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Query: UNIPROT:P14784 (IL-2 receptor)
 3,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ficoll-separated and monocyte-depleted mononuclear cells isolated from normal leukapheresis products were cryopreserved. These cells were incubated with or without 1,000 U/ml of recombinant interleukin-2 (rIL-2) for 4 days, and their lymphokine-activated killer (LAK) and natural killer (NK) activities were measured. IL-2 activation induced a significant increase in the expression of the CD25 antigen. There was no change in CD2, CD3, CD4, CD8, CD16, CD56 and CD57 cell marker expression. Cryopreservation did not induce any change in the membrane antigen expression and in the lymphocyte subsets. The NK activity was well preserved and the decrease of LAK activity of IL-2-activated cells after cryopreservation was not significant. In contrast, cells activated before cryopreservation had a significantly lower cytotoxic activity and the number of cells expressing the IL-2 receptor was also significantly reduced. However, the decrease of CD56 expression was not significant. CD25 expression seemed to be proportional to the LAK activity of the cells. This study demonstrated that cryopreserved lymphocytes, after 4 days of culture with rIL-2, could be as active and could express the CD25 and CD56 cell surface markers in the same manner as fresh LAK cells.
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PMID:The influence of cryopreservation on activity and surface markers of lymphokine-activated killer cells. 176 4

Two signals are required for the in vitro activation of Lyt2+ T suppressor cells (Ts) from mice tolerized with 2,4-dinitrobenzene sulfonate (DNBS) to produce soluble suppressor factors (SSF) which suppress the transfer of contact sensitivity to dinitrofluorobenzene (DNFB). Recognition of DNP/class I MHC (signal one) stimulates the Ts to synthesize SSF. Release of SSF requires a soluble mediator (signal two) produced by the interaction of L3T4+ T cells from tolerant mice with I-A on metabolically functional cells in the DNP-presenting cell population. The purpose of this study was to examine the nature of this second Ts activation signal. Coculture of tolerant spleen cells and glutaraldehyde-fixed (Glu-) DNP-labeled spleen cells (DNP-SC) resulted in the synthesis but not release of SSF. Addition of either IL-1 or IL-2 to these cultures induced SSF release. Treatment of such cultured cells with the anti-murine IL-2 receptor antibody PC 61.5.3 blocked the IL-2- and IL-1-stimulated release of SSF. Release of SSF was also blocked when tolerant cells were cultured with (unfixed) DNP-SC in the presence of a monoclonal anti-IL-2 antibody. IL-2 but not IL-1 was able to stimulate the Ts to release synthesized SSF in the absence of L3T4+ TH activity. First, addition of IL-2 to cocultures of tolerant cells and DNP-presenting I-A- cells induced release of the synthesized SSF, whereas addition of IL-1 did not. Second, IL-2 also stimulated SSF release in cocultures of L3T4+ T cell-depleted tolerant cells and Glu-DNP-SC, whereas IL-1 did not. Tolerant cells pretreated with IL-2 and then washed were able to synthesize and release SSF upon culture with Glu-DNP-SC. Pretreatment of tolerant cells with IL-1 did not stimulate SSF release upon subsequent culture with Glu-DNP-SC. These results indicate that the Lyt2+ Ts from DNBS-tolerant mice express IL-2 receptors and IL-2 is the lymphokine which induces the Ts to release synthesized SSF. Thus, IL-2 provides a differentiative signal during the functional activation of these regulatory T cells.
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PMID:Soluble factors in tolerance and contact sensitivity to DNFB in mice. X. IL-2 is the activation signal mediating release of synthesized suppressor factor. 182 30

The aim of the present work was to study regulatory interactions between MHC class I molecules and the interleukin (IL)-2, IL-3, and IL-4 receptors and functional interactions between the receptors for IL-2 and IL-4. Our major observations were: (1) quiescent splenic T cells exposed to specific anti-MHC class I antibodies become responsive to IL-2 and IL-4 stimulation; (2) T-cell clones (CTLL-2 and HT-1) grown at high cell density or low IL-2 concentrations become refractory to IL-2 and IL-4 stimulation. After exposure to anti-class I antibodies the refractory cells recover responsiveness to lymphokine-induced proliferation; (3) IL-2 receptor expression is non-inducible in class I-negative T-lymphoma cells, but is inducible following class I gene transfection of the cells; (4) exposure of T-cells and clones to IL-2 receptor antibody increases the responsiveness to IL-4 stimulation; (5) IL-2 and IL-4 act synergistically at low and substimulatory lymphokine levels; and (6) IL-3 responsiveness of hemopoietic cells is not influenced by exposure to anti-MHC class I antibody. It is concluded that class I molecules are of importance for the functional expression of the receptors for IL-2 and IL-4 and that these receptors are functionally interrelated.
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PMID:T-cell activation. IV. Evidence for a functional linkage between MHC class I, interleukin-2 receptor, and interleukin-4 receptor molecules. 183 52

The in vitro effect of synthetic human growth hormone-releasing hormone (GHRH) on mitogen-induced lymphocyte proliferation and lymphokine secretion was investigated. Peripheral blood mononuclear cells (PBMC) of healthy adults were incubated in the presence and absence of increasing concentrations (from 0.006 to 50 micrograms/ml) of two forms of GHRH differing in amino-acid sequence (GHRH 1-44 and GHRH 1-29) or of increasing concentrations (from 0.0012 to 20 U/ml) of recombinant human insulin (rh-insulin). Low concentrations of GHRH 1-29 increased phytoemoagglutinin (PHA)-induced lymphoproliferation, while high concentrations inhibited lymphocyte response, interleukin-2 (IL-2) secretion and IL-2 receptor expression on activated cells. A toxic effect was excluded since no differences in cell viability were observed between cells cultured with and without hormone. GHRH 1-44 did not affect PHA-induced lymphoproliferation, IL-2 production and IL-2 receptor expression. Low concentrations of rh-insulin increased PHA-elicited lymphoproliferation, while high concentrations did not decrease lymphocyte response. The present study suggests that GHRH modulates in vitro human T lymphocyte functions.
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PMID:Influence of growth hormone-releasing hormone (GHRH) on phytohemagglutinin-induced lymphocyte activation: comparison of two synthetic forms. GHRH and PHA-induced lymphocyte activation. 183 62

The role of activated T cells in the mediation of antitumor responses has been documented in several experimental models. In some of these, interleukin-2 (IL-2) has been used as a means to induce and expand the antitumor effects of the T cells. IL-2 has been tested in clinical trials for cancer treatment. Surprisingly, T cells appear to be inactivated by IL-2 in these clinical trials. T cells obtained from peripheral blood after IL-2 therapy showed decreased responses to mitogens and alloantigens, did not proliferate in vitro in response to IL-2, and did not mediate non-major histocompatibility complex-restricted cytotoxicity or targeted lysis in the presence of bispecific monoclonal antibodies. In this study, we present evidence that these post-IL-2 therapy T cells are not irreversibly inactivated; they can be activated in vitro by anti-CD3 monoclonal antibody together with IL-2 to upregulate the p55 component of the IL-2 receptor and proliferate. Nevertheless, following activation by anti-CD3 and IL-2, the level of targeted T-cell cytotoxicity mediated by the post-IL-2 therapy T cells was significantly lower than that by pre-IL-2 therapy T cells. Although in vivo treatment with IL-2 alone induces natural killer (NK) cells to mediate lymphokine-activated killer activity, these data suggest that the T-cell lytic function is inhibited by this treatment and only partially reversible by subsequent T-cell receptor activation using anti-CD3 mAb. Exposure of T cells to anti-CD3 mAb prior to in vivo IL-2 treatment generates T-cell lytic activity in vitro. These results, together with preclinical murine studies, suggest that a combined in vivo protocol of anti-CD3 mAb and IL-2, starting first with the anti-CD3 mAb, may cause activation of the T cells in addition to the activation of NK cells and thus warrant clinical testing.
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PMID:Activation of human T cells obtained pre- and post-interleukin-2 (IL-2) therapy by anti-CD3 monoclonal antibody plus IL-2: implications for combined in vivo treatment. 183 66

The effects of human recombinant interleukin-6 (hrIL-6) on antibody-dependent cellular cytotoxicity (ADCC) activity mediated by human peripheral blood mononuclear cells (PMNC) were investigated. Human PMNC were preincubated for 24 h with various concentrations of hrIL-6 and were used as effector cells in a 4-h 51Cr-release assay. The ability of hrIL-6 to augment ADCC was measured using anti-colorectal carcinoma mAbs D612, 17.1A and 31.1 (each directed against a distinct tumor antigen) and using three human colorectal carcinoma cell lines, LS-174T, WiDr and HT-29, as targets. A significant increase in ADCC activity was observed after PMNC were preincubated in 100-400 U/ml but not in lower concentrations of hrIL-6. Variations in activities of PMNC among donors were observed. Non-specific mAb showed no effect in augmenting ADCC activity. hrIL-6 treatment did not augment non-specific (non-mAb-mediated) cytotoxicity. The enhancement of ADCC activity was blocked by the addition of an antibody against hrIL-6 but not by an antibody to the IL-2 receptor (capable of blocking the induction of lymphokine-activated killer cell cytotoxicity by IL-2), suggesting that hrIL-6 augmentation of ADCC activity may not be mediated through IL-2. These results demonstrate that hrIL-6 augments ADCC activity of human PMNC using mAbs to human tumor antigens and human tumor cells as targets, suggesting a potential role for IL-6 in combination with anti-cancer antibodies for cancer immunotherapy.
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PMID:Human recombinant interleukin-6 enhances antibody-dependent cellular cytotoxicity of human tumor cells mediated by human peripheral blood mononuclear cells. 183 75

In this present study, lymphokine (IL-2/IL-4) production in VSV-induced Th cell (L3T4+Lyt-2- VSV-immune T cells) and memory CTL populations (L3T4-Lyt-2+ VSV-immune T cells) has been assessed in order to gain some understanding as to why the Lyt-2+ subset (L3T4-independent Th cell pathway) fails to provide Th cell function for anti-VSV CTL responses. Our studies demonstrated that following specific antigen (VSV, H-2 antigen) or mitogen stimulation, lymphokine activity was detected in the supernatants obtained from VSV-induced Th but not VSV memory CTL populations. The presence of blocking concentrations of PC61, a monoclonal antibody (mAb) to the IL-2 receptor (IL-2R), revealed augmented lymphokine activity only in the VSV-induced Th cell supernatant. VSV-induced Th cells secreted both IL-2 and IL-4 following stimulation with VSV. Two lines of evidence supported the view that both these lymphokines were important for an anti-VSV CTL response: (1) mAb to either IL-2 or IL-4 inhibited CTL maturation and (2) the combination of exogenous IL-2 and IL-4 reconstituted a class I-restricted. VSV-specific CTL response in Th cell-depleted T cell cultures. The failure to detect lymphokine production in bulk cultures of the VSV memory CTL population was consistent with limiting dilution (LD) analysis of lymphokine-producing cells in the spleen of VSV-immune mice. Thus, approximately 1/15,000 Lyt-2-depleted, VSV-immune T cells were positive for lymphokine production following VSV stimulation, whereas less than 1/1,000,000 L3T4-depleted, VSV-immune T cells were scored as lymphokine-secreting cells following stimulation with this same virus. Similarly, precursor estimates for lymphokine-producing cells against allogeneic class I antigens demonstrated that the majority of lymphokine-producing cells also resided in the L3T4+ subset. Lymphokine-secreting Lyt-2+ cells were detected at low but not high cell densities suggesting that Lyt-2+ cells may secrete another lymphokine(s) that inhibits IL-2/IL-4 production. Thus, these studies demonstrate an obligatory requirement for the L3T4-dependent Th cell pathway for optimal CTL responses derived from either CTLp or memory CTLs.
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PMID:T helper cells in cytotoxic T lymphocyte development: analysis of the cellular basis for deficient T helper cell function in the L3T4-independent T helper cell pathway. 185 Jun 63

Interleukin-2 (IL-2) belongs to a series of mediators that are produced by T cells and exert multiple, pleiotropic effects in an autocrine or paracrine fashion. IL-2 plays a fundamental role in the ontogeny of developing T cells in the thymus and supports the growth or effector function of a wide array of immunologically relevant cells, including macrophages and B and NK lymphocytes, as well as a variety of different T-cell subpopulations. Nonetheless, the function of this lymphokine must be highly controlled in vivo to avoid systemic effects that might endanger the specificity of an immune response and result in autoimmune reactions. Accordingly, various mechanisms guarantee compartmentalization of IL-2, that is, chronological and spatial restriction of IL-2 production, bioavailability, and state of responsiveness. The secretion of IL-2, as well as the expression of the two components of the high-affinity IL-2 receptor (IL-2R), are developmentally controlled during ontogeny and, within the cellular immune system, are restricted to defined pre- and intrathymic stages of immature T cells or T-cell precursors. In the peripheral lymphoid organs, IL-2 is produced by a defined population of mature CD4+ T lymphocytes in which the IL-2 gene is transcribed or silenced, depending on the combination of antigenic and nonspecific activation signals to which the cell is exposed. Thus, the absence of certain costimulatory signals leads to a long-lasting inactivation of the IL-2 gene, a phenomenon that accompanies nondeletional T-cell tolerance. IL-2 has a short half-life and is secreted in apposition to the cell with which the T cell interacts. Expression of the high-affinity IL-2R is activation-dependent in most cell types. Thus, different mechanisms, intervening in all compartments relevant for the action of IL-2, together contribute to a restriction of IL-2 effects, conferring a relative specificity to this pleiotropic mediator.
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PMID:Interleukin-2: counteracting pleiotropy by compartmentalization. 187 49

We have used the technique of in situ hybridization to investigate the transcription of genes encoding the CD3 complex and the lymphokine interleukin 4 (IL-4) by human pro-T cells--i.e., cells that phenotypically resemble those T-cell precursors that colonize the thymus during early intrathymic development. CD1-2-3-4-7+8-45+ pro-T cells isolated from postnatal thymi via immunoselection with a panel of specific monoclonal antibodies are already committed to the T-cell lineage because most of them transcribe the genes encoding the delta and epsilon chains of the CD3 complex. About half of such pro-T cells synthesize IL-4 mRNA in the absence of any exogenous stimulation. Upon culture with IL-4, pro-T cells extensively proliferate and differentiate into functionally competent, mature gamma delta T cells expressing a T-cell receptor repertoire similar to that of gamma delta T cells that can be found in postnatal thymus. The IL-4 response of pro-T cells is not mediated by induction of the interleukin 2 (IL-2)-IL-2 receptor pathway and, unlike IL-2-driven T-cell differentiation, does not require the presence of stromal cells. Taken altogether, these findings suggest that an autocrine IL-4-mediated pathway might be implicated in early thymocyte differentiation--namely, in the generation of T cells bearing the gamma delta T-cell receptor.
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PMID:Involvement of the interleukin 4 pathway in the generation of functional gamma delta T cells from human pro-T cells. 188 11

Adherent lymphokine-activated killer cells (A-LAK) are highly potent cytotoxic cells, which are shown to be derived not only from natural killer (NK)/K cells but phenotypically also from T cells. The generation and phenotypical and functional characterisation of these T-cell-derived A-LAK are described. In contrast to non-adherent cells (NA-LAK) and unseparated LAK (UN-LAK), these mostly CD3+ CD56+ CD8+ cells display a high degree of expansion following initial interleukin-2 (rIL-2) activation and further culturing in autologous conditioned medium. A comparison of cytotoxic activities of cultured cells reveals a significantly higher oncolytic ability of A-LAK cells against both K562 and Daudi cells than that of cultured controls of NA-LAK and UN-LAK. In addition, A-LAK are characterised by a marked endogenous cytokine release of interferon gamma, tumour necrosis factor alpha and IL-6 as well as by their shedding of p55 IL-2 receptor after exposure to IL-2. The results demonstrate A-LAK to be the lymphocyte subpopulation with the most cytotoxic activity and endogenous cytokine release after exposure to IL-2. The improvement of techniques for long-term cultures may be of interest for future therapeutic approaches.
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PMID:High release of tumor necrosis factor alpha, interferon gamma and interleukin-6 by adherent lymphokine-activated killer cells phenotypically derived from T cells. 190 99


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