正常皮肤中单核巨噬细胞和树枝状细胞的分布规律

目的：观察正常真皮内的单核-巨噬细胞和树枝状细胞的分布、排列规律，探讨单核-巨噬细胞在皮肤免疫防御中的作用。方法：正常皮肤8例，取面部、躯干、四肢近端、四肢远端、手掌和足跖6个部位皮肤，进行纵行与水平切片。CD1a和CD68单克隆抗体染色，观察朗格汉斯细胞（LC）和单核．巨噬细胞的分布形态和密度。结果：真皮浅层CD68阳性细胞呈网状分布，其密度为361-562个／mm^2。真皮内血管周围及附属器周围亦见CD68阳性细胞。真皮深层CD68阳性细胞多为树枝状，散在分布于粗大的胶原纤维之间。不同解剖部位真皮浅层CD68阳性细胞密度分别为：四肢远端562个／mm^2，腹部517个／mm^2，面部509个／mm^2，手掌507个／mm^2，四肢近端472个／mm^2，足跖361个／mm^2。真皮浅层CD68阳性细胞在手掌和足跖部位高于相应部位的表皮内CD1a和CD68细胞。结论：在真皮浅层形成数层单核．巨噬细胞网，此网在接近真表皮交界处较致密。真皮内单核-巨噬细胞的这种分布形式说明这些细胞在真皮内有明确的方向性，其防御的方向是穿透表皮进入真皮的入侵物。

Thy-1抗原与Thy-1^+表皮树枝状细胞

Thy—1抗原是一种糖蛋白。在小鼠的T淋巴细胞,胸腺细胞,神经原细胞及纤维母细胞,大鼠的胸腺细胞、神经原细胞及纤维母细胞,人类的神经原细胞,所有哺乳动物的肌上皮细胞表面均相继被发现有表达。

大鼠NSAIDs肠病肠道获得性免疫的变化

目的探讨非甾体类消炎药（non-steroid anti-inflammatory drugs,NSAIDs）引起肠病时SD大鼠回肠s Ig A、树突状细胞、浆细胞的变化。方法清洁级SD大鼠34只,雌雄各半,年龄8周,体质量200～220 g,分为药物损伤模型组（阿司匹林组）和对照组（生理盐水组）,每组17只。药物损伤模型组腹腔注射阿司匹林,100 mg/kg,每天2次;对照组腹腔注射等量生理盐水,每天2次。2周后处死大鼠,在距回盲瓣5 cm近端肠管切取回肠段2 cm。ELISA法检测回肠组织s Ig A水平,免疫组化法检测回肠组织CD205、CD38阳性染色细胞数量。结果阿司匹林组与对照组比较,阿司匹林注射组大鼠回肠黏膜s Ig A降低（P〈0.05）,树突状细胞和浆细胞数量增多（P〈0.01）。结论 NSAIDs肠病发生后,树突状细胞和浆细胞数量增多,这提示肠道发生适应性免疫反应。但最终肠道黏膜内s Ig A分泌明显较少,这可能与分泌型Ig A形成过程受损相关,最可能发生在Ig A与SC在上皮细胞内装配的过程中。这说明,NSAIDs肠病不仅损害肠黏膜屏障,还可致体液免疫紊乱。

Indoleamine 2,3-dioxygenase (IDO) is essential for dendritic cell activation and chemotactic responsiveness to chemokines

Indoleamine 2, 3-dioxygenase (IDO) is a rate-limiting enzyme for the tryptophan catabolism. In human and murine cells, IDO inhibits antigen-specific T cell proliferation in vitro and suppresses T cell responses to fetal alloantigens during murine pregnancy. In mice, IDO expression is an inducible feature of specific subsets of dendritic cells (DCs), and is important for T cell regulatory properties. However, the effect of IDO and tryptophan deprivation on DC func- tions remains unknown. We report here that when tryptophan utilization was prevented by a pharmacological inhibitor of IDO, 1-methyl tryptophan (1MT), DC activation induced by pathogenic stimulus lipopolysaccharide (LPS) or inflam- matory cytokine TNF-α was inhibited both phenotypically and functionally. Such an effect was less remarkable when DC was stimulated by a physiological stimulus, CD40 ligand. Tryptophan deprivation during DC activation also regu- lated the expression of CCR5 and CXCR4, as well as DC responsiveness to chemokines. These results suggest that tryptophan usage in the microenvironment is essential for DC maturation, and may also play a role in the regulation of DC migratory behaviors.

Prolongation of liver allograft survival by dendritic cells modified with NF_(-k)B decoy oligodeoxynucleotides

AIM: To induce the tolerance of rat liver allograft by dendritic cells (DCs) modified with NF-κB decoy oligodeoxynucleotides (ODNs).METHODS: Bone marrow (BM)-derived DCs from SD rats were propagated in the presence of GM-CSF or GM-CSF+IL-4 to obtain immature DCs or mature DCs. GM-CSF+IL-4-propagated DCs were treated with double-strand NF-κB decoy ODNs containing two NF-κB binding sites or scrambled ODNs to ascertain whether NF-κB decoy ODNs might prevent DC maturation. GM-CSF-propagated DCs, GM-CSF+NF-κB decoy ODNs or scrambled ODNs-propagated DCs were treated with LPS for 18 h to determine whether NF-κB decoy ODNs could prevent LPS-induced IL-12 production in DCs. NF-κB binding activities, costimulatory molecule (CD40, CD80, CD86) surface expression, IL-12 protein expression and allostimulatory capacity of DCs were measured with electrophoretic mobility shift assay (ENSA),flow cytometry, Western blotting, and mixed lymphocyte reaction (MLR), respectively. GM-CSF-propagated DCs, GM-CSF+IL-4 -propagated DCs, and GM-CSF+NF-κB decoy ODNs or scrambled ODNs-propagated DCs were injected intravenously into recipient LEW rats 7 d prior to liver transplantation and immediately after liver transplantation.Histological grading of liver graft rejection was determined 7 d after liver transplantation. Expression of IL-2, IL-4 and IFN-γ, mRNA in liver graft and in recipient spleen was analyzed by semiquantitative RT-PCR. Apoptosis of liver allograft-infiltrating cells was measured with TUNEL staining.RESULTS: GM-CSF-propagated DCs, GM-CSF+NF-κB decoy ODNs-propagated DCs and GM-CSF+ scrambled ODNs-propagated DCs exhibited features of immature DCs, with similar low level of costimulatory molecule(CD40, CD80,CD86) surface expression, absence of NF-κB activation,and few allocostimulatory activities. GM-CSF+IL-4-propagated DCs displayed features of mature DCs, with high levels of costimulatory molecule (CD40, CD80, CD86) surface expression, marked NF-κB activation, and significant allocostimulatory activity. NF-κB decoy ODNs completely abrogated IL-4-induced DC maturation and allocostimulatory activity as well as LPS-induced NF-κB activation and IL-12 protein expression in DCs. GM-CSF+NF-κB decoy ODNs-propagated DCs promoted apoptosis of liver allograft-infiltrating cells within portal areas, and significantly decreased the expression of IL-2 and IFN-γ mRNA but markedly elevated IL-4 mRNA expression both in liverallograft and in recipient spleen, and consequently suppressed liver allograft rejection, and promoted liverallograft survival.CONCLUSION: NF-κB decoy ODNs-rnodified DCs canprolong liver allograft survival by promoting apoptosis of graft-infiltrating cells within portal areas as well as down-regulating IL-2 and IFN-γ mRNA and up-regulating IL-4 rnRNA expression both in liver graft and in recipient spleen.

Induction of hepatitis C virus-specific cytotoxic T and B cell responses by dendritic cells expressing a modified antigen targeting receptor

AIM: To find a novel antigen (Ag) presentation strategy to improve the immune responses induced by dendritic cell (DC)vaccine expressing hepatitis C virus (HCV) core antigen (pcDNA3HCV C-Fc) in Balb/c mice (H-2d).METHODS: pcDNA3HCV C-Fc plasmid and eukaryotic expression vector pcDNA3 were injected into mice sc. Immune responses to pcDNA3HCV C-Fc were studied. Meanwhile the effect of pcDNA3HCV C-Fc on anti-translated subcutaneous tumor of SP2/0 cells stably expressing HCV C Ag (SP2/0-HCV C-FC) was also studied. Anti-HCV C in serum was detected by enzyme-linked immunoadsordent assay (ELISA) and HCV specific cytotoxic T lymphocyte (CTL) activity was measured by LDH release assay. After 3 wk of DNA immunization,the cells of SP2/0-HCV C-FC were inoculated into mice subcutaneously and tumor growth was measured every 5 d.The survival rate and living time of mice were also calculated.RESULTS: After 4 wk of DC immunization, the A450 nm values of sera in mice immunized with pcDNA3HCV C-Fc-DC and pcDNA3-DC were 0.56±0.17 and 0.12±0.03 respectively. The antibody titres in mice codeliveried with pcDNA3HCV C-Fc with DC were significantly higher than those of mice injected with pcDNA3-DC. The HCV specific CTL activities in mice coinjected with DC and pcDNA3HCV C-Fc or empty expression vectors were(73.2±3.1) % and (24.4±8.8) %, which were significantly higher than those of mice injected with water.The DC vaccine could evidently inhibit tumor growth, prolong the survival time of mice and improve the survival rate of mice and these effects could be improved by HCV C-Fc (pcDNA3HCV C-Fc) gene codelivered.CONCLUSION: DC vaccine has a strong antigenicity in humoral and cellular immunities, which can be promoted by transduced pcDNA3HCV C-Fc expressing HCV C or Fc.Thus, pcDNA3HCV C-Fc-transduced DCs may be a promising candidate for a CTL-based vaccine against HCV.

Entecavir up-regulates dendritic cell function in patients with chronic hepatitis B

AIM: To investigate the in vitro effect of entecavir (ETV on the function of dendritic cells (DCs) derived from chronic hepatitis B (CHB) patients. METHODS: Mononuclear cells were isolated from peripheral blood of patients with CHB. DCs wer incubated with RPMI-1640 medium supplemented wit fetal bovine serum, IL-4, granulocyte-macrophag colony-stimulating factor (GM-CSF). DCs were treate with or without ETV on the fourth day. Cell surfac molecules, including CD1a, CD80, CD83 and HLA-DR were assessed by flow cytometry. Concentrations of IL- and IL-12 in the supernatant were assayed by enzyme linked immunosorbent assay (ELISA). The ability of th generated DCs to stimulate lymphocyte proliferation wa observed. RESULTS: Compared with CHB control group, th expression levels of CD1a (29.07 ± 3.20 vs 26.85 ± 2.80 CD83 (25.66 ± 3.19 vs 23.21 ± 3.10), CD80 (28.00 ± 2.7 vs 25.75 ± 2.51) and HLA-DR (41.96 ± 3.81 vs 32.20 ± 3.04) in ETV-treated group were higher (P < 0.05). ETV treated group secreted significantly more IL-12 (157.6 ± 26.85 pg/mL vs 132.60 ± 22.00 pg/mL (P < 0.05) an had a lower level of IL-6 in the culture supernatant (83.0 ± 13.88 pg/mL vs 93.60 ± 13.61 pg/mL, P < 0.05) tha CHB control group. The ability of DCs to stimulate th proliferation of allogeneic lymphocytes was increase in ETV-treated group compared with CHB control grou (1.53 ± 0.09 vs 1.42 ± 0.08, P < 0.05).CONCLUSION: Entecavir can enhance the biological activity of DCs derived from CHB patients.

Potentially probiotic bacteria induce efficient maturation but differential cytokine production in human monocyte-derived dendritic cells

AIM: To analyze the ability of nine different potentially probiotic bacteria to induce maturation and cytokine production in human monocyte-derived dendritic cells (moDCs). METHODS: Cytokine production and maturation of moDCs in response to bacterial stimulation was analyzed with enzyme-linked immunosorbent assay (ELISA) and flow cytometric analysis (FACS), respectively. The kinetics of mRNA expression of cytokine genes was determined by Northern blotting. The involvement of different signaling pathways in cytokine gene expression was studied using specific pharmacological signaling inhibitors. RESULTS: All studied bacteria induced the maturation of moDCs in a dose-dependent manner. More detailed analysis with S. thermophilus THS, B. breve Bb99, and L. lactis subsp. cremoris ARH74 indicated that these bacteria induced the expression of moDC maturationmarkers HLA class Ⅱ and CD86 as efficiently as pathogenic bacteria. However, these bacteria differed in their ability to induce moDC cytokine gene expression. S. thermophilus induced the expression of pro-inflammatory (TNF-α, IL-12, IL-6, and CCL20) and Th1 type (IL-12 and IFN-γ) cytokines, while B. breve and L. lactis were also potent inducers of anti- inflammatory IL-10. Mitogen-activated protein kinase (MAPK) p38, phosphatidylinositol 3 (PI3) kinase, and nuclear factor-kappa B (NF-κB) signaling pathways were shown to be involved in bacteria-induced cytokine production. CONCLUSION: Our results indicate that potentially probiotic bacteria are able to induce moDC maturation, but their ability to induce cytokine gene expression varies significantly from one bacterial strain to another.

Effects of dendritic cells transfected with full-length wild-type p53 and stimulated by gastric cancer lysates on immune response

AIM: To investigate the effects of dendritic cells (DCs) transfected with full-length wild-type p53 and stimulated by gastric cancer lysates on immune response.METHODS: The wild-type p53 was transduced to DCs with adenovirus, and the DCs were stimulated by gastric cancer lysates. The surface molecules (B7-1, B7-2, MHC-I, MHC-II) of all DCs were detected by FACS, and the ability of the DCs to induce efficient and specific immunological response inanti-^51Cr-labeled target cells was studied. BALB/c mice injected with DCs and Mk28 were established, and CTL response in mice immunized with Lywt-p53DC was evaluated.Tumor-bearing mice were treated with Lywt-p53DC.RESULTS: The surface molecules of Lywt-p53DC had a high expression of B7-1 (86.70±0.07%), B7-2 (18.77±0.08%),MHC-I (87.20±0.05%) and MHC-II (56.70±0.07%); T lymphocytes had a specific CTL lysis ability induced by Lywt-p53DC; the CTL lysis rate was as high as 81%. The immune protection of Lywtp-53DC was obvious, the tumor diameter in Lywtp-53DC group was 3.10+0.31 ram, 2.73±0.23 ram,3.70±0.07 mm on d 13, 16 and 19, respectively, which were smaller than control, DC, wtp53DC and LyDC group (P<0.05). Tumor growth rate in Lywtp53DC group was slower than that in other groups (P<0.05).CONCLUSION: DCs transfected with wild-type p53 and stimulated by gastric cancer lysates have specific CTL killing activity.

Heparanase expression,degradation of basement membrane and low degree of infi ltration by immunocytes correlate with invasion and progression of human gastric cancer

AIM: To disclose the mechanisms that accelerate or limit tumor invasion and metastasis in gastric cancer patients. METHODS: The heparanase expression,continuity of basement,degree of infiltration by dendritic cells and lymphocytes in gastric cancer tissues from 33 the early and late stage patients were examined by immunohistochemistry,in situ hybridization and transmission electron microscopy. RESULTS: Heparanase mRNA expression in the late stage patients with gastric cancer was stronger than that in the early stage gastric cancer patients. In the early stage gastric cancer tissues,basement membrane (BM) appeared intact,whereas in the late stage,discontinuous BM was often present. The density of S100 protein positive tumor infi ltrating dendritic cells (TIDC) in the early stage gastric cancer tissues was higher than that in the late stage. The infiltrating degree of tumor infi ltrating lymphocytes (TIL) in the early stage patients whose tumor tissues contained a high density of TIDC was signifi cantly higher than that in the late stage gastric cancer tissues patients with a low density of TIDC. There were few cancer cells penetrated through the continuous BM of cancer nests in the early stage gastric cancers,but many cancer cells were found outside of the defective BM of cancer nests in the late stage. CONCLUSION: Our results suggest that strongheparanase expression is related with the degradation of BM which allows or accelerates tumor invasion and metastasis. However,high density of TIDC and degree of infi ltration by TIL are associated with tumor progression in human gastric cancers.

Studies on the allostimulatory function of dendritic cells from HCV-HIV-1 co-infected patients

There is increasing recognition of the potential morbidity and mortality associated with HIV-1 and hepatitis C (HCV)co-infection. HIV appears to adversely affect HCV disease while the reciprocal effect of HCV on HIV remains controversial.We therefore studied the effect of co-infection on dendritic cell function versus HIV infection alone, as previous work has shown that HCV impairs dendritic cell (DC) function. HIV-1 positive individuals with HCV were matched for CD4count, HIV- 1 RNA viral load and therapy, to HIV- 1 positive patients without HCV. Monocyte-derived DC were generated and mixed leukocyte reactions were performed. We assessed allostimulatory capacity with and without administration of exogenous Thl cytokines, using thymidine uptake and cell division analyses with the vital dye CFSE. We found that monocyte-derived DC from co-infected individuals showed no significant differences in allostimulatory capacity to ex vivo generated DC from HIV-1 infected individuals without HCV. Unlike the situation with HCV infection alone, this impairment was not reversed by increasing concentrations of either interleukin-2 or -12. Monocyte-derived DC from HIV-1 and HCV co-infected individuals have a similar allostimulatory capacity to DC from matched patients with HIV-1alone. These findings are compatible with results of prior clinical studies that found no evidence that HCV co-infection altered HIV disease progression and has implications for immunotherapeutic approaches in co-infected individuals.

IgSF13, a novel human inhibitory receptor of the immunoglobulin superfamily, is preferentially expressed in dendritic cells and monocytes

A novel inhibitory receptor of immunoglobin superfamily (IgSF), IgSF member 13 (IgSF13), has been identified from human dendritic cells (DC). IgSF13 is a type Ⅰ transmembrane protein containing an N-terminal signal peptide, a extracellular region with a single Ig Ⅴ-like domain, a transmembrane region, and a cytoplasmic tail with two classical immunoreceptor tyrosine-based inhibitory motifs (ITIM), suggesting its inhibitory function. IgSF13 shows significant homology to human CMRF35 and pIgR. IgSF13 gene is mapped to chromosome 17q25.2, very close to that of CMRF35. IgSF13 is preferentially expressed in myelo-monocytic cells, including monocytes, monocyte-derived DC, and monocyte-related cell lines. Upon pervanadate treatment, IgSF13 was hyper-phosphorylated and associated with Src homology-2 domain-containing phosphatases SHP-1 and SHIP, but not SHP-2. The identification of IgSF13 as a novel ITIM-bearing receptor selectively expressed by DC and monocytes suggests that it may be potentially involved in the negative regulation of specific leukocyte population.

艾滋病毁坏免疫系统的关键机制找到了吗?

艾滋病如何毁坏免疫系统?为什么,艾滋病患者只有1%或更少的细胞携带病毒,而大量的 T 辅助细胞遭到破坏?这是有关艾滋病的最费解的迷。洛克菲勒大学(New York,NY)的研究者认为他们已经找到了谜底,并认为正在进行的工作可能已经改观了开发疫苗和治疗方法的前景。这些科学家发现,树枝状细胞在行使其将抗原送至 T 细胞的正常功能同时,可能拖带上了 HIV 病毒。树枝状细胞/抗原/T 细胞相互作用时,HIV 就可能到达被抗原激活的 T 细胞。活化状态的 T 细胞迅速增殖,在 HIV 病毒毁坏细胞之前,HIV 数量猛增。然而,许多问题仍不清楚,如:树枝状细胞如何携带 HIV?

新生儿下唇粘膜原发性恶性黑色素瘤一例报告

患儿,女性,40天,维族。出生后无意中发现下唇内侧粘膜有一小米粒大小之红点,第7天长成为包谷粒大的肿物,红色,10余天直径达2cm。即在乡卫生所按炎症处理无效,肿物继续增大,影响饮食,于1986年5月13日前来我院治疗。

Acute myeloid leukemia cells inhibit the differentiation and maturation of dendritic cells and induce the generation of regulatory T cells

Objective:To investigate the effects of soluble factors secreted by acute myeloid leukemia(AML) cells on the phenotypical and functional properties of DCs derived from normal mononuclear cells. Methods:Mononuclear cells were cul-tured with interleukin-4(IL-4) and granulocyte-macrophage colony-stimulating factor(GM-CSF),in the presence or absence of 24 h culture supernatants from fresh primary AML cells,to generate immature DCs. The maturation of DCs was induced by cytokines IL-1beta,IL-6,tumor necrosis factor-alpha(TNF-alpha),and prostaglandin-2(PGE-2). The phenotypic alterations of DCs and DCs-primed CD4+ T cells were evaluated using flow cytometry. Precursor frequency(PF) was calculated to monitor the allostimulatory effects of DCs on CD4+ and CD8+ T cells. Results:AML cell supernatant-treated DCs showed significantly lower expression of co-stimulatory molecules CD80 and CD86,and reduced response to cytokines IL-1beta,IL-6,TNF-alpha,and PGE-2. The allostimulatory effects of AML cell supernatant-treated DCs on CD4+ and CD8+ T cells were significantly lower than those of normal mature DCs [PF:(1.8 ± 0.5)% vs.(5.2 ± 1.6)% for CD4+ T cells,(2.1 ± 0.6)% vs.(6.5 ± 2.0)% for CD8+ T cells,P < 0.01]. These AML supernatant-induced DCs could also induce allogeneic CD4+ T cells to differentiate into CD4+CD25high T cells,which had immunophenotyping characteristics of regulatory T cells,i.e. they expressed Foxp3 but not active maker CD69. Conclusion:This study demonstrates that soluble factors secreted by AML cells can inhibit development and functions of DCs. In addition,AML supernatant-induced DCs can induce the generation of CD4+CD25high T cells from CD4+ T cells,which may be a mechanism of increased prevalence of CD4+CD25high regulatory T cells and immune dysfunction in AML patients.

Effect of Arsenic Trioxide with Various Concentrations on Dendritic Cells in the Conducting Airways of Asthmatic Mice

To investigate the effect of arsenic trioxide (As2O3 )with three different concentration groups on the distribution and recruitment of dendritic cells(DCs) in the conducting airways of asthmatic mice. Methods: Fifty BALB/c mice were divided into 5 groups at random: control group, asthmatic group, therapeutic groups with low dose(1 mg/kg), moderate dose( 5 mg/lqg) and high dose( 10 mg/kg) of As2O3. The immunohistochomistry, scanning electron microscope and computerized image analysis were applied to detect airway DCs, respectively. Results: We demonstrated from the control mice that all intraepithelial NLDC-145 DCs throughout the respiratory tree cotdd be accounted for a network of cells with dendritic cell morphology, and the density of DCs varied from(500±50) cells/ram^2 epithelial surface in the large airways, to(60±10)cells/mm^2 epithelial surface in the small airways(P<0.05).The DCs characteristic of spiny and long processes were impressively observed by the scanning electron microscope. Comtmred with the control mlce,the density,but not the distribution of NLDC-145 DCs was significantly upregulated in the conducing airways of asthmatic mice(P<0.01) .Compared with the asthmatic mice, the densilies, but not the distributions of NLDC-145 DCs were significantly down regulated in the conducting airways of the thempeutic groups with three varying concentrations of As2O3(P<0.01 )while there were no statistical differences between each other(P>0.05).Conchsion : Our findings suggest that it might be an important therapeutic mechanism of As2 03 to downregulate not the distribution but the density of DCs in the conducting airways of asthmatic mice,and low dose of As203 has potential value in treating asthma.

巨大皮肤黑素棘皮瘤

A 45-year-old male cook was seen for the evaluation and removal of a "mole o n my eye" of steady growth during the previous 6 months. The patient stated that he had had a "brown spot" above his left eye for 17 years prior to its recent e nlargement; it was now partly blocking the vision in his left eye. He denied a h istory or family history of cutaneous tumors, including skin cancer. On examinat ion, a 2.5-cm ×.0.5-cm ×.0.8-cm, horn-like, darkly pigmented, cutaneous no dule was evident extending from the left upper eyelid downwards to below the low er eyelid (Figs 1 and 2). He also had scattered, skin-colored, 2-3-mm cystic papules on his anterior mid-chest. A shave excision specimen was obtained from the eyelid nodule. Microscopic examination demonstrated acanthosis, hyperkeratos is, and papillomatosis (Fig. 3). Large dendritic cells with abundant melanin gra nules were spread throughout the epidermis. In addition, small basaloid or spino us keratinocytes were present in the malpighian layer.