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Back to Postdoctoral Fellowship Projects
Rose G. Mage, Laboratory of Immunology, NIAID(301-496-6113)/email: rmage@niaid.nih.gov and
Robert F. Bonner, Laboratory of Integrative and Medical Biophysics, NICHD (301-435-1946)/email: bonner@helix.nih.gov:
A RABBIT MODEL OF SYSTEMIC LUPUS ERYTHEMATOSUS: USE OF EXPRESSION MICRODISSECTION TECHNOLOGY FOR PROTEOMIC AND GENE EXPRESSION STUDIES OF CELLS FROM BRAIN AND LYMPHOID TISSUES OF AFFECTED ANIMALS - Systemic Lupus Erythematosus (SLE), a complex, chronic autoimmune disorder that predominately affects women in the childbearing years, is symptomatically diverse and etiologically multifactorial, with both genetic and environmental factors contributing to disease initiation and progression; as yet, no known cure or preventive strategy exists. In addition to known presenting clinical symptoms, including rash, inflammation (arthritis, nephritis), and neurological dysfunction (including seizures), a particular subset of patients having neuropsychiatric lupus may present dramatically with sudden onset of psychosis, and/or severe neurological/cognitive impairment that persists over time. Serological markers of SLE include autoantibodies to various nuclear antigens, including dsDNA. Animal models of SLE developed thus far predominantly use inbred strains of mice genetically susceptible to spontaneously developing a lupus-like disease and may diverge significantly from the human situation. We propose here that studying SLE in a different model, using immunization of genetically defined, pedigreed but non-inbred rabbits, will provide novel data pertinent to human SLE that will be further enhanced when current NHGRI sequencing of the rabbit genome is complete. Development of such a rabbit model is already in progress in the Mage laboratory. Confirmation of a previously published but unconfirmed report in non-pedigreed rabbits was achieved using a peptide sequence shared by both the spliceosomal autoantigen Sm B/B’ and EBV. We found that SLE-like autoantibody serology, including anti-dsDNA antibodies, developed in more than half of the 25 genetically related rabbits immunized thus far with either of two discrete MAP-peptides. The second peptide is found in the neuronal NMDA 2b glutamate receptor sequence. A similar peptide is recognized by some anti-dsDNA antibodies of mice and humans, making it of particular relevance to our interest in neuropsychiatric lupus. To date, five generations of related responding rabbits have been bred, and genetic linkage and female sex concordance with serology, pathology and/or clinical manifestations will be studied further independently within the Mage laboratory. It is proposed here that studying certain aspects of this SLE model in a co-mentoring relationship with the laboratory of Dr. Robert Bonner will provide both unique, cutting edge information about this model of SLE as well significant material for the expanded application and further development of Dr. Bonner’s novel expression laser microdissection technology (Tangrea et al., 2004). The latter will be invaluable for undertaking gene expression and proteomic analyses of brain tissue from immunized responder rabbits having SLE-like serology or symptoms. Identification of changes in expression of CNS genes and the identification and quantitation of neuronal epitopes bound by SLE-like autoantibodies from immunized rabbits will increase understanding of immune effects on brain function that may contribute to the development of neuropsychiatric lupus. In addition, an earlier successful collaboration between the Bonner and Mage labs (Mage et al., 2004), using a laborious precursor of the newly available technology, may be substantially extended. Expression microdissection technology coupled with gene sequencing will also be used with lymphocytes in tissue from responder rabbits to determine whether autoantibody-producing B-lymphocytes are clonally related and whether cross-reactive SLE-like autoantibodies develop when the sequences of rearranged antibody heavy and light chain genes diversify by somatic mutation and gene conversion The ultimate benefit from, and goal of, this co-mentored project would be to achieve a greater understanding of the etiology and progression of human SLE, including neuropsychiatric lupus, in order to arrive at potential therapeutic and/or preventive measures for the many women afflicted with this autoimmune disease.
Tangrea, M.A et al., Operator-Independent Retrieval of Cells for Molecular Profiling
Diagn Mol Pathol 13, 208-212, 2004
Mage, R. G., Bonner, R. F., and Obiakor, H. Microdissection of single or small numbers of cells for analyses of DNA and RNA by PCR. PCR Technology: Current Innovations, 2nd Edition, T. Weissensteiner, H. G. Griffin, and A. Griffin, eds. CRC Press, pp. 29-36, 2004.
