The natural history of lymphocyte subsets infiltrating the pancreas of NOD mice

Abstract

A longitudinal study of lymphocytic infiltration in the endocrine pancreas of non-obese diabetic mice was performed to investigate the role of different lymphocyte subsets in the pathogenesis of diabetes. The incidence of insulitis and the percentage of mononuclear cell subsets in the pancreas were evaluated in non-obese diabetic mice of various ages (5, 9, 13, 17, 22, 29 and 36 weeks). Cryostat sections of pancreas were stained with heamatoxilin-eosin or with different monoclonal antibodies against total T lymphocytes, helper T lymphocytes, cytotoxic/suppressor T lymphocytes, activated interleukin 2 receptor positive lymphocytes and B lymphocytes. A monoclonal antibody against Class-II antigens was also used. Positive cells were revealed by the immunoperoxidase technique. Insulitis was found in 5 weeks old mice but to a lesser extent than in adult animals. No significant variation between infiltrating cell subsets was found in different age groups. T lymphocytes ranged between 20.4% and 28.1%, B lymphocytes between 28.8% and 30.8% and Class-II positive cells between 22.8% and 32.2%. Interleukin 2 receptor positive cells ranged between 5.5% and 8.5% as detected with AMT-13 monoclonal antibody which recognise the interleukin 2 binding site. A higher percentage of activated cells was observed using another monoclonal antibody (7D4) directed against a different epitope of the interleukin 2 receptor, suggesting the presence of activated lymphocytes with interleukin 2 receptors saturated by interleukin 2. No insulin-containing cells were found to express Class-II molecules as demonstrated by a double immunofluorescence technique. Most infiltrating mononuclear cells were found to be positive for Class-II and L3T4 antigens or to be Class-II positive and express surface immunoglobulins.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of glutamic acid decarboxylase-activated T cells with I-Ag7tetramers

“…reports that more CD4 ϩ T cells infiltrated the islets (45,46). However, the tetramer staining results showed that the tetramers detected T cells infiltrating the islets of NOD mice with a percentage that is not significantly above the background (data not shown).…”

IFNγ/TNFα synergism in MHC class II induction: effect of nicotinamide on MHC class II expression but not on islet-cell apoptosis

“…Previous studies showing the aberrant expression of MHC class II molecules did not clearly demonstrate their expression on islet cells because macrophages could not be ruled out as a source of MHC class II molecules [5,31,32]. MIN6N8 cells are representative insulinoma cells of NOD origin that produce and secrete insulin according to ambient glucose concentrations.…”

Lymphocyte vaccination protects prediabetic non-obese diabetic mice from developing diabetes mellitus

“…In mice vaccinated at 6 weeks of age, insulitis is barely detectable [12] and, typically, therapies initiated at this stage have a much greater chance of successfully preventing diabetes. Such early studies, therefore, are useful for indicating whether a therapy has any potential for human IDDM, but not for planning the timing of clinical intervention, since there is not an equivalent early stage of the disease in man that can be readily identified.…”