Poster Abstracts for Category A: Biomedicine, epidemiology & agriculture Poster A02 Cancer Immunotherapy by Interleukin-21: Theoretical Evaluation of Potential Treatment Strategies Moran Elishmereni, Antonio Cappuccio, Zvia Agur Institute for Medical BioMathematics (IMBM) Abstract: Interleukin-21 (IL-21) participates in the transition from innate to adaptive immunity, and facilitates tumor eradication in vivo. To study the prospects of IL-21 as an immunotherapeutic agent, cancer-immune system interactions were mathematically modeled, focusing on IL-21-mediated NK/CTL effects. The model retrieved murine melanoma and fibrosarcoma growth dynamics from various experiments. Computer simulations suggest that, in non-immunogenic malignancies, clinical use of IL-21 should include a tumor mass-dependent therapeutic strategy, faithfully amplifying the natural anticancer immunity. Contact: moran [at] imbm.org Keywords: Immunomodulation, Biomathematical Modeling Poster A04 Models for Antigen Receptor Gene Rearrangement: CDR3 Length Ravit Saada (1), Moran Weinberger (2), Ramit Mehr (1) (1) Bar-Ilan University; (2) University of Toronto Abstract: In V(D)J recombination, CDR3 lengths are distributed almost normally. Is this just due to stochasticity, or has rearrangement been evolutionarily optimized? Using a simulation of all DNA modifications included in gene rearrangement, we suggest that specific biases govern the rearrangement process, and that V(D)J recombination parameters most likely reflect the optimal conditions under which rearrangement occurs. We also found that identical rearrangements of the heavy chain are highly unlikely to occur within one human lifetime, for the light chain this probability is not negligible. Contact: mehrra [at] mail.biu.ac.il Keywords: Immunoglobulin Gene Rearrangement, CDR3 Poster A06 New Derivatives of DPPacid as Tyrosinase Inhibitors: Structure-Activity Relationships Soliman Khatib (1,2), Jacob Vaya (1,2) (1) Laboratory of Natural Medicinal Compounds, Migal-Galilee Technological Center; (2) Department of Biotechnology and Environmental Science, Tel-Hai Academic College, Israel Abstract: The present study was to investigate the effect of DPP-esters (DPP-OR), with various hydrophobic R groups, on tyrosinase activity. New derivatives of DPPacid were synthesized, methyl, ethyl, isopropyl and octyl forming DPP-esters (DPP-OR), and their inhibitory effect was tested. Structure-activity relationship studies were performed using the Autodock program to calculate docking parameters related to the interaction between tyrosinase and its potential inhibitors. Contact: solimankh [at] migal.org.il Keywords: Tyrosinase, Inhibitor, Dppacid, SAR, Autodock Poster A07 Developing a Predictive Tool for Prostate Cancer Metastases using the TRAMP Model Itai Kela (1), Alon Harmelin (2), Judith Chermesh (2), Tami Danon (1), Tova Waks (1), Avi Orr-Urtreger (4), Eytan Domany (3), Zelig Eshhar (1) (1) Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel; (2) Department of Veterinary Resources, The Weizmann Institute of Science, Rehovot, Israel; (3) Department of Physics of Complex Systems, The Weizmann Institute of Science, Rehovot, Israel; (4) Genetic Institute, Tel-Aviv Sourasky Medical Center, Tel-Aviv University, Tel-Aviv, Israel Abstract: TRAMP is a genetically engineered mouse model that mimics the pathology of clinical prostate cancer [Greenberg 2003]. We use TRAMP to determine if the ability to determine at diagnosis which patient will develop or already has progressed to disseminated disease will significantly impact the clinical management of cancer. We observed heterogeneity between TRAMP strains and amongst individual mice in time of tumor appearance, cancer progression rate, and time of metastases appearance. These pathological observations are interesting since the oncogenic signal in inbred TRAMP mice initiates cancer at a similar time. Contact: itai.kela [at] weizmann.ac.il