterization of the recombinant monoclonal antibody reagents to validate their individual and collective diagnostic utility; and (ii) to develop and validate a multiplex dipstick test device for concurrent detection of a set of leading causes of acute fever in a single urine sample. The deliverable will be a simple diagnostic device with the potential to diagnose either/both Plasmodium falciparum, Plasmodium vivax and Leptospira, which combines the need to improve specific diagnosis of AFI with the need to address alternative causes of acute fever.The broader impact/commercial potential of this project, if successful, will be the delivery of a rapid diagnostic tool that addresses a major challenge faced by people in low resource settings with high burdens of global health diseases, i.e. how to manage acute fever without the benefit of rapid differential diagnostic tests. Although individual tests for each potential cause of fever would be beneficial, it is often not feasible or practical to rapidly select, run, and interpret multiple individual tests in these settings. The cost implications for such individual testing also will be prohibitive. Therefore, a multiplex rapid device as envisaged here that will evaluate groups of symptomatically related febrile diseases is urgently needed. It will offer both medical and logistical benefits for rapid testing of leading causes of acute febrile illness in a single urine sample. It will deliver a single answer multi-disease diagnostic with broader impact, and offer differential diagnosis through a multiplexed assay rather than individual testing, most suitable in resource limited settings where diagnostic laboratory capacities are limited. This multiplex urine dipstick test is designed to be a foundational platform device to which other diagnostic reagents for acute fever can be iteratively added to suit a particular region.