摘要:

AbstractNatural killer cells (NK) have been reported to down‐regulate the initiation of T cell responses in animal models. In the current study, highly purified CD16 + human NK cells were obtained by cell sorting and their effect on the stimulation of allogeneic T cells (MLR) determined. NK cells did not directly stimulate T cell proliferation. However, when added to a population of loosely adherent mononuclear cells (LAM), NK enhanced the ability of these accessory cells to stimulate T proliferation. This effect was not reproduced by the addition of sorted CD5 + T cells, sorted CD16 – cells, or control lymphocytes to the MLR. The effect of NK on the MLR was not restricted by class II antigens and was similar to the effect of adding IL‐1 to MLR cultures. These results demonstrate that human NK cells are capable of enhancing a T cell response.

ISSN:0741-5400    

DOI:10.1002/jlb.43.4.291

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractIn vitro exposure of macrophages and neutrophils to inorganic dusts can enhance their oxidative metabolism, however the effects of inorganic dust inhalation on lung‐inflammatory cell‐oxidative metabolism remain unknown. To address this issue, we studied the superoxide anion release from lung inflammatory cells obtained by bronchoalveolar lavage from 19 sheep exposed repeatedly to UICC chrysotile B asbestos (100 mg) over an 18 month period and 10 sheep exposed to a single exposure of quartz (100 mg) over a 6 month period. Exposure to asbestos and quartz did not induce an increase in the spontaneous release of superoxide from inflammatory cells. However lung‐inflammatory cells from sheep exposed to asbestos released much higher levels of superoxide in the presence of phorbol myristate acetate (PMA) than did cells of unexposed sheep. In quartz exposed animals, superoxide release with PMA stimulation remained significantly increased up to 2 months after a single quartz infusion. These results suggest that inorganic dust inhalation primes lung inflammatory cells in vivo and markedly enhances their capacity to release toxic oxygen radicals.

ISSN:0741-5400    

DOI:10.1002/jlb.43.4.299

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractHuman monocytes (MN) produce O2‐and H2O2when stimulated by agonists. Dichlorofluorescin diacetate (DCFH‐DA) has been used as a substrate for measuring intracellular oxidant production in neutrophils. DCFH‐DA is hydrolyzed by esterases to dichlorofluorescin (DCFH), which is trapped within the cell. This nonfluorescent molecule is then oxidized to fluorescent dichlorofluorescin (DCF) by action of cellular oxidants. DCFH‐DA can not be appreciably oxidized to a fluorescent state without prior hydrolysis. We have examined the utility of DCFH‐DA for the assessment of monocyte oxidative responses. The levels of intracellular fluorescence measured by flow cytometry were considerably less than expected from reported levels of O2‐‐production or chemiluminescence assays. Compared with neutrophils, monocytes produced minimal increases in DCF fluorescence after stimulation with phorbol myristate acetate as measured by flow cytometry, but both cell types showed increases in fluorescence when bulk cell suspensions were measured by spectrofluorometry. To determine the intracellular location of the DCFH, bulk fluorescence measurements were made on both whole and sonicated cell preparations. When intact mononuclear cells were preloaded with DCFH‐DA, then sonicated and oxidized with added excess H2O2, the increase in fluorescence was only 30% of the fluorescence of mononuclear cell sonicates to which DCFH‐DA was added and oxidized in a similar manner. These results suggest that a portion of the DCFH‐DA incorporated by intact cells, is not susceptible to oxidation by the added H2O2. Addition of NaOH to induce hydrolysis of any residual DCFH‐DA in the sonicates of DCFH‐DA‐loaded intact mononuclear cells resulted in a further increase in fluorescence upon addition of H2O2, suggesting that a significant portion of the DCFH‐DA was not hydrolyzed despite ample uptake of this dye by these cells. In contrast, no further increase in fluorescence was observed in sonicates of DCFH‐DA‐loaded intact neutrophils, suggesting complete hydrolysis of all incorporated DCFH‐DA to DCFH. When monocytes were allowed to phagocytose DCFH‐DA‐loadedStaphylococcus aureus, intracellular fluorescence was measurable by flow cytometry, indicating intracellular oxidation of the fluorochromes. We therefore propose that in monocytes the mechanism of intracellular processing of these fluorochromes differs from that in neutrophils owing to differences in intracellular localization of fluorochromes, site of oxidant production, and/or accessibility of the DCFH‐DA to esterolysis.

ISSN:0741-5400    

DOI:10.1002/jlb.43.4.304

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractGenetic variations in the development of casein‐induced amyloidosis exist among inbred strains of mice: CBA/J and C57BL/6J mice are susceptible, while A/J strain mice are resistant to this disease. Amyloidosis is usually induced by daily injections of an inflammatory stimulus for 2‐3 wk. The deposition of amyloid in experimental animals can be accelerated by injection of a material called amyloid‐enhancing factor (AEF); when injected concomitantly with an inflammatory stimulus, AEF provokes appearance of amyloidosis as early as 2 days after injection. AEF is extracted from amyloid laden or from normal organs (although in small amount).Our studies were designed to determine if the resistance to amyloidosis seen in A/J mice was either due to a lack of AEF production or to an inability of these mice to respond to AEF. A standard source of CBA/J‐derived AEF facilitated the development of amyloidosis in the organs of both the susceptible (CBA/J, C57BL/6J) and the resistant A/J mice. On the contrary, amyloidosis was only induced in susceptible CBA/J hosts when material derived from susceptible (CBA/J, C57BL/6J) animals was injected. CBA/J mice injected with A/J‐derived AEF preparation did not develop amyloidosis. These results thus suggest that the determination of resistance or susceptibility to secondary amyloidosis could operate at the level of AEF production.

ISSN:0741-5400    

DOI:10.1002/jlb.43.4.311

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractThe oxidative metabolic burst of stimulated human polymorphonuclear leukocytes (PMNs) has been evaluated by the measurement of oxygen consumption, chemiluminescence, and oxygen radicals (O2‐, H2O2,OH‐) derived from activation of the hexose monophosphate shunt (HMPS). PMNs from patients with chronic granulomatous disease (CGD) are shown to lack functional NADPH oxidase and undetectable oxygen radical generation. However, using single cell analysis by flow cytometry and 2′,7′‐dichlorofluorescin (DCFH) oxidation by H2O2, significant DCFH oxidation by the PMA stimulated CGD PMNs was observed. Furthermore, 1mM potassium cyanide enhanced DCFH oxidation by control and CGD PMNs. DCFH oxidation by cells from an obligate heterozygous mother of an X‐linked CGD patient was intermediate. These observations suggest that a PMA induced oxidase enzyme is present in CGD cells.

ISSN:0741-5400    

DOI:10.1002/jlb.43.4.317

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractHuman mononuclear cells were previously shown to produce interferon‐alpha (IFN) during 14 hr assays using herpes simplex virus type‐1 infected fibroblasts [NK(HSV‐FS)]. In this study, we have compared the effectors responsible for mediating NK(HSV‐FS) cytolytic activity to those which produce IFN‐alpha. Both activities were found to reside in non‐adherent fractions, negative for non‐specific esterase‐staining cells. Like cells mediating NK cytolytic activity, IFN‐alpha producing cells were found in light density Percoll gradient fractions. However, although NK(HSV‐FS) and IFN production were largely overlapping, peak IFN production was consistently found in fractions slightly less dense than peak NK(HSV‐FS) activity. IFN production was greatly augmented in fractions enriched for dendritic cells on hypertonic metrizamide gradients. The cells which produce IFN‐alpha were phenotypically distinct from cytolytic NK effector cells: they lacked the Leu‐11, Leu‐7 and NKH1 cell surface markers shown to be present on both NK(HSV‐FS) and NK(K562) effector cells. In addition, the IFN‐alpha producing cells were found to be negative for a number of other markers characteristic of T cells, B cells or macrophages but were positive for Ia and HLA. The cells which produced IFN in response to UV‐inactivated HSV antigen and to HSV‐infected Raji cells were also found to be Leu‐11 negative, and Ia positive. We conclude that the cells which produce IFN in response to HSV are a light density, Ia positive population which are distinct from NK cytolytic effector cells and co‐purify with cells bearing a dendritic morphology. These results support our earlier findings that NK(HSV‐FS) activity and IFN production are independent of one another and can segregate independently in vivo.

ISSN:0741-5400    

DOI:10.1002/jlb.43.4.323

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractThe presence of macrophages both within and around human bladder transitional cell carcinomas xenografted into nude mice has been examined using Immunocytochemical staining. Nine different xenograft lines derived from bladder tumors of eight patients were stained for F4/80, MHC II and PGP‐1 labelled cells. The results revealed considerable heterogeneity both within and between tumors. All of the tumors generated some macrophage response at the tumor periphery, and this was marked in two instances, UCRU‐BL‐13, passage 9 and UCRU‐BL‐17, passage 2. In only two tumors was there substantial penetration of the tumor epithelium by macrophages, though infiltrating la+, F4/80+, PGP‐1+cells were sometimes seen spreading along the base of the epithelial sheets. Three of the tumors were characterized by the presence of L3T4+T lymphocytes at the invasion front. The presence of macrophages or lymphocytes either at the invasion front or within the tumors did not correlate with the pathological grade of the tumors. PGP‐1 monoclonal antibodies also stained granulocytes, which were present within the tumor mass in UCRU‐BL‐15, passage 2, possibly reflecting the production by the tumor of G‐CSF. In addition, the PGP‐1 antibodies stained some of the bladder tumors cells themselves, and, in some cases, the interstitial structures within the tumors. The significance of this staining is not yet understood. The xenografted tumors will provide a useful model to examine the constraints on tumor therapy using macrophage activating stimuli.

ISSN:0741-5400    

DOI:10.1002/jlb.43.4.335

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractA simplified method is described for purification of dendritic cells from human peripheral blood. The method is based on depletion of phagocytes with carbonyl iron and magnet, followed by centrifugation of nonphagocytic cells on Percoll and elimination of contaminating T lymphocytes, B lymphocytes, natural killer cells, and monocytes from the low‐density cell fraction by treatment with monoclonal antibodies and complement. The purity of enriched dendritic cells was about 80% and these cells represented 0.2% of the starting mononuclear cell population. Dendritic cells were potent autologous and allogeneic stimulators in mixed leukocyte cultures.

ISSN:0741-5400    

DOI:10.1002/jlb.43.4.343

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractEndotoxin is a potent inflammatory stimulus and induces polymorphonuclear leukocyte (PMNL) infiltration into tissues. Macrophage (MΦ) derived IL‐1 has been proposed as a mediator of this response. TNFα is also produced by MΦs in response to endotoxin and both IL‐1 and TNF enhance PMNL adhesion to vascular endothelium in vitro. We investigated the activity of recombinant human IL‐1α, IL‐1β, and TNFα in inducing PMNL infiltration into the skin of rabbits using a quantitative51Cr labelled blood leukocyte assay. IL‐1α and IL‐1β induced progressive PMNL accumulation, the 50% maximal response being induced by ≈ 20 units. In comparison, TNFα even at 100,000 U, induced only mild PMNL accumulations, although IL‐1α and TNFα were similarly active in inducing PMNL adherence to human umbilical vein endothelium. The human TNFα preparation was pyrogenic and induced acute, transient neutropenia in rabbits upon i.v. infusion. IL‐1α, IL‐1β and TNFα are often secreted simultaneously by MΦs, therefore we investigated their action in combination. The combination of IL‐1α with IL‐1β was nearly additive in inducing PMNL accumulation, i.e., 87% of predicted result based on the sum of the responses to individual components. The combination of TNFα with either IL‐1, each in submaximal doses, resulted in 65‐125% greater than the additive response. No such effect was observed when these monokines were injected in combination with PMNL chemotactic stimuli. These results indicate a complex interaction between inflammatory monokines in the regulation of PMNL accumulation in vivo.

ISSN:0741-5400    

DOI:10.1002/jlb.43.4.349

出版商:Wiley    

年代:1988

数据来源: WILEY

摘要:

AbstractLead (Pb) has been shown to alter various parameters of immune function such as host resistance and antibody formation. In addition, various heavy metals have been implicated as inducers of autoimmunity. In these experiments, macrophages, isolated from the peritoneal cavity of mice exposed to various doses of lead in vivo as well as cells exposed in vitro were tested for the following immunologic parameters: phagocytosis, antigen presentation, interleukin 1 production, and their ability to stimulate the autologous mixed lymphocyte reaction (AMLR). The results obtained indicate that Pb appears to alter the ability of macrophages to present antigen by enhancing the AMLR while having no effect on phagocytosis or IL‐1 production. These data suggest that Pb may interfere with antigen‐specific interactions between macrophages and T cells.

ISSN:0741-5400    

DOI:10.1002/jlb.43.4.357

出版商:Wiley    

年代:1988

数据来源: WILEY