PROJECT SUMMARY / ABSTRACT
This proposal comprises a five-year research and career development program for Melanie H. Smith, MD, PhD
to achieve independence as an investigator at the intersection of immunology and stromal biology in the human
synovium. Dr. Smith is an Assistant Attending Physician in the Division of Rheumatology at Hospital for Special
Surgery (HSS) and an Assistant Attending Professor of Medicine at Weill Cornell Medical College in New York
City. She will conduct research under the joint mentorship of Dr. Laura Donlin (HSS) and Dr. Alexander Rudensky
(Memorial Sloan Kettering Cancer Center) focused on understanding the role of synovial fibroblasts in
rheumatoid arthritis (RA). Dr. Smith will engage in career development activities including didactics, workshops
in grant writing and leadership, conferences, and acquisition of technical skills and scientific expertise. These
activities will be augmented through regular input from her scientific advisory team. This training grant will
generate key skills, data, and publications necessary to become an R01-funded independent investigator.
Synovial fibroblasts (FLS) are the most abundant resident cells in the synovium and are implicated in multiple
aspects of RA pathogenesis. FLS specifically within the synovial lining layer exhibit evidence of extensive
activation and are selectively defined by accessibility of AP-1 transcription factor motifs. Here we will test the
contributions of toll like receptor (TLR) ligands from the synovial fluid, and local expression of epidermal growth
factor receptor (EGFR) ligands in activating AP-1 in FLS. The central hypothesis is that these activators of AP-
1, which are present in the synovial lining microenvironment, prime lining FLS to mount heightened responses
to cytokines derived from infiltrating leukocytes, and that AP-1 driven gene expression drives FLS functional
specialization. We will use primary human synovial fibroblasts both in culture and directly isolated from synovial
tissue along with selective agonists, targeted inhibitors and CRISPR interference to interrogate the mechanistic
basis and functional consequences of the FLS activation observed specifically in lining FLS. The significance of
this proposal lies in the identification of key factors responsible for FLS activation that may further the
development of FLS-targeted therapies in RA. This proposal is innovative in the investigation of non-cytokine
driven priming in the establishment of inflammatory memory and the identification of the specific transcription
factors involved using advanced sequencing methods as well as CRISPR in primary human FLS. Long-term, Dr.
Smith aims to apply the expertise gained in this proposal to identify environmental and inflammatory signals that
maintain and regulate synovial inflammation to improve treatment of RA.