Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P14784 (IL-2 receptor)
 3,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been shown that the antithyroid drug methimazole (MMI) may affect B cells and possibly accessory cell function. In the present study we investigated in detail the effects of MMI on T cell in vitro proliferation. The following variables were evaluated: T cell proliferation following stimulation with phytohemagglutinin (PHA), and anti-CD3 or anti-CD2 monoclonal antibodies; interleukin-2 (IL-2) and gamma-interferon (gamma-IFN) production by PHA-stimulated T cells in bulk culture and by T cell clones; PHA-induced IL-2 receptor expression; LPS-induced interleukin-1 production by accessory cells. The results obtained failed to demonstrate any effect of MMI on T cells in vitro proliferation, whatever the activation pathway considered. In addition, IL-2 and gamma-IFN productions were substantially unaffected by the drug, as well as IL-1 production by accessory cells. However, a slight reduction of PHA-induced IL-2 receptor expression was observed. Although the hypothesis of an effect of MMI on some specialized T cell functions cannot be ruled out, it is likely that the supposed "immunosuppressive" effect of the drug does not concern primarily the T lymphocyte.
 ...
PMID:The effect of methimazole on the immune system is unlikely to operate directly on T lymphocytes. 212 30

In this study the effect of anti-cluster designation (CD) 2 monoclonal antibodies (mAb) on the activation of a cloned human T cell line, HY837, after triggering the CD3/T cell receptor (TcR) complex by anti-CD3 or anti-TcR mAb is described. HY837, which reacts with a series of mAb directed at different epitopes on the TcR, could be induced to proliferation and interleukin 2 (IL-2) production by soluble mAb directed at the CD3/TcR complex in the absence of accessory cells. mAb directed at the CD2 epitope T11-1 were shown to block the IL-2 production by HY837, as well as the expression of the IL-2 receptor, induced by anti-CD3 mAb, resulting in the inhibition of the proliferative response. The effect of anti-CD2 mAb on the proliferative response of HY837, induced by anti-CD3 mAb, was not due to a competition for Fc binding sites. In contrast, the proliferative responses and IL-2 production of HY837, induced by mAb directed at the TcR, were shown to be enhanced by the action of the anti-CD2 mAb. These results indicate that effects mediated by anti-CD3/TcR mAb cannot always be extrapolated to antigen-mediated effects and show that anti-CD2 mAb may regulate the T cell response, induced by mAb directed at the CD3/TcR complex, depending on which part of this complex is triggered during activation.
 ...
PMID:Regulation by anti-CD2 monoclonal antibody of the activation of a human T cell clone induced by anti-CD3 or anti-T cell receptor antibodies. 244 43

Malignant cells of a patient with acute leukemia expressed hematopoietic stem cell antigens such as CD34 and HLA-class II but lacked lineage specific differentiation markers. The leukemic blasts differentiated into mature T cells within 14 days in the presence of a T cell conditioned medium or with a mixture of highly purified interleukin-2 (IL-2) plus recombinant interleukin-3 (IL-3) and recombinant granulocyte/macrophage colony-stimulating factor (GM-CSF). Phenotypically, the maturing cells acquired the T cell-specific differentiation antigens CD2, CD3, and CD8, whereas immature differentiation antigens such as CD34 and Leu19 as well as HLA-class II and the IL-2 receptor CD25 were concomitantly down-regulated within 14 days of in vitro culture. This in vitro maturation involved two to three synchronized cell divisions. Beyond 10 days of culture the leukemic cells produced mRNA specific for the T cell receptor beta and alpha chain, but at no time transcription of T cell receptor gamma chain-specific message was detectable. To our knowledge, these data represent the first in vitro model demonstrating the differentiation of phenotypically mature T cells from immature leukemic cells induced by the combined activities of IL-2 plus IL-3 and GM-CSF.
 ...
PMID:Generation of mature CD3+ and T cell receptor (TCR) + T cells from a leukemic analogue of the putative human stem cell by T cell conditioned medium containing IL-3, IL-2, and GM-CSF. 245 58

We examined the role of the T-cell antigen CD2 in the regulation of erythropoiesis by the lymphokine cascade. T-cell interleukin-2 (IL-2) receptors (p55) were induced via triggering of the antigen receptor-associated CD3 epitope. Before CD3 triggering T cells were preincubated with a CD2-blocking (Leu-5b) or isotype control antibody. T-cell pellets were employed during incubation to facilitate interaction between T-cell LFA-3 and CD2. CD2 blockade caused a 66% to 79% inhibition of p55 expression after three to six days of culture with IL-2. Next we assessed the effect of CD2 blockade on IL-2. Next we assessed the effect of CD2 blockade on IL-2-induced inhibition of BFU-E in autologous cocultures containing CD3-triggered T cells. IL-2 caused a dose-dependent inhibition (52% to 92%) of BFU-E in the presence but not in the absence of CD3-triggered T cells. T-cell CD2 blockade prior to CD3 triggering caused a 65% to 87% abrogation of IL-2-induced inhibition of BFU-E at 10 to 10(2) U/mL IL-2. Preincubation of CD3-triggered T cells with isotype control antibody had no effect on IL-2-induced erythroid inhibition. Day 3 supernatants from CD3-triggered T cells or CD2-blocked, CD3-triggered T cells established in the presence of IL-2 were next assessed for modulation of BFU-E. CD3-triggered T-cell supernatants caused a 77% +/- 9% inhibition of BFU-E. Blockade of CD2 caused a 95% abrogation of T-cell-mediated BFU-E inhibition. In addition, CD2 blockade reduced interferon-gamma (IF gamma) release (84 to 128 U/mL) from CD3-triggered T cells by 81% at day 3 of culture. In control experiments, the addition of IF gamma-neutralizing monoclonal antibody to CD3-triggered T-cell supernatant established in the presence of IL-2 caused 75% abrogation of IL-2 inhibition of BFU-E. We conclude that blockade of the CD2 T-cell determinant induces down modulation of (a) T-cell p55 IL-2 receptor expression, (b) IL-2-induced inhibition of BFU-E, and (c) IL-2-induced marrow T-cell IF gamma release. These data suggest that the T-cell CD2 determinant can exert a regulatory effect on the control of erythropoiesis by the lymphokine cascade.
 ...
PMID:The T-cell CD2 determinant mediates inhibition of erythropoiesis by the lymphokine cascade. 245

The addition of autologous erythrocytes to unfractionated human mononuclear cell cultures results in enhancement of B cell responses to antigens and mitogens. This costimulating effect of red cells is abrogated by their preincubation with anti-LFA-3 monoclonal antibody. Preincubation of mononuclear cells with anti-CD2 monoclonal antibodies (anti-Leu 5b, OKT11, used singly) has a down-regulating effect on B cell activation and no enhancement of B cell responses is seen when red cells are added to anti-CD2-treated cultures. These results demonstrate a functional effect on B cells of the interaction between the CD2 molecule on T lymphocytes and its natural ligand, LFA-3. The precise mechanism by which this costimulating effect on B lymphocytes takes place is unclear. The study of T cell populations and T cell activation markers shows that the addition of erythrocytes causes a small but reproducible increase in the number of cells expressing the IL-2 receptor and the addition of IL-2 enhances the response of mononuclear cells to antigenic stimulation in the presence of erythrocytes. However, the supernatants of mononuclear cell cultures stimulated with pokeweed mitogen in the presence of autologous erythrocytes show decreased levels of IL-2, compared to supernatants of cells stimulated with pokeweed mitogen alone. The same supernatants show increased levels of interferon-gamma, but the addition of this lymphokine to cultures stimulated with pokeweed mitogen has no potentiating effect. It is possible that the effect of erythrocytes is mediated by other growth and/or differentiation factors, and additional studies will be required to clarify this point.
 ...
PMID:The interaction of CD2 with its LFA-3 ligand expressed by autologous erythrocytes results in enhancement of B cell responses. 246 Feb 48

The activation of resting T cells to interleukin 2 (IL-2) production and DNA synthesis via Ti-CD3 is dependent on accessory cells (AC). Using positively selected, resting T cells activated with particle-bound anti-CD3, we investigated the ability of various cell lines to function as AC. We found that cell lines able to act as AC all expressed LFA-3, while cell lines not expressing LFA-3 were unable to provide AC signals. This applied to CD3+, CD4+, and CD8+ T cells. Sheep red blood cells (SRBC), which express LFA-3-like molecules, also had a weak, but significant AC function in this test system. Both CD4+ and CD8+ T cells activated with particle-bound anti-CD3 could be induced to enter DNA synthesis in the absence of AC when monoclonal antibodies reacting with CD2 were present instead of AC. IL-2 production could be detected in the latter cultures but not when positively selected CD3+ or CD2+ T cells were cultured alone. Our data suggest that activation of resting T cells via CD3 will lead to IL-2 receptor expression, while the interactions between LFA-3 and its ligand CD2 provide the necessary secondary signals for IL-2 production and induction of DNA synthesis.
 ...
PMID:Accessory cell-dependent T-cell activation via Ti-CD3. Involvement of CD2-LFA-3 interactions. 246 80

HIV selectively inhibited the proliferative response of clonal CD4+ T lymphocytes to alloantigen while other alloantigen-dependent responses were unperturbed. Specifically, impaired blastogenesis could be dissociated from alloantigen-specific induction of the B cell activation molecule CD23, IL-4 release, and inositol lipid hydrolysis. In addition, membrane expression of pertinent T cell receptor molecules, including CD2, CD3, and T cell antigen receptor (Ti), remained intact. Using two MHC class II-specific human CD4+ helper T cell clones, the proliferative defect was shown to be an early consequence of HIV infection, occurring within 4 d of viral inoculation and preceding increases in mature virion production. It was generalizable to three distinct methods of T cell activation, all independent of antigen-presenting cells: anti-CD3 mediated cross-linking of the CD3/Ti complex; anti-CD2 and phorbol 12-myristic 13-acetate (PMA); and anti-CD28 plus PMA. These abnormalities were not mitigated by addition of exogenous IL-2, even though expression of the IL-2 receptor (CD25) was unaltered. These studies define a selective blockade in T cell function early after HIV exposure that could serve as a model for certain in vivo manifestations of AIDS.
 ...
PMID:Human immunodeficiency virus infection of helper T cell clones. Early proliferative defects despite intact antigen-specific recognition and interleukin 4 secretion. 247 Jul 86

CD28 is an antigen of 44 kDa which is expressed on the membrane of the majority of human T cells. The present study examines the functional effects of an anti-CD28 monoclonal antibody (mAb 9.3) on T cell activation induced with immobilized anti-CD3 mAb OKT3 or with mitogens, in the absence of accessory cells. To this end, we used blood resting T cells that were completely depleted of accessory cells (monocytes, B cells, and natural killer cells), and consequently did not respond to recombinant interleukin-2 (rIL-2), to immobilized OKT3, to PHA, or to Con A. Addition of mAb 9.3 to the cultures enhanced IL-2 receptor expression (Tac antigen) on PHA- or immobilized OKT3-stimulated T cells and induced IL-2 receptors on Con A-stimulated T cells. Moreover, addition of mAb 9.3 to cultures of T cells stimulated with PHA, Con A, or immobilized OKT3 resulted in IL-2 production. Soluble mAb 9.3 was a sufficient helper signal for T cell proliferation in response to PHA or immobilized OKT3. Crosslinking of mAb 9.3 by culture on anti-mouse IgG-coated plates enhanced the helper effect and was an essential requirement for the induction of T cell proliferation in response to Con A. No other anti-T cell mAb (anti-CD2, -CD4, -CD5, -CD7, -CD8) was found to provide a complete accessory signal for PHA or Con A stimulation of purified T cells. T cell proliferation induced by the combination of PHA and mAb 9.3 was strongly inhibited by the anti-IL-2 receptor mAb anti-Tac. In conclusion, mAb 9.3 can provide a signal bypassing monocyte requirement in T cell activation with immobilized OKT3, PHA, and Con A, resulting in an autocrine IL-2-dependent pathway of proliferation.
 ...
PMID:The anti-T cell monoclonal antibody 9.3 (anti-CD28) provides a helper signal and bypasses the need for accessory cells in T cell activation with immobilized anti-CD3 and mitogens. 253 66

Activation of human-purified T cells can be mediated by pairwise combinations of monoclonal antibodies directed against T11.1 and T11.2 epitopes on the CD2 molecule. Monoclonal antibodies (mAbs) reactive with either the alpha and beta chains of the lymphocyte-function-associated antigen-1 (LFA-1) molecule or one of its ligands, intercellular adhesion molecule-1 (ICAM-1), were found to accelerate anti-CD2-induced proliferation. This effect was seen on thymocytes and resting or preactivated T cells (phytohemagglutinin blasts and alloproliferative T cell clones) and could be observed, following the introduction of anti-LFA-1 or -ICAM-1 mAbs, up to 50 hr after the CD2 stimulatory signal. This effect was equally abrogated by 55 kDa anti-interleukin-2 (IL-2) receptor mAb, but neither the expression of IL-2 receptor nor the production of IL-2 was modified. The effects of anti-LFA-1 or anti-ICAM-1 on T cell activation through the CD2 pathway were therefore opposite to those observed in the CD3 pathway, where both mAbs strongly delayed T cell proliferation.
 ...
PMID:Monoclonal antibodies against LFA-1 or its ligand ICAM-1 accelerate CD2 (T11.1 + T11.2)-mediated T cell proliferation. 257 21

T cells can be divided into unprimed virgin (T0) and primed memory (T') subpopulations by their expression of different isoforms of the leukocyte common antigen. We have separated the CD4+ T cells into T0 and T' subpopulations and examined their capacity to respond to activation signals via the CD2 receptor molecule. On stimulation with a mitogenic combination of anti-CD2 antibodies, the T' population was induced to express IL-2 receptor, increased levels of the 4F2 antigen and to proliferate, whereas the response of the T0 populations was reflected solely by a minimal increase in the 4F2 antigen. The addition of IL-2 or monocytes to T0 cells stimulated with anti-CD2 antibodies did not enhance their expression of the IL-2 receptor or proliferation. However, T0 cells stimulated with the triad of anti-CD2 antibodies, monocytes, and IL-2 responded with high levels of IL-2 receptor expression and proliferation. The T0 subpopulation could also be induced to respond when cultured with anti-CD2 antibodies and phorbol myristate acetate. The results suggest that in order to respond to stimulation via the CD2 molecule, virgin T helper cells require additional signals that can be jointly provided by monocytes and IL-2. In contrast, memory T helper cells can be activated via CD2 signal transduction alone.
 ...
PMID:Virgin and memory T cells have different requirements for activation via the CD2 molecule. 257 87


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>