摘要:

AbstractWe evaluated the concept that the vascular entrance of both bacterial and nonbacterial participate material could lead to hepatic parenchyma) cell injury, either due to post‐phagocytic Kupffer cell activity or the margination of activated leukocytes in the liver. Injection of denatured, collagen‐coated particles as well as heat‐killed bacteria were used as particulate challenges. Hepatic parenchymal cell injury in vivo during postoperative sepsis was evaluated by plasma aspartate aminotransferase (AST) and ornithine carbamyl transferase (OCT) enzyme levels over 3‐72 h. AST and OCT levels elevated following either laparotomy plus cecal ligation (mild sepsis) or laparotomy plus cecal ligation with puncture (severe sepsis), with the peak level at 24 h. In addition, the direct intravenous injection of either nonbacterial foreign particles or heat‐killed Pseudomonasaeruginosainto normal rats also produced a dose‐dependent elevation of AST and OCT. The plasma level of either AST or OCT actually increased 350‐400% after injection of the non‐bacterial particles. A similar dose related elevation in enzymes followed the intravenous injection of heat‐killed Pseudomonas. To differentiate the potential contribution of activated hepatic Kupffer celts versus activated marginated neutrophils to the in vivo hepatic injury, we determined the release of the hepatic specific enzyme OCT by cultured hepatic parenchymal cells when they were exposed to isolated Kupffer cells or isolated PMNs that were activated by exposure to dead bacteria. Bacteria alone when added to cultured hepatocytes did not induce significant OCT release. In contrast, activated PMNs but not Kupffer cells induced a significant (p<0.05) release of OCT from parenchymal cells into the culture media. Thus, in vivo transient hepatic parenchymal cell injury with post‐operative sepsis may be mediated by the margination of activated PMNs in the liver.

ISSN:0741-5400    

DOI:10.1002/jlb.43.3.193

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractWe studied the effect of low‐density lipoprotein (LDL) oxidized by opsonized zymosan‐stimulated polymorphonuclear leukocytes (PMN) on natural killer (NK) cell activity. Oxidized LDL inhibited NK cell activity in a dose‐dependent manner, whereas normal LDL left it unaffected. However, oxidized LDL did not inhibit antibody‐dependent cell‐mediated cytotoxicity (ADCC). Moreover, a positive correlation was observed between the amount of thiobarbituric acid‐reacting substances (TBARS) on the sample of oxidized LDL and the degree of inhibition of NK cell activity. We also showed that oxidized LDL suppressed the binding capacity of purified large granular lymphocytes (LGL) to target cells without changing the lytic activity. These results therefore suggest that activated PMN can modulate NK cell activity by oxidizing LDL.

ISSN:0741-5400    

DOI:10.1002/jlb.43.3.204

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractThis communication reports the results of studies designed to investigate the ability of recombinant murine interleukin‐1 (rIL‐1) to enhance the recovery of hematopoiesis following administration of sub‐lethal whole body irradiation (2 Gy). Mice were administered rIL‐1 (100 and 500 units) i.p. Twenty‐four hours later these mice were administered 2 Gy radiation. Irradiated control mice were given only phosphate buffered saline (PBS). Animals were then serially sacrificed (on days 1, 2, 4, 7, 9, and 12 following irradiation) and their peripheral blood was analyzed for indices (packed red cell volume, WBC, platelets, and differential). Femoral bone marrow was harvested and assayed for their stem cell content—erythroid (CFU‐E, BFU‐E), granulocyte‐macrophage (CFU‐GM), and megakaryocyte (CFU‐MEG). Irradiated mice pretreated with rIL‐1 demonstrated accelerated hematopoietic recovery as measured by higher WBC, platelets and femoral stem cell content than PBS‐treated irradiated controls. These results indicate IL‐1 may be an effective radioprotective agent against the hematotoxicity induced by ionizing radiation.

ISSN:0741-5400    

DOI:10.1002/jlb.43.3.211

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractThe concentrations of tumor necrosis factor (TNF) produced by human peripheral blood mononuclear cells (MNC) were measured using a radioimmunoassay (RIA) for human TNF. This was developed using a rabbit antiserum against human recombinant TNF (Hu rTNF), and Hu rTNF labeled with Na1251 by a modification of the chloramine T method. This RIA doesnotdetect human lymphotoxin, interieukin‐1 alpha or beta, interleukin 2, interleukin 6, interferon alpha or gamma, granulocyte‐macrophage‐colony stimulating factor, and C5a des arg. A good correlation (r = 0.89) was found between the RIA and the cytolytic bioassay for TNF. The sensitivity of the RIA is between 3 and 78 pg/ml (median 11 pg/ml).The mean concentration of TNF in 24‐h culture supernatants of human MNC exposed to different concentrations of lipopolysaccharide (LPS) was found to increase in dose‐dependent fashion and then level off between 50 and 100 ng/ml. The concentrations of IL‐1 beta and alpha detected by specific RIAs in these supernatants were between 0.2 and 19 ng/ml and 0.04 and 1 ng/ml, respectively. The amount ot TNF produced by human MNC in vitro was determined in a cohort of 50 normal volunteers. Without exogenous stimuli, TNF concentrations were almost always below the detection limit; with 0.5 ng/ml LPS, the median concentration of TNF was 2 ng/ml, and with PHA the median was 3.8 ng/ml. In cultures performed in the presence of indomethacin significantly (p<0.005) more TNF was produced.Using this RIA, we could detect TNF in the circulation of mice injected with Hu rTNF. When plasma samples of patients with febrile illnesses were added directly to the RIA, TNF was not detectable, with the exception of patients with malaria.These studies demonstrate the range and sensitivity of LPS‐induced and mitogen‐induced production of immunoreactive TNF by human MNC in vitro without interference of similar cytokines in bioassays.

ISSN:0741-5400    

DOI:10.1002/jlb.43.3.216

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractElutriator‐purified human monocytes were cultured in a serum‐free (SF) medium, and various serum proteins and functional activating agents were assessed for their effects on the in vitro maturation of human monocytes to macrophages. Following 3 days of suspension culture in Teflon labware, 60% of the monocytes were easily recovered. When varying concentrations of human AB serum (HuAB) were employed, human monocyte maturation progressed rapidly; the kinetics of this maturation process during cell suspension culture were very similar to the pattern observed following adherence culture. In contrast, when SF medium was employed, a marked retardation of the monocyte maturation process was observed; this could not be attributed to any changes in cell recovery and/or viability. Thus, cells could be maintained in their monocytoid form for 3 days when cultured in SF medium. When HuAB was added after 3 days of culture, human monocyte maturation into macrophages proceeded at a normal rate.We attempted to characterize certain of the serum protein(s) found in HuAB which promoted the monocyte maturation process. Human immunoglobulin G (IgG) was found to be the most potent serum protein in increasing 5′‐N activity and decreasing peroxidase activity of suspension cultured monocytes. Immunoglobulin M (IgM) and albumin (Alb) were shown not to have significant monocyte maturation activity. Heat‐treated human gamma globulin and IgG purified by high‐performance liquid chromatography (HPLC) were shown to have patterns identical with that of untreated HGG and IgG with regard to promoting monocyte maturation; F(ab′)2was not an active maturation promoter, indicating the need for an intact Fc portion of the IgG molecule. Fibrinogen and fibronectin also had maturation promoting activity.Finally, addition of the potent monocyte functional activators, muramyl dipeptide (MDP), polyriboinosinic:polyribocytidilic acid (Poly I:C), and lipopolysaccharide (LPS) had no effect on the monocyte maturation process. Thus, neither cell adherence or activation appear to be critical for the monocyte to macrophage maturation process. Instead, we hypothesize that in addition to proper nutritional support, a group of serum proteins (unified mainly by their ability to interact with monocyte membrane receptors) appear to be the principal promoters of this process.

ISSN:0741-5400    

DOI:10.1002/jlb.43.3.224

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractExperiments have been carried out to assess the ability of purified protein‐free lipopolysaccharide (LPS) and lipid A‐associated protein (LAP) containing LPS to activate macrophages from C3H/HeJ endotoxin‐unresponsive mice. Assays for in vitro activation have included cytotoxic and cytostatic effects on a simian virus 40 (SV40)‐ transformed fibroblast cell line. While neither preparation of LPS would effect C3H/HeJ macrophage activation for either cytostasis or cytolysis, the addition of murine interferon gamma to cultures of LAP‐LPS stimulated C3H/HeJ macrophages resulted in cells which were both cytotoxic and cytostatic. These results suggest that LAP can provide one component of the triggering mechanism but, of itself, is insufficient to effect full activation. A second signal, which can be provided by murine interferon gamma, appears also to be required.

ISSN:0741-5400    

DOI:10.1002/jlb.43.3.232

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractPhytohemagglutinin (PHA), concanavalin A (Con A), pea lectin, and wheat germ agglutinin (WGA) have been used to investigate their binding properties to Jurkat 77 6.8 leukemic human T cells and their ability to induce these cells to produce interieukin‐2 (IL‐2). Binding studies showed that the Jurkat cells fixed 0.82 ± 0.11 μg pea lectin, 2.02 ± 0.17 μg Con A, 1.85 ± 0.07 μg PHA and 8.88 ± 0.61 μg WGA. Scatchard plots were linear, indicating that the binding process was homogeneous with respect to the binding constant. PHA and Con A bound with the highest affinity [K (apparent)‐9 × 109M−1], followed by pea lectin and WGA [K, (apparent) =3 × 109M−1]. The number of lectin binding sites was in agreement with the results of saturation experiments. We also evaluated the effect of the presence of 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) on the binding process. Results show that there were no gross alterations in the value of (apparent) K in the case of PHA and WGA. In contrast, the presence of TPA decreased the affinity of Con A and modified the Scatchard profile for pea lectin, which was curvilinear with a concavity turned upward. In this case, data were (apparent) K1= 17.7 × 109M−1(“high‐affinity” sites) and (apparent) K2= 2.6 × 109M−1(“low‐affinity” sites). The four lectins shared the ability to stimulate Jurkat 77 6.8 cells to secrete IL‐2. Optimal lectin concentrations were 20 μg/ml (PHA) and 50 μg/ml (WGA and Con A). Pea lectin failed to display a dose‐response relationship, and IL‐2 production increased proportionally with lectin concentration. Con A was the most efficient stimulator (250 U/ml), followed by WGA (160 U/ml) and PHA (108 U/ml). Addition of TPA potentiated Jurkat cell response. In this case, Con A and pea lectin were the most efficient stimulators (470 U/ml), followed by PHA (316 U/ml) and WGA (271 U/ml). Here, also, pea lectin failed to show a dose‐response relationship. Our data do not reveal an obvious relationship between the binding parameters and the ability of the lectins to induce IL‐2 production. We suggest that the efficiency of the four lectins to stimulate IL‐2 production in the case of the Jurkat 77 6.8 variant is most likely related to the nature of their specific cell surface receptor(s).

ISSN:0741-5400    

DOI:10.1002/jlb.43.3.238

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractTHP‐1 is an acute monocytic leukemia cell line which acquires phenotypic and functional monocytoid‐like features following incubation with mezerein. The current study concerned the modulation of these features by rIFNγ. rIFNγ induces the time‐dependent enhancement of HLA‐DR expression in the presence or absence of mezerein but has no effect on the expression of Leu‐M1, Leu‐M2, or Leu‐M3 antigens. CSF‐1 production following mezerein activation was reduced by incubation in the presence of 103and 104units/ml rIFNγ. This was confirmed through both biological assays with mouse bone marrow cells and an indirect ELISA. In contrast, the concentration of growth inhibitory activity in conditioned medium was increased by rIFNγ. A small but significant increase in IL‐1β concentration in conditioned medium was detected using a sensitive double‐antibody ELISA and a radioimmunoassay. The results infer that the functional characteristics of this leukemia cell line are modulated by rIFNγ in a manner qualitatively similar to that reported for IFNγ treated normal monocytes.

ISSN:0741-5400    

DOI:10.1002/jlb.43.3.248

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractThe susceptibility of fractionated porcine peripheral blood leukocytes (PBL) to pseudorabies virus (PRV) was studied by flow cytometry and defined by viral antigen expression. Viral antigens on the surface of infected cells and cell viability were evaluated by forward angle light scatter (FALS), 90‐degree light scatter (90LS), green fluorescence (FITC‐anti‐PRV), and red fluorescence (propidium iodide). Approximately 10% of infected mononuclear cells from healthy pigs expressed cell‐surface PRV antigen. Cell‐surface fluorescence and cell type were confirmed by sorting live positive cells for microscopy. In sorted positive samples, the lymphocyte versus monocyte ratio was approximately 50%:50%, defined by morphology. Positive lymphocytes represent 5.75% of total mononuclear cells. When cells were stimulated with phytohemagglutinin (PHA) and lipopolysaccharide (LPS) before infection, mitogen‐stimulated T‐lymphoblasts showed increased susceptibility to PRV (40.7% positive) and died of infection. Monocytes, particularly adherent monocytes, were highly susceptible (40% to 71.4% positive). Granulocytes appeared to be refractory. The relative susceptibility of various PBL populations was compared by normalizing lymphocyte susceptibility to 1 as follows: resting total lymphocytes (1); B‐lymphocytes (0.67); T‐lymphoblasts (7.08); total monocytes (4.27); adherent cells (4.03 to 10.88); adherent monocytes (6.95 to 12.42); granulocytes (0.24). These findings suggest a possible mechanism by which PRV could have an immunosuppressive effect as well as a pathway for dissemination of PRV.

ISSN:0741-5400    

DOI:10.1002/jlb.43.3.256

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractCancer chemotherapeutic agents modify the human immune system in diverse ways including both immunosuppression and immunostimulation. We evaluated the effects of mitomycin‐C on rat Kupffer cell phagocytosis, C3b receptor binding, and lysosomal enzyme activity. Kupffer cell cultures were greater than 95% pure. Phagocytosis of IgG‐coated sheep red blood cells was demonstrated by 84% of control cells but by only 25% of cells isolated two weeks following mitomycin‐C administration (p<0.0005). This depression in phagocytic ability had returned to control levels by four weeks post‐treatment. Similarly, C3b receptor binding of IgM and complement coated sheep red blood cells was observed in 88% of control Kupffer cells, but declined to 47% at two weeks after drug administration (p<0.005) and returned to normal after four weeks. Lysosomal enzyme activity was not impaired by mitomycin‐C. Histologically severe ulceratlon of the colon of treated animals was seen one and two weeks after drug administration, but healed by four weeks post‐mitomycin‐C treatment. Depression of macrophage function as a consequence of cancer chemotherapy may have important clinical consequences in host defense against bacteria and tumor metastases.

ISSN:0741-5400    

DOI:10.1002/jlb.43.3.265

出版商:Wiley    

年代:1988

数据来源: WILEY