Regional variations in the distribution of small intestinal intraepithelial lymphocytes in alymphoplasia (aly/aly) mice and heterozygous (aly/+) mice.

Regional variations in intraepithelial lymphocytes (IELs) in the small intestine were examined in alymphoplasia mutant (aly/aly) mice, which are characterized by the systemic absence of lymph nodes and Peyer's patches, and heterozygous (aly/+) mice. The small intestines were taken from 10 to 12-week-old mice and divided equally into 3 parts (the proximal, middle and distal parts). IELs were isolated from each part of the intestine and analyzed with a flow cytometer. The number of IELs in the distal part was significantly fewer in aly/aly mice compared with aly/+ mice, although the total number of small intestinal IELs were comparable between them. As to the IELs subsets, regional variations in alphabeta T cells and gammadelta T cells were observed in aly/+ mice, but they disappeared in aly/aly mice. However, regional variations in composition of alphabeta T cell subsets were similarly observed in both aly/aly mice and aly/+ mice. This indicates that, although not essential, mesenteric lymph nodes (MLN) and/or Peyer's patches may modify the regional variations in IELs.     

Immunodeficiency of alymphoplasia mice (aly/aly) in vivo: structural defect of secondary lymphoid organs and functional B cell defect

Alymphoplasia mice (aly/aly) have been shown to be deficient for a nuclear factor-kappaB-inducing kinase involved in signal transduction of lymphotoxin beta receptor (LT-betaR) and of CD40, resulting in structural defects of secondary lymphoid organs and highly increased susceptibility to viral infections. We analyzed the anti-viral immune response of bone marrow chimeras (BMC) between aly/aly mice and (C57BL/6 x DBA2)F1 mice (B6D2F1) to evaluate in vivo whether the structural defects of secondary lymphoid organs or intrinsic B or T cell defects led to immunodeficiency in aly/aly mice. Transfer of aly/aly bone marrow into B6D2F1 mice (aly/aly-->B6D2F1) led to excellent T but poor B cell reconstitution of recipients. Antiviral cytotoxic T cell (CTL) responses of aly/aly-->B6D2F1 BMC were clearly improved compared to aly/aly mice whereas virus-neutralizing IgG reponses were virtually absent. Therefore, the inefficient CTL response was predominantly caused by the structural defect of secondary lymphoid organs and not by an intrinsic T cell defect. In contrast, B cells of aly/aly origin were unable to undergo isotype switch after viral infections, indicating an intrinsic B cell defect in vivo. Overall, aly/aly mice show the combined immunodeficient phenotype of mice deficient for LT-3R with B cells functionally deficient for CD40.     

Impaired function of dendritic cells in alymphoplasia (aly/aly) mice for expansion of CD25+CD4+ regulatory T cells

Alymphoplasia (aly/aly) mice are from a naturally occurring strain with a mutation in nuclear factor-kappa B inducing kinase (NIK). The NIK mutation causes disruption of the architecture of the thymus and spleen and aly/aly mice show decreased numbers of CD25+CD4+T cells in the spleen. For the expansion of CD25+CD4+T cells, interactions between dendritic cells (DCs) and CD25+CD4+ regulatory T cells are necessary. We investigated the ability of DCs to induce expansion of CD25+CD4+T cells. We found that DCs are reduced in the spleen of aly/aly mice, and showed low expressions of CD80, CD86 and MHC class II molecules on the surface. DCs from aly/aly mice showed decreased ability to present ovalbumin (OVA) to T cells from OVA specific TCR transgenic mice, and a decreased ability for alloantigen presentation. Further, DCs showed a decreased ability to induce expansion of CD25+CD4+T cells in vitro. Our results suggested that the impairment of DCs in aly/aly mice is responsible, at least in part, for the decreased numbers of CD25+CD4+T cells in the periphery of aly/aly mice.     

The splenic marginal zone is absent in alymphoplastic aly mutant mice

aly is a unique spontaneous autosomal recessive mutation in mice that causes a deficiency in the systemic lymph nodes (LN) and Peyer's patches (PP). aly also induces abnormal histological findings in the spleen and a deficiency in humoral and cell-mediated immune functions, although lymphocytes of the aly/aly mouse show virtually normal immune responses in vitro. We studied the structure of the spleen of aly mice in detail by immunohistochemistry and electron microscopy. We found that the spleen of the aly/aly mouse was deficient in the expression of specific antigens for marginal metallophils (MM), marginal zone macrophages (MZM) and fibroblastic reticular cells (FRC), which are components of the marginal zone (MZ) of the spleen. Morphological analysis indicated that the aly/aly spleen is deficient in the structure of MZ, which may, in part, account for the severe immunodeficiency in the aly/aly mouse. We then performed reciprocal bone marrow transplantation experiments (BMT) between normal and aly mice and found a clear correlation between the formation of LN and the development of the splenic MZ in these mice; i.e. successful development of LN was invariably associated with the appearance of the MZ structure, whereas the failure of LN development was always associated with the absence of the development of MZ. These BMT results suggest that a common factor may regulate the generation of both LN and MZ of the spleen.     

REGIONAL VARIATIONS IN THE DISTRIBUTION OF SMALL INTESTINAL INTRAEPITHELIAL LYMPHOCYTES IN ALYMPHOPLASIA (aly/aly) MICE AND HETEROZYGOUS (aly/+) MICE

Regional variations in intraepithelial lymphocytes (IELs) in the small intestine were examined in alymphoplasia mutant (aly/aly) mice, which are characterized by the systemic absence of lymph nodes and Peyer's patches, and heterozygous (aly/+) mice. The small intestines were taken from 10 to 12-week-old mice and divided equally into 3 parts (the proximal, middle and distal parts). IELs were isolated from each part of the intestine and analyzed with a flow cytometer. The number of IELs in the distal part was significantly fewer in aly/aly mice compared with aly/+ mice, although the total number of small intestinal IELs were comparable between them. As to the IELs subsets, regional variations in αβ T cells and γδ T cells were observed in aly/+ mice, but they disappeared in aly/aly mice. However, regional variations in composition of αβ T cell subsets were similarly observed in both aly/aly mice and aly/ + mice. This indicates that, although not essential, mesenteric lymph nodes (MLN) and/or Peyer's patches may modify the regional variations in IELs.     

Osteopontin is a novel marker of pancreatic ductal tissues and of undifferentiated pancreatic precursors in mice.

Matricellular proteins mediate both tissue morphogenesis and tissue homeostasis in important ways because they modulate cell-matrix and cell-cell interactions. In this study, we found that the matricellular protein osteopontin (Opn) is a novel marker of undifferentiated pancreatic precursors and pancreatic ductal tissues in mice. Our analysis also underscored a specific, dynamic profile of Opn expression in embryonic pancreatic tissues that suggests the participation of this protein's function in processes involving cell migration, cell-cell interactions, or both. Surprisingly, our analysis of Opn-deficient pancreata did not reveal obvious alterations in the morphology or differentiation of these tissues. Therefore, in embryonic pancreatic tissues, it is possible that other proteins act redundantly to Opn or that this protein's function is dispensable for pancreas development. Finally, the maintenance of Opn expression in pancreatic tissues of adults argues for a possible function of this protein in injury and pathologic responses.     

Clinical neurology and brain histopathology in NZB/NZW F1 lupus mice

Active generalized systemic lupus erythematosus (SLE), clinical neurological deficits and histological lesions in the brains were present in New Zealand Black/New Zealand White (NZB/W) F1 mice at 10 to 18 months of age. Clinical neurological abnormalities of the central nervous system (CNS) were detected with a standardized neurological examination and scoring procedure. Active generalized SLE was present in all mice of this group, as determined by elevated serum anti-DNA antibodies and by the presence of glomerulonephritis. High titres of serum anti-cardiolipin antibodies were present in almost all mice. On histopathological examination, most of the brains had prominent mononuclear cell infiltration around cerebral and hippocampal blood vessels and in the choroid plexus. A subgroup of these mice, having higher clinical neurological scores, had correspondingly higher brain histopathological scores. The neurological and histological abnormalities were compatible with a diagnosis of CNS SLE. In contrast, 2-month-old NZB/W, 5-month-old C57Bl/6 and 14-month-old C57Bl/6 mice had low neurological scores, low serum anti-DNA antibody titres, low or absent anti-cardiolipin antibodies and no evidence of brain or kidney pathological lesions.     

葡萄多酚对雨蛙肽诱导的急性胰腺炎胰腺组织的保护作用

 目的:研究葡萄多酚对雨蛙肽诱导的小鼠急性胰腺炎（AP）的保护作用。方法: 2月龄ICR雌鼠共21只,随机分为正常对照组（NC组）、AP模型组（AP组）和药物处理AP组,每组7只。造模前,药物处理AP组小鼠连续7 d胃内灌注葡萄多酚（1.5 g/kg）水溶液,NC组和AP组小鼠则以同法给予生理盐水作为对照。第7天开始造模。AP组以及药物处理AP组小鼠予以腹腔注射雨蛙肽(50 μg/kg)造模,每小时1次,共注射7次;NC组小鼠同法注射等量生理盐水。于24 h处死小鼠取其胰腺及肺组织。测量各组胰腺组织的相对重量、病理形态学改变、巨噬细胞的浸润情况及炎症因子、氧化应激分子的表达水平;检测肺脏组织的髓过氧化物酶（MPO）活性以考察远隔器官的炎症。 结果: 与AP组小鼠相比,药物处理AP组小鼠胰腺组织的水肿、炎症以及空泡的评分明显降低（P<0.05）,但坏死和病理总评分没有明显变化;巨噬细胞的浸润明显减少;肿瘤坏死因子α(TNF-α)和单核细胞趋化蛋白1(MCP-1)的表达水平也明显降低(P<0.05);超氧化物歧化酶1（SOD-1)、SOD-2和NADPH氧化酶2（NOX-2）的表达水平也明显降低（P<0.05, P<0.05, P<0.01）。此外,药物处理AP组小鼠肺组织的MPO活性显著降低（P<0.01）,提示中性粒细胞的浸润减少。结论: 葡萄多酚对雨蛙肽诱导的小鼠急性胰腺炎胰腺组织具有明显保护作用,机制与下调炎症因子和氧化应激分子的表达有关。     

Development of pancreatic islets in pancreatic polypeptide-overexpressing mice

Recently we produced pancreatic polypeptide transgenic (PPTG) mice and found that PP was overexpressed in pancreatic islets. The present study examines development of four islet hormones in PPTG mice at embryonic days (ED) 15, 17, and 19, and in adult animals. Adult PPTG mice showed massive aggregation of PP-positive cells and glucagon-positive cells seen at the central area of the islets. Confocal laser microscopic study showed that three islet hormones (insulin, glucagon and PP) were completely overlapped in islets of PPTG mice. Overlapping of somatostatin/glucagon and somatostatin/PP were also increased at the peripheral area of the islets in adult PPTG mice compared to wild-type mice. In prenatal development of pancreatic islets of PPTG mice, somatostatin/glucagon overlapping cells appeared at ED 15, two days earlier than in wild-type mice. Differentiation of these somatostatin/glucagon double-positive cells into single-positive cells was disturbed in the PPTG mice during perinatal to postnatal periods. Differentiation of glucagon/insulin-double positive cells into single-positive cells was disturbed remarkably in postnatal development of the islets of PPTG mice. The present results suggest that early and overexpression of PP may engender the early appearance of somatostatin producing cells; however, that may disturb differentiation of multihormonal immature endocrine cells into single hormonal mature endocrine cells.     

Comparative histopathology in mouse typhoid among genetically diverse mice

Genetically resistant CBA and A/J mice and susceptible BALB/c and C57BL/6 mice were challenged with either an identical infective dose or a minimal lethal dose of Salmonella typhimurium . The histopathological progression of the disease was examined in tissue sections prepared by the JB-4 Plus resin embedding method and compared between the resistant and susceptible mice. In a fatal disease, the lesions in both animal hosts began with focal abscesses within the first three days post infection. Mononuclear cell infiltration started by day 4 and transformed the lesions into granulomata. Well-formed granulomata were evident by day 7 and persisted in sublethally infected resistant mice. Massive bacterial proliferation and extensive tissue degeneration marked the terminal stage of a lethal challenge. There were no distinguishable features that would identify the tissue response to infection in a resistant host from a susceptible one, except that the lesions in the sublethally infected resistant mice advanced slower and were discrete and self-limiting.     

A new mutation,aly, that induces a generalized lack of lymph nodes accompanied by immunodeficiency in mice

We have found a new spontaneous autosomal recessive mutation in mice that causes a systemic absence of lymph nodes and Peyer's patches. The name “alymphoplasia”, with the gene symbol “uly”, is proposed for this mutant. The spleen of alylay mice is devoid of well-defined lymphoid follicles, and the thymus does not show a clear cortical-medullary distinction. The mutant homozygotes are deficient in both humoral and cell-mediated immune functions, and are highly susceptible to infections. They have a reduced level of IgM and severely depressed levels of IgG and IgA in their sera, and do not reject allogeneic skin grafts. However, they have mature T and B cells as determined from their cell surface antigens. The results of bone marrow transplantation experiments suggest a mesenchymal disorder as a possible cause of the lack of lymph nodes and of immunodeficiency in the aly mouse. The aly mutant mouse may be a useful animal model of primary immunodeficiency, as are the nu (nude) and scid (severe combined immunodeficiency) mice.     

Impaired protective immunity and T helper 2 responses in alymphoplasia (aly) mutant mice infected with Trichinella spiralis

The alymphoplasia (aly) mutation of mice prevents the development of systemic lymph nodes and Peyer's patches. The mutant homozygotes (aly/aly) are partially deficient in both humoral and cell-mediated immune functions. In the present study, we show that adult worm expulsion was slightly delayed and that T helper 2 (Th2)-type responses were partially defective in aly/aly mice after infection with Trichinella spiralis. Male aly/aly and aly/+ mice (8-weeks old) were infected with 400 muscle larvae. There was no difference in worm recovery between the two groups on day 5. However, worm recovery in aly/aly mice was significantly higher than that in aly/+ mice on day 14. Mucosal mast cells increased in number and peaked 14 days after infection in aly/+ mice. aly/aly mice were deficient in their mucosal mast cell response through out the primary infection. To examine the existence of mast cell precursors, aly/aly mice were treated with recombinant interleukin-3 (rIL-3) before infection. The mast cell response was poorly induced in aly/aly mice treated with rIL-3. An immunoglobulin E (IgE) response was not detected in aly/aly mice during the course of infection. Serum IgG1 levels in aly/aly mice were significantly lower than that of aly/+. The serum IgG2a levels increased in both strains of mice. However, IgG2a production in aly/aly mice on day 14 was half as much as that in aly/+mice. Stimulation of splenic T cells in vitro with anti-CD3 monoclonal antibody (mAb) showed that spleen cells from aly/+ mice on day 5 produced more IL-4 than spleen cells from aly/aly mice. IL-4 production from aly/aly mice on day 14 was half that from aly/+ mice. Interferon-gamma (IFN-gamma) was produced in both aly/aly and aly/+ mice on day 14. Proliferation assay showed that T cells of aly/aly mice responded poorly when cultured with antigen-presenting cells. These results suggest that aly gene is needed for the induction of protective immunity and Th2 responses in mice infected with T. spiralis.     

Nematode infection in Alymphoplasia (aly) mice: worm species-dependent differential effect of defects of the gut-associated lymphatic tissue system

Mice homologous for the alymphoplasia mutation (aly) show the systemic absence of secondary lymphoid tissues, with disorganized splenic architecture, including the absence of the germinal centre and follicular dendritic cells. In this study, we examined the influence of defects of gut-associated lymphoid tissue (GALT), such as Peyer's patches and the mesenteric lymph nodes, on the host response to helminth infection in aly/aly mice. The present study showed that most of the worms were expelled by day 7 after Nippostrongylus brasiliensis infection in both control aly/+ and aly/aly mice. In aly/aly mice, the number of peripheral blood eosinophils, intestinal goblet cells and mucosal mast cells were increased by N. brasiliensis infection in aly/aly mice to the same level as in the controls. Conversely, aly/aly mice developed more severe Heligmosomoides polygyrus infections than control aly/+ mice, as demonstrated by increased faecal egg counts, with reduced immune responses such as the numbers of intestinal goblet cells and mucosal mast cells. These results suggested that the dependency of GALT in activation of Th2 responses against gastrointestinal nematodes was different depending on the species of nematode.     

Sequential histopathology of cavitary liver abscess. Formation induced by axenically grown Entamoeba histolytica

Multiple hamster liver passage of Entamoeba histolytica trophozoites with intervening recovery into axenic culture caused increased virulence as measured by increase in the size of the lesion produced. Lesions produced by amebae that had not been liver-passaged did not persist; however, multiply liver-passaged substrains produced large, fluid-filled abscesses one month to six weeks after inoculation. Six days after inoculation, lesions consisted of multiple granulomas, lymphocytes, and E histolytica trophozoites. Large, fluid-filled abscesses produced by liver-passaged substrains lacked the granulomatous appearance of the earlier lesions. The abscesses had a fibrous wall, with E histolytica trophozoites at the inner aspect. To our knowledge, the evolution of early granulomatous lesions into a cavitary abscess with features closely resembling those of human amebic abscess has not been reported previously in the experimental disease in the hamster.     

肥胖小鼠脂肪组织中炎症因子的表达

目的 探讨肥胖对小鼠脂肪中炎症因子分泌的影响及其作用的分子机制。方法 随机选取20只Lepob/ob肥胖小鼠作为研究对象,同窝野生型C57BL/6 J小鼠作为对照组。测定小鼠体重、脂肪重量、血糖、葡萄糖耐量和胰岛素耐量;HE染色观察白色和褐色脂肪细胞的状态,并对脂肪细胞直径进行统计学分析;Western blotting检测诱导型一氧化氮合酶(iNOS)、核因子κB（NF-κB）、蛋白激酶B（Akt）和p-Akt的蛋白表达;Real-time PCR分析白色和褐色脂肪中CC-趋化因子配体2(CCL2)、CD44、集落刺激因子2(CSF2)、胶质纤维酸性蛋白（GFAP）、Iba1、白细胞介素(IL)-1α、IL-6、IL-7、JUN和S100β mRNA的表达。结果 与对照组相比,Lepob/ob 小鼠的体重随年龄的增长而显著增加（P<0.001）,白色脂肪重量、皮下脂肪重量及血糖显著升高（P<0.01,P<0.01,P<0.01）,葡萄糖耐量较低（P<0.001）并产生胰岛素抵抗（P<0.001）;脂肪细胞直径显著增大,且各个脂肪组织均有巨噬细胞浸润灶出现;脂肪细胞内Janus蛋白酪氨酸激酶2(JAK2)、p-JAK2、iNOS、NF-κB、Akt和p-Akt蛋白表达均显著升高（P<0.05）;CCL2、CD44、IL-1α、IL-6、IL-7、JUN和S100β mRNA表达均显著升高。 结论 肥胖诱导小鼠脂肪组织中炎症因子显著表达,促使细胞分泌传导紊乱,导致炎症级联发生。     

Origin of pancreatic ductal adenocarcinoma from atypical flat lesions: a comparative study in transgenic mice and human tissues

Pancreatic ductal adenocarcinoma (PDAC) and its precursor lesions, pancreatic intraepithelial neoplasia (PanIN), display a ductal phenotype. However, there is evidence in genetically defined mouse models for PDAC harbouring a mutated kras under the control of a pancreas-specific promoter that ductal cancer might arise in the centroacinar-acinar region, possibly through a process of acinar-ductal metaplasia (ADM). In order to further elucidate this model of PDAC development, an extensive expression analysis and molecular characterization of the putative and already established (PanIN) precursor lesions were performed in the Kras(G12D/+) ; Ptf1a-Cre(ex1/+) mouse model and in human tissues, focusing on lineage markers, developmental pathways, cell cycle regulators, apomucins, and stromal activation markers. The results of this study show that areas of ADM are very frequent in the murine and human pancreas and represent regions of increased proliferation of cells with precursor potential. Moreover, atypical flat lesions originating in areas of ADM are the most probable precursors of PDAC in the Kras(G12D/+); Ptf1a-Cre(ex1/+) mice and similar lesions were also found in the pancreas of three patients with a strong family history of PDAC. In conclusion, PDAC development in Kras(G12D/+); Ptf1a-Cre(ex1/+) mice starts from ADM and a similar process might also take place in patients with a strong family history of PDAC.     

Ⅱ型糖尿病模型db／db小鼠胰岛α细胞超微结构变化

目的:观察Ⅱ型糖尿病模型 db/db 小鼠胰岛α细胞的超微结构变化,探讨α细胞的病理改变与Ⅱ型糖尿病病因的关系.方法:选取 3、5、8 月龄尾静脉空腹血糖高于10.1 mmol/L,且肥胖的 db/db 自发性精尿病小鼠作为糖尿病组;选取相应年龄段尾静脉空腹血糖低于 6.0 mmol/L,体质量正常的 db/ m 表型正常小鼠作为对照组.于相应年龄段取胰尾,透射电镜观察胰岛α细胞超微结构.结果:精尿病组胰岛α细胞胞质内分泌颗粒数量增多,可见致密芯与界膜间的间隙变窄,有的消失;线粒体和粗面内质网增多,细胞器结构未见明显改变.结论:胰岛α细胞超微结构改变和功能异常可能与Ⅱ型糖尿病的发病有关.