Mechanisms of aberrant immune system responses
The human immune system is a highly complex, exquisitely orchestrated hierarchy of responses to pathogenic insults. The efficiency and plasticity of the immune system provides us with protection from infections caused by bacteria or viruses. Furthermore, our ability to manipulate these natural responses underlies the basis of protection from infectious diseases and, now, certain cancers, through preventative vaccination programs.
Aberrant immune responses, however, can result in conditions of autoimmunity, during which cells of the immune system mistakenly identify cells and tissues normally found in the body as “foreign” and mount destructive attacks against them. We are working to identify key regulatory molecules that contribute to autoimmunity, especially the autoimmune bone marrow failure syndrome, Aplastic Anemia. We aim to detail at the molecular and cellular level, the mechanisms of disease, to extrapolate these findings to understand their impact at the systems (whole animal) level and, further, to develop novel therapeutic approaches for treating disease.
One of our key proteins of interest is NOTCH1, a transmembrane receptor, shown to be a critical regulator of T cell activation, proliferation, and differentiation. We have identified it as an important contributor to disease pathology in Aplastic Anemia. We are now investigating NOTCH1-interacting partners to explore their cooperative role in autoimmune bone marrow failure.
To achieve this goal, my research is focused on the following primary objectives:
Defining novel pathways that mediate Notch signaling, both upstream and downstream of its expression
We are interested in determining those partners which interact with NOTCH1, both in the cytosol and the nucleus, to mediate its effects. These include proteins which associate directly with NOTCH1, as well a micro-RNAs which may be acting immediately up- and downstream of NOTCH1.
Dissecting the mechanisms of (auto)immune-mediated diseases using animal models of immune-mediated bone marrow failure and graft-vs-host disease
We have established a highly representative animal model of Aplastic Anemia. Using this model we can confirm in vitro observations made using mouse immune cells or peripheral blood mononuclear cells from patients with Aplastic Anemia who have not received prior treatment. We can also use this model to test the therapeutic potential of pharmacological inhibitors under clinically relevant conditions. Using a “humanized” model of graft-vs-host disease we are further able to study the molecular mechanisms that underlie the aberrant immune signaling responsible for this post-bone marrow transplant condition.
Exploring novel strategies for modulating immune system responses in the context of these disease models
Strong collaborations with faculty in the Dept. of Polymer Sciences and Engineering and the Dept. of Chemistry, we are exploring novel means of therapeutically modulating immune responses so as to create novel, specific and tunable means of controlling autoimmune responses. Our approaches include systemic and targeted delivery of nanoplatform carriers designed to release intracellular cargos of small interfering RNAs (siRNA), protein-specific antibodies, or small molecule inhibitors.