Islet-reactive T-cell clones from NOD mice provide an important approach to the investigation of antigens with relevance to type I diabetes. To identify a source of [beta]-cell antigen suitable for biochemical studies, we have used two islet-specific, diabetogenic T-cell clones to test [beta]-tumor cells. [beta]-tumor cell lines, maintained in continuous culture, were found to lose antigenicity rapidly. However, cells harvested directly from [beta]-tumors arising spontaneously in the transgenic NOD/Lt-Tg(RIPTag)1Lt mouse proved to be a potent source of [beta]-cell antigen for the T-cell clones. Subcellular fractionation of [beta]-tumor cells showed that the T- cell antigen was highly enriched in the [beta]-granule fraction and that this activity was associated with the granule membrane. Diabetes 43:197-203, 1994
The NOD mouse has been well established as a spontaneous animal model of autoimmune diabetes in which progression of the disease closely resembles that of type I diabetes in humans. In the NOD mouse, the characteristic intra-islet cellular infiltration known as insulitis begins at |6 weeks of age, and hyperglycemia may be observed starting at 3-4 months. Although T-cells are known to play an important role in this process, little is known about the antigens to which they are responding. To investigate more fully the involvement of T-cells in diabetes and to try to identify their target antigens, we have produced a panel of islet-specific T-cell clones from NOD mice.
As described previously, these islet-specific T-cell clones are all of the CD4 phenotype and respond in in vitro proliferation assays to whole islet cell antigen and NOD antigen-presenting cells (APC) [1,2]. The clones do not respond to either islet cells or APC alone. Analysis by flow cytometry of the T-cell clones for binding with anti-T-cell receptor (TCR) V[beta] antibodies and, in some cases, sequencing of TCR variable gene regions  have demonstrated monoclonality. The pathogenic properties of these clones have been demonstrated in vivo. A number of the clones have been shown to mediate islet graft destruction  and induce disease in young nondiabetic NOD recipients  and in several NOD F1 strains (J. Peterson and K. H., unpublished observations).
The in vitro antigen responses of the islet-specific T-cell clones in our panel have several properties in common. The clones are all major histocompatability complex-restricted, responding to islet antigen only in the presence of APC from the NOD mouse. Because the lines were selected by culture with NOD islet cells, all of the clones respond to islet antigen from NOD mice, and most also respond to islet cells from other mouse strains. In assays to measure cytokine production, all of the clones tested have displayed a Th1 phenotype by producing interleukin-2 (IL-2) and interferon-[gamma] (IFN-[gamma]) but not interleukin-4 (IL-4). In this study, we provide new information on the antigen response of islet-reactive clones from our panel, focusing in particular on two clones, BDC-2.5 and BDC-6.9.
RESEARCH DESIGN AND METHODS
Mice used as a source of normal islet antigen were purchased either from The Jackson Laboratory (Bar Harbor, ME) or Taconic Farms (Germantown, NY) or bred in...