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

The cytopathic effects of HIV-1 produced by direct infection of human T cells do not account for the disproportionate loss of CD4-positive lymphocytes during the course of HIV infection. Previous studies have demonstrated the inhibition of uninfected human T cell activation and proliferation by the HIV-1 envelope glycoproteins, presumably due to gp120-CD4 interactions. To examine the ability of HIV-1 to inhibit T cell proliferation in the absence of both direct infection and gp120-CD4 interactions, we tested the effect of HIV-1 on mouse T cell proliferation. Culture media containing HIV-1 released from infected cells inhibited T lymphocyte proliferation in response to interleukin-2 (IL-2). Studies to explore the mechanism of this inhibition suggested that the decrease in proliferation resulted from interactions between HIV-1 and the mouse cells, but did not involve IL-2/IL-2 receptor interactions. We used monoclonal antibodies to demonstrate that the HIV-1 envelope glycoproteins were required for the inhibition of murine T cell proliferation. Anti-gp120 antibodies completely restored proliferation, indicating that the surface protein gp120 was primarily required for the inhibition of proliferation. However, antibodies directed against the transmembrane protein of HIV-1 (gp41) also partially restored lymphocyte proliferation. The functional significance of the HIV-1 envelope protein epitopes recognized by the monoclonal antibodies is discussed.
Virology 1992 Dec
PMID:CD4-independent inhibition of lymphocyte proliferation mediated by HIV-1 envelope glycoproteins. 128 Mar 85

Stimulation of T-lymphocytes derived from some patients with common variable immunodeficiency (CVID) syndrome results in defective proliferation. The underlying mechanism is related to the inability of stimulated cells to secrete IL-2 while the expression of IL-2 receptor (IL-2R) is normal. We have identified a patient whose peripheral T-cells failed to proliferate and secrete IL-2 upon stimulation. The addition of recombinant IL-2 restored proliferation. The defect did not seem to be caused by accessory cell failure since the patient's adherent cells produced IL-1 and IL-6, and addition of allogeneic irradiated cells did not induce proliferation. Stimulation of CVID T-cells with phorbol esters and Ca2+ ionophore induced both IL-2 secretion and proliferation, indicating the absence of a defect in the transcription and/or translation of the IL-2 gene. The patient's T-cells expressed high levels of CD3. The majority of T-cells expressed the CD38 molecule which is normally found on thymocytes or activated T-cells but not peripheral blood T-cells and HLA-DR, another activation marker. However, CD25 (the IL-2R) and CD1, a marker of more immature thymocytes, were not expressed. Finally, the patient's cells were sensitive to an in vitro corticosteroid treatment. The possibilities that this patient's T-cells represent anergic T-cells or not fully matured thymocytes are discussed.
Clin Immunol Immunopathol 1992 Dec
PMID:An unusual T-cell surface phenotype in vivo correlates with the failure to proliferate and produce IL-2 in vitro in a patient with common variable immunodeficiency. 128 May 40

We examined the effect of FK506 on the activation, proliferation and differentiation of human B lymphocytes in vitro. FK506 inhibited the proliferative response of resting B cells induced by Staphylococcus aureus Cowan strain I (SAC) and phorbol myristate acetate (PMA) in a dose-dependent manner. Inhibition of cell proliferation by FK506 was caused by a selective block of G0 to G1 phase transition leading to cell arrest. In addition, the proliferative response of in vivo-activated B cells and lymphokine-driven B cell proliferation were also found to be sensitive to FK506. Interestingly, FK506 did not affect the expression of activation antigens such as CD23, IL-2 receptor (CD25), and transferrin receptor (CD71). Finally, FK506 had little effect on B cell antibody generation in a T cell-independent system. Conversely, FK506 suppressed neither proliferation nor immunoglobulin secretion in a human B lymphoblastoid cell line. These results indicate that FK506 has discrete effects on the different stages of the B cell maturation.
Transplantation 1992 Dec
PMID:The distinct effects of FK506 on the activation, proliferation, and differentiation of human B lymphocytes. 128 61

High-affinity IL-2 receptors are expressed by T cells activated in response to foreign histocompatibility antigens but not by normal resting T cells. To exploit this difference in IL-2R expression, anti-Tac, a murine monoclonal antibody specific for the IL-2R alpha subunit, was used to inhibit organ allograft rejection. To enhance its effector function, anti-Tac was armed by chelation with yttrium-90, a pure beta-emitting radionuclide. Animals received no immunosuppression (n = 5, group I, controls), unmodified anti-Tac (n = 5, 1 mg/kg q.o.d., group II), or 90Y-anti-Tac (n = 5, 1.6 mCi/kg divided into four doses, group III). The animals in group IV (n = 4) were treated identically to those in group III with the exception that 5 micrograms/kg/dose of granulocyte colony-stimulating factor was administered intramuscularly on the days when the yttrium-90 was given and on postoperative days 12 through 35 in order to reduce hematopoietic toxicity. Mean graft survival +/- S.E.M. for the control group was 8.2 +/- 0.5 days as compared with 13.8 +/- 2.1 days (P < 0.05) for those monkeys treated with unmodified anti-Tac. Graft survival was further prolonged in animals of group III that received 90Y-anti-Tac, with a mean graft survival of 45.0 +/- 11.8 days; however, three of the five monkeys retained viable grafts within this group but died secondary to bone marrow suppression. In comparison, the monkeys in group IV that were treated with G-CSF in conjunction with 90Y-anti-Tac had a mean graft survival of 49.2 +/- 2.9 days. In contrast to group III there were no deaths in the group (IV) receiving G-CSF. Furthermore, animals in group IV had a reduced magnitude and shortened duration of irradiation-induced neutropenia when compared with that observed in group III animals that did not receive G-CSF. Thus, treatment with 90Y-anti-Tac in conjunction with G-CSF may have potential applications in organ transplantation and the treatment of IL-2 receptor-expressing neoplastic diseases.
Transplantation 1992 Dec
PMID:Prolongation of graft survival in primate allograft transplantation by yttrium-90-labeled anti-Tac in conjunction with granulocyte colony-stimulating factor. 128 66

It has been observed that neopterin, a specific marker of macrophage activation, increases during cancer immunotherapy with IL-2, and this effect is mediated by interferons produced by IL-2-stimulated lymphocytes. Moreover, our previous studies have shown that neopterin rise during IL-2 immunotherapy is associated with an enhanced release of soluble IL-2 receptor (SIL-2R), which may suppress IL-2-dependent immune functions. This finding would suggest that neopterin increase may be related to the generation of suppressive events, which occur during IL-2 immunotherapy. On the basis of the documented modulatory effect of IL-3 on macrophage functions, we have evaluated the influence of IL-3 on neopterin secretion during IL-2 immunotherapy. The study was performed in advanced lung cancer patients. We have investigated 9 immunotherapeutic courses consisting of IL-2 (6M IU/day s.c. for 5 days/week for 3 weeks) plus IL-3 (1 microgram/(kg x day) i.v. for 14 days, starting 7 days before IL-2). The results were compared to those found during 18 courses with IL-2 alone. Mean neopterin levels increased significantly during IL-2 alone, but not in response to IL-3 plus IL-2. SIL-2R rise was significantly higher during IL-2 than during IL-3 plus IL-2. Mean numbers of NK cells and activated lymphocytes increased significantly in both groups of patients, but were significantly lower at the end of the treatment in patients receiving IL-2 alone than in those treated with IL-3 plus IL-2.(ABSTRACT TRUNCATED AT 250 WORDS)
Biol Chem Hoppe Seyler 1992 Dec
PMID:Modulation of macrophage response to interleukin-2 immunotherapy by interleukin-3 in cancer patients. 129 6

The soluble sonicated extract (SE) from Actinobacillus actinomycetemcomitans inhibited primary T cell-dependent antibody responses in vivo. The production of IgG and IgM to sheep red blood cells (SRBC) was depressed when mice were treated with high concentrations of SE plus SRBC. Preinjection of SE 3 days prior to SRBC completely inhibited IgG production. SE plus SRBC-primed mice showed markedly depressed CD4/CD8 ratios relative to phosphate-buffered saline plus SRBC- or SRBC-immunized mice. SE-sensitized mice showed low blastogenic activity to concanavalin A (Con A) depending on sensitized periods induced by SE. This inhibitory mechanism was, in part, clarified by a suppression of IL-2 synthesis, IL-2 receptor expression and IL-6 secretion by the splenic T cells stimulated with Con A. These results support the hypothesis that the severe infection of A. actinomycetemcomitans suppresses the immune response by affecting CD4/CD8 ratios, followed by lymphokine production and finally antibody responses.
Oral Microbiol Immunol 1992 Dec
PMID:Immunosuppressive effect induced by Actinobacillus actinomycetemcomitans: effect on immunoglobulin production and lymphokine synthesis. 129

A significant elevation in the percentage of CD4+ and CD8+ T-lymphocytes expressing major histocompatibility complex (MHC) Class II antigens was observed in the blood of cats shortly after they were experimentally infected with feline immunodeficiency virus (FIV). In addition to an increase in the relative proportion of T-lymphocytes expressing Class II antigens, there was an increase in the density of Class II antigens on the cell surface. These elevations were still evident at the completion of the 5 month study. A second group of cats that had been infected with FIV for almost 5 years, and with either normal or abnormally low levels of CD4+ T-lymphocytes, had similar elevations in MHC II expression, suggesting that such abnormalities are lifelong. Cats with chronic (2 year) feline leukemia virus (FeLV) infection or dual FIV/FeLV infections also showed similar alterations in MHC II expression on CD4+ and CD8+ T-lymphocytes, suggesting that these alterations were not FIV specific. Feline T-lymphocytes expressed more MHC II antigen and interleukin-2 (IL-2) receptor following stimulation in vitro with conconavalin A and IL-2, demonstrating that feline T-lymphocytes respond to activation signals in a manner similar to T-lymphocytes of other species. However, changes in MHC II expression on T-cells of FIV infected cats were not explainable by viral induced T-cell activation alone, because FIV infected cats with elevated MHC II expression did not have coincident elevations in IL-2 receptor expression.
Vet Immunol Immunopathol 1992 Dec
PMID:Persistent upregulation of MHC class II antigen expression on T-lymphocytes from cats experimentally infected with feline immunodeficiency virus. 136 10

Productive infection of cells by human immunodeficiency virus type 1 (HIV-1) is associated with the activation state of the cell and its obligatory expression of the interleukin-2 receptor (IL-2R), the latter providing a new target for antiviral therapy. A quantitative RNA-RNA hybridization assay is employed to detect production of HIV-1 RNA and to show that two IL-2 diphtheria toxin-related fusion proteins (DAB486IL-2 and its more potent, truncated form DAB389IL-2) inhibit HIV-1 RNA production in infected cells. A mutant form of DAB486IL-2 containing a single point mutation that inactivates the adenosine diphosphate ribosyltransferase activity of the toxin does not inhibit HIV RNA production, even though the molecule binds to the IL-2R. The active fusion proteins inhibit viral RNA replication in cells infected with HIV-1 clinical isolates as well as with a ZDV-resistant strain of HIV-1. These results indicate that IL-2 receptor-targeted fusion proteins can be utilized to inhibit HIV-1 replication effectively in infected human lymphocytes.
J Acquir Immune Defic Syndr (1988) 1992 Dec
PMID:Inhibition of HIV-1 RNA production by the diphtheria toxin-related IL-2 fusion proteins DAB486IL-2 and DAB389IL-2. 145 29

Interleukin 2 (IL-2) can stimulate the proliferation of various kinds of T-cell lines. The receptor for IL-2 is composed of at least two subunits (alpha and beta), of which beta subunit plays the major role in transducing growth signals into the cells. A nonreceptor-type tyrosine kinase, Lck, is associated with IL-2 receptor beta subunit, and the binding of IL-2 to its receptor induces the activation of Lck. On the other hand, it has been shown that stimulation of T-cells with IL-2 causes rapid activation of Ras protein. In this paper, we describe that both of the two regions in IL-2 receptor beta subunit, the indispensable region for the induction of cell growth (serine-rich region) and the binding region of Lck protein (acidic region), are required for the activation of Ras. These two regions are also required for tyrosine phosphorylation of an 85-kDa cellular protein (p85) and the accumulation of fos and jun mRNAs. This observation suggests also that the activation of a receptor-associated tyrosine kinase in response to IL-2-stimulation is primarily responsible for subsequent activation of the pathway through Ras to Fos and Jun.
J Biol Chem 1992 Dec 15
PMID:Interleukin 2-induced activation of Ras requires two domains of interleukin 2 receptor beta subunit, the essential region for growth stimulation and Lck-binding domain. 146 37

The aim of this study was to examine the cytokine production and cytokine responsiveness of the first T-cell receptor (TcR) positive cells that appear in the murine fetal thymus, namely TcR V gamma 3 cells. It is shown that IL-2-cultured fetal TcR V gamma 3 thymocytes were capable of producing IL-3, GM-CSF, TNF-alpha and IFN-gamma upon TcR triggering. IL-2, IL-4, IL-5 and IL-6 could not be detected. With regard to cytokine responsiveness, TcR V gamma 3 cells proliferated to a high extent when high concentrations of rIL-2 were added. rIL-4 or rIL-7 alone, but not rIL-1 alone, were capable of inducing a modest proliferation of TcR V gamma 3 thymocytes. When combined with low concentrations of IL-2, a synergistic effect could be observed with IL-1, IL-4 or IL-7. It is shown that the synergistic effect of IL-2 with IL-4 was mainly due to induction of IL-2 receptor expression. The synergistic effect of IL-2 and IL-7 on the proliferation of TcR V gamma 3 cells could only be partially inhibited by anti-IL-2 receptor MoAb, and this antibody had no effect on the IL-2 + IL-1 cultures. These observations can explain the extensive proliferation of TcR V gamma 3 thymocytes during fetal life and they indicate that TcR V gamma 3 thymocytes have the potential to play a functional role during fetal thymus development.
Scand J Immunol 1992 Dec
PMID:Cytokine production and responsiveness of fetal T-cell receptor V gamma 3 thymocytes. 146 22


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