Distinct roles of CSF family cytokines in macrophage infiltration and activation in glioma progression and injury response

Gliomas attract brain‐resident (microglia) and peripheral macrophages and reprogram these cells into immunosuppressive, pro‐invasive cells. M‐CSF (macrophage colony‐stimulating factor, encoded by the CSF1 gene) has been implicated in the control of recruitment and polarization of macrophages in several cancers. We found that murine GL261 glioma cells overexpress GM‐CSF (granulocyte–macrophage colony‐stimulating factor encoded by the CSF2 gene) but not M‐CSF when compared to normal astrocytes. Knockdown of GM‐CSF in GL261 glioma cells strongly reduced microglia‐dependent invasion in organotypical brain slices and growth of intracranial gliomas and extended animal survival. The number of infiltrating microglia/macrophages (Iba1⁺ cells) and intratumoural angiogenesis were reduced in murine gliomas depleted of GM‐CSF. M1/M2 gene profiling in sorted microglia/macrophages suggests impairment of their pro‐invasive activation in GM‐CSF‐depleted gliomas. Deficiency of M‐CSF (op/op mice) did not affect glioma growth in vivo and the accumulation of Iba1⁺ cells, but impaired accumulation of Iba1⁺ cells in response to demyelination. These results suggest that distinct cytokines of the CSF family contribute to macrophage infiltration of tumours and in response to injury. The expression of CSF2 (but not CSF1) was highly up‐regulated in glioblastoma patients and we found an inverse correlation between CSF2 expression and patient survival. Therefore we propose that GM‐CSF triggers and drives the alternative activation of tumour‐infiltrating microglia/macrophages in which these cells support tumour growth and angiogenesis and shape the immune microenvironment of gliomas. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Immunization with 60 kD Ro peptide produces different stages of preclinical autoimmunity in a Sjögren's syndrome model among multiple strains of inbred mice

Sjögren's syndrome is a chronic illness manifested characteristically by immune injury to the salivary and lacrimal glands, resulting in dry mouth/eyes. Anti‐Ro [Sjögren's syndrome antigen A (SSA)] and anti‐La [Sjögren's syndrome antigen B (SSB)] autoantibodies are found frequently in Sjögren's subjects as well as in individuals who will go on to develop the disease. Immunization of BALB/c mice with Ro60 peptides results in epitope spreading with anti‐Ro and anti‐La along with lymphocyte infiltration of salivary glands similar to human Sjögren's. In addition, these animals have poor salivary function/low saliva volume. In this study, we examined whether Ro‐peptide immunization produces a Sjögren's‐like illness in other strains of mice. BALB/c, DBA‐2, PL/J, SJL/J and C57BL/6 mice were immunized with Ro60 peptide‐274. Sera from these mice were studied by immunoblot and enzyme‐linked immunosorbent assay for autoantibodies. Timed salivary flow was determined after pharmacological stimulation, and salivary glands were examined pathologically. We found that SJL/J mice had no immune response to the peptide from Ro60, while C57BL/6 mice produced antibodies that bound the peptide but had no epitope spreading. PL/J mice had epitope spreading to other structures of Ro60 as well as to La, but like C57BL/6 and SJL/J had no salivary gland lymphocytic infiltration and no decrement of salivary function. DBA‐2 and BALB/c mice had infiltration but only BALB/c had decreased salivary function. The immunological processes leading to a Sjögren's‐like illness after Ro‐peptide immunization were interrupted in a stepwise fashion in these differing mice strains. These data suggest that this is a model of preclinical disease with genetic control for epitope spreading, lymphocytic infiltration and glandular dysfunction.     

Bcl‐3 deficiency protects against dextran‐sodium sulphate‐induced colitis in the mouse

Bcl-3 is a member of the IκB family of proteins and is an essential negative regulator of Toll-like receptor-induced responses. Recently, a single nucleotide polymorphism associated with reduced Bcl-3 gene expression has been identified as a potential risk factor for Crohn''s disease. Here we report that in contrast to the predictions of single nucleotide polymorphism (SNP) analysis, patients with Crohn''s disease and ulcerative colitis demonstrate elevated Bcl-3 mRNA expression relative to healthy individuals. To explore further the potential role of Bcl-3 in inflammatory bowel disease (IBD), we used the dextran-sodium sulphate (DSS)-induced model of colitis in Bcl-3^−/− mice. We found that Bcl-3^−/− mice were less sensitive to DSS-induced colitis compared to wild-type controls and demonstrated no significant weight loss following treatment. Histological analysis revealed similar levels of oedema and leucocyte infiltration between DSS-treated wild-type and Bcl-3^−/− mice, but showed that Bcl-3^−/− mice retained colonic tissue architecture which was absent in wild-type mice following DSS treatment. Analysis of the expression of the proinflammatory cytokines interleukin (IL)-1β, tumour necrosis factor (TNF)-α and IL-6 revealed no significant differences between DSS-treated Bcl-3^−/− and wild-type mice. Analysis of intestinal epithelial cell proliferation revealed enhanced proliferation in Bcl-3^−/− mice, which correlated with preserved tissue architecture. Our results reveal that Bcl-3 has an important role in regulating intestinal epithelial cell proliferation and sensitivity to DSS-induced colitis which is distinct from its role as a negative regulator of inflammation.     

Evaluation of in vivo genotoxicity induced by N‐ethyl‐N‐nitrosourea,benzo[a]pyrene,and 4‐nitroquinoline‐1‐oxide in the Pig‐a and gpt assays

The recently developed Pig‐a mutation assay is based on flow cytometric enumeration of glycosylphosphatidylinositol (GPI) anchor‐deficient red blood cells caused by a forward mutation in the Pig‐a gene. Because the assay can be conducted in nontransgenic animals and the mutations accumulate with repeat dosing, we believe that the Pig‐a assay could be integrated into repeat‐dose toxicology studies and provides an alternative to transgenic rodent (TGR) mutation assays. The capacity and characteristics of the Pig‐a assay relative to TGR mutation assays, however, are unclear. Here, using transgenic gpt delta mice, we compared the in vivo genotoxicity of single oral doses of N‐ethyl‐N‐nitrosourea (ENU, 40 mg/kg), benzo[a]pyrene (BP, 100 and 200 mg/kg), and 4‐nitroquinoline‐1‐oxide (4NQO, 50 mg/kg) in the Pig‐a (peripheral blood) and gpt (bone marrow and liver) gene mutation assays. Pig‐a assays were conducted at 2, 4, and 7 weeks after the treatment, while gpt assays were conducted on tissues collected at the 7‐week terminal sacrifice. ENU increased both Pig‐a and gpt mutant frequencies (MFs) at all sampling times, and BP increased MFs in both assays but the Pig‐a MFs peaked at 2 weeks and then decreased. Although 4NQO increased gpt MFs in the liver, only weak, nonsignificant increases (two‐ or threefold above control) were detected in the bone marrow in both the Pig‐a and the gpt assay. These findings suggest that further studies are needed to elucidate the kinetics of the Pig‐a mutation assay in order to use it as an alternative to the TGR mutation assay. Environ. Mol. Mutagen. 54:747–754, 2013. © 2013 Wiley Periodicals, Inc.     

来氟米特对NOD鼠颌下腺唾液分泌功能的保护作用

目的:探讨来氟米特对干燥综合征模型NOD鼠唾液腺分泌功能减退的治疗作用。方法:将NOD鼠随机分配为4组:预防用药组、预防对照组、治疗用药组、治疗对照组;检测毛果芸香碱刺激后唾液流率变化;苏木精和伊红染色后比较平均浸润灶数目及面积的变化;流式细胞术检测颌下腺、脾脏组织中CD3 +T、CD4 +T、CD8 +T、CD44 +CD62L -CD4 +T、CD19 +B、CD138 +B细胞水平的变化;CBA法检测血清炎症因子TNF-α、IL-17A、IL-6水平变化。 结果:预防用药及治疗用药组唾液流率( t=-5.81, P<0.001;t=-3.61, P<0.05)、浸润灶平均数目( t=3.95, P<0.01;t=4.94, P<0.001)、浸润灶平均面积( t=3.18, P<0.05;t=2.35, P<0.05)均具有明显改善。颌下腺组织中CD3 +CD4 +T( t=2.39, P<0.05;t=3.82, P<0.01)、CD44 +CD62L -CD4 +T( t=3.53, P<0.05;t=3.36, P<0.05)细胞明显下调。脾组织中CD3 +T( t=6.08, P<0.001;t=2.76, P<0.05)、CD3 +CD4 +T( t=3.73, P<0.05;t=2.39, P<0.05)、CD19 +B( t=5.88, P<0.001;t=4.23, P<0.01) 、CD138 +B( t=4.30, P<0.001;t=4.46, P<0.01)细胞也均明显下降。此外,用药组小鼠血清IL-17A水平均降低( t=4.15, P<0.01;t=3.36, P<0.01),预防用药组TNF-α水平下降( t=4.56, P<0.001),但IL-6水平变化无统计学意义。 结论:本研究提示来氟米特可预防、改善NOD鼠唾液腺功能减退及抑制体内免疫活化,为评估来氟米特对干燥综合征的治疗作用提供了理论依据。     

Regulation of Abortion by γλ T Cells

PROBLEM: T cells are present at the feto-maternal interface, but their function during pregnancy has not been fully elucidated. T cells bearing γλ T-cell receptor (TCR) may be particularly important, as some subsets can react to trophoblast cells by producing cytokines, such as interleukin-2 (IL-2). METHOD: We depleted T cells bearing the γλ receptor by injecting monoclonal antibodies (mAB) into females of the abortion-prone animal model CBA x DBA/2. We investigated the percentage and number of γλ T-cell receptor positive (TCR)⁺ cells in decidua and spleen during pregnancy in control and γλ-depleted female mice. Pregnant females were also exposed to ultrasonic sound stress to boost the abortion rate. RESULTS: Stress failed to increase the abortion rate in the γλ TCR-depleted mice. FACScan analysis show that the ratio of cells bearing the γλ TCR dramatically decreased after injection of mAB to the γλ TCR in spleen and decidua, these cells recovered six days after depletion, showing a change in cytokine pattern. Levels of TNF-α in decidual γλ T cells decreased; similar effects of decreasing Th₁ cytokines could be observed in splenic γλ T cells. We further identified increased levels of intracellular TNF-α in the Vλ4 subset in the decidua, compared to spleen. CONCLUSIONS: Trophoblast recognition by the Vλ4 T-cell subset in the decidua may cause the release of abortogenic cytokines such as TNF-α. Depletion of such γλ TCR T cells during early pregnancy may promote successful pregnancy outcome in normal pregnancy and prevent stress-induced abortions.     

Induction of Experimental Antiphospholipid Antibody Syndrome in PL/J Mice Following Immunization With β2GPI

PROBLEM: Immunization with β₂-glycoprotein I (β₂GPI) induces antiphospholipid antibodies (aPL) in normal mice and rabbits. Recently we reported early onset of autoimmunity in MRL/++ mice following immunization with β₂GPI. There is a close association between aPL with thrombosis, recurrent fetal loss, and intrauterine growth retardation. In this study we evaluated the effect of β₂GPI-induced aPL on pregnancy outcomes in an inbred strain of mice (PL/J). METHOD: Three groups of seven-week-old female PL/J mice (12 per group) were studied. Group A was immunized with β₂GPI and group B with ovalbumin; group C was not immunized. After two booster injections, the mice were tested for aPL, anti-DNA by ELISA, and for ANA by indirect immunofluorescence. Platelet count and pregnancy outcomes were studied at the age of 14 weeks. RESULTS: The aPL and anti-DNA levels were higher at 12 and 14 weeks in group A; the optical densities (OD) were 1.72±0.6 and 0.699±0.25 for group A, 0.091 ±0.040 and 0.230±0.47 for group B, and 0.0435±0.003 and 0.119±0.026 for group C (comparing group A with groups B and C combined, P<0.001). ANA titers rose in groups A and B by age, but they were significantly higher at 14 weeks in group A. The mean titers were 1/286, 1/90, and 1/16 for A, B, and C, respectively (P<0.001). The platelet counts were not significantly different among the three groups. The litter size was significantly smaller in group A, as evidenced by the numbers of viable fetuses among the mice that became pregnant in each group: 0.75, 2.45, and 5.5 in groups A, B, and C, respectively. Seven pregnant mice in group A had complete resorption, seven pregnant mice in group B showed focal (partial) resorption areas, and only one mouse in group C had complete resorption of the embryos, as shown by histopathological studies, although the fecundity rate was similar in the three groups. CONCLUSION: Our data suggest a pathogenic role for β₂GPI-induced aPL in the development of experimental models of APS in PL/J mice.     

Induction of germline-length mutations at the minisatellites PC-1 and PC-2 in male mice exposed to polychlorinated biphenyls and diesel exhaust emissions

PC-1 and PC-2 are hypervariable mouse minisatellites. The rates of spontaneous germline-length mutation have been shown to vary between different mouse strains. PC-1 is composed of GGCAG repeat units and PC-2 of GGCAGGA. Minisatellites frequently mutate by gaining or losing repeat units. Such length mutations in mini- and microsatellites have been associated with human disease and may therefore be an important endpoint in genetic toxicity testing. Carcinogenic activity of many chemicals is associated with their ability to induce heritable mutations. Since minisatellites are highly prone to mutate to new lengths, which can be assayed by Southern analysis, we used this method to detect heritable genetic effects in mice. Male mice exposed to diesel exhausts and/or polychlorinted biphenyls (PCB) were investigated for effects on the germline mutation frequenallele lengths in parents and offspring. For PC-1 significantly higher mutation frequencies were found in males treated with diesel exhausts + PCB (6 of 35 alleles) and with PCB alone (6 of 51 alleles) as compared to the males in the control group (0 of 43 alleles). The mutation frequency in the diesel exhaust group was not significantly increased (2 of 43 alleles). For PC-2 the only mutation found occurred in the PCB group (1 of 51 alleles). This in vivo study demonstrates—for the first time—chemically induced minisatellite mutations in the germline. Environ. Mol. Mutagen. 30:254–259, 1997 © 1997 Wiley-Liss, Inc.