Fellowship for Benjamin Shaw: Translating Genetic Risk Factors to Therapies: From Big Data to Druggable Targets

PROJECT SUMMARY Genome-wide association studies (GWAS) provide insight to underlying etiologies of disease not obvious through clinical evaluation or pathophysiology alone. Genetic variants associated with complex, often refractory diseases such as Alzheimer’s Disease (AD) and Multiple Sclerosis (MS) may hold the key for the next generation of treatment options. Leveraging genetic data with current standards of care and known pathophysiology can provide a strong premise for mechanistic studies and novel drug targets. As a case in point, antibodies against PCSK9, a proprotein convertase, drastically reduce blood LDL and are highly effective, even in statin-tolerant patients. Targeting PCSK9 was only rational after early genetic association studies uncovered a link between PCSK9 and very low levels of LDL. This case study is a prime example of the rationale behind my current work studying the molecular genetics of CD33 in AD under Dr. Steve Estus. We are investigating how the AD- protective single nucleotide polymorphism (SNP) modulates protein, and thereby cellular, function. I have also identified CLEC16A as a potentially high-impact target for my future postdoctoral studies – variants within this gene are strongly associated with MS (p = 5 x 10-8 to 5 x 10-24); one of the protective variants, rs8056098, is associated with reduced disease severity and progression; and murine data suggest Clec16a knockout mice have fewer circulating B cells, a clinically effective phenotype as shown by standard-of-care treatments such as ocrelizumab and fingolimod. In Specific Aim 1, I detail how my training in molecular biology and genetic concepts has allowed me to conceive independent hypotheses and carry out complex experiments. My doctoral work up to now regarding the molecular genetics of CD33 and its association with protection from AD has provided training in GWAS interpretation, quantitative PCR, immunoassays such as Western blotting and co-immunoprecipitation, and cell culture including transfection and genome editing strategies. In Specific Aim 2, I will continue to develop as a scientist and finish my doctoral work, carrying out increasingly complex studies to include measuring time- and dose-dependent protein phosphorylation in situ, intracellular calcium flux assays in vitro, and high-parameter flow cytometry in human peripheral blood samples. In Specific Aim 3, I will extend my doctoral training to include work with human tissue samples and mouse models of MS. I have not yet identified a specific postdoctoral mentor, but my ideal mentor will have experience conducting human subjects research, mouse models of MS, and a strong track record of training fellows to become tenure-track faculty. I will leverage my current training in molecular genetics to identify which of the MS-associated CLEC16A SNPs are functional, my training-in-progress to identify the functional effects of these SNPs at the protein and intracellular signaling levels, and my future training with murine models and human subjects to establish a high-impact, translational career, combining genetic, clinical, and pathology findings for pharmacological breakthroughs.