Effect of Modified Diabetic Splenocytes on Mice Injected with Multiple Low-Dose Streptozotocin

Abstract

This work reports the effects of a previous injection of mitomycin-modified splenocytes from multiple-low dose streptozotocin-treated mice (mld-sz) on autoimmune diabetes produced by mld-sz. Our work shows that a previous inoculation of modified mononuclear splenocytes from mld-sz mice prevents alterations in glycemia, in insulin secretion (IS) pattern from isolated perifused islets, and in mass of pancreatic islets. Immunohistochemistry showed an alteration in the number of beta, but not of alpha or delta cells. While a mononuclear intra-islet infiltration was observed in mld-sz mice, a predominantly polar or peri-islet infiltration was seen in vaccinated mice. Islet-associated mononuclear cells from mld-sz mice produced diabetes and induced a diminished IS when transferred to normal receptors. Those cells from previously vaccinated mld-sz mice had no effect when injected into normal receptors. In addition, they also inhibited the damage induced in normal receptors by the islet-associated mononuclear cells from mld-sz animals. Cellular death was also prevented by previous vaccination. Our results suggest that vaccination with modified splenocytes from mld-sz mice is capable of shifting the islet cells infiltration pattern from an aggressive one toward a protective one and thus preventing the ß cell destruction observed in mld-sz mice.

Early Manifestations in Multiple-low-dose Streptozotocin-induced Diabetes in Mice

“…23 The immunologic component in the mld-SZ diabetic model is highlighted by the absence of diabetes development in T-cell-deficient mice and by the protective effects of immunosuppressive or anti-inflammatory compounds 4,9,22,24,25 or vaccination with modified autoreactive lymphocytes. 5,6 It has been shown that mld-SZ administration depresses some constituents of the immune system, such as CD4 + T cells and some T-cell reactions, whereas macrophage activity and nonspecific cytotoxicity and production of interferon-g are activated. 26,27 Immune responses regulated by local cytokines may contribute to the diabetic state induced by mld-SZ because reduction and up-regulation of T H 2-type cytokines were, respectively, associated with susceptibility and resistance to mld-STZ-induced diabetes.…”

“…In these mice, a diminished insulin secretion is present 15 days after the transfer procedure, and a preferential trapping of transferred lymphocytes in islets of recipient mice was observed. 5,6,8,9 The aim of this study was to investigate the ability of mononuclear spleen cells (MSs) from treated mice to impair insulin secretion in normal recipient mice or in cultured dispersed rat islet cells at different days after mld-SZ administration. With this purpose, we studied insulin secretion patterns in mice transferred with MSs isolated from mld-SZ donors and the capacity of MSs from mld-SZ mice to exert an in vitro antib-cell immune aggression.…”

“…This treatment results in cellular and humoral immune reactions against b cells, presumably made antigenic by mld-SZ injections. [2][3][4][5][6][7] Another animal model consists of an adoptive transfer of splenic lymphocytes from mld-SZ diabetic donors to healthy syngeneic recipients. In these mice, a diminished insulin secretion is present 15 days after the transfer procedure, and a preferential trapping of transferred lymphocytes in islets of recipient mice was observed.…”

Short administration of polyclonal anti-T cell antibody (ALS) in NOD mice with extensive insulitis prevents subsequent development of autoimmune diabetes

“…Multiple slides (3e4) randomly selected from each pancreas were evaluated for mononuclear cell infiltration. Severity of infiltration was classified into five categories as previously reported [19]: no infiltration, polar islet infiltration, peri-islet (surrounding) infiltration, intra-islet infiltration, and extensive intra-islet infiltration covering the entire islet. For immunohistochemical staining, tissues were fixed in Bouin's solution, processed, and paraffin-embedded.…”

Inhibition of Nitric Oxide Generation in Mononuclear Splenocytes from Multiple-Low-Dose-Streptozotocin Diabetic Mice

“…In these mice, a diminished insulin secretion is present 15 days after the transfer procedure, and a preferential trapping of transferred diab.MS in islets of recipient mice was observed. Diab.MS obtained as early as day 4, were able to impair insulin secretion in transferred normal syngeneic recipients (Buschard et al, 1977;Pastorale et al, 2002;Karabatas et al, 2000 and.…”