This study addresses in-depth the prevalence, cause, and correction of low MHC class I expression on lymphoid cells in Sjogren's syndrome and will seek to determine if the phenomenon is central to the autoimmune process and disease pathogenesis. It will seek evidence that insufficient autologous peptide presentation is the result of defective transporter protein function. The proposal is timely because of advances in understanding the autoimmune pathogenesis of diabetes, which should now be applied to the study of Sjogren's syndrome and other immune-mediated disease. Our recent studies of autoimmune diabetes, both in humans and in murine models, have demonstrated a functional defect in endogenous presentation of self-peptide fragments in the groove of major histocompatibility complex (MHC) class I molecules, associated with decreased cell surface expression of class I antigens on lymphocytes. We believe that two genes (Tap-1 and Tap-2) in the MHC class II region, which control the delivery and association of endogenous peptides to class I molecules, may be involved in the diabetic tolerance defect. This grant will investigate the hypothesis that defective MHC class I expression/function is present and potentially pathogenic in patients with Sjogren's syndrome. Preliminary results show low cell surface expression of MHC class I molecules as well as a defect in the presentation of self- antigens in lymphocytes from individuals with Sjogren's syndrome. These results suggest that our model of failed tolerance caused by insufficient MHC class I/self-peptide presentation in diabetes may also be operative in Sjogren's syndrome. A new understanding of the disease mechanism in Sjogren's syndrome could lead to novel approaches to diagnosis and treatment of this serious disease.
The aims of this grant are therefore: (1) Quantitate MHC class I expression on peripheral blood lymphocytes from large numbers of Sjogren's syndrome patients of diverse clinical and ethnic composition; (2) Evaluate class I intracellular processing by biochemical means; (3) Measure transporter message and protein in Sjogren's syndrome cells; (4) Attempt to correct low class I expression in Sjogren's syndrome cells by cytokine treatments; (5) Attempt to correct low class I expression in Sjogren's syndrome cells by transfecting intact transporter genes; and, (6) Investigate class I deficient mice as a new animal model for Sjogren's syndrome.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE011151-04
Application #
2377653
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Project Start
1994-03-01
Project End
1999-02-28
Budget Start
1997-03-01
Budget End
1999-02-28
Support Year
4
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
City
Boston
State
MA
Country
United States
Zip Code
02199
Hayashi, Takuma; Faustman, Denise L (2002) Development of spontaneous uterine tumors in low molecular mass polypeptide-2 knockout mice. Cancer Res 62:24-7
Hayashi, T; Faustman, D L (2001) Selected contribution: Association of gender-related LMP2 inactivation with autoimmune pathogenesis. J Appl Physiol 91:2804-15
Hayashi, T; Faustman, D (2000) Essential role of human leukocyte antigen-encoded proteasome subunits in NF-kappaB activation and prevention of tumor necrosis factor-alpha-induced apoptosis. J Biol Chem 275:5238-47
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Hayashi, T; Faustman, D (2000) Defective function of the proteasome in autoimmunity: involvement of impaired NF-kappaB activation. Diabetes Technol Ther 2:415-28
Hayashi, T; Faustman, D (1999) NOD mice are defective in proteasome production and activation of NF-kappaB. Mol Cell Biol 19:8646-59
Fu, Y; Yan, G; Shi, L et al. (1998) Antigen processing and autoimmunity. Evaluation of mRNA abundance and function of HLA-linked genes. Ann N Y Acad Sci 842:138-55
Yan, G; Shi, L; Fu, Y et al. (1997) Screening of the TAP1 gene by denaturing gradient gel electrophoresis in insulin-dependent diabetes mellitus: detection and comparison of new polymorphisms between patients and controls. Tissue Antigens 50:576-85
Yan, G; Fu, Y; Faustman, D L (1997) Reduced expression of Tap1 and Lmp2 antigen-processing genes in the nonobese diabetic (NOD) mouse due to a mutation in their shared bidirectional promoter. J Immunol 159:3068-80
Shi, L; Yan, G; Fu, Y et al. (1997) Human TAP1 polymorphisms detected by denaturing gradient gel electrophoresis. Tissue Antigens 49:421-6

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