Therapy of human tumors in NOD/SCID mice with patient-derived reactivated memory T cells from bone marrow

In an analysis of 84 primary-operated breast cancer patients and 11 healthy donors, we found that the bone marrow of most patients contained memory T cells with specificity for tumor-associated antigens. Patients' bone marrow and peripheral blood contained CD8+ T cells that specifically bound HLA/peptide tetramers. In short-term culture with autologous dendritic cells pre-pulsed with tumor lysates, patients' memory T cells from bone marrow (but not peripheral blood) could be specifically reactivated to interferon-gamma-producing and cytotoxic effector cells. A single transfer of restimulated bone-marrow T cells into NOD/SCID mice caused regression of autologous tumor xenotransplants associated with infiltration by human T cells and tumor-cell apoptosis and necrosis. T cells from peripheral blood showed much lower anti-tumor reactivity. Our findings reveal an innate, specific recognition of breast cancer antigens and point to a possible novel cancer therapy using patients' bone-marrow-derived memory T cells.     

Transient chemokine receptor blockade does not prevent, but may accelerate type 1 diabetes in prediabetic NOD mice.

The influx of autoreactive lymphocytes into the site of an autoimmune inflammation is mediated by certain chemokines. Autoimmune insulitis in type 1 diabetes is viewed as the result of destructive Th-1-cells and their corresponding antigen-presenting cells infiltrating the pancreatic islets. Blocking the chemokine receptors that mediate a Th-1-reaction has been shown to reduce autoimmunity in other experimental autoimmune disorders. We used the NOD mouse model to investigate the potency of anti-CCR2 and anti-CCR5 antibodies to inhibit the influx of Th-1-cells into the pancreatic islets, thus preventing diabetes onset. Eleven-week-old female NOD mice were treated with 500 microg of a monoclonal anti-CCR5 or anti-CCR2 or an isotype control antibody every third day over two weeks. We did not observe any preventive effect in either treatment group, but accelerated diabetes onset in the anti-CCR5 treated group. The number of autoantigen-specific Th-1-cells detected in the two treated groups was not reduced, but increased in the anti-CCR5 group. Redundancy within the chemokine system may account for this lack of prevention, or the intervention may have come too late in the disease process. Furthermore, blocking Th-1 chemokine receptors in the late autoimmune process may also inhibit regulatory T-cells, thus accelerating rather than preventing the disease.     

Experimental infection of NOD/SCID mice reconstituted with human CD34+ cells with Epstein-Barr virus

Epstein-Barr virus (EBV)-induced lymphoproliferative disease is an important complication in the context of immune deficiency. Impaired T-cell immunity allows the outgrowth of transformed cells with the subsequent production of predominantly B-cell lymphomas. Currently there is no in vivo model that can adequately recapitulate EBV infection and its association with B-cell lymphomas. NOD/SCID mice engrafted with human CD34(+) cells and reconstituted mainly with human B lymphocytes may serve as a useful xenograft model to study EBV infection and pathogenesis. We therefore infected reconstituted mice with EBV. High levels of viral DNA were detected in the peripheral blood of all infected mice. All infected mice lost weight and showed decreased activity levels. Infected mice presented large visible tumors in multiple organs, most prominently in the spleen. These tumors stained positive for human CD79a, CD20, CD30, and EBV-encoded RNAs and were light chain restricted. Their characterization is consistent with that of large cell immunoblastic lymphoma. In addition, tumor cells expressed EBNA1, LMP1, and LMP2a mRNAs, which is consistent with a type II latency program. EBV(+) lymphoblastoid cell lines expressing human CD45, CD19, CD21, CD23, CD5, and CD30 were readily established from the bone marrow and spleens of infected animals. Finally, we also demonstrate that infection with an enhanced green fluorescent protein (EGFP)-tagged virus can be monitored by the detection of infected EGFP(+) cells and EGFP(+) tumors. These data demonstrate that NOD/SCID mice that are reconstituted with human CD34(+) cells are susceptible to infection by EBV and accurately recapitulate important aspects of EBV pathogenesis.     

TLR3-involved modulation of pregnancy tolerance in double-stranded RNA-stimulated NOD/SCID mice

This study aims to extend understanding of the relationship between TLR3-involved cell signaling and dsRNA-induced embryo resorption. Upon stimulation of dsRNA, the resorption rate of embryos was boosted dramatically in syngeneic mating BALB/c mice, but not significantly influenced in syngeneic mating NOD/SCID mice. Accordingly, there was an enhanced cell surface expression of TLR3 on placental CD45(+) cells derived from BALB/c mice, concomitant with both increased percentages of CD45(+)CD80(+) cells and CD8alpha(+)CD80(+) cells in flow cytometric analysis. In addition, both increased IL-2 and decreased IL-10 expression could be observed in CD45(+) cell group in the intracellular detection by flow cytometry. In contrast, no such trends were observed in NOD/SCID model, and its resorption rate of embryos was kept at a low level throughout pregnancy. Neutralizing Abs against TLR3 could abrogate the embryo rejection induced by dsRNA in BALB/c mice, and simultaneously could reduce the CD80(+) percentage in the CD45(+) cell group. These results indicate that the interaction between dsRNA and TLR3 may be involved in the mobilization of CD45(+)CD80(+) and CD8alpha(+)CD80(+) cells, followed by the up-regulation of IL-2 and down-regulation of IL-10 expression at the feto-maternal interface, and finally resulting in embryo rejection. The relatively low responsiveness of NOD/SCID mice may be one of the reasons why these mice appeared to be resistant to dsRNA-induced embryo resorption.     

Valproic acid affects the engraftment of TPO-expanded cord blood cells in NOD/SCID mice

Hematopoietic stem and progenitor cells (HSPC) can improve the long-term outcome of transplanted individuals and reduce the relapse rate. Valproic acid (VPA), an inhibitor of histone deacetylase, when combined with different cytokine cocktails, induces the expansion of CD34+ cell populations derived from cord blood (CB) and other sources. We evaluated the effect of VPA, in combination with thrombopoietin (TPO), on the viability and expansion of CB-HSPCs and on short- and long-term engraftability in the NOD/SCID mouse model. In vitro, VPA+TPO inhibited HSPC differentiation and preserved the CD34+ cell fraction; the self-renewal of the CD34+ TPO+VPA-treated cells was suggested by the increased replating efficiency. In vivo, short- and long-term engraftment was determined after 6 and 20 weeks. After 6 weeks, the median chimerism percentage was 13.0% in mice transplanted with TPO-treated cells and only 1.4% in those transplanted with TPO+VPA-treated cells. By contrast, after 20 weeks, the engraftment induced by the TPO+VPA-treated cells was three times more effective than that induced by TPO alone, and over ten times more effective compared to the short-term engraftment induced by the TPO+VPA-treated cells. The in vivo results are consistent with the higher secondary plating efficiency of the TPO+VPA-treated cells in vitro.     

Generation of transgenic mice on an NOD/SCID background using the conventional microinjection technique

Humanized mice, which refers to immunodeficient mice repopulated with the human immune system, are powerful tools for study in the field of immunology. It has been difficult, however, to generate these transgenic (Tg) mice directly from such strains as the NOD/SCID mouse. In this study, we describe a method developed by us for the generation of Tg mice on an NOD/SCID background. First, we obtained fertilized eggs efficiently by means of in vitro fertilization (IVF); then, we attempted to generate CAG-EGFP Tg mice on an NOD/SCID background, finding that delayed timing of the microinjection after the IVF improved the time to development of the two-cell-stage embryos and the obtainment of newborns. We successfully generated Tg mice and confirmed the germ-line transmission in the offspring. In conclusion, we established a novel system for directly generating transgenic mice on an NOD/SCID background. This novel system is expected to allow improved efficiency of the generation of humanized mice.     

Transfer from porcine insulin to human insulin in insulin-dependent diabetes mellitus: effects on insulin binding to IgG and glycemic control

Thirty type I diabetic patients who were treated for at least 2 years with a combination of regular and lente monocomponent porcine insulins were allocated in a double-blind study to either continued porcine insulin treatment or a transfer to the corresponding semi-synthetic human insulins. Insulin binding to IgG measured by an immunoelectrophoretic method, was followed at 3-month intervals for 1 year, and did not change after the transfer. The glycemic control, as assessed by hemoglobin A1 levels, tended to deteriorate in the human insulin group during the first 3 months of the trial and then return to the baseline level. It is concluded that a transfer from highly purified porcine insulin to human insulin apparently does not change the insulin binding to IgG in already sensitized patients.     

SCF modulates organ distribution and hematopoietic engraftment of CB-derived pluripotent HPC transplanted in NOD/SCID mice

BACKGROUND: During the engraftment process of transplanted HPC, the beta 1 integrins play an important role. An increased expression and adhesive function of these integrins has been shown in hematopoietic cell lines and peripheral blood-derived HPC after stimulation with SCF. In this study, we investigated the influence of SCF on the engraftment capability and tissue distribution of cord blood (CB) cells transplanted into NOD/SCID mice. METHODS: CB-derived mononuclear cells were injected i.v. into 40 sublethally irradiated NOD/SCID mice with or without the addition of 10 microg SCF/ mouse. Six weeks later, BM, liver, kidneys, brain and testicular tissue were analyzed for the prevalence of human cells. RESULTS: The mean proportion of human CD45+ CD71+ cells within the BM of all engrafted mice receiving SCF in addition to the cells was 1.7-fold higher than in the respective controls. By immunohistochemical staining, human cells were found in liver and kidneys of the engrafted animals, but not in neural tissues or testicles. In the kidneys, the proportion of human cells rose significantly from 0.07 +/- 0.3% to 0.24 +/- 0.05% with treatment with SCF, compared with untreated controls. Single human cells in the liver additionally stained positive for human albumin, indicating organ-specific differentiation of the transplanted cells. DISCUSSION: Our results indicate that stimulation with SCF modulates the tissue distribution of the progeny of the transplanted cells and improves the hematopoietic engraftment potential of transplanted CB cells.     

Control of metastasized pancreatic carcinomas in SCID/beige mice with human IL-2/TKD-activated NK cells

Pancreatic carcinoma, the fifth leading cause of cancer-related mortality, frequently presents the stress-inducible heat shock protein 70 (Hsp70) on the cell membrane. Therefore, we explored an immunological approach exploiting the efficacy of NK cells activated either with low dose IL-2 plus Hsp70-peptide TKDNNLLGRFELSG (TKD; IL-2/TKD) or with IL-2 alone in a xenograft pancreatic carcinoma model. An orthotopic injection of either 2.5 x 10(6) or 1 x 10(6) Colo357 cells in SCID/beige mice resulted in rapidly growing primary tumors and the development of hepatic metastases on days 5 and 10, respectively. In line with results of in vitro migration assays, these NK cells also had the capacity to infiltrate pancreatic tumors and liver metastases in tumor-bearing mice. In vitro, a combined treatment of NK cells with IL-2/TKD but neither of the two treatments alone causes a profound increase in the lytic capacity against Hsp70 membrane-positive Colo357 cells. In vivo, a single i.v. injection of these NK cells on day 15 post-tumor inoculation resulted in a significant reduction in tumor weights, a delayed onset of hepatic metastases, and a prolonged life expectancy. In contrast, identically treated T cells and NK cells treated with IL-2 alone were significantly less efficient in controlling pancreatic tumors and metastases. Most importantly, four repeated i.v. infusions of IL-2/TKD-activated NK cells eradicated primary tumors and prevented hepatic metastases. In summary, our mouse data have implicated that NK cells preactivated with IL-2/TKD might provide a novel therapeutic tool for the treatment of aggressive, Hsp70-positive pancreatic carcinoma.     

Fas and Fas ligand immunolocalization in pancreatic islets of NOD mice during spontaneous and cyclophosphamide-accelerated diabetes

During insulin-dependent diabetes mellitus, immune cells which infiltrate pancreatic islets mediate beta cell destruction over a prolonged asymptomatic prediabetic period. The molecular mechanisms of beta cell death in vivo remain unresolved. At least two major molecular processes of destruction have been proposed. One involves the Fas–FasL (Fas–Fas ligand) system and the other, the perforin pathway. Here, dual-label immunohistochemistry was employed to examine the intra-islet expression, distribution and cellular sources of Fas and FasL in the NOD mouse, during spontaneous diabetes (days 21, 40 and 90) and following acceleration of diabetes with cyclophosphamide (days 0, 4, 7, 11 and 14 after cyclophosphamide administration). The expression of the proteins was correlated with advancing disease. FasL was expressed constitutively in most beta cells but not in glucagon or somatostatin cells or islet inflammatory cells and paralleled the loss of insulin immunolabelling with advancing disease. It was also expressed in beta cells of non-diabetes prone CD-1 and C57BL/6 mice from a young age (day 21). Strong immunolabelling for Fas was first observed in extra-islet macrophages and those close to the islet in NOD and non-diabetes-prone mice. During spontaneous and cyclophosphamide diabetes, it was observed in a higher proportion of islet infiltrating macrophages than CD4 and CD8 T cells, concomitant with advancing insulitis. In cyclophosphamide-treated mice, the proportion of Fas-positive intra-islet CD4 and CD8 T cells at day 14 (with and without diabetes) was considerably higher than at days 0, 4, 7 and 11. At days 11 and 14, a proportion of Fas-positive intra-islet macrophages co-expressed interleukin-1 and inducible nitric oxide synthase. Fas was not detectable in beta cells and other islet endocrine cells during spontaneous and cyclophosphamide induced diabetes. Our results show constitutive expression of FasL in beta cells in the NOD mouse and predominant expression of Fas in intra-islet macrophages and to a lesser extent in T cells prior to diabetes onset. Interleukin-1 in intra-islet macrophages may induce Fas and inducible nitric oxide synthase expression in an autocrine and paracrine manner and mediate beta cell destruction or even death of some macrophages and T cells. However, other mechanisms of beta cell destruction during spontaneous and cyclophosphamide-accelerated diabetes and independent of Fas–FasL, require examination.     

Immunoregulation during disease progression in prediabetic NOD mice: inverse expression of arginase and prostaglandin H synthase 2 vs. interleukin-15.

Non-obese diabetic (NOD) mice spontaneously develop insulin dependent diabetes due to autoimmune destruction of beta-cells. The progression of insulitis can be accelerated and synchronized in the pancreas by a single injection of 250 mg/kg cyclophosphamide. In this study, we will report on three immune mediators that were not known to be expressed during insulitis until now. Early insulitis in ten-week-old female NOD mice was associated with strong expression of prostaglandin H synthase 2 in the pancreas and of arginase, an antagonist enzyme of the inducible NO synthase. After acceleration of insulitis progression by cyclophosphamide, expression of the two enzymes was downregulated within 24 h. There was strong concomitant upregulation of IL-15 gene expression that preceded lymphocyte invasion of islets and a rise of IFN-gamma mRNA levels by several days. The comparison of individual pancreata showed that the expression of IL-12 and IL-18 mRNA closely correlated with levels of IL-15 gene expression. We conclude that arginase and prostaglandin H synthase 2 expression is associated with peri-insulitis, while IL-15 is a candidate cytokine in driving destructive insulitis, as it elicits Th1-cytotoxic responses in lymphoid as well as in non-lymphoid immune cells and is unusually resistant to downregulation by antagonistic cytokines. This is the first report on arginase, prostaglandin H synthase 2 and IL-15 expression in pancreatic lesions of prediabetic NOD mice.     

Low plasma C4 concentrations: association with microangiopathy in insulin dependent diabetes.

Plasma C4 concentrations were measured in insulin dependent diabetics with and without microangiopathy and in controls. The diabetics had significantly lower C4 values than controls (p less than 0.001), and patients with insulin dependent diabetes and microangiopathy had lower values than those without this complication (p less than 0.001). There was a 7.1-fold increase in the prevalence of complications in the diabetics with low C4 values. Of 41 diabetics whose rate of albumin excretion was measured, 13 had increased rates and 11 of these had low C4 concentrations. Low plasma C4 concentration in insulin dependent diabetes is strongly associated with microvascular disease and may identify diabetics with a particular propensity to develop this complication.     

Centromeric interval of chromosome 4 derived from C57BL/6 mice accelerates type 1 diabetes in NOD.CD72 congenic mice

The nonobese diabetic (NOD) mouse is a useful model of autoimmune type 1 diabetes exhibiting many similarities to human type 1 diabetes patients including the presence of auto-reactive T cells and pancreas-specific autoantiboies. Multiple Idd loci control the development of diabetes in NOD mice. CD72, a B cell membrane-bound glycoprotein carrying a C-type lectin-like domain, is an inhibitory co-receptor of the B cell antigen receptor (BCR) that negatively regulates BCR signaling. Among four known haplotypes of mouse CD72, NOD mice carry the CD72^c haplotype, whereas most of the other inbred strains of mice carry either CD72^a or CD72^b. In this study, we generated congenic NOD.CD72^b mice that carry C57BL/6 (B6) mouse-derived centromeric chromosome 4 interval (24-45 cM) surrounding the CD72^b locus. Unexpectedly, NOD.CD72^b mice were not protected from diabetes, but rather exhibited accelerated development of both insulitis and diabetes. Our result defines novel locus or loci in the vicinity of CD72 gene that negatively control diabetes, indicating that NOD disease is under complex genetic controls of not only Idd genes but also disease-resistant genes.     

Hormone-sensitive lipase deficiency suppresses insulin secretion from pancreatic islets of Lep mice

It has long been a matter of debate whether the hormone-sensitive lipase (HSL)-mediated lipolysis in pancreatic β-cells can affect insulin secretion through the alteration of lipotoxicity. We generated mice lacking both leptin and HSL (Lep^ob/ob/HSL^−/−) and explored the role of HSL in pancreatic β-cells in the setting of obesity. Lep^ob/ob/HSL^−/− developed elevated blood glucose levels and reduced plasma insulin levels compared with Lep^ob/ob/HSL^+/+ in a fed state, while the deficiency of HSL did not affect glucose homeostasis in Lep^+/+ background. The deficiency of HSL exacerbated the accumulation of triglycerides in Lep^ob/ob islets, leading to reduced glucose-stimulated insulin secretion. The deficiency of HSL also diminished the islet mass in Lep^ob/ob mice due to decreased cell proliferation. In conclusion, HSL affects insulin secretary capacity especially in the setting of obesity.     

Demonstration of a splenic cytotoxic effector cell in mice of genotype SCID/SCID.BG/BG

Splenocytes from mice of genotype scid/scid.bg/bg were tested in vitro to characterize the nature of the immunological deficit in these doubly mutant animals. The cells were unresponsive to the mitogens LPS and Con A and to alloantigens, as predicted for scid/scid genotype. Splenocytes from scid/scid.bg/bg lysed the NK cell-sensitive target cell line YAC at levels approximately 50% lower than those observed for scid/scid splenocytes. Splenocytes from SCID-beige mice failed to lyse the NK-resistant, LAK-sensitive cell line P815 but showed high levels of activity against the murine placental cell line Be6. Lytic activity was found in both nonadherent and plastic adherent cells and was eliminated by pretreatment of the effectors with anti-asialo-GM1 and complement. Incubation of 1 x 10(5) splenocytes with hrIL-2 failed to induce blastogenesis in scid/scid.bg/bg cells but produced a response in cultures of scid/scid or bg/bg spleen cells. However, blastogenesis and elevated levels of LAK-type killing were observed following incubation of higher numbers of scid/scid.bg/bg splenocytes in hrIL-2. Thus, doubly mutant scid/scid.bg/bg mice have reduced NK cell activity, in comparison to scid/scid mice, and appear to possess LAK-like effector cells and LAK cell precursors.     

Combination therapy with an antioxidant and a corticosteroid prevents autoimmune diabetes in NOD mice.

Oxygen free radicals have been implicated as mediators of pancreatic islet beta cell damage in autoimmune, insulin-dependent diabetes mellitus (IDDM). In this study, we show that the antioxidant, probucol, produced only a small decrease in diabetes incidence in nonobese diabetic (NOD) mice, an animal model for human IDDM. However, combination of probucol with the antiinflammatory corticosteroid, deflazacort, produced an early synergistic effect, delaying diabetes onset by 3 weeks, and a later additive effect, decreasing diabetes incidence from 68% (17 of 25 mice) to 23% (6 of 26 mice, p < 0.005). Protection against diabetes by the combination of probucol and deflazacort was associated with a significant decrease in pancreatic islet infiltration by macrophages/lymphocytes (insulitis) and prevention of islet beta cell loss.     

Establishment of a new model of human multiple myeloma using NOD/SCID/gammac(null) (NOG) mice

We developed a new experimental animal model of human multiple myeloma using immunodeficient NOD/SCID/gammac(null) (NOG) mice. A human myeloma cell line, U266, was intravenously inoculated into 20 NOG mice, all of which developed hind leg paralysis and distress around 6 weeks after transplantation. Pathological studies showed that only the bone marrow was infiltrated with U266 cells, and no cells were present in other organs. Osteolytic lesions in cortical bones and loss of trabecular bones were prominent in U266-transplanted NOG mice. In contrast, U266 cells were not detected in CB17scid or NOD/SCID mice 6 weeks after intravenous inoculation. Human IgE, produced by U266 cells, was detected in the serum of U266-transplanted NOG mice by ELISA. The results indicated that this hu-myeloma NOG model might be useful for studying the pathogenesis of myeloma and related osteolytic lesions, and are suggestive of its applicability to the future development of new drugs.     

Proliferation of functional human natural killer cells with anti‐HIV‐1 activity in NOD/SCID/Jak3null mice

Natural killer cells, a critical component of the innate immune system, eradicate both virus‐infected cells and tumor cells through cytotoxicity and secretion of cytokines. Human NK cell research has largely been based on in vitro studies because of the lack of appropriate animal models. In this study, a selective proliferation model of functional human NK cells was established in NOD/SCID/Jak3^null (NOJ) mice transplanted with peripheral blood mononuclear cells (PBMC) and K562 cells. The antiviral effects of NK cells were evaluated by challenging this mouse model with HIV‐1. The percentage of intracellular p24⁺ T cells and the amount of plasma p24 was decreased compared with NOJ mice transplanted with PBMC. Our findings indicate that NK cells have an anti‐HIV‐1 effect through direct cytotoxicity against HIV‐1‐infected cells. These mice provide an important model for evaluating human NK function against human infectious diseases such as HIV‐1 and malignancies.