Originally as a physician, after spending three years in full-time research (Joint Diseases Laboratories, Shriners Hospital, Montreal, Canada and NIH/NIDR Bethesda), I have fundamentally changed my career converting my clinical experience and training to biomedical science. My major research interest during the past 30 years has been autoimmunity and autoimmune regulation of T and B cells in rheumatoid arthritis (RA) and ankylosing spondylitis (AS), and its corresponding animal models. I have generated monoclonal antibodies (mAbs) to cartilage antigenic components, and used these mAbs for immuno-electron microscopic localization of cartilage matrix molecules in aging and diseased cartilages. During the production of mAbs, serendipitously, I (and my immediate colleagues) “discovered” cartilage proteoglycan (PG) aggrecan-induced arthritis (PGIA) in genetically susceptible (arthritis-prone) BALB/c mice.
I have had a long-standing interest and commitment to training of medical students for histopathology, and later on scientists and physician-scientists. In addition to mentoring pre- and postdoctoral trainees in my laboratory and faculty members, I was PI of numerous R01, P01 and R21 NIH grants; I was always funded since I moved to the USA.
My early research was thymosin-producing epithelioid cells expected to control early T cell selection in mouse embryos and the mechanisms of Wasting syndrome. Simultaneously, I studied cartilage and bone development as well as cartilage repair and bone healing in animal models, and immunogenicity/antigenicity of cartilage and bone non-collagenous macromolecules. This included numerous histochemistry (mostly enzyme and immune histochemistry), biochemical and immunological methods. I was the first to localize proteoglycan (PG) aggrecan and link protein by immune electron microscopy in cartilage tissue, and first described the autoimmune potential of cartilage PG in patients with RA or ankylosing spondylitis. I/we have sequenced the core proteins of mouse and canine cartilage PG aggrecans, and described splice variants of human PG aggrecan. These pioneer studies were repeated and extended in many laboratories.
My expertise in bone and cartilage biochemistry and biology was beneficial when I/we have studied the mechanism of aseptic loosening of total joint replacements, which studies then changed the orthopedic term/diagnosis from “cement disease” to “particulate disease”. Submicron-sized wear debris/particulates are phagocytized by macrophages, fibroblasts and osteoblast, trigger these cells to secrete pro-inflammatory cytokines and proteolytic enzymes leading to aseptic bone resorption and loosening of prosthetic device.
After I/we described the PG (aggrecan)-induced arthritis (PGIA) in BALB/c mice in 1987, a large number of studies focused on the immune pathomechanism of this model of RA and mapping studies of (auto)epitopes. PGIA model shares similarities with RA as indicated by clinical assessments, laboratory tests, and histopathology of diarthrodial joints. The development of the disease in genetically susceptible mice is based upon the development of cross-reactive immune responses between the immunizing (human) and self (mouse) cartilage PG. The recessive inheritance of disease susceptibility, as in RA, is dictated by both MHC- and non-MHC-associated genes. I/we identified dominant (arthritic) and subdominant epitopes of human and mouse (self) PG, tested the arthritogenic potential of human cartilage PG, and I generated recombinant human G1 domain (a globular domain of PG which carry all arthritogenic epitopes. This model was used to test the efficacy of Leflunomide (component 418). Numerous laboratories use the PGIA model all over the world, and human studies led to the identification of citrullinated PG epitopes in RA patients.
A fourth and most recent research direction is the genetic and epigenetic alterations in PGIA model and in RA patients. I/we identified over 25 quantitative trait loci (QTLs) in different genetic combination of F2 mice. A special select direction of these genetic studies was to generate congenic mice (a short resistant DBA2 allele in susceptible BALB/c background). These congenic mice were/are tested for arthritis susceptibility; genomic regions sequenced and mutated genes selected for in vitro and in vivo studies. Eight of these 25 QTL are syntenic with RA genomic risk loci. From these 8 overlapping RA risk loci we have selected mouse chromosomes 2 and 3, which are highly susceptible to arthritis and syntenic with human chromosomes 9 and 1. Mouse/human susceptible regions carry the PTPN22 (mChr3/hChr1) and C5/TRAF1/PHF19 (mChr2/hChr9) RA risk alleles. The mutated genes are studied in vitro and generating and testing gene-deficient mice for arthritis in susceptible BALB/c background, and allele-specific transgenic mice to rescue the gene deficiency-induced defect(s).
My Scopus API key: 458a8af4ddad17c0c313a5e8b8454348
My Orcid ID: https://orcid.org/0000-0002-1706-3820
MY NIH COMMONS: TGLANT
Research Areas: Autoimmunity, Rheumatoid Arthritis, Ankylosing Spondylitis, Genetics, Periprosthetic osteolysis
My Faculty Profile at Rush University Medical Center:
https://www.rushu.rush.edu/faculty/tibor-t-glant-md-phd
Education:
MD, University of Medical School (DOTE) Debrecen, Hungary
PhD, University of Medical School (DOTE) Debrecen, Hungary
DMsc. Hungarian Academy of Sciences, Budapest, Hungary