University of Virginia Health System

Autoimmunity plays an important role in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). The emphasis of my laboratory is on the genetic and environmental factors important for these disorders. We have been focused on the mouse model NZM2328 for SLE.  This model was characterized by our laboratory and was used to identify genetic loci for susceptibility of SLE.  A locus controlling nephritis and anti-dsDNA antibody production was identified. The disassociation of ANA and lupus nephritis was demonstrated in a congenic strain (NZM2328.C57L/J.c4).

The laboratory is focused on identification of the genes involved in the pathogenesis of SLE. In addition, autoantigens which are the target for nephritis in NZM2328.C57L/J.c4 are to be identified.  A separate loci for acute and chronic glomerulonephritis (GN) were identified on the distal portion of chromosome 1.  The genetic data were confirmed by the phenotypes of a congenic strain (NZM238.C574Jc1).  Further mapping by the generation of intrachromosomal recombinant strains of the C1 congenic resulted in an informative strain NZM2328.R27, showing that acute GN need not progress to chronic GN and that acute GN and chronic GN are under separate genetic control. 

Current efforts are to elucidate the genes controlling these phenotypes.  In addition, the hypothesis that molecular mimicry initiates the initial autoimmune response, which diversifies to multiple autoantigens, resulting in end organ damage in suitable hosts is being tested. The role of MHC in this process in both mice and men is being investigated. In this regard, bacterial and viral agents sharing cross reactive T and B cell epitopes with human autoantigens are logical candidates for molecular mimics in this process.

There is also interest in the pathogenesis of Sjögren’s syndrome. In collaboration, the laboratory is interested in the mechanisms of autoantibody diversification and the role of T cells in the pathogenesis of glomerulonephritis.  There is also a new interest on the cellular basis of immunoregulation.