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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The stability and recovery of six human recombinant cytokines (tumour necrosis factor (TNF), interferon-alpha (IFN-alpha), IFN-gamma, interleukin-1 alpha (IL-1 alpha), IL-1 beta, and IL-6) from whole blood was investigated with a view to optimizing blood collection and storage procedures prior to performing immunoassays. Blood from healthy volunteers was subjected to various processing and storage procedures. Blood samples were treated with either: ethylenediamine tetraacetic acid (EDTA) (1.5 mg/ml blood) (E); EDTA/Trasylol (1.5 mg and 1000 KIU/ml blood) (ET); heparin (30 IU/ml) (H) or allowed to clot (serum). The bloods were spiked with individual cytokines, split into aliquots and kept at 4 degrees C or RT. In the first instance spiked bloods from healthy volunteers (n = 5 per cytokine) were processed using sterile and non-pyrogenic materials and procedures. At regular time intervals, samples were cold spun, separated, flash frozen and assayed for the appropriate cytokine using RIA/IRMA methods. In a further study, timed separation was repeated with spiked blood from healthy volunteers (n = 5 per cytokine) using normal commercially available blood collection materials and procedures. In a third study, spiked blood from healthy volunteers (n = 3 per cytokine) was processed under sterile and non-pyrogenic conditions, and the blood samples separated, aliquoted and flash frozen within half hour of collection. These were then subjected to repeated cycles of freeze thawing at 4 degrees C or RT before assaying. In general, the stability of cytokines in whole blood was improved by storage at 4 degrees C and/or rapid separation. There was no significant difference between samples handled under sterile, non-pyrogenic conditions and those collected using normal blood collection procedures. The blood collection procedures described in this paper did not induce any of the six cytokines in the unspiked blood. Overall, EDTA-treated samples performed most consistently. The addition of trasylol did not significantly affect the results. Most of the cytokines appeared unaffected by up to three freeze thaw cycles. The stability and recovery of the spiked cytokines varied from least stable to most stable spiked cytokine as follows; TNF-alpha less than IL-6 less than IFN-gamma less than IL-1 alpha less than IFN-alpha less than IL-1 beta. The recovery of spiked IFN-gamma from heparinized plasma samples was considerably higher than any other plasma or serum samples. The recovery of spiked TNF-alpha and IL-6 from serum samples was consistently lower than amounts recovered from plasma samples (anticoagulant treated).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Measuring cytokine levels in blood. Importance of anticoagulants, processing, and storage conditions. 138 3

We have shown that acute (GVH) reactions produced in the parental-F1 hybrid combination, A/J----(C57BL/6 x A/J)F1 result in the activation of two cytotoxic cell populations: a host-derived Thy-1+/- natural killer (NK) cell with a lytic spectrum confined to YAC-1 targets, and a donor-derived Thy-1+ NK-like cell that has the ability to lyse target cells that are normally insensitive to lysis by NK cells. Cold-target inhibition (CTI) experiments have shown that the greater range of target cell killing seen in the NK-like population is mediated by a single effector cell with a broadened lytic repertoire. Percoll density fractionation studies have revealed that NK and NK-like cells co-fractionate, suggesting that both are large granular lymphocytes. We we have also shown that NK-like cells do not express either Lyt-2 or L3T4 markers. We have also observed that there is a close temporal relationship between elevated levels of interleukin-2 (IL-2) secretion by spleen cell cultures from mice with GVH disease and the subsequent emergence of splenic NK activity in both acute [A/J----(C57BL/6 x A/J)F1] and chronic (A/J----CBA x A/J)F1 GVH reactions. We have also noted that, despite high levels of IL-2 secretion, mice with chronic GVH reactions do not generate NK-like activity. Interferon (IFN) measurements have shown that, although increased IFN activity can be detected in both acute and chronic models, a preponderance of IFN-alpha/beta and some IFN-gamma is produced in the acute reaction, whereas only IFN-gamma can be detected in the chronic model. These results suggest that, although IL-2 may participate in augmenting conventional NK activity, IL-2 by itself does not generate NK-like activity. We suggest that IFN-alpha/beta may be the cytokine that, either alone or in concert with IL-2, triggers the NK-like cell response. The NK-like cell described in our study resembles a phenotypically identical, donor-derived large granular lymphocyte, identified by others, in close proximity to dead or dying epithelial cells in mice with GVH disease [14]. It has been suggested that these cells may mediate tissue injury. If in fact these graft-derived NK-like cells are involved in the pathogenesis of acute GVH disease, our present findings suggest that they must first be activated by an appropriate complement of cytokines that includes IFN-alpha/beta.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Natural killer (NK) cell activity in mice with acute graft-versus-host reactions: characterization of a Thy-1+ NK-like cell with a broadened spectrum of lytic activity in the spleen and lymph nodes. 170 18

Tonsil B cells were analyzed for their capacity to interact directly with NK cells in vitro. A specific, direct interaction between NK cells and B cells could be detected by direct conjugation and by cold target inhibition using the B lymphoblastoid cell line BJA.B as a labeled target. The data further suggest that the B cell interaction with NK cells specifically activates the NK effectors and induces their production of IFN-gamma. The NK-interactive population of tonsil B cells were characterized as low-buoyant density cells (by Percoll gradient fractionation) that stained more brightly with Hoechst 33342, both characteristics of activated B cells. Immunofluorescent staining of NK cell-B cell conjugates allowed determination of the cell-surface antigenic phenotype of conjugate-forming B cells. B cell targets were ICAM-1bri, 4F2+, TfR+, CD32+, BB1+, and CD77-. They tended to be CD38-, but overlapped the CD38+ population. No correlation was seen with CD37, CD44, CD75, CD76, HC2, or Ig kappa. This phenotype is most consistent with a late activation stage of differentiation, just before and overlapping the expression of CD38. These B cells do not appear significantly sensitive to NK-mediated cytolysis, suggesting that NK cell cytokine synthesis and secretion (e.g., IFN-gamma) may be more important in the NK cell regulation of the humoral response.
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PMID:Characterization of a subset of human B lymphocytes interacting with natural killer cells. 194 Mar 41

Hyper-IgE syndrome is a rare immunodeficient disorder characterized by recurrent severe staphylococcal infections of the skin and sinopulmonary tract, chronic eczematoid rashes, coarse facial features, mild eosinophilia, and markedly elevated serum IgE levels. Hyperimmunoglobulinemia D, depressed DTH, and varying degrees of pathogenesis of this syndrome is unknown. The clinical manifestations and the recent research findings indicated the followings: 1) increased production of IL-4: hyperimmunoglobulinemia E, increased number of Fc epsilon R(+)-cells in peripheral blood, 2) defective production of IFN-gamma: abnormal local inflammatory responses (formation of cold abscesses), chemotactic defect in the circulating neutrophils (abnormalities in IFN-gamma/IL-8 pathway), depressed DTH, 3) T-cell immunodeficiency?-chronic dermatitis? 4) genetic factors (frequent familial occurrence, characteristic facial appearance with broad nasal bridge). These observations led us to postulate that both the increased production of IL-4 and the defective production of IFN-gamma may be the immunopathological bases of this syndrome. Recently, these cytokines were demonstrated to be secreted by different subsets of helper T-cells, designated TH1 and TH2, in murine system, suggesting that the regulatory imbalances between IL-4 and IFN-gamma in this syndrome might be due to the differential activation or inactivation of these helper T-cell subsets.
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PMID:[Hyper IgE syndrome--a disease of imbalanced activation of helper T-cell subsets?]. 214 8

Intratumoral heterogeneity has been proposed as a possible basis for immunotherapeutic failure when tumor-specific agents such as tumor infiltrating lymphocytes (TIL) are employed for cancer therapy. To examine this issue, highly specific oligoclonal MHC class I-restricted cytolytic TIL grown in bulk culture from patient 397 were used to immunoselect a TIL-resistant variant tumor from the autologous cultured melanoma line 397-mel. Four cycles of immunoselection produced tumor 397-R4, a variant completely resistant to 397 TIL but not to allogeneic LAK cell lysis in 4-h 51Cr release assays. By flow microfluorometry analysis, this tumor variant had not lost MHC molecules, adhesion molecules, or a variety of tumor-associated Ag expressed by the parent tumor but showed decreased expression of many Ag examined. Failure of 397-R4 to cold target inhibit TIL lysis of 397-mel suggested that cell-surface modification was at least one mechanism causing TIL resistance. The inherent lysability of 397-R4 was equal to 397-mel, as confirmed by lectin-dependent cellular cytotoxicity, lysis by non-MHC restricted allogeneic TIL, and lysis by a second line of 397 TIL grown independently from tumor 397. Treatment of 397-R4 with IFN-alpha or IFN-gamma, +/- TNF-alpha for 72 h before cytolytic assays enhanced TIL lysis of this target slightly, and enhanced surface expression of MHC class I and II molecules and the adhesion molecule ICAM-1. The resistant phenotype of 397-R4 was evident in all clones of 397-R4 examined and has been maintained in serial culture for over 13 mo and through passage in nude mice, suggesting that such stable tumor variants may provide an in vivo escape mechanism from specific immune reagents such as TIL. Evolving patterns of TIL culture clonality over time, as well as the spontaneous emergence of different clones in two long term TIL cultures grown under identical conditions from the same source of cryopreserved tumor, were documented by analyzing TCR gene rearrangements and suggest that TIL from different culture passages or lines may be used to overcome resistant tumor subpopulations.
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PMID:Immunoselection of a human melanoma resistant to specific lysis by autologous tumor-infiltrating lymphocytes. Possible mechanisms for immunotherapeutic failures. 216 May 3

The effect on CTL lysis of treatment of CTL targets with IFNs has been investigated. Treatment of targets for alloreactive CTL with either IFN-alpha beta or IFN-gamma markedly augmented cytotoxicity. Cold competition experiments implied that CTL recognized the same target structure on both untreated and IFN-treated cells. This augmented lysis is presumably caused by IFN increasing expression of target MHC antigens. In the case of SFV-specific lysis of SFV-infected fibroblasts, IFN-alpha beta or IFN-gamma treatment somewhat reduced CTL lysis, but less so than Ab + C lysis which was abolished at moderate IFN concentrations; in the case of SFV-infected lymphoblastoid cells, CTL lysis remained the same or was slightly increased, whilst Ab + C lysis was reduced at moderate IFN concentrations and abolished at high IFN concentration; in the case of MSV/MLV-infected fibroblasts, CTL lysis was moderately increased whilst Ab + C lysis was decreased. IFN therefore increases virus-specific CTL cytotoxicity relative to viral antigen expression.
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PMID:The effect of interferon treatment of targets on susceptibility to cytotoxic T-lymphocyte killing: augmentation of allogeneic killing and virus-specific killing relative to viral antigen expression. 241 76

We have recently reported that IL 2-activated killer (LAK) cells are capable of lysing cultured human monocytes. In an effort to protect autologous monocytes from lysis, we treated monolayer cultures of adherent PBMC with various doses of human rIFN-gamma and assessed their susceptibility to LAK cells. IFN-gamma was shown to lessen the sensitivity of monocytes to lysis in a dose-dependent manner. Similar treatment of FMEX, an NK-resistant melanoma tumor cell line, with IFN-gamma did not affect its susceptibility to LAK lysis. Kinetic studies demonstrated that as little as 2 h incubation with IFN-gamma was sufficient for the protective effects to take effect. Additionally, monocytes that were pulsed with IFN-gamma for 2 h, washed, and then cultured in medium alone retained their resistance to lysis for at least 3 days. Cold target inhibition studies showed that IFN-treated and untreated monocytes could effectively compete with each other for binding sites on LAK cells. Furthermore, binding studies demonstrated that there was no significant difference between the number of conjugates formed by using either IFN-treated or untreated monocytes. This indicates that resistance to lysis induced by IFN treatment affects a post-binding event and not an initial recognition signal. From these studies, it was apparent that treatment of monocytes with IFN-gamma lessened their sensitivity to LAK-mediated lysis. Thus, it may be possible through a specific sequence of IFN-gamma and IL-2 treatment that LAK activity could be manipulated against some tumor cells, but not normal cells, to abrogate some of the toxicity seen with this type of cancer therapy.
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PMID:Protection of cultured human monocytes from lymphokine-activated killer-mediated lysis by IFN-gamma. 246 May 57

To test the hypothesis that susceptibility to NK cell-mediated cytolysis varies inversely with the levels of target cell class I HLA expression, NK-susceptible K562 and MOLT-4 target cells have been transfected via electroporation with cloned human class I HLA-A2 and HLA-B7 genes. Stably transfected cells expressing varying levels of cell-surface class I HLA have been selected by fluorescent activated cell sorting and tested for susceptibility to NK-mediated cytolysis by freshly isolated peripheral blood NK cells from nine normal volunteers as well as by cloned human NK effectors and tumor cells from a patient with an NK cell lymphoproliferative disorder. Expression of class I HLA did not alter the susceptibility of K562 or MOLT-4 target cells to NK-mediated cytolysis by any of the effectors tested. In addition, the class I HLA-expressing transfectant cells were identical to mock transfected cells in their ability to compete for lysis in cold target inhibition assays. Treatment of both mock-transfected and class I HLA-transfected K562 cells with IFN-gamma resulted in decreased susceptibility to NK-mediated cytolysis which was independent of the total level of class I HLA expression. These results demonstrate that the level of target cell class I HLA expression is not sufficient to determine susceptibility or resistance to NK-mediated cytolysis of the classical NK targets K562 and MOLT-4.
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PMID:Susceptibility to natural killer cell-mediated cytolysis is independent of the level of target cell class I HLA expression. 249 7

We previously demonstrated that IL-2 promotes the adhesion of NK cells to endothelial cells (EC) and that EC are readily lysed by lymphokine-activated killer (LAK) cells in vitro, suggesting that cell mediated endothelial injury may contribute to the capillary leak syndrome observed in patients treated with IL-2. In this investigation, we sought to determine the effects of EC activation on the in vitro susceptibility of EC to LAK cell-mediated cytolysis. Despite increased binding of CD16+ lymphocytes to TNF-activated EC monolayers, prior exposure of EC to any of several IL-2-inducible cytokines including TNF-alpha, IL-1 beta, and IFN-gamma not only failed to render the EC more vulnerable to cytolysis but increased their resistance to LAK cells in 111Indium release cytolysis assays. This decrement in susceptibility to cytolysis resulting from prior exposure to cytokines preceded any detectable increase in HLA class I or II Ag expression. In cold target competition experiments with LAK cell effectors and radiolabeled K562 target cells, TNF-primed EC were no more competitive than unstimulated EC, and in assays with unstimulated PBMC effectors, the addition of unlabeled TNF-activated EC actually increased the cytolysis of the radiolabeled tumor cells. The effects of various cytokines and lymphocyte preparations on EC permeability were also evaluated. In these experiments, saphenous vein EC were cultured on porous filter disks, exposed to cytokines or lymphocytes, and the diffusion of 125I-BSA through the filters was then measured. Exposure to IL-2, IFN-gamma, or TNF-alpha did not increase the diffusion of the BSA through the EC-coated filters, whereas LAK cells markedly increased their permeability. Consistent with the results of the cytolysis assays, pretreatment of the EC with TNF, IL-1, or IFN-gamma diminished the LAK cell-induced increase in BSA diffusion. These results suggest that although circulating IL-2-inducible cytokines such as TNF and IFN-gamma may activate EC in vivo and contribute to lymphocyte margination and lymphopenia, they may not be directly responsible for the IL-2-induced capillary leak syndrome and may actually protect EC from LAK cell-mediated injury.
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PMID:Activated endothelial cells resist lymphokine-activated killer cell-mediated injury. Possible role of induced cytokines in limiting capillary leak during IL-2 therapy. 252 94

The relative ability of TNF and lymphotoxin (LT) to inhibit the growth of five human tumor cell lines was examined both in the presence and absence of IFN-gamma. Two adenocarcinoma lines, HT-29 and SK-CO-1, were 20- and 320-fold more sensitive to the inhibitory effects of TNF and LT in 3- to 4-day proliferation assays. In contrast, the breast carcinoma line BT-20 showed only a one- to twofold difference. The MCF-7 and ME-180 cell lines exhibited intermediate behavior. These results parallel the reported disparate potencies of TNF and LT in their effects on endothelial cells, hematopoietic development and their abilities to sustain a mixed lymphocyte response. Radiolabeled TNF binding studies showed two classes of receptors (Kd 0.04 to 0.15 nM and 0.2 to 1.0 nM) on the highly sensitive SK-CO-1 line. HT-29 cells also appeared to possess some high affinity-binding sites, whereas the BT-20 line completely lacked the high affinity form. Thus the presence of high affinity-binding sites correlated with increased sensitivity to the antiproliferative effects of TNF. Cold TNF competed with the binding of radiolabeled human TNF three- to fivefold better than LT for binding to all three lines. These relatively small differences between the TNF and LT receptor-binding characteristics are insufficient to explain the dramatic disparity in their antiproliferative properties. Likewise, the absolute concentrations of the unlabeled cytokines necessary to block the binding of 125I-TNF were 10- to 150-fold higher than the levels necessary to elicit the biologic response. Thus, the receptor binding data conflict with the growth inhibitory effects. This discrepancy is discussed in terms of either separate receptors for TNF and LT or more complex phenomena such as receptor cooperativity possibly resulting from multivalent interactions with the trimeric form of TNF.
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PMID:Studies on the differing effects of tumor necrosis factor and lymphotoxin on the growth of several human tumor lines. 255 May 45


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