RESUMO
Parathyroid adenoma is the most common cause of primary hyperthyroidism which leads to abnormal calcium homeostasis, hypercalcemia, and reduction in bone density. A 37-year-old female referred from a private health facility with a 1-year history of upper back swelling and pain. The pain was worse when sitting down for long periods and with movement and relieved by rest. There was no antecedent history of trauma, but the patient had noticed poor appetite and weight loss. There were no constipation, no abdominal discomfort, and no symptom suggestive of hyperthyroidism or hypothyroidism. General physical examination revealed kyphoscoliosis, and vital signs were within normal limits. Spine X-ray showed features of cervical spondylosis. Computed tomography (CT) scan and magnetic resonance imaging showed pathologic fractures of the right 9 thrib, anterior wedge compression, and reduction of T4 vertebrae with other abnormalities at T4-T5, T5-T6, T7-T8, T10-T11, and L4-L5 vertebrae. Bone marrow aspiration and serum electrophoresis were within normal limits. Serum calcium showed hypercalcemia. A CT scan of the neck was done which showed features of a right superior parathyroid adenoma. Blood count, other serum electrolytes, and thyroid function tests were all normal. A parathyroidectomy with right thyroid lobectomy was done. Histopathological examination of the resected parathyroid gland showed a diagnosis of parathyroid adenoma. A high index of suspicion is needed to diagnose this unusual presentation of parathyroid adenoma. Radiological imaging is an important tool for early diagnosis.
RESUMO
In an analysis of lymphocyte functions of systemic lupus erythematosus (SLE) patients, B cell abnormalities such as a lack of mitogen-responsive B cells and a predominance of spontaneous IgA-secreting cells (SC) were found. Lymphocyte functions of 20 SLE patients were studied. Impaired proliferative response to B cell mitogen, Staphylococcus aureus strain Cowan I (Cowan I), was observed, whereas the response to T cell mitogen phytohemagglutinin was normal. High levels of spontaneous IgA-SC were observed in SLE patients (greater than 10(2) cells/10(4) peripheral blood mononuclear cells [PBMC]), whereas spontaneous IgM-, IgG-, or IgE-SC were not proportionately increased. The number of spontaneous IgA-SC decreased with time in culture and became undetectable by day 5 of culture. In contrast, spontaneous immunoglobulin- (IgM, IgG, and IgA) SC were not observed in healthy volunteers (less than 10 cells/10(4) PBMC). Moreover, in SLE patients failure of induction of immunoglobulin-secreting cells (ISC) was observed when B cells were stimulated by Cowan I and B cell differentiation factor at any day tested, whereas ISC were induced in healthy volunteers on day 6 of culture. Depletion of T cells or macrophages did not affect the results obtained. These results suggest that the abnormalities observed in SLE B cells are not due to the in vitro direct effects of suppressor macrophages or suppressor T cells, and that the condition of the predominance of spontaneous IgA-SC and the unresponsiveness to exogenous stimulation may be emblematic of hyperactive B cells in SLE.
Assuntos
Células Produtoras de Anticorpos/imunologia , Linfócitos B/imunologia , Imunoglobulina A Secretora/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Antígenos de Diferenciação de Linfócitos B , Antígenos de Superfície/imunologia , Diferenciação Celular , Humanos , Ativação Linfocitária , Fito-Hemaglutininas/imunologia , Staphylococcus aureus/imunologiaRESUMO
Expressions and functional roles of novel IL-2 binding molecules (p70, 75) in the differentiation of B cells into Ig secreting cells were explored by using human several B cell lines and tonsillar B cells. Affinity-crosslinking studies revealed that five of nine B cell lines expressed p70 and p75 without detectable Tac antigen (p55) expression and the expression was associated with B cell maturation. In tonsillar B cells, small high-density B cells did not express p70 and p75, whereas large low-density B cells, which were thought to be activated in vivo, expressed them. Binding assays of radiolabeled IL-2 showed that the affinity of these molecules was intermediate (kD = 1-3 nM, 700-3,000 sites/cell). Furthermore, high concentrations of IL-2 (greater than 100 U/ml) induced Ig productions in large B cells and two of five cell lines. These results taken together suggest that B cells may express novel IL-2 binding molecules, associated with B cell differentiation and differentiate into Ig secreting cells by IL-2 through novel IL-2 binding molecules.
Assuntos
Linfócitos B/metabolismo , Interleucina-2/metabolismo , Receptores Imunológicos/isolamento & purificação , Antígenos de Superfície/biossíntese , Linfócitos B/citologia , Linfócitos B/imunologia , Diferenciação Celular , Linhagem Celular , Relação Dose-Resposta Imunológica , Humanos , Imunoglobulinas/biossíntese , Interleucina-2/fisiologia , Cinética , Ativação Linfocitária , Peso Molecular , Receptores Imunológicos/fisiologia , Receptores de Interleucina-2 , Membro 7 da Superfamília de Receptores de Fatores de Necrose TumoralRESUMO
The ligand for CD40 (CD40L) is a membrane protein on activated T cells that induces B cell proliferation and differentiation. Several mutations of the CD40L gene were reported responsible for defective class switching of B cells in an X-linked immunodeficiency with hyper IgM (X-HIM). We studied four affected males from three families and found three independent mutations including new mutations of CD40L gene. In every X-HIM patient tested, however, anti-CD40 plus IL-10 did not induce class switching from IgM to IgG or IgA, even in the presence of Staphylococcus aureus Cowan I strain (SAC). CD4+ T cell clones, expressing CD40L on their surface, also did not rescue IgG or IgA induction by X-HIM peripheral blood B cells in vitro. But signaling through CD40 induced both B cell proliferation and IgE secretion when IL-4 was added to the culture. Taken together, these results show that in vitro signaling through CD40 rescues IgE but not IgG or IgA secretion by peripheral blood X-HIM B cells and suggest that in vivo CD40 and CD40L interaction might be necessary for IgG and IgA differentiation in X-HIM.
Assuntos
Antígenos CD/fisiologia , Antígenos de Diferenciação de Linfócitos B/fisiologia , Imunoglobulina M/biossíntese , Imunoglobulinas/biossíntese , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/imunologia , Cromossomo X , Sequência de Aminoácidos , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Sequência de Bases , Linfócitos T CD4-Positivos/imunologia , Antígenos CD40 , Células Cultivadas , Criança , Pré-Escolar , Feminino , Humanos , Imunoglobulina A/biossíntese , Imunoglobulina E/biossíntese , Imunoglobulina G/biossíntese , Imunoglobulina M/genética , Interleucina-1/farmacologia , Interleucina-4/farmacologia , Ativação Linfocitária , Masculino , Dados de Sequência Molecular , Proteínas Recombinantes/farmacologia , Valores de Referência , Transdução de Sinais , Linfócitos T/imunologiaRESUMO
The age-associated changes of the expression of IL-2 binding molecules p55/Tac(alpha chain) and p70/75(beta chain) were examined after phytohemagglutinin (PHA) stimulation. The expressions of both p55/Tac molecules and p70/75 molecules were significantly reduced in the aged compared with those in the young persons. The amounts of p55/Tac and p70/75 molecules on T cells from the aged were 55% and 59% of those on young ones, respectively. The ratio of the amount of p70/75 to that of p55/Tac in aged T cells was 0.28 and that in young ones was 0.26. The ratio was somewhat higher in the aged but not significantly. We also examined the kinetics of IL-2 internalization mediated by its receptor. The calculated t1/2 of receptor-mediated IL-2 internalization was 17 min in the aged and 16 min in the young, respectively. There was no kinetic difference between the 2 groups. The percentage of the internalized IL-2 to the sum total was 58.2% in the aged and 73.4% in the young (P less than 0.02). the amount of internalized IL-2 in T cells from the aged was 48.6% of that from the young (P less than 0.01).
Assuntos
Envelhecimento/metabolismo , Interleucina-2/metabolismo , Receptores de Interleucina-2/metabolismo , Linfócitos T/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletroforese em Gel de Poliacrilamida , Humanos , Técnicas In Vitro , Cinética , Ativação Linfocitária , Fragmentos de Peptídeos/metabolismo , Fito-Hemaglutininas/farmacologiaRESUMO
Proliferative response of T cells from aged persons was significantly reduced to a specific antigen tuberculin-active peptide (TAP) determined by [3H]TdR uptake and FCM in comparison to that from the young. Cytokinetic analysis for the proliferative response to TAP showed that, in the aged, the clonal size or the number of the first generation responding cells to TAP was not significantly reduced but the ability to repeat replication was more profoundly affected. Neither the delayed entry into the cell replication nor prolongation of the cell cycle time could explain these results. Similar results have been reported on the proliferative response of T cells to mitogen: PHA (Phytohemagglutinin). Expression of Tac-antigen on T cells determined by anti-Tac antibody binding with FACS after stimulation with either TAP or PHA was found to be reduced significantly in the aged. Both the numbers of high and low affinity IL-2 receptors determined by radiolabelled IL-2 binding assay were also reduced in the aged, but the degree of reduction in number of high affinity ones was more pronounced than that in low affinity ones. Tac-positive T cells were isolated with the use of anti-Tac rosette methods and stimulated with recombinant IL-2 (r-IL-2). Their proliferative response was significantly lower in the aged than that in the young at any concentration of r-IL-2 examined. The number of the first generation responding cells to r-IL-2 in purified Tac-positive T cells from the aged was 82% of that from the young whereas the proliferative response by aged T cells was 39% of that by young ones when the cells were allowed to repeat replication for 3 days. The mechanisms of these multifactorial defects in proliferation of T cells from aged persons were discussed.
Assuntos
Envelhecimento/imunologia , Proteínas de Bactérias , Interleucina-2/biossíntese , Receptores Imunológicos/análise , Linfócitos T/imunologia , Adulto , Idoso , Feminino , Citometria de Fluxo , Humanos , Interleucina-1/farmacologia , Ativação Linfocitária , Masculino , Peptídeos/imunologia , Fito-Hemaglutininas/farmacologia , Receptores de Interleucina-2 , Formação de Roseta , Tuberculina/imunologiaRESUMO
The abilities of highly purified B cells to repeat replication for clonal expansion and to differentiate into immunoglobulin secreting cells (ISC) were examined in the aged and young groups. B cells from the aged showed twofold less proliferative response to B cell mitogen Cowan 1 (SAC) than those from the young. The original clone size of SAC responding B cells determined by colchicine block and [3H] thymidine [( 3H] TdR) uptake was not significantly reduced in the aged whereas the ability to repeat replication to expand clonal size was significantly reduced. B cells from aged and young persons were induced into ISC by combined stimulation with SAC and partially purified B cell differentiation factor (BCDF) free of IL-2 activity. ISCs for IgG and IgA were rather increased or at least not reduced in number in the aged as compared with those in the young. We also determined the IL-2 and BCDF activity produced by T cells from aged and young persons. Upon PHA stimulation, the aged T cells produced tenfold less IL-2 activity and threefold higher BCDF activity than did young T cells. Approximately threefold increase in spontaneous secretion of BCDF activity by aged T cells was found as compared with young T cells. The inverse correlation between the IL-2 activity and BCDF activity was found when both activities were determined in the same samples.
Assuntos
Envelhecimento/imunologia , Linfócitos B/imunologia , Substâncias de Crescimento/biossíntese , Interleucina-2/biossíntese , Ativação Linfocitária , Linfocinas/biossíntese , Linfócitos T/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Diferenciação Celular , Células Cultivadas , Feminino , Humanos , Imunoglobulina G/metabolismo , Interleucina-4 , Masculino , Mitógenos/farmacologiaRESUMO
The proportion of CD8 positive cells in the peripheral blood AET-rosette forming T cells from aged persons was significantly reduced than that from young persons. The difference in the proportion between aged and young groups became more significant after proliferative response to a mitogen phytohemagglutinin (PHA) or a specific antigen tuberculin active peptide (TAP). The purified macrophage-deprived T cells (Twp), CD4 (T4) positive cells or CD8 positive cells were prepared from aged or young persons. These cell preparations lost proliferative response to PHA or TAP but showed marked proliferative response to the combined stimulation to 1 microM of ionomycin and 1 nM of phorbol-12-myristate-13-acetate (PMA) at usual culture cell density (2.5 X 10(5)/ml). Proliferative responses of these cell preparations to the combined stimulation were significantly reduced in the aged than those in the young and the magnitude of the difference in the proliferative responses between aged and young groups was more pronounced in CD8 positive cell population than in CD4 positive cell population. Although the cell preparations were relatively independent of exogenous IL-2 for the proliferative response to the combined stimulation of ionomycin and PMA at usual culture cell density, they needed exogenous IL-2 for sustained proliferation at lower culture cell density (5 X 10(3)/ml). These IL-2-dependent proliferative responses to the combined stimulation in the aged were significantly lower than those in the young and again the difference in the proliferative magnitude between aged and young groups was greater in CD8 positive population. The mechanism(s) of age-related change of the proportion and proliferative ability of T subsets were discussed.
Assuntos
Envelhecimento/imunologia , Proteínas de Bactérias , Ativação Linfocitária , Linfócitos T/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Éteres/farmacologia , Feminino , Humanos , Técnicas In Vitro , Interleucina-2/imunologia , Ionomicina , Masculino , Peptídeos/farmacologia , Fito-Hemaglutininas/farmacologia , Mitógenos de Phytolacca americana/farmacologia , Linfócitos T/classificação , Tuberculina/farmacologiaRESUMO
Synergistic effects of B-cell mitogen Staphylococcus bacteria strain Cowan I (Cowan I) plus T-cell activator pokeweed mitogen (PWM) in generating immunoglobulin-secreting cells (ISC) from human peripheral blood mononuclear cells (MNC) were investigated. ISC were assayed by reverse plaque-forming cells uing protein A-coated red blood cells. Low concentrations of PWM plus Cowan I gave superadditive effects on ISI induction, generating 3-20 times as many ISC as optimal amounts of either mitogen alone. The mitogens together and separately showed similar kinetics of ISC; synergy was observed at every day tested. IgM ISC represented 10% of initial MNC from all cell donors tested even if the donors were low responders to either mitogen alone. The numbers of ISC obtained are higher than previous reports and more uniform among donors, making this a superlative method for studies on normal human immunoglobulin secretion.
Assuntos
Linfócitos B , Imunoglobulina M/biossíntese , Mitógenos/farmacologia , Linfócitos T , Células Produtoras de Anticorpos/citologia , Diferenciação Celular , Humanos , Cinética , Mitógenos de Phytolacca americana/farmacologia , Staphylococcus/imunologiaRESUMO
Human B-cell lines were screened for stimulation of immunoglobulin production by incubation with lymphokine (LK) or tumor promoter, phorbol myristic acetate (PMA). One group of lines had essentially no immunoglobulin-secreting cells (ISC) under any condition (less than 0.01%), detected by a reverse plaque assay. Another group of lines had high levels of ISC (greater than 5%) which was not increased substantially by inducing agents. In a third group of IgM and IgG lines, there were intermediate levels of ISC which could be increased by LK, PMA or both agents. No evidence for isotype switching in a number of stimulated IgM and IgG cell lines was detected. Clone SKW6.4 of an IgM line was highly responsive to a B-cell-inducing factor (BIF) in LK. BIF for SKW6.4 and IgG line ARH-77 was weakly binding to DEAE cellulose, about 20,000 mol. wt., and separable from IL-2 by blue agarose chromatography. IL-2 did not stimulate secretion in SKW6.4 with or without purified BIF. In Clone SKW6.4, BIF stimulated ISC per recovered cell up to 30-fold by day 1 of culture, and these plateau levels of about 6% ISC were maintained for longer than 4 days. Treatment of cells with BIF for less than 1 day was sufficient to produce maximum effect on this clone for the succeeding 4 days. Cells stimulated with BIF and then subcultured at day 3 without BIF showed ISC numbers increasing but at a slower rate than the total population, suggesting that the induced differentiation state is long-lived (half-life of % ISC greater than 6 days) and that ISC produce some daughter ISC.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Linfócitos B/imunologia , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Linfócitos B/efeitos dos fármacos , Linhagem Celular , Substâncias de Crescimento/farmacologia , Humanos , Interleucina-4 , Linfocinas/farmacologia , Acetato de Tetradecanoilforbol/farmacologia , Fatores de TempoRESUMO
A 24-year-old woman had suffered from recurrent bacterial infections and clinical manifestations of systemic lupus erythematosus (SLE). Laboratory findings disclosed an elevated level of serum IgM, markedly decreased IgG, IgA, IgD and IgE levels, and low levels of serum complement. Both the CD40 and CD40 ligands appeared to be normally expressed. Assays of in vitro immunoglobulin production by lymphocytes showed that IgM was produced normally and that IgE but not IgG or IgA production was rescued by signaling through CD40 on B cells. The proliferative response of lymphocytes to phobol ester was markedly decreased, suggesting some impairment of signal transduction in the patient's lymphocytes.
Assuntos
Ligação Genética , Hipergamaglobulinemia/genética , Imunoglobulina M/sangue , Síndromes de Imunodeficiência/genética , Lúpus Eritematoso Sistêmico/genética , Adulto , Antígenos CD40/análise , Ligante de CD40 , Carcinógenos/farmacologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/imunologia , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Linfócitos/química , Linfócitos/citologia , Linfócitos/efeitos dos fármacos , Glicoproteínas de Membrana/análise , Ésteres de Forbol/farmacologia , Cromossomo XRESUMO
Evidence of an acquired T cell-specific deficiency distinct from acquired immunodeficiency syndrome (AIDS) in a 63-yr-old Japanese female is provided. Recently, this patients suffered from primary invasive pulmonary aspergillosis. Skin tests to purified protein derivative of tuberculin (PPD) and Aspergillus antigens were negative. Upon admission to our hospital, her lymphocytes were exclusively unresponsive to T cell mitogens (concanavalin A, phytohemagglutinin, and OKT 3). The level of cells defined by monoclonal antibodies (CD1, CD2, CD3, CD4, WT31, and CD5) was less than 3%. In contrast, no decrease in the number of red blood cells, platelets, neutrophils or B cells was apparent. Five years ago, the patient had a normal white blood cell and lymphocyte count. However, over the following 4 yr, she developed lymphopenia. With medication, her pulmonary disease recovered, while lymphopenia still continued. The levels of immunoglobulins, complements and enzyme activities (adenosine deaminase and purine nucleoside phosphorylase) were normal. Moreover, several tests for HIV (ELISA and Western bolt) were negative suggesting that the T cell-specific deficiency was not a congenital immunodeficiency or AIDS but rather a new type of acquired immunodeficiency.
Assuntos
Síndromes de Imunodeficiência/etiologia , Linfócitos T/imunologia , Síndrome da Imunodeficiência Adquirida/imunologia , Aspergilose/complicações , Feminino , Citometria de Fluxo , Humanos , Síndromes de Imunodeficiência/complicações , Síndromes de Imunodeficiência/imunologia , Técnicas In Vitro , Contagem de Leucócitos , Pneumopatias Fúngicas/complicações , Ativação Linfocitária , Linfopenia/etiologia , Linfopenia/imunologia , Pessoa de Meia-Idade , Infecções Oportunistas/complicaçõesAssuntos
Síndromes de Imunodeficiência/etiologia , Adolescente , Adulto , Linfócitos B/imunologia , Criança , Substâncias de Crescimento/biossíntese , Humanos , Interleucina-2/biossíntese , Interleucina-4 , Ativação Linfocitária , Linfocinas/biossíntese , Pessoa de Meia-Idade , Linfócitos T/imunologia , Linfócitos T Reguladores/imunologia , gama-Globulinas/análiseRESUMO
Synergistic effects of B cell mitogen Staphylococcus bacteria strain Cowan I (Cowan I) plus T cell mitogens in generating immunoglobulin-secreting cells (ISC) from human peripheral blood mononuclear cells (MNC) were investigated. ISC were assayed by reverse plaque-forming cells with protein A-coated red blood cells. Low concentrations of pokeweed mitogen (PWM) plus Cowan I gave superadditive effects on ISC induction, generating 3 to 10 times as many ISC as optimal amounts of either mitogen alone. The mitogens together and separately showed similar kinetics of ISC; synergy was observed at every day tested. Plaque-forming cells of IgM, IgG, and IgA classes all showed strong synergy, together routinely representing 20% of initial MNC. At day 7 of culture, over 80% of non-E-rosetting cells were ISC. Cell donors tested gave these strong responses even if they were low responders to either mitogen alone. Cowan I plus other T cell mitogens, PHA, Con A, and protein A, also provided good signals for B cell activation. Cowan I induced marked proliferation of purified B cells, but T cell-helper signals were required for differentiation to ISC. T cell-helper factor, induced by PWM or PHA, also showed synergistic effects with Cowan I in induction of ISC. Purified B cells did not respond to T cell-helper factor(s) alone to proliferate or differentiate to ISC. These results indicate that optimal ISC induction occurs with a B cell mitogen plus T cell signals acting synergistically.
Assuntos
Linfócitos B/imunologia , Imunoglobulinas/biossíntese , Mitógenos/farmacologia , Linfócitos T/imunologia , Células Produtoras de Anticorpos/imunologia , Sinergismo Farmacológico , Humanos , Imunoglobulina A/biossíntese , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Cinética , Mitógenos de Phytolacca americana/farmacologia , Solubilidade , Staphylococcus/imunologiaRESUMO
Human peripheral blood mononuclear cells were depleted of surface IgM+ or IgD+ cells and assayed for mitogen-induced differentiation to immunoglobulin-secreting cells (ISC) of IgM, IgG and IgA classes. Stimulatory agents included T cell-dependent pokeweed mitogen, B cell mitogen Staphylococcus aureus bacteria strain Cowan I, and a combination of the two which gives uniform, high levels of ISC from all normal donors. Depletion of either IgM- or IgD-bearing B lymphocytes resulted in loss of cells bearing the other Ig class and blocked most of the mitogenic reactivity to anti-IgM and anti-IgD. Proliferative responses to Cowan I in these depleted populations were about 20% that of unfractionated mononuclear cells. Depletion of T cells increased the mitogenic response to Cowan I and to the two antibody preparations, showing that they are T-independent mitogens. Depletion of IgD+ cells caused partial loss of mitogen-induced IgM ISC (22%-60% of unseparated controls) but no loss of IgG or IgA ISC. Depletion of IgM-bearing cells caused complete loss of IgM ISC, but no loss of IgG or IgA ISC. We previously demonstrated that anti-IgM ISC, but no loss of IgG or IgA ISC. We previously demonstrated that anti-IgM antibody blocked mitogen induction of Ig secretion of these three classes in spleen cells, but only IgM secretion in blood mononuclear cells. Together, the results suggest that the majority of cells in normal blood responding to mitogens to mature to IgG or IgA production belong to IgM-, IgD- B cell subjects, in contrast to precursors of secreting cells for these isotypes in the spleen. Thus, these blood precursors appear to be more mature than the corresponding spleen cells.
Assuntos
Células Produtoras de Anticorpos/citologia , Imunoglobulinas/biossíntese , Ativação Linfocitária , Linfócitos/imunologia , Anticorpos Anti-Idiotípicos/imunologia , Células Produtoras de Anticorpos/imunologia , Linfócitos B/classificação , Linfócitos B/citologia , Linfócitos B/imunologia , Separação Celular , Humanos , Imunoglobulina A/biossíntese , Imunoglobulina D/biossíntese , Imunoglobulina D/imunologia , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Imunoglobulina M/imunologia , Linfócitos/classificação , Linfócitos/citologia , Receptores de Antígenos de Linfócitos B/classificação , Receptores de Antígenos de Linfócitos B/imunologia , Proteína Estafilocócica A/farmacologiaRESUMO
Phytohemagglutinin (PHA) stimulated T cells from patients with systemic lupus erythematosus (SLE) showed hyporesponsiveness to interleukin 2 (IL-2) and expressed less p70/75 IL-2R than healthy controls. Ionomycine (IM, calcium ionophore) which selectively upregulated p70/75 expression, induced less p70/75 in patients with SLE than in healthy controls. However, intracellular calcium levels of T cells from patients with SLE increased as much as those from healthy controls, when T cells were stimulated by IM or PHA. Our results suggest that an impaired expression of p70/75 IL-2R in T cells from patients with SLE is not due to a defective calcium influx but to the events after the rise of calcium levels.
Assuntos
Cálcio/metabolismo , Membranas Intracelulares/metabolismo , Lúpus Eritematoso Sistêmico/metabolismo , Receptores de Interleucina-2/metabolismo , Linfócitos T/metabolismo , Adulto , Divisão Celular/efeitos dos fármacos , Feminino , Humanos , Interleucina-2/farmacologia , Ionomicina/farmacologia , Lúpus Eritematoso Sistêmico/patologia , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Fito-Hemaglutininas/farmacologia , Linfócitos T/patologiaRESUMO
There are two interleukin-2 receptor (IL-2R) subunits (p55 and p70/75) on human lymphocytes. Induction of the expressions of these IL-2R subunits was examined by the protein kinase-C (PK-C) activator (phorbol myristate acetate, PMA) and the calcium ionophore, ionomycine (IM). IM induced predominantly p70/75 expression on human T and B cells as indicated by the results of chemical crosslinking studies and binding assays. In contrast, PMA induced p55 expression significantly. These results suggest that the calcium-calmodulin and PK-C pathways regulate p70/75 and p55 expressions differently, and indicate that these intracellular signal messengers could control the responsiveness to IL-2, changing the affinity and number of receptors in vivo.
Assuntos
Linfócitos B/imunologia , Receptores de Interleucina-2/biossíntese , Linfócitos T/imunologia , Linfócitos B/efeitos dos fármacos , Linhagem Celular , Células Cultivadas , Humanos , Ionomicina/farmacologia , Cinética , Substâncias Macromoleculares , Peso Molecular , Tonsila Palatina/imunologia , Receptores de Interleucina-2/isolamento & purificação , Receptores de Interleucina-2/metabolismo , Linfócitos T/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
Persistent diabetes mellitus with marked hyperglycemia was induced in mice by the administration of streptozotocin. In these streptozotocin-induced diabetic mice, resistance to tubercle bacillus challenge and primary as well as secondardy humoral immune responses against foreign erythrocytes were markedly depressed. The T-cell function in delayed hypersensitivity to 2,4-dinitro-1-fluorobenzene and bacterial phagocytic activity or peritoneal macrophages were markedly depressed. In contrast, the B-cell function in antibody production against T-independent antigen and the intracellular killing of bacteria in peritoneal macrophages were intact. We concluded that depression of the T-cell function or the phagocytic activity of macrophages or both may be the main immunological defect in these mice.
Assuntos
Formação de Anticorpos , Diabetes Mellitus Experimental/imunologia , Fagocitose , Linfócitos T/imunologia , Animais , Linfócitos B/imunologia , Eritrócitos/imunologia , Teste de Tolerância a Glucose , Hipersensibilidade Tardia , Memória Imunológica , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Tuberculose/imunologiaRESUMO
Expression of p70/75 IL-2-binding molecules and their functional roles in induction of Ig secretion by IL-2 were examined in human B cells. IL-2, at high concentrations induced higher levels of Ig secretion in Staphylococcus aureus strain Cowan I (SAC)-activated B cells than at low concentrations. About 50% of SAC-activated B cells, lacking Tac antigen, were also responsive to Ig secretion by IL-2, although the required dose of IL-2 was higher than that for Tac-positive B cells. H-31 antibody which recognizes Tac antigen did not inhibit the induction of Ig secretion by high concentrations of IL-2 in both Tac-negative and Tac-positive B cells, suggesting that IL-2 might induce Ig secretion through a receptor distinct from Tac antigens. In contrast, IL-2 was ineffective in the absence of SAC stimulation even at high concentrations. Upon analysis by SDS-PAGE, p70/75 IL-2-binding molecules were detected on Tac-negative SAC-activated B cells. Similar IL-2-binding molecules distinct from Tac antigen (p55) were detected in both Tac-positive B and T cells. However, neither p55 nor p70/75 IL-2-binding molecules could be detected in the absence of SAC stimulation. These observations suggest that p70/75 IL-2 binding molecules are induced in human B-cells in the presence or absence of Tac antigen by SAC stimulation and these determinants play an important function in the transduction of IL-2 associated signal for B cell differentiation.