体外诱导人外周血单个核细胞向肝样细胞的分化

背景:外周血具有收集方便、供者不需麻醉、无骨髓穿刺痛苫等优点,利用人外周血干细胞移植的方法来获得转分化后的肝样细胞临床应用前景较好.目的:探讨人外周血单个核细胞在肝细胞生长因子及成纤维细胞生长因子4诱导下分化为肝样细胞的可行性.设计、时间及地点:细胞学体外对照观察,于2007-05/10在中国科学院大连化物所1806组细胞培养室和大连医科大学附属第一医院中心实验室完成.材料:外周血由大连市红十字血液中心11名健康志愿献血者提供.肝细胞生长因子、巨噬细胞集落刺激因子、成纤维细胞牛长因子4为Peprotech公司产品.方法:采集志愿者外刷血,密度梯度离心法分离外周血单个核细胞,加入RPMI1640液培养2h后,去除未贴壁细胞.将贴壁细胞分为4组:对照1组加入含140μmol/L β-巯基乙醇、体积分数为0.1胎牛血清的RPMl1640液培养6 d;对照2组、肝细胞生长因子组、成纤维细胞生长因子组均在其基础上向RPMI1640液中加入5 μg/L巨噬细胞集落刺激因子、0.4μg/L白细胞介素3.洗涤后,对照组换用含胎牛血清的RPMI1640培养液继续培养20 d,肝细胞生长因子组在其基础上加入20 μg/L肝细胞生长因子,成纤维细胞生长因子组加入10μg,L成纤维细胞生长因子4.主要观察指标:诱导分化过程中细胞形态学变化,免疫荧光检测诱导后甲胎蛋白及白蛋白的表达.结果:刚分离的单个核细胞形态呈较均一的圆形,活细胞率＞95%,培养2 h后贴壁细胞呈毛糙的圆形,6 d后肝细胞生长因子组、成纤维细胞生长因子组细胞呈集落样生长,细胞趋向融合,对照组细胞未形成集落,旱单个细胞生长.经诱导培养后,4 d时部分细胞体积变大,向类圆形细胞转变,随培养时间延长,类圆形细胞比例增加,至20 d后细胞数量逐渐减少;对照组培养20d后多数细胞呈梭形或纤维样,少部分细胞呈圆形.诱导培养后第6,10,14,20天,肝细胞生长因子组、成纤维细胞生长因子组甲胎蛋白、白蛋白均呈阳性表达,对照组各时间点均呈阴性表达. 结论:在肝细胞生长因子及成纤维细胞生长因子4诱导条件下,人外周血单个核细胞具有向肝样细胞分化的潜能.     

High temperature affects the phagocytic activity of human peripheral blood mononuclear cells

Abstract

Background: The ability for engulfment of pathogens and inert particles is the key hallmark of the phagocytic cells. Phagocytes play a significant role in the modulation of local or extended inflammation. Since fever activates a number of factors linked with the immune response it was the goal of this study to examine the in vitro effect of hyperthermia on the phagocytic capacity, the number of phagocytic cells and the viability of human peripheral blood mononuclear cells (PBMC) at 37 and 40°C. Methods: PBMC were incubated with 0.8 μm polysterene latex beads, for 2 hours at 37 and 40°C. The number of phagocytic cells, and that of latex particles internalized by each individual cell was counted with a light microscope. In addition, the percentage of viable cells and the number of active metabolic cells was evaluated. Results: A temperature of 40°C significantly increased the number of phagocytic cells and the phagocytic index by 41 and 37% respectively, as compared to cells incubated at 37°C. While the number of vital cells (trypan blue test) did not differ statistically at both temperatures, the number of active metabolic cells (XTT test) after 2 h of incubation at 40°C was 17% higher as compared with that at 37°C. However, the number of active metabolic cells after 24 h of incubation at 40°C was 51% lower compared with cells incubated at 37°C. Conclusions: The increased phagocytic capacity of human peripheral blood monocytes at high temperature further enlightens the immunomodulatory effect of fever in the immune responses during inflammation.     

Effects of cryopreservation on immune responses: VI. An inexpensive method for freezing human peripheral blood mononuclear cells.

To determine the true usefulness of the commercially available inexpensive freezing unit (Mr Frosty) for cryopreservation of peripheral blood mononuclear cells (PBMCs), functional assays were carried out on cells that were frozen in this unit. The responses of these cells were compared with those of controlled rate frozen and fresh cells. Cell viability, recovery, proliferative responses to both phytohemagglutinin (PHA) and pokeweed mitogen (PWM), as well as interleukin (IL)-1 secreting activities of cells frozen in this container were closely comparable to controlled rate frozen cells. Although, the mean immunoglobulin (Ig) and IL-2 secreting abilities of these frozen cells were lower than the controlled rate frozen cells, these responses were still comparable to fresh cells in several of the individuals. Based on these results and considering the cost involved in controlled rate freezing method, we recommend this inexpensive unit for freezing PBMCs for subsequent immunological studies.     

In vitro generation of antigen-specific hemolytic plaque-forming cells from human peripheral blood mononuclear cells

We have described a culture and assay system for the sensitization of human peripheral blood mononuclear cells with a T cell-dependent antigen, sheep erythrocytes, in the absence of nonspecific stimulatory agents and with the subsequent generation of macroscopic hemolytic plaques. We have shown that the antibody produced by the plaque-forming cells generated in this culture system is specific for the sensitizing antigen, and that the plaques created are not false plaques because their formation is inhibited by cycloheximide. The success of this system can be attributed to several critical factors including large numbers of peripheral blood mononuclear cells (5 x 10(6) culture), a prolonged period of incubation (10-11 d), continuous rocking during the entire period of incubation, culturing in large (35-mm) flat-bottomed culture dishes in the presence of human plasma, and the appropriate antigen concentration (5 x 10(6) sheep erythrocytes/culture). Furthermore, the generation of macroscopic hemolytic plaques requires plaquing sensitized peripheral blood mononuclear cells in target cell monolayers fixed in an agarose matrix with an incubation period of 2-3 h. We have further shown that the antigen-specific response measured by this system is dependent on adherent cells and T lymphocytes. At least one population of the helper T cells is sensitive to 2,000 rad irradiation. This system is simple, sensitive, and should serve as an effective tool for the analysis of cellular interactions involved in the generation of human antigen-specific plaque-forming cells, the genetic control the human immune response, and the pathophysiology of altered immunoregulation in disease.     

人外周血单个核细胞向肝样细胞转化的体外诱导培养方法

背景：外周血单个核细胞在体外条件下可向肝样细胞转化。目的：探索体外诱导外周血单个核细胞向肝样细胞分化的培养方法。方法：采用密度梯度离心法联合贴壁法纯化肝硬化患者外周血单个核细胞,以含巨噬细胞集落刺激因子、白细胞介素3及β-巯基乙醇培养基培养6d后,诱导组用含肝细胞生长因子,成纤维细胞生长因子4的培养基培养14d;以未诱导培养的单个核细胞及L02肝脏细胞系为对照。结果与结论：外周血单个核细胞呈透明圆形、类圆形,用巨噬细胞集落刺激因子、白细胞介素3及β-巯基乙醇培养基培养6d后,部分细胞向成纤维样细胞生长,诱导后部分细胞呈多边形,多角形,14d后细胞形态逐渐接近肝细胞,并表达白蛋白、甲胎蛋白、角蛋白18。说明在一定的诱导条件下,外周血单个核细胞在体外可以向肝样细胞分化。     

In vitro kinetic study of the immunosuppressive effect of deoxymethylspergualin on human peripheral blood mononuclear cells.

The immunosuppressive mechanism of Deoxymethylspergualin (MeDSG) was investigated in human subjects by in vitro assay. In an allogeneic mixed lymphocyte reaction (MLR), MeDSG was added at different times. A moderate immunosuppressive activity against allogeneic blastogenesis was seen even when MeDSG was added on the 4th day from the initiation of culture. In the cell-mediated lymphocytolysis (CML) assay, MeDSG was added to bulk MLR in CML in the same manner. For the strong suppression of CML, however, MeDSG should be added to bulk MLR within 2 days from the initiation of culture. There was a difference in immunosuppressive kinetic pattern of MLR and CML induced by MeDSG. In the study of the effect of MeDSG on the interleukin-2 (IL-2) production of allogeneic blast cells, MeDSG showed only a slight suppression. In the MeDSG induced regulator cell assay, these cells induced no suppression of fresh CML, even when they were adoptively transferred to fresh bulk MLR in CML at different times. In the subset analysis of surface phenotypes of allogeneic blast cells in MLR, IL-2R+ cells and CD8+ LFA1+ cells treated with MeDSG, were significantly decreased. These results indicate that MeDSG acts on a comparatively early stage of the afferent phase in allogeneic stimulation and suppresses development of cytotoxic lymphocytes strongly, without inhibition of IL-2 production or suppressive regulator cell induction.     

Effects of the herbal medicine "Sai-rei-to" on in vitro interferon-gamma production of peripheral blood mononuclear cells

The herbal medicine "Sai-rei-to" has been used in the treatment of swellings and edemas for about 3000 years in China. Recently, this drug has been prescribed as an adjuvant in the treatment of rheumatoid arthritis (RA) among Japan's western medicine doctors. It is thought to possess regulatory effects on the immune system, although its mode of action is not yet fully described. In the present in vitro study, we at first induced interferon-gamma (IFN-gamma) in the cultures of peripheral blood mononuclear cells of healthy volunteers by adding pokeweed mitogen (PWM), phytohemagglutinin (PHA), recombinant interleukin-2 (IL-2), or control medium. We then added "Sai-rei-to" to these cultures and investigated the effects of this drug on IFN-gamma production levels. The results demonstrated that "Sai-rei-to" had 2 different effects: (i) it inhibited the IFN-gamma production in cultures with PWM or PHA (which induced large volumes of IFN-gamma), and (ii) it increased IFN-gamma production in the cultures with IL-2 (IL-2 induced only small volumes of IFN-gamma). These findings indicate that "Sai-rei-to" possesses regulatory effects on the IFN-gamma production. IFN-gamma is an important cytokine in the immune system, and it has also attracted attention as a factor related to the pathogeneses of RA. Therefore, concomitant administration of such a medicine which can appropriately control IFN-gamma production in vivo could be beneficial for RA patients from the immunological viewpoint. Clinical experience in the past has shown that "Sai-rei-to" has a very low incidence of side effects, and can be administered orally for long periods. We expect that concomitant administration of "Sai-rei-to" with current therapy could be clinically useful in the management of RA patients.     

Effects of antimicrobial agents on spontaneous and endotoxin-induced cytokine release of human peripheral blood mononuclear cells

 Because the immunomodulatory effects of antibiotics could possibly influence the degree of the systemic and local response to infection, knowledge of their intrinsic influence on the host's inflammatory response appears to be essential. Therefore, this study investigated the effects of frequently used antimicrobial agents (β-lactams, quinolones gentamicin, vancomycin and metronidazole) on the in-vitro tumor necrosis factor (TNF)-α and interleukin (IL)-6 production of isolated human peripheral blood mononuclear cells (PBMNC), cultured with or without endotoxin, in comparison with those effects obtained in a whole-blood assay system. In the presence of ciprofloxacin, ofloxacin, gentamicin, vancomycin, and metronidazole, a significant inhibition of the endotoxin-stimulated TNF-α production of human peripheral blood mononuclear cells (PBMNC) was found at therapeutic levels. Only ofloxacin showed a significant inhibitory influence on the endotoxin-induced IL-6 production of PBMNC. In the whole-blood assay, significant effects were not detectable. None of the antibiotics showed cytotoxicity. It is concluded that, at present, the direct immunological effects of antibiotics should be interpreted carefully with regard to the experimental conditions, and regardless of the therapeutic implications. To assess the potential direct immunomodulatory effect of antimicrobial agents, different cell culture procedures should be used. Received: October 19, 2001 / Accepted: February 15, 2002     

Oxygen consumption of human peripheral blood mononuclear cells in severe human sepsis

OBJECTIVE: During sepsis, after an initial stimulation immune cells down-regulate their functions, leading to a state of immunosuppression. Because the mechanisms of such down-regulation are unclear, we investigated the hypothesis of an energetic failure of immune cells to participate in immune dysfunction. DESIGN: Cohort of septic shock patients to study peripheral blood mononuclear cells (PBMCs) biological energy in comparison to healthy volunteer cells. SETTING: Critical care unit and laboratory, university hospital. SUBJECTS: Eighteen severe sepsis or septic shock patients and 32 healthy volunteers. INTERVENTIONS: Ex vivo measurement of oxygen consumption in PBMCs taken from patients. The PBMCs' mitochondrial oxidative phosphorylation was investigated using adenosine diphosphate stimulation. The plasma factors implication was tested, using healthy cells incubated in septic plasma, or septic cells incubated in healthy plasma, at different time points of sepsis. The relationship between monocyte human leukocyte antigen-DR expression and bioenergetic results was tested. MEASUREMENTS AND MAIN RESULTS: Baseline oxygen consumption was higher in septic PBMCs (p < .01), with an attenuated response to adenosine diphosphate stimulation (p < .01). Oxygen consumption of healthy PBMCs incubated in septic plasma mimicked the septic cell response, with amplitude depending on the duration of sepsis (days 0-28). Septic cells incubated in healthy plasma partially recovered normal patterns. Septic plasma incubation increased the fraction of decoupling oxygen consumption (p = .021). A relationship between oxygen consumption (baseline or adenosine diphosphate stimulated) and human leukocyte antigen-DR expression was observed for incubation with plasma sampled at different time points of septic shock. CONCLUSION: Energetic failure of PBMCs in sepsis may be a factor associated with the modulation of immune response and human leukocyte antigen-DR phenotype, partially driven by plasma factors.     

Anti-inflammatory compound resveratrol suppresses homocysteine formation in stimulated human peripheral blood mononuclear cells in vitro.

Inflammation, immune activation and oxidative stress play a major role in the pathogenesis of cardiovascular disorders. In addition to markers of inflammation, moderate hyperhomocysteinemia is an independent risk factor for cardiovascular disease, and there is a link between the activation of immunocompetent cells and the enhanced formation of homocysteine in vitro. Likewise, anti-inflammatory drugs and nutrients rich in antioxidant vitamins are able to reduce cardiovascular risk and to slow down the atherogenic process. Resveratrol, a phenolic antioxidant synthesized in grapes and vegetables and present in wine, has also been supposed to be beneficial for the prevention of cardiovascular events. Apart from its strong antioxidant properties, resveratrol has also been demonstrated to act as an anti-inflammatory agent. In this study the influence of resveratrol on the production of homocysteine by stimulated human peripheral blood mononuclear cells (PBMCs) was investigated. Results were compared to earlier described effects of the anti-inflammatory compounds aspirin and salicylic acid and of the lipid-lowering drug atorvastatin. Stimulation of PBMCs with the mitogens concanavalin A and phytohemagglutinin induced significantly higher homocysteine accumulation in supernatants compared with unstimulated cells. Treatment with 10-100 muM resveratrol suppressed homocysteine formation in a dose-dependent manner. Resveratrol did not influence the release of homocysteine from resting PBMCs. The data suggest that resveratrol may prevent homocysteine accumulation in the blood by suppressing immune activation cascades and the proliferation of mitogen-driven T-cells. The effect of resveratrol to down-regulate the release of homo-cysteine was comparable to the decline of neopterin concentrations in the same experiments. The suppressive effect of resveratrol was very similar to results obtained earlier with aspirin, salicylic acid and atorvastatin; however, it appeared that doses of compounds needed to reduce homocysteine levels to 50% of stimulated cells were always slightly lower than those necessary to achieve the same effect on neopterin concentrations. The influence of resveratrol and of all the other compounds on homocysteine production appears to be independent of any direct effect on homocysteine biochemistry.     

Infection of human peripheral blood mononuclear cells by varicella-zoster virus

The infection of human peripheral blood leukocytes by varicella-zoster virus (VZV) was studied using an infectious center assay, indirect immunofluorescence and electron microscopy. Subsets of freshly isolated leukocytes were prepared, including granulocytes, mononuclear cells from Ficoll-Hypaque gradients, lymphocytes, and glass-adherent monocytes. When each of these populations was inoculated with VZV (MOI = 0.1), there was no evidence of effective infection. However, when monocytes were cultured in vitro for 7 days, they differentiated into macrophages that were productively infected with VZV. Peak percentages of infectious macrophages were detected 8-24 h after inoculation (mean 17.5%; range 10.2-30.4%). Using indirect immunofluorescence, viral antigens were detected in the cytoplasm and at the nuclear membranes of infected macrophages between 24 and 72 h after infection. Electron microscopy demonstrated the appearance of viral particles in the nucleus by 24 h. Large numbers of virions, often collected in tubules or vacuoles, were present in the cytoplasm at 48 h. The difference between the infection of fresh monocytes and cultured macrophages by VZV might reflect differences in their metabolic or differentiation state. The possible significance of these observations to VZV infection of immunocompromised hosts is discussed.     

Sandwich enzyme immunoassay for human interleukin-1 alpha produced in vitro by peripheral blood mononuclear cells

We describe a new high pressure liquid chromatography (HPLC) method for quantitative determination of urinary lysozyme. The method is simple, reproducible and with detection limit of 0.2 microgram. Before HPLC analysis the urine was purified using a Sep-Pak C18 cartridge. Lysozyme concentration was significantly higher in patients with chronic renal failure than in a control group (p less than 0.001). The concentration of lysozyme in urine is shown to be a sensitive indicator of renal damage.     

Effect of immunosuppressive drugs on DNA repair in human peripheral blood mononuclear cells

Introduction

Cancer is a major cause of mortality among transplant recipients. Immunosuppressive treatment is a modifiable factor contributing to this phenomenon. Cyclosporine in kidney transplant recipients was associated with reduced UV-induced DNA repair by peripheral blood mononuclear cells (PBMC) and increased cancer rate. H₂O₂ is a common cellular reactive oxygen species (ROS), which induces DNA damage followed by DNA repair.

Aim

To investigate the effect of currently used immunosuppressive drugs on DNA repair.

Methods

H₂O₂-induced DNA repair by human PBMC was tested in vitro in the presence of the calcineurin inhibitors (CNI) cyclosporine and tacrolimus, mycophenolic acid (MPA), and the mammalian target of rapamycin (mTOR) inhibitors sirolimus and everolimus, at low to high non-toxic concentrations. The effect of combination therapy at maintenance levels was also tested.

Results

Cyclosporine and tacrolimus suppressed DNA repair throughout the tested dose range. In contrast, MPA, sirolimus and everolimus did so only at the high doses. Maintenance doses of a combination of tacrolimus and MPA, the most frequent treatment regimen, reduced DNA repair, while MPA with sirolimus or everolimus did not.

Conclusion

In an attempt to reduce the risk of post-transplantation malignancy, treatment protocols may be modified by reducing CNI dose.     

Effects of exercise on microRNA expression in young males peripheral blood mononuclear cells

MicroRNAs are increasingly seen as targets of drug discovery because they influence gene function acting both to silence and subtly modulate protein translation. Little is known about effects of dynamic physiological states on microRNA regulation in humans. We hypothesized that microRNA expression in peripheral blood mononuclear cells (PBMCs) would be affected by brief exercise. Twelve young men performed brief bouts of heavy exercise. PBMC microRNA was analyzed before and immediately after exercise using the Agilent Human microRNA V2 Microarray. Exercise altered expression level of 34 microRNAs (FDR < 0.05). Many of them play roles in inflammatory processes (e.g., miR-125b[↓], down-regulated by proinflammatory factor LPS; and miR-132[↑], 125b[↓] and let-7e[↓] involved inTLR4 signaling). Using previous exercise data in PBMCs, we linked the microRNA changes to specific gene pathways. This analysis identified 12 pathways including the TGF-β and MAPK signaling. We also compared exercise-associated microRNA changes in PBMCs with the exercise-associated microRNAs previously identified in neutrophils. Nine microRNAs were affected in both PBMCs and neutrophils, but only six changed in the same direction. A commonly occurring physiologic perturbation, brief heavy exercise, changes microRNA profiles in PBMCs, many of which are related to inflammatory processes. The pattern of change suggests that exercise differentially influences microRNAs in leukocyte subtypes.     

Effects of methylcobalamin (vitamin B12) on in vitro cytokine production of peripheral blood mononuclear cells.

Recently in Japan, one form of vitamin B12, methylcobalamin also known as methyl B12, has attracted the attention of physicians as a therapy for patients with rheumatoid arthritis. However, its immunological actions in vivo are still unknown. In this study, we induced the in vitro production of such cytokines as interleukin-6 (IL-6), interferon-gamma (IFN-gamma), and interleukin-1 beta (IL-1 beta) by adding various mitogens (phytohemagglutinin:PHA, concanavalin A: ConA, or pokeweed mitogen:PWM) as well as recombinant interleukin-2, and we investigated the effects of methyl B12 (final concentration, 8-8,000 ng/ml) on the production of these cytokines by peripheral mononuclear cells. As compared to the controls, IL-6 production induced by PHA and ConA on Day 4 of the culture was suppressed by an average 60-70% when methyl B12 (80-8,000 ng/ml) was added to the medium. IFN-gamma production decreased dose-dependently with methyl B12, i.e., it decreased to 46% of the control when this production was induced by rIL-2, and decreased to 56-66% when it was induced by mitogens. The effect of methyl B12 on IL-1 beta production on Day I of the culture was small. These findings indicate that methyl B12 suppresses mainly the cytokine production of T lymphocytes. Such suppressive effects as shown in the in vitro situation are expected to be expressed also in vivo in patients with rheumatoid arthritis, especially at articulation lesion sites.     

Effect of acyclovir on the proliferation of human fibroblasts and peripheral blood mononuclear cells.

The effect of acyclovir on human cells was measured. A concentration of 50 to 100 microM inhibited the division of fibroblasts to a variable extent, depending on the experimental design and the confluency of the monolayer. The magnitude of this effect was less than that caused by human leukocyte interferon when these antiviral agents were compared at clinically relevant concentrations. Acyclovir also inhibited thymidine incorporation by peripheral blood mononuclear cells stimulated by either phytohemagglutinin or three different herpesvirus antigens. A linear dose-response curve was observed with these cells, and their proliferation was inhibited 50% by 100 microM acyclovir. Inhibition was exerted on T-cell proliferation without apparent effect on the release of lymphokines or on monocyte function.