Humanization of VLR antibodies for therapeutic applications

DESCRIPTION provided by applicant Currently there is no FDA approved therapeutic antibody capable of depleting long lived plasma cells A plasma cell specific monoclonal antibody could be used to treat plasma cell malignancies multiple myelomas which are fatal and for which there is no effective treatment and antibody mediated autoimmune and severe allergic disease e g systemic lupus erythematosus and asthma Immunoglobulin Ig based monoclonal antibodies that recognize plasma cell surface antigens such as CD and CD are being evaluated for plasma cell targeting however these antigens are expressed by many other cell types which complicates plasma cell targeting and creates the potential for side effects NovAbandapos s scientific founders discovered that primitive jawless fish lampreys and hagfish use highly diverse leucine rich repeat LRR based antibodies called Variable Lymphocyte Receptors VLRs for antigen recognition instead of the Ig based antibodies used by all higher vertebrates Due to the vast evolutionary distance between humans and lampreys million years highly conserved human proteins and carbohydrates that are andquot invisibleandquot to mammalian immune systems because of self tolerance are likely to be immunogenic in lampreys Capitalizing on the lack of tolerance to mammalian antigens and the unique structural features of the lamprey VLR antibodies NovAb has developed VLR monoclonal antibodies specific for novel plasma cell restricted antigens in humans and non human primates However the plasma cell specific VLR antibodies will need to be engineered before they can be used therapeutically Because VLR antibodies will be seen as foreign antigens by the mammalian immune system in their native form we propose to make andquot humanizedandquot variants using human LRR receptors as scaffolds to limit immunogenicity We will also construct VLR chimeric proteins to allow them to interface with effector mechanisms of the human immune system such as Fc receptors and complement pathways to facilitate the depletion of target cells PUBLIC HEALTH RELEVANCE The long term goal of this project is to generate a therapeutic antibody capable of depleting malignant and pathological plasma cells NovAbandapos s scientific founders discovered that jawless fish lampreys and hagfish have an alternative type of adaptive immune system that uses Variable Lymphocyte Receptors VLRs composed of leucine rich repeats for antigen recognition instead of the immunoglobulin based antibodies found in all jawed vertebrates Using the lamprey immune system as a discovery tool we have developed VLR monoclonal antibodies that are specific for plasma cells in humans and non human primates In the proposed studies we will engineer the plasma cell specific VLR antibodies to decrease immunogenicity and to interface with immune effector mechanisms in order to deplete plasma cells in vivo