Research Interests - Dr. Rebecca Roberts

The goal of my laboratory is to understand the role of proteolysis in disease.  Proteolysis is the enzymatic hydrolysis of proteins.  We are currently working on the role of proteolysis in Systemic Lupus Erythematosus (SLE).  This autoimmune disease afflicts mainly women and is influenced by hormones such as estrogen.  Among the disease processes associated with SLE are altered apoptosis and the production of antibodies autoreactive to targets such as histones, DNA, RNA, cathepsin G, and the proteasome.   Although SLE patients often display enhanced MHC class II expression, the role of antigen presentation in this disease is not well understood.  Proteolysis is a fundamental element of MHC class II-restricted antigen presentation.  Lysosomal proteases called cathepsins are necessary for both the generation of antigenic epitopes and the degradation of the MHC class II-associated invariant chain (Ii).  The ability to identify and characterize the proteases involved in these processes is essential in understanding the full spectrum of the disease.

The link between SLE and sex hormones such as estradiol is documented, yet the mechanism of action remains unknown.  Estradiol has been shown to alter the gene expression of cathespin D.  Cathepsin expression and activity may be influenced directly by estrogens or indirectly via a change in cytokine profiles.

Environmental estrogens such as bisphenol A (BPA) may act as immune modulators and affect disease progression.  BPA is used in the manufacture of polycarbonate plastics and epoxy resins widely found in food containers.  It is also a component of dental sealants and is released into the saliva following application.  While structurally different from estradiol, BPA binds and activates estrogen receptors with high affinity.  In 2000, the Endocrine Disruptors Low Dose Peer Review panel concluded that exposure to astonishingly low doses of BPA may have physiological effects on fetal development and that further studies on the physiological effects of the compound are warrented.  Few papers have been published concerning BPA and immune function to date. 

My lab investigates the effect of hormones (natural and environmental; specifically estradiol and BPA) on the proteases involved in MHC class II antigen processing and presentation in NZB/NZW (Lupus-prone) and control mice to better understand the relationship between hormones and SLE progression. 

Students working in my lab will have the opportunity to become proficient in cell culture, SDS-PAGE, western blot, animal maintenance & handling, protein assays, GC-MS, peptide synthesis and other general biochemical techniques and data analyses.

pictures:  top left, Roberts with Caroline Biswanger ('05) and Ryan Lenhart ('06) doing cell culture; middle right, Derese Getnet ('04) and Ella Lazo ('04) present their research at the American Society for Cell Biology annual meeting in San Francisco (December 2002); bottom left, Tom Seegar ('04) and Danielle Falkowski ('06) discuss their research at the Sigma Xi Symposium held at St. Joseph's University (April 2004); bottom right, Ryan Lenhart wins 2nd prize for his presentation at the Mid-Atlantic Pharmacology Society Meeting (October 2004); bottom middle, left to right: Nik Stasulli ('09), Laura Seczech ('09), Laura Davis ('07), Carmelina Staino ('09), Priya Patel ('08), Bill Stanert ('08), Theresa Leichner ('08), Derek Zimmer ('07).

PAST AND PRESENT MEMBERS OF THE ROBERTS LABORATORY: