Increased serum transforming growth factor-beta1 in human colorectal cancer correlates with reduced circulating dendritic cells and increased colonic Langerhans cell infiltration

Cancer-related cytokines may interfere with the differentiation and migration of dendritic cells (DCs) and with the associated up-regulation of co-stimulatory molecules in vitro. We determined whether cytokines affected the distribution and activation of DCs in patients with colorectal cancer by measuring the levels of serum cytokines [transforming growth factor (TGF)-beta1 and vascular endothelial growth factor (VEGF)], DC numbers and phenotype from peripheral blood and mesenteric lymph nodes draining the cancer, and the infiltration of DCs into colorectal cancer. A significant increase in the serum level of TGF-beta1 correlated with a significant reduction in the level of circulating DCs in cancer patients that was associated with an increased infiltration of Langerhans cells into colorectal mucosa. The prevalence but not intensity of co-stimulatory molecule expression in circulating and mesenteric lymph node DCs was reduced in patients with colorectal cancer compared to patients with inflammatory bowel conditions. There was no correlation between co-stimulatory molecule expression and serum TGF-beta1. Thus the circulating DC depletion in colorectal cancer could be explained by a TGF-beta1-related DC redistribution from the circulation into the colorectal cancer and adjacent mucosa where DC levels were increased. There was an impairment of DC activation within colorectal cancer that was not related to serum level of cytokines.     

Activated human CD4+ T cells induced by dendritic cell stimulation are most sensitive to transforming growth factor-beta: implications for dendritic cell immunization against cancer.

The secretion of immunosuppressive factors like transforming growth factor-beta (TGF-beta) by tumor cells has been recognized as one of the mechanisms involved in tumor immunological escape. This study aimed to examine whether dendritic cell (DC) immunization could reverse TGF-beta-induced immunosuppression by simulating the in vivo interaction among infused DCs, host T cells, and tumor-secreted TGF-beta in an in vitro study. We found that both immature and mature DCs were relatively resistant to TGF-beta. The addition of TGF-beta to naive human CD4+ T cells, which are required by genetically modified DC to elicit antitumor immunity, resulted in their hyporesponsiveness to DC stimulation in a dose-dependent manner. When activated by allogeneic DCs in the presence of TGF-beta, CD4+ T cells displayed a reduced capacity to proliferate. More importantly, activated CD4+ T cells induced by DC stimulation were very sensitive to TGF-beta, and this susceptibility was enhanced by their previous exposure to TGF-beta. The underlying mechanism was linked to TGF-beta-induced apoptosis of activated T cells. However, the presence of stimulation from DC or antibodies to CD3 plus CD28 could partly reverse the immunosuppressive effect of TGF-beta on activated CD4+ T cells. Taken together, our results indicate that the efficacy of DC immunization may be impaired by tumor-derived TGF-beta.     

转化生长因子-β1诱导大鼠毛乳头细胞转分化为成纤维细胞的研究

目的 研究大鼠触须毛乳头细胞在转化生长因子-β1（TGF-β1）诱导作用下转分化为成纤维细胞的可能性,从新的角度探讨增生性瘢痕的形成机制.方法 消化收集第4代毛乳头细胞,处理组以 TGF-β1（10 ng/mL）处理细胞4 d;对照组加入正常培养基（不含胎牛血清的DMEM/F12培养液）,每隔24 h观察两组细胞生长形态及生长方式;分别用实时一步法RT-PCR和流式细胞仪检测细胞α平滑肌肌动蛋白（α-SMA）、波形蛋白（Vimentin）的mRNA表达和蛋白表达,Western blotting检测成纤维细胞特异蛋白（FSP1）的表达.结果流式细胞仪检测TGF-β1诱导48 h、72 h后α-SMA表达明显低于对照组（P〈0.01）;TGF-β1诱导48 h、72 h、96 h后Vimentin表达明显高于对照组（P〈0.01）.实时一步法RT-PCR检测Vimentin的mRNA表达逐渐增强,α-SMA的mRNA表达在48 h后明显下降（P〈0.01）,但96 h后表达又有所增加;Western blotting法检测FSP1表达在诱导48 h后逐渐增加（P〈0.01）.结论 毛乳头细胞经TGF-β1诱导后,失去其典型的细胞形态及生长方式,而表现出成纤维细胞的细胞形态及生长方式;其相对特异性标记物α-SMA的表达下降,而成纤维细胞的相对特异性标记物Vimentin和FSP1表达增加.故TGF-β1可诱导大鼠毛乳头细胞转分化为成纤维细胞.     

CD4+ CD25+ transforming growth factor-beta-producing T cells are present in the lung in murine tuberculosis and may regulate the host inflammatory response

CD4(+) CD25(+) regulatory T cells produce the anti-inflammatory cytokines transforming growth factor (TGF)-beta or interleukin (IL)-10. Regulatory T cells have been recognized to suppress autoimmunity and promote self-tolerance. These cells may also facilitate pathogen persistence by down-regulating the host defence response during infection with Mycobacterium tuberculosis. We evaluated TGF-beta(+) and IL-10(+) lung CD4(+) CD25(+) T cells in a murine model of M. tuberculosis. BALB/c mice were infected with approximately 50 colony-forming units of M. tuberculosis H37Rv intratracheally. At serial times post-infection, lung cells were analysed for surface marker expression (CD3, CD4, CD25) and intracellular IL-10, TGF-beta, and interferon (IFN)-gamma production (following stimulation in vitro with anti-CD3 and anti-CD28 antibodies). CD4(+) lung lymphocytes were also selected positively after lung digestion, and stimulated in vitro for 48 h with anti-CD3 and anti-CD28 antibodies in the absence and presence of anti-TGF-beta antibody, anti-IL-10 antibody or rmTGF-beta soluble receptor II/human Fc chimera (TGFbetasrII). Supernatants were assayed for elicited IFN-gamma and IL-2. Fluorescence activated cell sorter analyses showed that TGF-beta- and IL-10-producing CD4(+) CD25(+) T cells are present in the lungs of infected mice. Neutralization of TGF-beta and IL-10 each resulted in increases in elicited IFN-gamma, with the greatest effect seen when TGFbetasrII was used. Elicited IL-2 was not affected significantly by TGF-beta neutralization. These results confirm the presence of CD4(+) CD25(+) TGF-beta(+) T cells in murine pulmonary tuberculosis, and support the possibility that TGF-beta may contribute to down-regulation of the host response.     

食管癌组织中血管内皮生长因子的表达对树突状细胞的影响

目的：研究食管癌组织中血管内皮生长因子（VEGF）的表达对树突状细胞（DC）的影响。方法：对94例食管癌组织采用辣根过氧化物酶（HRP）标记的链霉亲和素-生物素法（LSAB）,分别检测VEGF、S100蛋白的表达水平,并分析VEGF与S100^＋ DC的相关性。结果：食管癌组织中VEGF的表达率为74.46%（70/94）,VEGF的表达与患者的临床分期及癌组织的分化呈正相关（r=0.864,0.803,P〈0.05）。临床分期越晚,病癌组织的分化越低,癌组织内S100^＋ DC的密度越小（r=-0.763,-0.908,P〈0.05）。随着癌组织内VEGF表达量的上升,S-100^＋ DC的密度降低,二者呈负相关（r=-0.817,P〈0.05）。结论：食管癌组织中VEGF的表达可降低S100^＋DC的密度,从而影响机体的免疫功能。     

Mechanisms of immune suppression by interleukin-10 and transforming growth factor-beta: the role of T regulatory cells

Specific immune suppression and induction of tolerance are essential processes in the regulation and circumvention of immune defence. The balance between allergen-specific type 1 regulatory (Tr1) cells and T helper (Th) 2 cells appears to be decisive in the development of allergy. Tr1 cells consistently represent the dominant subset specific for common environmental allergens in healthy individuals. In contrast, there is a high frequency of allergen-specific interleukin-4 (IL-4)-secreting T cells in allergic individuals. Allergen-specific immunotherapy can induce specific Tr1 cells that abolish allergen-induced proliferation of Th1 and Th2 cells, as well as their cytokine production. Tr1 cells utilize multiple suppressor mechanisms, such as IL-10 and transforming growth factor-beta (TGF-beta) as secreted cytokines and various surface molecules, such as cytotoxic T-lymphocyte antigen 4 and programmed death-1. IL-10 only inhibits T cells stimulated by low numbers of triggered T-cell receptors, which depend on CD28 costimulation. IL-10 inhibits CD28 tyrosine phosphorylation, preventing the binding of phosphatidylinositol 3-kinase p85 and consequently inhibiting the CD28 signalling pathway. In addition, IL-10 and TGF-beta secreted by Tr1 cells skew the antibody production from immunoglobulin E (IgE) towards the non-inflammatory isotypes IgG4 and IgA, respectively. Induction of antigen-specific Tr1 cells can thus re-direct an inappropriate immune response against allergens or auto-antigens using a broad range of suppressor mechanisms.     

Papillary carcinoma of the thyroid: evidence for a role for hepatocyte growth factor (HGF) in promoting tumour angiogenesis

The pattern of vascularization of papillary carcinoma was investigated in tumour sections from 31 cases and in primary cultures from 12 cases. Tumour sections were immunostained for von Willebrand Factor (vWF) to visualize blood vessels; for endothelial-specific nitric-oxide-synthase (EC-NOS), as a marker of endothelial cell activation; and for Ki-67 to evaluate endothelial cell proliferation. It was found that endothelial cells lining venous vessels located in peritumoural fibrous tissue were intensely EC-NOS-positive and occasionally Ki-67-positive. Capillary vessels of tumour papillae were not stained for Ki-67 and were weakly EC-NOS-positive. Primary cultures of papillary carcinoma cells were used as a potential source of factors active on endothelial cells. It was found that thyroid tumour cells contain RNAs for angiopoietin, vascular endothelial growth factor (VEGF), and VEGF-C; moreover, they release large amounts of VEGF into culture supernatants and exert chemotactic activity in vitro for the endothelial cell line SIEC. The ability of papillary carcinoma cells to release angiogenic factors could be stimulated in vitro. Hepatocyte growth factor (HGF; 25 ng/ml) induced a 1.2- to 5-fold increase in the amount of VEGF released by tumour cells and a 1.2- to 4.2-fold increase in the amount of chemotactic activity present in culture supernatants. Met protein, the high affinity HGF-receptor, is overexpressed in a large proportion of cases of papillary carcinoma. These findings are consistent with the possibility that HGF-Met protein interaction is one of the molecular mechanisms promoting the vascularization of papillary carcinoma of the thyroid.     

Insulin-like growth factor I messenger RNA and protein are expressed in the human lymph node and distinctly confined to subtypes of macrophages,antigen-presenting cells,lymphocytes and endothelial cells

Insulin-like growth factor I (IGF-I) is a potent hormone that stimulates growth and differentiation and inhibits apoptosis in numerous tissues. Preliminary evidence suggests that IGF-I exerts differentiating, mitogenic and restoring activities in the immune system but the sites of synthesis of local IGF-I are unknown. Identification of these sites would allow the functional role of local IGF-I to be clarified. The presence of IGF-I in non-immune cells suggests that it acts as a trophic factor, while its occurrence in subtypes of lymphocytes or antigen-presenting cells indicates paracrine/autocrine direct regulatory involvement of IGF-I in the human immune response. The present study investigated the location of IGF-I messenger RNA and protein on archival human lymph node samples by in situ hybridization, immunohistochemistry and double immunofluorescence staining using an IGF-I probe and antisera specific for human IGF-I and CD3 (T lymphocytes), CD20 (B lymphocytes), CD68 (macrophages), CD21 (follicular dendritic cells), S100 (interdigitating dendritic cells) and podoplanin (fibroblastic reticular cells). Numerous cells within the B- and T-cell compartments expressed the IGF-I gene, and the majority of these cells were identified as macrophages. Solitary follicular dendritic cells exhibited IGF-I. A few T lymphocytes, and no B lymphocytes, contained IGF-I immunoreactive material. Furthermore, IGF-I immunoreactive cells outside the follicles that did not react with CD3, CD20, S100 or podoplanin markers were identified as high-endothelial venule (HEV) cells. From this we conclude that the main task of IGF-I in human non-tumoral lymph node may be autocrine and paracrine regulation of the differentiation, stimulation and survival of lymphocytes, antigen-presenting cells and macrophages and the differentiation and maintenance of HEV cells.     

芪丹颗粒剂对大鼠肺纤维化模型的干预作用及对TGF-β1、TNF-α表达的影响

目的：探讨芪丹颗粒剂对博莱霉素A5所致大鼠肺纤维化的干预作用及可能的机制。 方法： SD大鼠经气管内一次性灌注博莱霉素A5(5 mg/kg)诱导肺纤维化，随后分别每日给予芪丹颗粒剂灌胃（芪丹组，3 125 mg/kg）、氢化可的松腹腔注射（氢可组，25 mg/kg）进行干预。对照组气管内灌注和灌胃均用生理盐水。各组动物均于药物干预后第7、14、28 d分别处死。用苏木素-伊红（HE）评价肺组织病理学变化、免疫组化（SABC法）测定肺组织TGF-β1、TNF-α蛋白的表达。 结果： 芪丹组肺泡炎及肺纤维化程度均明显轻于模型组和氢可组，TGF-β1、TNF-α蛋白的表达亦显著低于模型组和氢可组（P<0.01）。 结论： 芪丹颗粒剂可明显减轻博莱霉素A5诱导的大鼠肺纤维化的程度, 其作用机制可能部分通过降低TGF-β1、TNF-α蛋白的表达而实现。     

Age-dependent decrease in serum transforming growth factor (TGF)-beta 1 in healthy Japanese individuals; population study of serum TGF-beta 1 level in Japanese

Transforming growth factor-beta1 (TGF-beta1), a multi-functional cytokine, is involved in regulating a variety of cellular activities and the serum/plasma TGF-beta1 level is altered with various diseases. However, most published reports have described adult patients, and so we investigated the clinical significance of serum TGF-beta1 level in pediatric patients. The diagnostic application of the measurement of serum TGF-beta1 level depends critically on the control value, however, there is no information on the control value of serum TGF-beta1 for children. In the present study, we determined the serum TGF-beta1 level of healthy Japanese children as a control value with enzyme-linked immunosorbent assay (ELISA). The serum TGF-beta1 level of children (0-14 years old) was significantly higher than that of adults (over 15 years old) (p < 0.01). Thus, it is recommended that when the serum TGF-beta1 levels of patients are evaluated, they should be compared with those of age-matched controls.     

Social isolation stress augments angiogenesis induced by colon 26-L5 carcinoma cells in mice

We have previously shown that tumor necrosis factor-α (TNF-α), which is an important angiogenesis-related factor, was over-secreted in male BALB/c mice under social isolation stress as compared with the control, and closely associated with a remarkable elevation of tumor invasion and metastasis of colon 26-L5 carcinoma cells. In the present study, we explored the effect of isolation stress on the angiogenesis caused by colon 26-L5 carcinoma cells in vivo and in vitro. Social isolation lead to the enhancement of tumor growth after intrahepatic implantation with a fragment of colon 26-L5 tumor. Angiogenic response (number of vessels oriented towards tumor mass) and tumor growth (size) were significantly increased in the socially isolated mouse relative to that in the group-housed mice. Furthermore, higher protein level of hepatic TNF-α was found in the stressed mice than that in the control. Expression of mRNA for vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) were also elevated in the tumor regions and liver tissues of the stressed mice in comparison with that in group-housed mice. On the other hand, hepatic sinusoidal endothelial (HSE) cells treated with TNF-α exhibited a marked promotion of the migration, invasion, expression of mRNA for matrix metalloproteinase (MMP)-9, and tube-like formation, but no cytotoxicity against the cells in vitro. The above data suggest that the social isolation stress augmented the tumor-induced angiogenesis probably by up-regulating the angiogenesis-related factors, including TNF-α, VEGF and HGF, and consequently mediating the functions of endothelial cells such as migration, invasion, and tube-like formation.     

Interleukin-6- and tumour necrosis factor alpha-mediated expression of hepatocyte growth factor by stromal cells and its involvement in the growth of endometriosis

BACKGROUND: We investigated the expression of the hepatocyte growth factor (HGF) gene and protein by the stromal cells derived from women with or without endometriosis and its regulation by interleukin-6 (IL-6) and tumour necrosis factor alpha (TNFalpha). METHODS: Stromal cells immunoreactive to vimentin were isolated from the eutopic and ectopic endometrium of 18 infertile women with endometriosis and 12 women without endometriosis. The production of HGF in the culture media of basal and IL-6- or TNFalpha-stimulated stromal cells was examined with an enzyme-linked immunosorbent assay. The mRNA expression of HGF and its receptor c-Met in the stroma was investigated by RT-PCR. The localization of HGF and c-Met in isolated stromal cells and in intact tissue was examined by immunohistochemistry. The effect of HGF on the growth of stromal cells alone or in combination with IL-6 or TNFalpha was examined in a bromodeoxyuridine (BrdU) incorporation study. RESULTS: The production of HGF in the culture medium of stromal cells was significantly increased after single or combined treatment with either IL-6 or TNFalpha when compared with non-treated cells. The production of HGF by stromal cells derived from the eutopic endometrium of women with endometriosis was significantly higher than that of cells from women without endometriosis. This effect was paralleled by increased expression of HGF and c-Met mRNA, as demonstrated by RT-PCR. The BrdU incorporation study indicated that the addition of HGF enhanced the growth of endometrial and endometriotic stroma alone or in combination with IL-6 or TNFalpha. CONCLUSION: IL-6 and TNFalpha are involved in the production of HGF by endometrial stromal cells and may be involved in the growth of endometriosis by an autocrine mechanism.     

Roles of tumour necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta), and IL-10 in the modulation of intercellular adhesion molecule-1 (ICAM-1) expression by macrophages during mycobacterial infection

Profiles of ICAM-1 expression on cultured murine peritoneal macrophages infected with Mycobacterium avium complex (MAC) were examined, with special reference to modulating roles of TNF-alpha, TGF-beta, and IL-10. When macrophages were infected with MAC, ICAM-1 expression, measured by microscopic counting of ICAM-1+ macrophages stained with anti-ICAM-1 antibody, ELISA, and flow cytometric analysis, was rapidly increased, peaking at day 3 (early-phase up-regulation) due to endogenous TNF-alpha, and thereafter gradually declined to the normal level within 1 week or more (late-phase down-regulation). The late-phase ICAM-1 down-regulation was also seen in macrophages phagocytosing heat-killed MAC and those stimulated with lipopolysaccharide but not in macrophages phagocytosing latex beads. ICAM-1 mRNA expression was augmented markedly at day 1 after MAC infection and thereafter decreased. While TNF-alpha and IL-10 production by MAC-infected macrophages was observed during the first 3 days, TGF-beta production was initiated from day 3 and continued until day 14. Exogenously added TGF-beta strongly inhibited the early-phase increase in ICAM-1 expression by infected macrophages, and the blockade of endogenous TGF-beta with anti-TGF-beta antibody markedly inhibited late-phase ICAM-1 down-regulation. Moderate blocking effect was also observed for anti-IL-10 antibody. On the other hand, late-phase ICAM-1 down-regulation was not prevented by the addition of exogenous TNF-alpha. Therefore, TGF-beta and IL-10, especially the former, appear to play active roles in the late-phase down-regulation of ICAM-1 in MAC-infected macrophages during long-term cultivation.     

Differential effects of transforming growth factor-β1 on IgA vs. IgG2b production by lipopolysaccharide-stimulated lymph node B cells: a comparative study with spleen B cells

Transforming growth factor-β1 (TGF-β1) is a multifunctional cytokine that promotes IgA/IgG2b switching and secretion. Here, we show a differential effect of TGF-β1 on Ig production by lipopolysaccharide-stimulated spleen and lymph node (LN) B cells. Exogenous TGF-β1 increased IgA production in B cell cultures and IgG2b production by spleen B cells. In contrast, IgG2b was suppressed by TGF-β1 in cultures of LN B cells, although endogenous TGF-β was required for IgG2b production in LN B cell cultures. The suppressor properties of exogenous TGF-β1 (0.5 ng/ml) on IgG2b production by LN B cells were also seen when testing IgG1 or IgG2a induced by interleukin-4 or interferon-γ, respectively. These differences between B cells from each lymphoid tissue appeared to be related to a different TGF-β antiproliferative effect, since proliferation of LN B cells was extremely sensitive to TGF-β1 and IgG2b production was more sensitive than IgA to the TGF-β-mediated suppression. However, by counteracting the antiproliferative effect of TGF-β1 with a CD40 agonistic mAb (IC10), the IgG2b response by LN B cells was still lacking. IC10 was nevertheless inhibitory for IgG2b production in most cases, while increasing secretion of IgA in the very same cultures. Taken together, the results suggest that functional differences between spleen and LN B cells do exist, at least with regard to the immunomodulating properties of TGF-β on both proliferation and Ig production. Moreover, functional differences exist between cells committed for IgA and IgG2b regarding their sensitivity to the antiproliferative activity of TGF-β1 and the effect of CD40-derived signals on Ig secretion.     

Activation of Rac1-PI3K/Akt is required for epidermal growth factor-induced PAK1 activation and cell migration in MDA-MB-231 breast cancer cells

Epidermal growth factor (EGF) may increase cell motility,an event implicated in cancer cell invasion and metastasis.However,the underlying mechanisms for EGF-induced cell motility remain elusive.In this study,we found that EGF treatment could activate Ras-related C3 botulinum toxin substrate 1 (Rac1),PI3K/Akt and p21actived kinase (PAK1) along with cell migration.Ectopic expression of PAK1 K299R,a dominant negative PAK1 mutant,could largely abolish EGF-induced cell migration.Blocking PI3K/Akt signalling with LY294002 or Akt siRNA remarkably inhibited both EGF-induced PAK1 activation and cell migration.Furthermore,expression of dominant-negative Rac1 (T17N) could largely block EGF-induced PI3K/Akt-PAK1 activation and cell migration.Interestingly,EGF could induce a significant production of ROS,and N-acetyl-L-cysteine,a scavenger of ROS which abolished the EGF-induced ROS generation,cell migration,as well as activation of PI3K/Akt and PAK,but not Rac1.Our study demonstrated that EGF-induced cell migration involves a cascade of signalling events,including activation of Rac1,generation of ROS and subsequent activation of PI3K/Akt and PAK1.     

Tsc1 mutant neural stem/progenitor cells exhibit migration deficits and give rise to subependymal lesions in the lateral ventricle

Subependymal nodules (SENs) and subependymal giant cell astrocytomas (SEGAs) are common brain lesions found in patients with tuberous sclerosis complex (TSC). These brain lesions present a mixed glioneuronal phenotype and have been hypothesized to originate from neural stem cells. However, this hypothesis has not been tested empirically. Here, we report that loss of Tsc1 in mouse subventricular zone (SVZ) neural stem/progenitor cells (NSPCs) results in formation of SEN- and SEGA-like structural abnormalities in the lateral ventricle, the consequence of abnormal migration of NSPCs following Tsc1 loss.     

Increased frequency and function of KIR2DL1–3+ NK cells in primary HIV‐1 infection are determined by HLA‐C group haplotypes

The acquisition and maintenance of NK‐cell function is mediated by inhibitory killer‐cell immunoglobulin‐like receptors (KIRs) through their interaction with HLA class I molecules. Recently, HLA‐C expression levels were shown to be correlated with protection against multiple outcomes of HIV‐1 infection; however, the underlying mechanisms are poorly understood. As HLA‐C is the natural ligand for the inhibitory receptors KIR2DL1 and KIR2DL2/3, we sought to determine whether HLA‐C group haplotypes affect NK‐cell responses during primary HIV‐1 infection. The phenotypes and functional capacity of NK cells derived from HIV‐1‐positive and HIV‐1‐negative individuals were assessed (N = 42 and N = 40, respectively). HIV‐1 infection was associated with an increased frequency of KIR2DL1–3⁺ NK cells. Further analysis showed that KIR2DL1⁺ NK cells were selectively increased in individuals homozygous for HLA‐C2, while HLA‐C1‐homozygous individuals displayed increased proportions of KIR2DL2/3⁺ NK cells. KIR2DL1–3⁺ NK cells were furthermore more polyfunctional during primary HIV‐1 infection in individuals also encoding for their cognate HLA‐C group haplotypes, as measured by degranulation and IFN‐γ and TNF‐α production. These results identify a novel relationship between HLA‐C and KIR2DL⁺ NK‐cell subsets and demonstrate that HLA‐C‐mediated licensing modulates NK‐cell responses to primary HIV‐1 infection.