Study on mechanism of increased allergenicity induced by Ara h 3 from roasted peanut using bone marrow-derived dendritic cells

Little information was so far available about allergenic mechanism of the roasted peanut allergens during initial stages of allergy.The purpose of this study was to determine the influence of roasting(150℃,20 min)on biochemical and biological properties of Ara h 3,a major peanut allergen.Allergenicity of roasted peanut emulsion to mice,differences in uptakes between Ara h 3 purified from raw peanuts(named as Ara h 3-Raw)and that purified from roasted peanuts(named as Ara h 3-Roasted)by bone marrow-derived dendritic cells(BMDCs)and the implication of cell surface receptors involving in uptake,and changes in glycosylation and structure of Ara h 3 after roasting were analyzed in this study.This study suggested that roasting increased allergenicity of peanut to BALB/c mice.Maillard reaction and structural changes of Ara h 3 induced by roasting significantly altered the uptake of Ara h 3-Roasted by BMDCs,and modified Ara h 3 fate in processes involved in immunogenicity and hyper allergenicity,indicating that food processing pattern can change food allergenicity.

Probiotic Bio-Three induces Th1 and anti-inflammatory effects in PBMC and dendritic cells

AIM:To investigate the immune response of peripheral blood mononuclear cells(PBMCs)and dendritic cells (DCs)that were stimulated by probiotic preparations. METHODS:PBMCs were isolated,cultured,and stimulated with Bio-Three(a mixture of Bacillus mesentericus, Clostridium butyricum and Enterococcus faecalis;105, 10 6 and 10 7 CFU/mL for 24 h).Cytokine production of (1)circulating PBMCs;(2)PBMCs stimulated by probiotic preparation;(3)monocyte-derived DCs;and(4)DC andT cell co-culture was determined by enzyme-linked immunosorbent assay.Phenotypic analysis of circulating PBMCs was also investigated by flow cytometry.Blood was obtained from individuals who consumed Bio-Three (10 9 CFU/d B.mesentericus,C.butyricum and E.faecalis) for 2 wk,or those who did not take probiotics orally. RESULTS:In culture supernatants,interferon-γ(IFN-γ) and interleukin(IL)-10 production increased,but IL-4 and tumor necrosis factor-α(TNF-α)production by PBMCs decreased after 1 and 2 wk of probiotic treatment.Flow cytometry was also performed on day 14 and detected enhanced expression of CD11b,HLA-DR, CD4,CD45RA,CD25,CD44 and CD69 in response to Bio-Three.Furthermore,IL-10 and IL-12 were upregulated in supernatants of monocyte-derived DCs,and IFN-γand IL-10 were enhanced in supernatants of CD4 + T cells co-cultured with DCs. CONCLUSION:Bio-Three appeared to stimulate the Th1 immune response,downregulate pro-inflammatory cytokines(TNF-α)and upregulate anti-inflammatory cytokine(IL-10).Probiotics could be effective in activation of PBMCs and DCs.

Relationship between the Changes of VEGF Level and Dendritic Cells in Peripheral Blood of Patients with Hepatocellular Carcinoma after Transcatheter Arterial Chemoembolization

In order to investigate the relationship between the VEGF level and the counts of dendritic cells （DCs） in peripheral blood of patients with hepatocellular carcinoma （HCC） before and after transcatheter arterial chemoembolization （TACE）, the peripheral blood was obtained from 37 patients with HCC who treated by TACE. The blood was obtained on the day before TACE, the first day, the 7th day and the 15th day after TACE respectively. The counts of DCs were quantified by flow cytometry. The plasma VEGF level was measured by ELESA kit. It was shown after TACE, the counts of DCs in peripheral blood were decreased significantly （P〈0.05）, and the VEGF level in peripheral blood was increased significantly （P〈0.05）. The counts of DCs in peripheral blood had an inverse correlation with the plasma VEGF level （r=-0.57, P〈0.05） after TACE. It was concluded that in patients with HCC after TACE, the increased plasma VEGF level appeared to have the effect to suppress the maturation of DCs, which may contribute to reduction of the body＇s anti-tumor immunity effect, with a consequence of recur and metastasis of tumor.

Recognition of HBV antigens and HBV DNA by dendritic cells

BACKGROUND: Hepatitis B virus (HBV) is a hepatotropic, noncytopathic, DNA virus which can cause acute and chronic infection. Viral persistence is associated with a weak or absent specific immune responses to HBV, particularly the cellular immune response. Dendritic cells (DCs) are professional antigen-presenting cells with a unique T cell stimulatory aptitude that play a crucial role in the instruction of adaptive immune responses upon infection. An impaired function of DCs was suggested by recent studies to account for the T and B cell hyporesponsiveness in chronic HBV infection. This review summarizes recent insights into the recognition of HBV antigens by DCs. DATA SOURCES: Studies were identified by searching MEDLINE and/or PubMed for articles using the key words 'hepatitis B virus (HBV)', 'dendritic cells', 'C-type lectins', 'mannose receptor', 'toll-like receptor', and 'dendritic cell-specific intercellular-adhesion-molecule-3 grabbing nonintegrin (DC-SIGN)' up to December 2009. Additional papers were identified by a manual search of the references from the key articles. RESULTS: DCs play an important role in the progress of hepatitis B, especially in the recognition of HBV. There are three main ways of recognition of HBV antigens by DCs. First, HBV DNA can be recognized by DCs through toll-like receptor 9 (TLR9) which activates the NF-kappa B signal pathway and p38 MAPK to up-regulate the expression of interferon (IFN) regulatory factor 7 (IRF-7) in a manner independent of type I IFN signaling, resulting in secretion of type I IFN and inflammatory cytokines, and induction of DC maturation and the adaptive immune response. Second, HBc/HBeAg cannot be recognized by DCs, but DNA or ssRNA encapsulated within HBcAg can be internalized by DCs through TLRs. Third, HBsAg can be internalized by DCs through the mannose receptor, which lacks the ability to induce DC maturation without the assistance of DC-SIGN. Meanwhile, there is some cross-talk among the three mechanisms, which induces an effective anti-viral response or HBV persistence. CONCLUSIONS: On the basis of these recognition processes, methods have been used to enhance the efficacy of DC-based vaccine against HBV and have been useful in the clinical application of HBV vaccine therapy. But the interactions between HBV antigens/HBV DNA and DCs are not clear, and cross-talk between TLRs and various ligands makes HBV antigen recognition by DCs more complicated. More efforts should be made to define the mechanisms and develop effective vaccines and therapies. (Hepatobiliary Pancreat Dis Int 2010; 9:584-592)

HBsAg loading on dendritic cells in patients with chronic hepatitis B: expressions of phenotypic molecules

BACKGROUND: The antigen reducing ability of dentritic cells (DCs), a kind of antigen presenting cells (APCs) initiating immune response, is associated with the specific immune tolerance of chronic hepatitis B(CHB) patients. However, the dysfunction of DCs can be possibly reversed by the stimulation of antigen peptides. In this study, DCs were cultured from peripheral blood monocytes (PBMCs) in patients with CHB in vitro, and the expression of phenotypic molecules on DCs loaded by different concentrations of HBsAg was observed. METHODS: Forty patients with CHB were divided randomly into 4 groups(10 patients in each group). PBMCs were isolated, and DCs were cultured after addition of granulocyte/macrophage colony-stimulating factor (GMCSF) and interleukin 4(IL-4). On the 9th day, DCs of the experimental groups were loaded at HBsAg concentrations of 2.5mg/L, 5mg/L and 10mg/L for 24 hours, whereas those of the control group were not loaded. An electron microscope was used to analyze the morphological changes of the DCs. The expression of phenotypic molecules on DCs in different groups was detected with flow cytometry. RESULTS: A combination of GM-CSF and IL-4 produced DCs from PBMCs in patients with CHB after being cultured for 9 days, whose morphological changes were tested by an electron microscope. The expression of phenotypic molecules on DCs in the control group was as low as CD83 (8.02±3.99)%, CD80(8.77±2.06)%, and MHC-DR (14.05±2.66)%. Loaded by different concentrations of HBsAg, the up-regulation of phenotypic molecules on DCs was found, with CD83(18.35±2.93)%, CD80(42.63±7.15)% and MHC-DR(47.49±6.59)% in 2.5mg/L HBsAg loading group, CD83(17.88±3.12)%, CD80(45.24± 10.93)% and MHC-DR(47.07±8.52)% in 5mg/L HBsAg loading group and CD83(16.74±2.86)%, CD80(44.59±6.99)% and MHC-DR(48.59±7.42)% in 10mg/L HBsAg loading group, respectively. Compared with the control group, the phenotypic molecules in the experimental groups were all different significantly (P<0.01), but among them, there were no differences (P>0.05). CONCLUSIONS: DCs cultured from PBMCs in the patients with CHB under the conditions of GM-CSF and IL-4 present on the typical dendritic morphology but are immature for expressing low phenotypic molecules. Loaded by different concentrations of HBsAg, the immature DCs can differentiate to mature DCs for expressing increasing phenotypic molecules.

Rapamycin combined with allogenic immature dendritic cells selectively expands CD4^+CD25^+Foxp3^+ regulatory T cells in rats

ReferencesReferencesBackgroundDendritic cells (DCs) can initiate the expansion of regulatory T cells (Tregs), which play an indispensable role in inducing transplantation tolerance. Some studies have investigated the effect of the immunosuppressant rapamycin (Rapa) on Tregs in vitro. However, the in vivo effect of Rapa combined with immature DCs (iDCs) on Tregs is unknown. This study was undertaken to determine whether allogenic iDCs combined with a short course of Rapa have the ability to selectively expand the CD4+CD25+Foxp3+ Tregs in a rat model.MethodsBrown Norway rats were injected intravenously with 2×106 Lewis iDCs followed by 1 mg/kg per day Rapa intraperitoneally for 7 consecutive days. On day 8, the levels of CD4+CD25+Foxp3+ Treg cells in peripheral blood and spleen cells were analyzed by flow cytometry. IL-2, IL-4, TGF-β1, and IFN-γ levels in serum were assessed by ELISA. The experimental animals were divided into four groups: control, Rapa-treated, iDC-treated, and combination-treated.ResultsCD4+CD25+Foxp3+ Tregs comprised 7%-8%of CD4+ T cells in control rats. Rapa combined with iDCs enhanced this percentage in the peripheral blood and spleen. However, the levels of Tregs did not significantly change after treatment with Rapa or iDCs alone. The levels of CD4+CD25?/sup>Foxp3+ T cells and CD4+ CD25+Foxp3?/sup> T cells in CD4+ T cells did not significantly change in the combined group. The TGF-β1 level in serum from the combined group increased significantly compared with the other groups.ConclusionsA significantly higher percentage of CD4+ CD25+ Foxp3+ Tregs was found in rats treated with allogenic iDCs and a short course of Rapa, along with an increase in the TGF-β1 level in serum. This improved protocol may be a promising therapeutic strategy to increase Tregs, which are beneficial to the induction of peritransplant tolerance.

Serum IL-10 from systemic lupus erythematosus patients suppresses the differentiation and function of monocyte-derived dendritic cells

The role played by cytokines, other than interferon （IFN）-a, in the differentiation and function of dendritic cells （DCs） in systemic lupus erythematosus （SLE）, remains unclear. Serum interleukin-10 （IL-10） levels are generally elevated in SLE patients, which might modulate the differentiation of DCs. In this study, DCs were induced from monocytes either by transendothelial trafficking or by culture with granulocyte-macrophage colony-stimulating factor （GM-CSF） ＋ IL-4 ＋ tumor necrosis factor （TNF）-a. Both systems were used to investigate the effects of elevated serum IL-10 level on DC differentiation in SLE patients. The results showed that monocyte-derived DCs induced by either SLE serum or exogenous IL-10 reduced the expression of human leukocyte antigen （HLA）-DR and CD80, decreased IL-12p40 level, and increased IL-10 level, and exhibited an impaired capacity to stimulate allogenic T-cell proliferation. These results indicate that serum IL-10 may be involved in the pathogenesis of SLE by modulating the differentiation and function of DCs.

Immune responses of dendritic cells combined with tumor-derived autophagosome vaccine on hepatocellular carcinoma

Background： To induce and collect tumor-derived autophagosomes （DRibbles） from tumor cells as an antitumor vaccine by inhibiting the functions of proteasomes and lysosomes. Methods： Dendritic cells （DCs） generated from peripheral blood mononuclear cell （PBMC） of hepatocellular carcinoma （HCC） patients were cocultured with DRibbles, and then surface molecules of DCs, as well as surface molecules on DCs, were determined by flow cytometry. Meanwhile, immune responses of the DCs-DRibbles were examined by mixed lymphocyte reactions. Results： DRibbles significantly induced the expression of CD80, CD83, CD86 and HLA-DR on DCs. The enzyme-linked immunosorbnent assay （ELISA） showed that IFN-γ, levels after vaccination increased than before in most patients, but CDS＋ proportion of PBMC increased only in nine patients. Higher levels of IFN-γ, were detected in the CD8＋ cells than CD4＋ T cells. These results suggested that DCs-DRibbles vaccine could induce antigen-specific cellular immune response on HCC and could prime strong CD8＋ T cell responses, supporting it as a tumor vaccine candidate. Conclusions： Our results demonstrate that HCC/DRibbles-pulsed DCs immunotherapy might be deployed as an effective antitumor vaccine for HCC immunotherapy in clinical trials.

Current advances in using tolerogenic dendritic cells as a therapeutic alternative in the treatment of type 1 diabetes

Type 1 diabetes(T1D)is an autoimmune disease characterized by the destruction of insulin-producingβ-cells of the pancreatic islets by autoreactive T cells,leading to high blood glucose levels and severe long-term complications.The typical treatment indicated in T1D is exogenous insulin administration,which controls glucose levels;however,it does not stop the autoimmune process.Various strategies have been implemented aimed at stoppingβ-cell destruction,such as cellular therapy.Dendritic cells(DCs)as an alternative in cellular therapy have gained great interest for autoimmune disease therapy due to their plasticity to acquire immunoregulatory properties both in vivo and in vitro,performing functions such as anti-inflammatory cytokine secretion and suppression of autoreactive lymphocytes,which are dependent of their tolerogenic phenotype,displayed by features such as semimature phenotype,low surface expression of stimulatory molecules to prime T cells,as well as the elevated expression of inhibitory markers.DCs may be obtained and propagated easily in optimal amounts from peripheral blood or bone marrow precursors,such as monocytes or hematopoietic stem cells,respectively;therefore,various protocols have been established for tolerogenic(tol)DCs manufacturing for therapeutic research in the treatment of T1D.In this review,we address the current advances in the use of tolDCs for T1D therapy,encompassing protocols for their manufacturing,the data obtained from preclinical studies carried out,and the status of clinical research evaluating the safety,feasibility,and effectiveness of tolDCs.

Inducible expression of endomorphins in murine dendritic cells

Bone marrow precursor cells were extracted from C57BL/6J mice aged 7-8 weeks, and dendritic cells were purified using anti-CD1 lc （a specific marker for dendritic cells） antibody-coated magnetic beads. Immunofluorescence staining revealed that the expression levels of endomorphin-1 and endomorphin-2 were upregulated in dendritic cells activated by lipopolysaccharide. An enzyme Jmmunoassay showed that lipopolysaccharide and other Toll-like receptor ligands promoted the secretion of endomorphin-1 and endomorphin-2 from activated dendritic cells. [3H]-thymidine incorporation demonstrated that endomorphin-1 and endomorphin-2 both inhibited the proliferation of T lymphocyte induced by activated dendritic cells. Furthermore, this immunosuppressive effect was blocked by CTOP, a specific antagonist of IJ-opioid receptors. Our experimental findings indicate that activated dendritic cells can induce the expression and secretion of endomorphins, and that endomorphins suppress T lymphocyte proliferation through activation of iJ-opioid receptors.

An Investigation on the Phenotype of Cultured Dendritic Cells from the Peripheral Blood of Patients with Breast Cancer

Objective To induce and culture the dendritic cells in the peripheral blood of breast cancer patients and research on their phenotype. Methods Mononuclear cells were isolated by Ficoll Hypaque centrifugation from 32 breast cancer patients peripheral blood. These cells were plated in six well culture plates(10 6/ml,2 ml/well) in RPMI 1640 medium supplemented with 10% heat inactivated fetal bovine serum,100 ng/ml GM CSF,20 ng/ml IL 4,and/or 20 ng/ml TNF α.Two hours later, nonadherent cells were gently removed and fresh medium was added. Cultured cells were analyzed by flow cytometry with fluorescence labeled monoclonal antibodies. Pictures of cultured and fluorescence stained cells were taken by confocal scanning microscope. Results The diameter of the cells was between 10 and 20 micron. Cells displayed a characteristic CD1a +,CD40 +,CD80 +, CD86 + and CD83 + phenotypes. All of these molecules were not specific for dendritic cells. CD1a and CD83 molecules could also be expressed on the surface of CD3 + T lymphocytes and CD19 + B lymphocytes, especially on activated lymphocytes. Conclusion The molecules of CD1a and CD83 are not specific phenotypes for dendritic cells. Currently, we still need to apply both cell morphology and costimulatory molecules such as CD40,CD80, and CD86 to the identification of dendritic cells.

Clinical and Pathological Implications of Increases in Tonsillar CD19+CD5+B Cells,CD208+Dendritic Cells,and IgA1-positive Cells of Immunoglobulin A Nephropathy

Objective:Several studies indicated that tonsillectomy can improve the prognosis of patients with immunoglobulin A nephropathy(IgAN).However,the relationship between tonsillar immunity and IgAN is still unclear.Methods:A total of 14 IgAN patients were recruited in the current study from May 2015 to April 2016 in Tongji Hospital.B cells,dendritic cells(DCs),and IgAl positive cells in human tonsils were detected using immunofluorescence and immunohistochemistry.Correlations between these cells and clinicopathologic features were evaluated.

Recombinant Vaccinia Virus is an Effective and Non-perturbing Vector for Human Dendritic Cells Transfected with Epstein-Barr Virus Latent Membrane Protein 2A

ObjectiveTo study the effects of dendritic cells (DC) transfected with recombinant vaccinia virus encoding Epstein Barr virus (EBV) latent membrane protein 2A(LMP2A) gene,and to provide evidence for further investigation on the therapeutic vaccines against EBV associated malignancies. MethodsMature DC were transfected with EBV LMP2A recombinant vaccinia virus (rVV LMP2A). Before and after the transfection,the expression of surface antigens on mature DC including CD1a,CD83,CD40,CD80,HLA DR was measured by fluorescence activated cell sorter (FACS) and the function of DC to stimulate allogeneic T cells proliferation was measured by mixed leukocyte reactions (MLR). ResultsLMP2A protein was highly expressed (66.1 %) in DC after the transfection of rVV LMP2A. No significant changes in the primary surface antigens expression and in the MLR were detected during the transfection. Transfected DC still had strong potential in stimulating the proliferation of allogeneic T cells. ConclusionRecombinant vaccinia virus was an effective and non perturbing vector to mediate the transfection of LMP2A into DC. The functions of mature DC were not affected significantly by the transfection of Vac LMP2A. This study could provide evidence for the further immunotherapy of EBV associated malignancies,e.g. nasopharyngeal carcinoma (NPC).

Bacteroides fragilis enterotoxin upregulates heme oxygenase-1 in dendritic cells via reactive oxygen species-,mitogen-activated protein kinase-,and Nrf2-dependent pathway

BACKGROUND Enterotoxigenic Bacteroides fragilis(ETBF)causes colitis and diarrhea,and is considered a candidate pathogen in inflammatory bowel diseases as well as colorectal cancers.These diseases are dependent on ETBF-secreted toxin(BFT).Dendritic cells(DCs)play an important role in directing the nature of adaptive immune responses to bacterial infection and heme oxygenase-1(HO-1)is involved in the regulation of DC function.AIM To investigate the role of BFT in HO-1 expression in DCs.METHODS Murine DCs were generated from specific pathogen-free C57BL/6 and Nrf2−/−knockout mice.DCs were exposed to BFT,after which HO-1 expression and the related signaling factor activation were measured by quantitative RT-PCR,EMSA,fluorescent microscopy,immunoblot,and ELISA.RESULTS HO-1 expression was upregulated in DCs stimulated with BFT.Although BFT activated transcription factors such as NF-κB,AP-1,and Nrf2,activation of NF-κB and AP-1 was not involved in the induction of HO-1 expression in BFT-exposed DCs.Instead,upregulation of HO-1 expression was dependent on Nrf2 activation in DCs.Moreover,HO-1 expression via Nrf2 in DCs was regulated by mitogenactivated protein kinases such as ERK and p38.Furthermore,BFT enhanced the production of reactive oxygen species(ROS)and inhibition of ROS production resulted in a significant decrease of phospho-ERK,phospho-p38,Nrf2,and HO-1 CONCLUSION These results suggest that signaling pathways involving ROS-mediated ERK and p38 mitogen-activated protein kinases-Nrf2 activation in DCs are required for HO-1 induction during exposure to ETBF-produced BFT.

IMMUNOTHERAPY OF SPONTANEOUS METASTATIC LUNG CANCER WITH TUMOR ANTIGEN-PULSED, INTERLEUKIN-12 GENE-MODIFIED DENDRITIC CELLS

Objective: To investigate the treatment of spontaneous metastatic lung cancer by tumor antigen-pulsed, interleukin-12 (IL-12) gene-modified dendritic cells (DC). Methods:The spontaneous metastatic lung cancer model, prepared by injection of the 3LL Lewis lung cancer cells into the footpads of C57BL/6 mice, was treated by subcutaneous vaccination with tumor antigen peptide mut1-pulsed, IL-12 gene-modified dendritic cells (DC-IL-12/mut1) derived from the normal bone morrow. After treatment, the lung weight, the number of lung metastatic nodes and the survival time of the tumor-bearing mice were observed, and the NK and CTL activity were determined respectively. The mice were divided into 8 groups with 12 mice in each group. Results: Compared with mice treated with mut1-pulsed, control LacZ gene modified DC and untreated DC, tumor-bearing mice treated with DC-IL-12/mut1 had the lightest lung weights (P<0.01), the least lung metastatic node number (P<0.01), the longest survival time (P<0.01), also with the induction of potent CTL activity (P<0.01) and NK activity (P<0.01). Conclusion: Tumor antigen-pulsed, IL-12 gene-modified dendritic cells have significant therapeutic effects on the spontaneous metastatic lung cancer, providing a new approach to treatment of lung tumors.

The interaction of dendritic cells and γδ T cells promotes the activation of γδ T cells in experimental autoimmune uveitis

Uveitis is a severe inflammatory disease that can cause visual impairment.Recently,activatedγδT cells were proved to play a central role in the development of experimental autoimmune uveitis(EAU).However,the mechanism underlyingγδT cell activation in EAU is incompletely known.In this study,we determined the percentage changes in and the phenotypes ofγδT cells and dendritic cells(DCs)obtained from the spleens of immunized C57BL/6(B6)mice,an animal model of EAU.We found that the number ofγδT cells and DCs obviously increased during the inflammation phase of EAU(days 16-20 of our experiment),and that during this time,γδT cells expressed high levels of CD69 and the integrin lymphocyte function-associated antigen-1(LF A-1)and secreted high levels of interleukin(IL)-17A.Moreover,DCs obtained during this phase expressed high levels of CD80,CD83,CD86,and intracellular cell adhesion molecule-1(ICAM-1).Furthermore,we studied the interaction between DCs andγδT cells by using flow cytometry and confocal microscopy in order to determine whether DCs affectedγδT-cell activation in vitro.Co-cultures of the two types of cells showed that DCs induced high levels of CD69,LFA-1,and I-17A inγδT cells.Imaging studies revealed contact between the DCs andγδT cells.This interaction was mediated by the accumulation of ICAM-1 and LFA-1 at the interface of DCs-γδT cells.Thus,the activation ofγδT cells in EAU was promoted by DCs interacting withγδT cells.

Novel heat shock protein Hsp70L1 activates dendritic cells and acts as a Th1 polarizing adjuvant

Heat shock proteins (HSPs) are reported to act as effective adjuvants to elicit anti-tumor and anti-infection immunity. Here, we report that Hsp70-like protein 1 (Hsp70L1), a novel HSP derived from human dendritic cells (DCs), has potent adjuvant effects that polarize responses toward Th1. With a calculated molecular weight of 54.8 kDa, Hsp70L1 is smaller in size than Hsp70 but resembles it both structurally and functionally. Hsp70L1 shares common receptors on DCs with Hsp70 and can interact with DCs, promoting DC maturation and stimulating secretion of the proinflammatory cytokines interleukin 12p70 (IL-12p70), IL-1beta, tumor necrosis factor-alpha (TNF-alpha), and the chemokines IP-10, macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and normal T cell expressed and secreted (RANTES). The induction of interferon-gamma-inducible protein 10 (IP-10) secretion by Hsp70L1 is not shared by Hsp70, and other functional differences include more potent stimulation of DC IL-12p70, CC-chemokine, and CCR7 and CXCR4 expression by Hsp70L1. Immunization of mice with the hybrid peptide Hsp70L1-ovalbumin(OVA)(257-264) induces an OVA(257-264)-specific Th1 response and cytotoxic T lymphocyte (CTL) that results in significant inhibition of E.G7-OVA tumor growth. The ability of Hsp70L1 to activate DCs indicates its potential as a novel adjuvant for use with peptide immunizations; the Hsp70L1 antigen peptide hybrid may serve as a more effective vaccine for the control of cancer and infectious diseases.

Lethal effect of mononuclear cells derived from human umbilical cord blood differentiating into dendritic cells after in vitro induction of cytokines on neuroblastoma cells

BACKGROUND： Dendritic cell is the most major antigen presenting cell of organism. It is proved in recent studies that human umbilical cord blood mononuclear cells induced and cultured in vitro by recombinant human granulocyte-macrophage colony stimulating factor （rhG-MCSF） and recombinant human interleukin-4 （rhlL-4） can generate a great many dendritic cells and promote the lethal effect of T cells on human neuroblastoma, but it is unclear that whether the lethal effect is associated with the most proper concentration of dendritic cells. OBJEETIVE： To investigate the lethal effect of human umbilical cord blood mononuclear cells induced in vitro by cytokines differentiating into dendritic cells on human neuroblastoma, and its best concentration range. DESIGN ： Open experiment SEI-FING： Department of Pediatrics, the Medical School Hospital of Qingdao University MATERIALS ： The study was carried out in the Shandong Provincial Key Laboratory （Laboratory for the Department of Pediatrics of the Medical School Hospital of Qingdao University） during September 2005 to May 2006. Human umbilical cord blood samples were taken from the healthy newborn infants of full-term normal delivery during October to November 2005 in the Medical School Hospital of Qingdao University, and were voluntarily donated by the puerperas. Main instruments： type 3111 CO2 incubator （Forma Scientific, USA）, type 550 ELISA Reader （Bio-Rad, USA）. Main reagents： neuroblastoma cell line SK-N-SH （Shanghai Institute of Life Science, Chinese Academy of Sciences）, RPMI-1640 culture fluid and fetal bovine serum （Hyclone）, rhlL-4 （Promega, USA）, rhG-MCSF （Harbin Pharmaceutic Group Bioengineering Co.Ltd）, rat anti-human CDla monoclonal antibody and FITC-labeled rabbit anti-rat IgG （Xiehe Stem cell Gene Engineering Co.Ltd）. METHODS： ① Human umbilical cord blood mononuclear cells obtained with attachment methods differentiated into human umbilical cord blood dendritic cells, presenting typical morphology of dendritic cells after in vitro induction by rhG-MCSF and rhlL-4. ② Different concentrations of dendritic cells[ dendritic cells： neuroblastoma cells=20：1,50：1,100：1 （2×10^8 L^-1,5×10^8 L^-1,1×10^9 L^-1）], 1×10^9 L^-1 T cells and 1×10^7 L^-1 neuroblastoma cells were added in the experimental group. 1 ×10^9 L^-1 T cells and 1 ×10^7 L^-1 neuroblastoma cells were added in the control group. ③ Main surface marker CDla molecules of dendritic cells were detected with indirect immunofluorescence, and the percent rate of dendritic cells was counted with ultraviolet light and expressed as the expression rate of CD1a^＋ cells. ④Single effector cells and target cells were respectively set in the experimental group and control group to obtain the lethal effect. The lethal effect of dendritic cells on neuroblastoma cells was indirectly evaluated by detecting cellular survival with MTT assay. The lethal effect（%）= （1-A experimentat well-A effector cell /A target cell well）×100%.⑤The expenmental data were presented as Mean ±SD, and paired t test was used. MAIN OUTCOME MEASURES： ① Morphological characters of dendritic cells in the process of induction and differentiation. ②CD1a^＋ cellular expression rate. ③Lethal effect of dendntic cells on neuroblastoma cells. RESULTS： ①Morphological characters of dendritic cells in the process of induction and differentiation： On the 15^th day after human umbilical cord blood mononuclear cells were induced by rhG-MCSF and rhlL-4, typical morphology of dendritic cells could be seen under an inverted microscope. ②Expression rate of CD1a^＋ cells was （43.12±5.83）%. ③Lethal effect of dendritic cells on neuroblastoma cells： Lethal effect of dendritic cells stimulated T cells in each experimental group （ dendritic cells： neuroblastoma cells=100：1,50：1, 20：1 respectively） on neuroblastoma cells was significantly higher than that in control group[（31.00 ±4.41 ）%, （30.92±5.27）%,（33.57±5.35）%,（26.23±5.20）%, t=3.51,2.98,4.24, P〈 0.01 ）; But the lethal effect of dendntic cells on neuroblastoma was significantly lower when their ratio was 100：1 and 50：1 in comparison with 20：1 （t=2.01,2.36, P 〈 0.05）, and no significant difference in lethal effect existed between the ratio at 100：1 and 50：1 （t=0.06,P 〉 0.05）. CONCLUSION： Dendritic cells differentiated from human umbilical cord blood mononuclear cells after in vitro induction of cytokines can promote the lethal effect of T cells on neuroblastoma cells. The lethal effect is associated with the concentration of dendritic cells within some range.

A summary about dendritic cells in skin diseases

Dendritic cellls (DCs) comprise an es se ntial component of the immune system, are crucial in the initiation of antigen s pecific immune responses. In this summary we focus on summarizing on the central role of DCs in skin diseases: Bullous dermatoses, Dermatitis, Psoriasis, Lichen Planus , Graft-versus-host disease, Connect Tissue Diseases, Virus Diseases, Fungi Diseases, HIV, Urticaria, Urticaria pigmentosa, Mastocytosis, Tumour, Sola r dermatoses. Moreover,in this summary we review the distribution and phenotype of DCs in human skin. Markers and phenotyps 's study have provided strong suppo rt for a concept in which DCs play an important role in the pothogenesis of som e skin diseases.

GENETICALLY MODIFIED DENDRITIC CELLS INDUCED SPECIFIC CYTOTOXITY AGAINST HUMAN HCC CELLS IN VITRO

Objective: to transduce the tumor associated antigen gene MAGE-1 and/or IL-12 gene into dendritic cells (DC) and to observe the in vitro cytotoxic effect induced by the genetically modified DC against the human hepatocellular carcinoma (HCC) cell line SMMC7721. Methods: the MAGE-1 gene was inserted into the retrovirus vector LXSN to construct the recombinant retrovirus LMSN. The monocyte-derived DCs were transfected at appropriate differentiation stage by LMSN and/or a recombinant adenovirus AdmiL-12, which containing murine IL-12 gene. The control groups included retrovirus LXSN transfected, adenovirus AdBGFP transfected and non-transfected DCs. The MAGE-1 gene expression was identified by western blot and the mIL-12 p70 secretion was detected by ELISA assay. The in vitro cytotoxicities against SMMC7721 induced by genetically modified and control groups of DC were tested by MTT assay. Results: The MAGE-1 expression was detected by a monoclonal antibody in DCs tranfected with LMSN but not in control groups. At 16 h, 24 h and 48 h after transfection with AdmIL-12, the concentration of the mIL-12 p70 in the culture medium was 580pg/106 cells, 960pg/106 cells and 1100pg/106 cells respectively. The mIL-12 p70 secretions were not detected in other groups. The lytic activity (as judged by % lysis) induced by each groups of DC was 94.2±5.2% (LMSN and AdmIL-12 cotransfected group), 78.9±3.6% (LMSN transfected groups), 52.6±9.7% (AdmIL-12 transfected group), 34.7±4.3% (LXSN transfected group), 36.3±3.8% (AdBGFP transfected group) and 3.9±2.0% (non-transfected group) respectively. Except for LXSN transfected and AdBGFP transfected group, the difference of the lytic activities between other groups were statistically significant (P<0.05). Conclusion: The MAGE-1 gene modified DCs can induce relatively specific cytotoxicty against SMMC7721 in vitro and thus suggested that those genetically engineered DCs have the potential to serve as novel vaccine for HCC. Transduction of exogenous IL-12 gene into DCs may further enhance DCs’ activity and the effectiveness of the above DC vaccine.