Autoimmune disease (AD) is a disease where antibodies incorrectly attack healthy self cells by binding to antigens. As a result of this self attacking patients experience long term sickness or even death. Current treatment methods include the use of non‐specific immunosuppressive medicines, which are somewhat effective at diminishing the effects of the disease. While effective, these therapies leave the patient with a significantly weakened immune system and decreased ability to fight off simple pathogens. This emphasizes the need for a more targeted treatment for AD. The work here focuses on the disease primary membranous nephropathy (PMN), which targets three domains of the phospholipase A2 receptor (PLA2R): the ricin domain and C‐type lectin domains numbers 1 and 7 (CTLD1 and CTLD7). The goal of this project is design of antigen specific treatment for PMN, which involves preventing autoantibodies from binding to the PLA2R antigen, through design of protein monobodies. In this work, the epitope regions on CTLD7 were predicted using the programs Epitopia and EPCES to define target sites for the epitope caps. The data suggest that there are three distinct epitope locations on CTLD7 that could be targeted by PMN autoantibodies. Currently, 26 epitope caps have been designed using the templates 3UYO and 5A40. The results show that in silico mutagenesis of protein monobodies enhanced binding of epitope caps to epitope sites on the CTLD7 domain from −4.94 Rosetta Energy Units (REU) on the 3UYO template to −5.094 REU, and −5.081 in 3UYO‐004‐OS and 3UYO‐022‐OS, respectively. In silico mutagenesis to the 5A40 template, producing the 5A40‐001‐OS cap, improved binding by approximately 2 REUs: improving the REU score from −5.618 to −7.596 to the CTLD7 domain. Results indicate that in the 5A40‐001‐OS cap, introduction of a negatively charged aspartate created an electrostatic interaction with CTLD7, which improved the potency of binding. The 5A40‐001‐OS cap along with 3UYO‐004‐OS and 3UYO‐022‐OS caps are being expressed in E. coli for further evaluation through ELISA assays. The results of this work could lead to a much safer and more antigen specific treatment for autoimmune disease.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

In autoimmune diseases antibodies incorrectly attack normal healthy cells, which can promote degradation of tissues and can lead to long‐term disease and death. Modern clinical therapies treating autoimmune disease include the use of immunosuppressive medicines. Although this therapy has shown success in slowing down the progression of autoimmune disorders, this treatment diminishes the patient's entire immune system's ability to fight off normal pathogens. This highlights the need for more specific treatment options for autoimmune disease that do not weaken the patient's entire immune system. Primary membranous nephropathy (PMN) is a kidney specific autoimmune disease currently being treated with immunosuppressive medicines. In patients with PMN, seventy percent of individuals produce autoantibodies that target the phospholipase A2 receptor (PLA2R). The goal of this research is to design PLA2R specific binding proteins (epitope caps) that will prevent the PLA2R autoantibodies from binding to the C‐type lectin domain number seven (CTLD7) on this antigen. Using Epitopia and EPCES, three possible epitope sites were identified and characterized. Binding strength of the binding proteins to the CTLD7 was measured through Rosetta Online Server that Includes Everyone. In silico mutations were made to the Monobody template 5FXB. Currently, we have produced three epitope caps (5FXB‐001‐LVG, 5FXB‐002‐LVG, 5FXB‐003‐LVG) with binding scores that are below out targeted binding score of −5.0 Rosetta energy units (REU). Currently protein expression and purification is underway to permit further evaluation of the epitope caps using ELISA assays to determine experimental binding proficiency. Furthermore, this research could provide patients with more specific methods of treatment for autoimmune disease than the contemporary treatment options such as, immunosuppressive therapies. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.