JSmithAbstractAngovFinal
- 1. Characterizing Novel Human Monoclonal Antibodies to PfCelTOS Jacob Smith, Pennsylvania State University Mentored By: Dr. Evelina Angov, Walter Reed Army Institute of Research Ms. Katherine Mallory, Walter Reed Army Institute of Research With malaria fatality rates close to one million deaths per year, the urgency for discovering a vaccine candidate is imminent. The Plasmodium protein cell- traversal protein for ookinetes and sporozoites (CelTOS) is a major player in the pre-erythrocytic stages of malaria parasite infection, providing the parasite with the cell-traversal abilities necessary for hepatocyte invasion. In addition, this protein is highly conserved among the Plasmodium species, providing scientists with an opportunity to develop species transcending vaccine approaches. Thus, we believe that targeting the immune response to this protein may interfere with the parasite’s ability to elicit an infection and result in protection. This study was focused on the most deadly species in humans, Plasmodium falciparum, and specifically, the PfCelTOS antigen, to characterize 10 unknown (novel) human monoclonal antibodies (Mabs). These Mabs were prepared via Kymouse technology, delivering high quality human antibodies by complementing human immune system genes with transgenic mice. Each Mab was initially tested via western and dot blot to the full length PfCelTOS as well as its C/N termini for a qualitative assessment of their reactivity to the protein. Next, enzyme-linked immunosorbent assay (ELISAs) were performed for more sensitive, quantitative results. Subsequent ELISAs to the PfCelTOS C/N termini and their respective long peptides determined fine specificity mapping of the Mabs to the protein. Cross reactivity of the MAbs between alternate species antigens from Plasmodium berghei (mouse), Plasmodium knowlesi (human) and Plasmodium vivax (human) were also determined via ELISA and western blot. Finally, immunofluorescent assays (IFAs) were performed to assess the ability of the Mabs to recognize the native protein on the surface of a sporozoite. The results show that a few of the unknown MAbs are positive, with strong binding to epitopes in both the C and N terminus regions of the PfCelTOS protein. The immunoreactivity and immunogenicity of these promising Mabs will be examined in more detail as the project develops.