GAD-reactive CD4+ Th1 cells induce diabetes in NOD/SCID mice.
Although glutamic acid decarboxylase (GAD) has been implicated in IDDM, there is no direct evidence showing GAD-reactive T cells are diabetogenic in vivo. To address this issue, 3-wk-old NOD mice received two injections of purified rat brain GAD; one mouse rapidly developed diabetes 3 wk later. Splenocytes from this mouse showed a proliferative response to purified GAD, and were used to generate a CD4+ T cell line, designated 5A, that expresses TCRs encoding Vbeta2 and Vbeta12. 5A T cells exhibit a MHC restricted proliferative response to purified GAD, as well as GAD65 peptide 524-543. After antigen-specific stimulation, 5A T cells secrete IFNgamma and TNFalpha/beta, but not IL-4. They are also cytotoxic against NOD-derived hybridoma cells (expressing I-Ag7) that were transfected with rat GAD65, but not nontransfected hybridoma cells. Adoptive transfer of 5A cells into NOD/SCID mice produced insulitis in all mice. Diabetes occurred in 83% of the mice. We conclude that GAD injection in young NOD mice may, in some cases, provoke diabetes due to the activation of diabetogenic T cells reactive to GAD65 peptides. Our data provide direct evidence that GAD65 autoimmunity may be a critical event in the pathogenesis of IDDM.
Zekzer
D
D
Section of Endocrinology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Wong
F S
FS
Ayalon
O
O
Millet
I
I
Altieri
M
M
Shintani
S
S
Solimena
M
M
Sherwin
R S
RS
D019264:Adoptive Transfer; D000818:Animals; D001324:Autoantigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002455:Cell Division; D003601:Cytotoxicity Tests, Immunologic; D003921:Diabetes Mellitus, Experimental / Q000276:immunology*; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D005968:Glutamate Decarboxylase / Q000008:administration & dosage / Q000276:immunology*; D006183:H-2 Antigens / Q000276:immunology; D064532:Histocompatibility Antigen H-2D; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008233:Lymphotoxin-alpha / Q000096:biosynthesis; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D051381:Rats; D018417:Th1 Cells / Q000276:immunology*
D001324:Autoantigens; D006183:H-2 Antigens; C024755:H-2K(K) antigen; D064532:Histocompatibility Antigen H-2D; D000949:Histocompatibility Antigens Class II; D008233:Lymphotoxin-alpha; D015847:Interleukin-4; D007371:Interferon-gamma; D005968:Glutamate Decarboxylase