个人简介

M.D. (Doctor of Medicine) Ph.D. (Doctor of Philosophy)

研究领域

Molecular Biology and Disease

Cell and molecular biology of GW proteins, GW bodies and their relationship to exosomes, mRNA degradation, microRNA and mRNA silencing. Cell and molecular biology of autoantigens in proteasomes, endosomes and the Golgi complex Investigation of antigen-antibody profiles in patients with systemic rheumatic diseases. Study of the pathogenic role of autoantibodies in systemic rheumatic diseases. Mechanisms of xenobiotic-induced autoimmunity and the effect of environmental toxins on immunity and autoimmunity. Mapping epitopes and determinants on autoantigens. Autoantibodies in paraneoplastic and neurodegenerative syndromes. Relationship of autoantigens to breast and prostate cancer. New diagnostic technologies (antigen arrays, microfluidics, nanotechnology) in immunology. Novel biomarkers (proteomics and metabolomics) in systemic autoimmune diseases. Identification of an Autoantigen (GW182) in a Novel Cytoplasmic Compartment (GW Bodies) We identified a novel cellular structure that contains a unique autoimmune antigen and multiple messenger RNAs. This complex was discovered using an autoimmune serum from a patient with motor and sensory neuropathy and contains a protein of 182 kDa. The gene and cDNA encoding the protein indicated an open reading frame with glycine-tryptophan (GW) repeats and a single RNA recognition motif (RRM). The index patient's serum stained discrete cytoplasmic speckles designated as GW bodies (GWBs) that do no overlap with the Golgi complex, endosomes, lysosomes or peroxisomes. The mRNAs associated with GW182 represent a clustered set of transcripts that are presumed to reside within the GW complexes. In collaboration with Dr. Edward K.L. Chan at the University of Florida, we are continuing studies to explore the hypothesis that the GW ribonucleoprotein complex is involved in the post-transcriptional regulation of gene expression by sequestering a specific subset of gene transcripts involved in cell growth and homeostasis. In the figure above, HeLa cells are stained with the index human antibody (green) and the nuclei counterstained with DAPI (blue). GWBs are cytoplasmic structures that vary in number and size from cell to cell. The current evidence on the role of GW182 and GWBs are published: Jakymiw A, Eystathioy T, Satoh M, Hamel JC, Fritzler MJ, Chan EKL. Disruption of GW bodies impairs mammalian mRNA interference. Nat Cell Biol 2005; 7:1167-1174. Eystathioy T, Chan EKL, Tenenbaum SA, Keene JD, Griffith KM, Fritzler MJ. A phosphorylated cytoplasmic autoantigen, GW182, associated with a unique population of human mRNAs within novel cytoplasmic speckles. Mol Biol Cell 13: 1338-1351, 2002. The clinical features of patients with anti-GW182 antibodies have been described and the B cell anti-GW182 response and epitopes defined. The most common clinical diagnosis of patients with anti-GW182 antibodies was Sjögren's syndrome (SjS) followed by mixed motor/sensory neuropathy, and systemiclupus erythematosus (SLE). Of interest, 9/18 (50%) and 3/18 (17%) of the sera that react with GWBs had autoantibodies to the 52 kDa and 60 kDa SS-A/Ro autoantigen respectively. Epitopes bound by the human autoantibodies were mapped to the GW-rich mid-part of the protein, the non-GW rich region, and the C-terminus of GW182 protein. None of the GW182 epitopes had significant sequence similarities to other known proteins. GW182 represents a new category of ribonucleoprotein autoantigens. Eystathioy T, Chan EKL, Takeuchi K, Mahler M, Luft LM, Zochodne DW, Fritzler MJ. Clinical and seriological associations of autoantibodies to GW bodies and a novel cytoplasmic autoantigen GW182. J Mol Med 81: 811-811, 2003. Monoclonal antibodies to GW182 have been generated and characterized. To enable a more detailed study of GW182 and GWBs in cells and tissues, including their role in mRNA processing, we developed four monoclonal antibodies (MAbs) that bind the human recombinant GW182 protein. These MAbs can be used for Western blot analysis and indirect immunofluorescence (IIF) on cultured cells and tissues. Of special interest, one of the MAbs, 2D6, can be used to identify GW182 and GWBs in formalinfixed and paraffin embedded tissues after employing an antigen retrieval method (ARM). All the MAbs described in this study immunoprecipitate the GW182 protein. Epitope mapping using overlapping 15-mer peptides representing the full length GW182 showed that the major antibody binding domains of these MAbs are distinct. These MAbs are valuable tools for cell biologists and pathologists to study the location and function of the novel GW182 protein in tissue culture cells, as well as cryopreserved or archived tissues. Eystathioy T, Chan EKL, Mahler M, Luft LM, Fritzler ML, Fritzler MJ. A panel of monoclonal antibodies to the novel GW182 protein and GW bodies. Hybridoma & Hybridomics 22: 79-86, 2003. The GW182 protein co-localizes with mRNA degradation associated proteins hDcp1 and hLSm4 in cytoplasmic GW bodies. The function of GWBs was not known, however more recent evidence suggested similarities between GWBs and cytoplasmic structures that contain hLSm proteins and hDcp1, the human homologue to a yeast decapping enzyme subunit. We used antibodies to hLSm4 and hDcp to show that both of these markers of an mRNA degradation pathway co-localize to the same structures as GW182. Control immunoblotting and/or immunoprecipitation experiments showed that anti-L-Sm4, anti-GW182 and anti-hDcp1 sera bound to their respective antigens, but did not cross-react with one another. Thus, our studies demonstrate that GW182, hLSm4 an hDcp1 are found in the same cytoplasmic structures and suggest that GW182 is involved in the same mRNA processing pathway as hLSm4 and hDcp1. Eystathioy T, Jakymiw A, Chan EKL, Séraphin B, Cougot N, Fritzler MJ. The GW182 protein co-localizes with mRNA degradation associated priteins hDcp1 and hLSm4 in cytoplasmic GW bodies. RNA 9: 1171-1173, 2003. IIF co-localization studies demonstrated that GW bodies co-localize with hLSm4 and hDcp1 in HEp-2 cells., A. Cytoplasmic bodies detected with the index human serum #18033 (Diluted 1/600) and rabbit anti-hLSm4 antibodies (diluted 1/200). C. Staining with the index patient serum #18033 (1/600 dilution) and rabbit anti-hDcp1 antibodies (diluted 1/600). D. IIF using the mAB 4B6 and the rabbit anti-hDcp1 antibodies (diluted 1/600). The secondary antibodies used were the following, Cy3 conjugated anti-human (IgG) and anti-mouse (IgG) antibodies (shown in the first column) and FITC conjugated anti-rabbit IgG antibodies (shown in the second column). The merged images are shown in the third column, which includes the DAPI stained nuclei. The scale bars in the left column are equal to 10 μm.

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Blondin D, Zhang Z, Shideler K, Hou H, Fritzler MJ, Mydlarski RP. The prevalence of non-organ specific autoantibodies in patients with pemphigus vulgaris. J Cutaneous Med & Surg 13: 82-87, 2009. PMID: 19298776 Mahler M, Fritzler MJ. PM1-Alpha ELISA: The assay of choice for the detection of anti-PM/Scl autoantibodies? Autoimmunity Rev 8: 373-378, 2009. PMID 19103309. Juřenčák R, Fritzler MJ, Tyrrell PN, Hiraki LT, Benseler SM, Silverman ED. Autoantibodies in Pediatric Systemic Lupus Erythematosus: Ethnic Grouping, Cluster Analysis and Clinical Correlations. J Rheumatol 36:416-21, 2009. PMID: 19208567. Nozawa K, Fritzler MJ, Takasaki Y, Wood MR, Chan EKL. Clustering of Golgi complex and other cytoplasmic organelles during apoptosis. Cell Biol Intl 33:148-57, 2009. PMID: 19000931 Lafyatis R, Kissin E, York M, Viger K, Fritzler MJ, Merkel P, Simms RW. B cell depletion with Rituximab in patients with diffuse cutaneous scleroderma. Arthritis Rheum Arthritis Rheum. 60:578-83, 2009. PMID: 19180481 Mahler M, Fritzler MJ. The changing landscape of the clinical value of the PM/Scl autoantibody system [editorial]. Arthritis Research & Therapy 11:R106, 2009. PMID: 19351430. Moser JJ, Chan EKL, Fritzler MJ. Optimization of immunoprecipitation-Western blot analysis in detecting GW182-associated components of GW/P Bodies. Nature Protocols 4: 674-485, 2009. PMID: 19373232. Lian SL, Li S, Fritzler MJ, Chan EKL. The C-terminal Half of Human Ago2 Binds to Multiple GW-rich Regions of GW182 and Requires GW182 to Mediate Silencing. RNA 15: 805-813, 2009, PMID: 19324964. El-Gabalawy HS, Robinson D, Hart DM, Elias B, Markland J, Peschken C, Schroeder M, Fritzler MJ, Cheang M, Oen K. Immunogenetic risks of anti-cyclical citrullinated peptide (CCP) antibodies in North American Native population with RA and their First Degree relatives. J Rheumatol 36:1130-5, 2009. PMID: 19411392 Schulte-Pelkum J, Fritzler MJ, Mahler M. Update on the Ro/SS-A Autoantibody system. Autoimmun Rev 8:632-7, 2009. PMID: 19393201 Moser JJ, Fritzler MJ, Ou Y, Rattner JB. The PCM-Basal Body/Primary Cilium Coalition. Seminars in Cell and Developmental Biology. Semin Cell Dev Biol. 2009 Jul 8. [Epub ahead of print] PMID: 19591955 Arnett FC, Gourh P, Shete S, Ahn CW, Honey RE, Agarwal SK, McNearney T, Fischbach M, Fritzler MJ, Mayes MD, Reveille JD. Major Histocompatibility Complex (MHC) Class II Alleles, Haplotypes, and Epitopes which Confer Susceptibility or Protection in the Fibrosing Autoimmune Disease Systemic Sclerosis: Analyses in Over 1300 American Caucasian, African and Hispanic Cases and 1000 Controls. Ann Rheum Dis Jul 12. [Epub ahead of print] PMID: 19596691 Assassi S, Fritzler MJ, Arnett FC, Norman GL, Shah KR, Gourh P, Manek N, Perry M, Ganesh D, Rahbar MH, Mayes MD. Primary Biliary Cirrhosis (PBC), PBC Autoantibodies, and Liver Function Abnormalities in a Large Population of Systemic Sclerosis Patients. J Rheumatol (in press). Schild-Poulter C, Su A, Shih A, Kelly OP, Fritzler MJ, Goldstein R, Haché RGJ. Association of autoantibodies to Ku and DNA repair proteins in connective tissue diseases. Rheumatology (Oxford) 47: 165-171, 2008. PMID: 18208821 Santiago M, Baron M, Miyachi K, Fritzler MJ. A Comparison of antibodies to cyclic citrullinated peptides in scleroderma, primary biliary cirrhosis and rheumatoid arthritis. Clinical Rheumatology 27: 77-83, 2008 PMID: 17570008. Nozawa K, Fritzler MJ, Ikeda K, Takasaki Y, Satoh M, Chan EKL. Differential anti-Golgi complex autoantibody production following murine lactate dehydrogenase-elevating virus infection. Immunopharmacology and Immunotoxiclogy 30:13-25, 2008. PMID 18306101. Zee JM, Shideler KK, Eystathioy T, Breucks AK, Fritzler MJ, Mydlarski RP. GW bodies: novel cytoplasmic compartments in normal human skin, Journal Invest Dermatology 128:2909-2912, 2008. PMID: 18548113 Fritzler MJ. Challenges to the Use of Autoantibodies as Predictors of Disease Onset, Diagnosis and Outcomes. Autoimmun Rev 7:616-620, 2008. PMID: 18603023. Miyachi K, Miyakawa H, Oda M, Horigome T, Fritzler MJ. Primary biliary cirrhosis and autoantibodies. Nihon Rinsho Meneki Gakkai Kaishi. 31:47-55, 2008. PMID: 18311042 Ioan-Facsinay A, Willemze A, Robinson D, Peschken C, Markland J, Elias B, Ménard H, Newkirk M, Fritzler MJ, Toes R, Huizinga T, El-Gabalawy H. Marked differences in fine-specificity and isotype usage of the anti-citrulline response in health and disease. Arthritis Rheum 58:3000-3008, 2008. PMID 18821680