Arthritis Foundation, Alabama Chapter
Professor of Pediatrics & Medicine
Director, Pediatric Rheumatology
|Address:||1825 University Blvd
Shelby Building, 306
Birmingham, AL 35294
|Members of the Laboratory|
B.S. (Biomedical Sciences), University of California, Riverside, CA
Pre-doctoral fellow (Howard Hughes Medical Institute), National Institutes of Health, Bethesda, MD
Ph.D. (Immunology), University of Chicago, Chicago, IL
M.D. UCLA, Los Angeles, CA
Residency (Pediatrics), Stanford Children’s Hospital, Palo Alto, CA
Fellowship (Pediatric Rheumatology), University of Washington, Seattle, WA
Post-doctoral Fellow (Howard Hughes Medical Institute scholar), Stanford University, Palo Alto, CA
CD154 (CD40 ligand) dysregulation in lupus. Systemic lupus erythematosus, the prototypic autoimmune disorder, affects 1 in 2,000 women in the United States. Although the etiology and pathogenesis are unclear, the over-expression of the TNF family member, CD154, on CD4 T lymphocytes clearly contributes to disease pathology, both in mouse models and in humans with disease. Ourultimate goal is to identify cis- and trans-acting elements that contribute to the dysregulated expression of CD154 in SLE and other autoimmune disorders. We initially characterized the human CD154 transcriptional promoter and demonstrated its cyclosporin A (CsA) sensitivity. We are currently probing the hCD154 gene locus by DNase I hypersensitive site mapping to identify novel regulatory elements. We have identified and partially characterized a 5’ transcriptional enhancer, a 3’ transcriptional enhancer, and a 3’ untranslated mRNA stability element. In addition, we have identified an uncharacterized 5’ hypersensitive site farther upstream of the transcription start site. We are currently exploring the activities of these various CD154 regulatory elements as transgenes in a mouse model of SLE. In conjunction, we have identified various transcription factors and RNA binding proteins, which had not been previously described to regulate CD154 expression. We are currently exploring these factors for their contributions to CD154 dysregulation in SLE.
Host transcription factors exploited by HIV-1. HIV-1, the cause of AIDS, has infected over 40 million individuals world-wide. Although vast improvements in therapy have been developed over the last decade, HIV-1 cannot be totally eliminated from the host due to its ability to enter a resting or latent state in CD4 T cells. Because HIV-1 relies on host transcription factors to replicate, we are exploring the role of the calcium activated nuclear factor of activated T cells (NFAT) transcription factors in regulating HIV-1 transcription. We and others have shown that the CsA-sensitive NFAT proteins bind to the proximal HIV-1 promoter/long terminal repeat (LTR) in vitro and up-regulate HIV-1 transcription. We have further demonstrated that NFAT proteins bind to the integrated HIV-1 LTR in primary human CD4 T cells in vivo by chromatin immunoprecipitation, and this binding is disrupted by the regulatory T cell transcription factor, FOXP3. In addition, we are attempting to exploit NFAT activation as a means of activating HIV-1 LTR activity in latently infected cells. Recently, we identified a novel binding site for the c-maf transcription factor located adjacent to the proximal NFAT sites in the HIV-1 LTR. Our studies reveal synergistic transcriptional activation and increased infection of HIV-1 by c-maf, NFAT2, and NFΚB p65 in primary human IL-4-producing CD4 T cells. Thus, c-maf will likely be a novel therapeutic target in the treatment of HIV-1.
My family, travel, skiing (water and snow), rock and roll music, golf.