Research

Research

Primary Immunodeficiency Diseases

Patients with primary immunodeficiency diseases (PID) are often unable to respond to viral, bacterial, and fungal infections, leaving them prone to life-threatening conditions. We are interested those patients with hypoplasia’s of the thymus. We are using both patient samples and mouse models pertaining to elucidate the causes of the thymic hypoplasia’s. Our studies focus on individuals with 22q11.2 deletion syndrome (affecting 1/4000 individuals) and a rare group of patients we discovered who harbor compound heterozygous mutations in FOXN1, a key transcription factor required for the formation of the thymus, hair extrusion and nail beds.

Developmental and Regenerative Processes

Stress, elicited by malnutrition, infections, trauma, surgery, alcoholism, steroid injections and even pregnancy, causes acute and chronic immune system abnormalities. The thymus is particularly sensitive to stress, undergoing atrophy and reduced T cell development. This causes a weakened immune system. We have identified different noncoding RNAs (miRNAs and lncRNAs) that regulate these stress responses.

We seek to delineate the mechanisms by which these noncoding RNAs govern either the development of the thymus (and pituitary) and the regenerative process needed for these tissues to return to normal functionality. Our studies use advanced molecular approaches to characterize the functions of the noncoding RNAs in this process, taking advantage of CRISPR/Ca9s genome editing. Manipulating the formation of key cell populations such as epithelial, mesenchymal, endothelial and precursor thymocytes may allow us to generate a thymus de novo.

Infections

Mycobacterium tuberculosis (Mtb) infects 1/3 of the World’s population. We seek to understand the pathogenic mechanisms whereby mycobacteria are able to subvert host immune responses. Using RNA sequencing approaches for small RNAs, we identified several Mtb encoded small noncoding RNAs (sncRNAs) produced in infected cells. These sncRNAs regulate both mycobacterial and mammalian gene expression. The molecular mechanisms leading to gene regulation are under investigation using loss- and gain-of-function techniques.