Development of a novel antibody to calcitonin gene-related peptide for the treatment of osteoarthritis-related pain.

OBJECTIVE: Investigate a role for calcitonin gene-related peptide (CGRP) in osteoarthritis (OA)-related pain. DESIGN: Neutralizing antibodies to CGRP were generated de novo. One of these antibodies, LY2951742, was characterized in vitro and tested in pre-clinical in vivo models of OA pain. RESULTS: LY2951742 exhibited high affinity to both human and rat CGRP (KD of 31 and 246 pM, respectively). The antibody neutralized CGRP-mediated induction of cAMP in SK-N-MC cells in vitro and capsaicin-induced dermal blood flow in the rat. Neutralization of CGRP significantly reduced pain behavior as measured by weight bearing differential in the rat monoiodoacetate model of OA pain in a dose-dependent manner. Moreover, pain reduction with neutralization of CGRP occurred independently of prostaglandins, since LY2951742 and NSAIDs worked additively in the NSAID-responsive version of the model and CGRP neutralization remained effective in the NSAID non-responsive version of the model. Neutralization of CGRP also provided dose-dependent and prolonged (>60 days) pain reduction in the rat meniscal tear model of OA after only a single injection of LY2951742. CONCLUSIONS: LY2951742 is a high affinity, neutralizing antibody to CGRP. Neutralization of CGRP is efficacious in several OA pain models and works independently of NSAID mechanisms of action. LY2951742 holds promise for the treatment of pain in OA patients.

Distinct signal thresholds for the unique antigen receptor-linked gene expression programs in mature and immature B cells.

Although it is well established that immature B lymphocytes are exquisitely sensitive to tolerance induction compared with their mature counterparts, the molecular basis for this difference is unknown. We demonstrate that signaling by B cell antigen receptors leads to distinct and mutually exclusive biologic responses in mature and immature B cells: upregulation of CD86, CD69, and MHC class II in mature cells and receptor editing in immature cells. These responses can be induced simply by elevation of intracellular free calcium levels, as occurs after receptor aggregation. Importantly, induction of immature B cell responses requires much smaller increases in intracellular free calcium than does induction of mature B cell responses. These differences in biologic response and sensitivity to intracellular free calcium likely contributes to selective elimination at the immature stage of even those B cells that express low affinity for self-antigens.

Differential regulation of B cell development, activation, and death by the src homology 2 domain-containing 5' inositol phosphatase (SHIP).

Although the Src homology 2 domain-containing 5' inositol phosphatase (SHIP) is a well-known mediator of inhibitory signals after B cell antigen receptor (BCR) coaggregation with the low affinity Fc receptor, it is not known whether SHIP functions to inhibit signals after stimulation through the BCR alone. Here, we show using gene-ablated mice that SHIP is a crucial regulator of BCR-mediated signaling, B cell activation, and B cell development. We demonstrate a critical role for SHIP in termination of phosphatidylinositol 3,4,5-triphosphate (PI[3,4,5]P(3)) signals that follow BCR aggregation. Consistent with enhanced PI(3,4,5)P(3) signaling, we find that splenic B cells from SHIP-deficient mice display enhanced sensitivity to BCR-mediated induction of the activation markers CD86 and CD69. We further demonstrate that SHIP regulates the rate of B cell development in the bone marrow and spleen, as B cell precursors from SHIP-deficient mice progress more rapidly through the immature and transitional developmental stages. Finally, we observe that SHIP-deficient B cells have increased resistance to BCR-mediated cell death. These results demonstrate a central role for SHIP in regulation of BCR signaling and B cell biology, from signal driven development in the bone marrow and spleen, to activation and death in the periphery.

B cell development: signal transduction by antigen receptors and their surrogates.

Constitutive signal transduction by B cell antigen-receptors and/or their surrogates appears to be critical for progression through multiple developmental checkpoints and for survival of mature B cells in the periphery. Antigen-induced signaling via the B cell receptor can compensate for defects in constitutive signaling and initiates receptor editing, apoptosis and anergy in normal mice - purging the repertoire of autoreactive cells. Thus development and survival of mature B cells seem to require continuous receptor signaling of a defined amplitude.

Expression and in-vivo modulation of alpha- and beta-adrenoceptors on human natural killer (CD16+) cells.

Expression and in-vivo modulation of beta- and alpha-adrenoceptors on peripheral human natural killer (CD16+) cells was investigated. Ligand binding studies revealed that CD16+ lymphocytes express beta2, alpha1-, alpha2- but not beta1-adrenoceptors. Infusion of adrenaline, but not noradrenaline, significantly decreased beta2- and alpha1-adrenoceptor numbers on NK cells. Both catecholamines did not appreciably alter alpha2-adrenoceptor numbers. Additional analyses showed that adrenaline administration increases alpha2-adrenoceptor numbers on peripheral mononuclear blood cells (PBMC) and T-cell subsets (CD4+, CD8+) in contrast to decreased receptor numbers on CD16+ cells. These data demonstrate a specific effect of increasing levels of circulating catecholamines on beta2-adrenoceptors on NK cells.

The effects of beta-adrenoceptor stimulation on adhesion of human natural killer cells to cultured endothelium.

1. The circulation of natural killer (NK) cells in vivo is influenced by physical exercise, mental stress, and infusion of beta-adrenoceptor agonists. We have previously presented in vitro data, showing that beta 2-adrenoceptor agonists induce detachment of NK cells from endothelial cells (EC), supporting the hypothesis that NK cells can be recruited from the marginating pool in blood vessels. 2. Because NK cells as well as EC express beta 2-adrenoceptors, the present study was conducted to investigate whether stimulation of the beta-adrenoceptors on NK cells, EC or both cell types is required to induce detachment from EC. 3. Cells were pretreated (15 min) with a selective beta 2-adrenoceptor antagonist, GR81706, at various concentrations. The duration of beta-adrenoceptor blockade was tested by determining the adenosine 3',5'-cyclic monophosphate (cyclic AMP) production induced by terbutaline (a beta 2-adrenoceptor specific agonist). This receptor-mediated response was effectively inhibited for at least 4 h, whereas the cyclic AMP production in response to forskolin (a direct activator of adenylate-cyclase) was not affected. 4. Functional adhesion assays were then performed to determine the role of beta-adrenoceptors on the different cell types involved (NK and EC) in catecholamine-induced detachment. Peripheral blood mononuclear cells were allowed to adhere for 1 h to monolayers of unstimulated EC in the presence or absence of cyclic AMP inducing agents, and the percentage of NK cells in the adhering lymphocyte fraction was determined by flow cytometry. 5. Both adrenaline (10(-5) M) and forskolin (10(-5) M) caused detachment of NK cells from EC. After blockade of the P2-adrenoceptors on NK cells by pretreatment with GR81706 (10-6 M), the effect of adrenaline on NK cells adhesion was pretented; after blockade of the beta2-adrenoceptors on EC, NK cell adhesion was still significantly reduced by adrenaline. In all cases, forskolin caused detachment of NKcells.6. To establish further that stimulation of beta-adrenoceptors on NK cells is sufficient to cause detachment,we showed that adrenaline also reduced adhesion of NK cells to monolayers of Chinese hamster ovary cells, which do not express beta-adrenoceptors.7. Together, these results show that stimulation of beta2-adrenoceptors on NK cells negatively influences their capacity to adhere to EC, and that beta2-adrenoceptors on EC play a negligible role in this phenomenon.

Immunologic, endocrine and psychological influences on cortisol-induced immunoglobulin synthesis in vitro.

In the present study, the relationship between psychological variables and hydrocortisone (HC)-induced immunoglobulin (Ig) production in vitro was investigated. Ninety-five human volunteers were selected based on their extreme (low or high) scores on a daily hassles and a symptoms questionnaire. Four groups were composed: (1) few hassles, few symptoms; (2) many hassles, few symptoms; (3) few hassles, many symptoms; and (4) many hassles, many symptoms. Incubating peripheral blood mononuclear cells (PBMC) for 2 weeks with HC (concentrations ranging from 10(-8) to 10(-6) M), resulted in a concentration-dependent rise in IgM and IgG secretion. In vitro IgM as well as IgG secretion were found to be related to plasma Ig levels. Plasma cortisol levels were positively associated with HC-induced IgG secretion. Furthermore, Ig secretion was found to depend on psychological profile, indicating a differential sensitivity of PBMC to HC for the four groups.

Psychobiological factors related to human natural killer cell activity and hormonal modulation of NK cells in vitro.

The present report investigated whether percentages of circulating natural killer (NK) cells and NK cell activity (NKCA) are associated with psychological variables. Subjects (n = 95) were selected, based on a combination of low or high scores on questionnaires on daily hassles and self-reported symptoms, to create four extreme groups. NK cell percentages were different between two of the four groups, only when the analysis was not controlled for gender, life style and endocrine parameters. No evidence was found for a relationship between group membership and NKCA. NKCA, however, was found to differ between men and women and to be associated with percentages of NK cells and intracellular levels of cAMP. Furthermore, the hypothesis was tested, that hormone-induced changes in NKCA in vitro are dependent on the individual's current stress profile. To investigate this issue, NKCA was measured after cells had been incubated with hydrocortisone (10(-6) or 10(-7) M) or the beta-adrenergic agonist isoprenaline (10(-5) or 10(-7) M) in vitro. Changes in NKCA were found to be related to plasma adrenaline levels, but no evidence was found for involvement of psychological variables. It is concluded that, in the current setting, there is no association between the combination of scores on the two psychological questionnaires, and NKCA or hormone-induced changes therein.

Catecholamine-induced leukocytosis: early observations, current research, and future directions.

Recent studies demonstrate that acute psychological stress in man affects lymphocyte circulation. It has been suggested that catecholamines are responsible for these changes. The present review summarizes findings regarding catecholamine-induced lympho- and leukocytosis, starting with observations dating back to the beginning of this century. Particular attention is given to the mechanisms of this phenomenon and the potential site of origin of newly appearing leukocytes. Characteristically, two phases are recognized after catecholamine administration: a quick (<30 min) mobilization of lymphocytes, followed by an increase in granulocyte numbers with decreasing lymphocyte numbers. Many studies have shown that catecholamines predominantly affect natural killer (NK) cell and granulocyte circulation, whereas T- and B-cell numbers remain relatively unaffected. The changes in lymphocyte circulation seem to be mainly mediated via activation of beta2-adrenoceptors, whereas granulocyte increases involve alpha-adrenoceptor stimulation. Results further indicate that the marginal pool and the spleen are the major sources for freshly recruited lymphocytes, whereas granulocytes are predominantly released from the marginal pool and the lung. Results from acute psychological stress or physical exercise models corroborate the results obtained with catecholamine administration. Together, the data demonstrate that components of the innate immune system participate in the classical fight/flight response.

Beta 2-adrenergic stimulation causes detachment of natural killer cells from cultured endothelium.

Physical exercise, mental stress, or infusion of beta-adrenergic agonists result in an increase in the number of natural killer (NK) cells in the peripheral circulation. In view of the specific migration pattern of NK cells in vivo, it has been suggested that these cells may be released from the marginating pool in blood vessels. In the present report, the in vitro effect of catecholamines on the adhesion of NK cells to unstimulated human endothelial cells (EC) was characterized. Peripheral blood mononuclear cells were allowed to adhere to monolayers of EC, after which the adherent lymphocyte fraction was analyzed phenotypically by flow cytometry. NK cells were found to adhere preferentially to EC, a process that was reversed by the addition of various adrenergic agonists. Catecholamines selectively affected adhesion of NK cells and had no effect on T cell adhesion to EC, as was determined by the use of purified cell populations. Detachment of NK cells from EC could be achieved by short incubations (5 min) with epinephrine (EPI) and was concentration-dependent, with an ED50 of 2 x 10(-10)M. Using a panel of alpha- and beta-adrenergic agonists and antagonists, we show that the detachment of NK cells is mediated via beta 2-adrenergic receptors. In line with the lower affinity for beta 2-adrenergic receptors, norepinephrine was less effective than EPI in inducing detachment of NK cells from EC. Direct activation of adenylate-cyclase with forskolin gave similar results as observed with EPI, indicating that signaling through cAMP is necessary to induce detachment of NK cells from EC. The results of the present study lend support to the hypothesis that catecholamines, via beta 2-adrenergic receptors, can induce recruitment of NK cells from the marginating pool to the circulating pool, by changing the adhesive interactions between NK cells and EC.

Adhesion of subsets of human blood mononuclear cells to endothelial cells in vitro, as quantified by flow cytometry.

Binding of leucocytes to endothelial cells (EC) is essential as an initial step in inflammatory responses. We present a rapid, non-radioactive method to measure adhesion of human lymphoid cells to EC using flow cytometry. Freshly isolated peripheral blood mononuclear cells (PBMC) were allowed to adhere to EC grown in 24-well plates. Non-adhering cells were removed, after which adhering cells and EC were dissociated using trypsin/EDTA. These samples were subsequently analysed by flow cytometry, using scatter properties to distinguish between adhering cells and EC. The ratio of the number of adhering leucocytes and EC was calculated to quantify adhesion. Results of the flow cytometric adhesion assay were comparable to those obtained with a conventional adhesion assay using chromium-labelled cells. We additionally show that by using the flow cytometric adhesion assay, adhesion of lymphocytes and monocytes present within the adhering PBMC can be quantified simultaneously. As a model, the contribution of LFA-1 (CD11a/CD18) and ICAM-1 (CD54) in adhesion of PBMC to EC was studied. It was found that adhesion of lymphocytes and monocytes is regulated differently by phorbol ester and that the relative contribution of LFA-1 and ICAM-1 differs for both cell types.

Developmental regulation of B lymphocyte immune tolerance compartmentalizes clonal selection from receptor selection.

B lymphocyte development is a highly ordered process that involves immunoglobulin gene rearrangements, antigen receptor expression, and a learning process that minimizes the development of cells with reactivity to self tissue. Two distinct mechanisms for immune tolerance have been defined that operate during early bone marrow stages of B cell development: apoptosis, which eliminates clones of cells, and receptor editing, which spares the cells but genetically reprograms their autoreactive antigen receptors through nested immunoglobulin L chain gene rearrangements. We show here that sensitivity to antigen-induced apoptosis arises relatively late in B cell development and is preceded by a functionally distinct developmental stage capable of receptor editing. This regulation compartmentalizes clonal selection from receptor selection.

Unique signaling properties of B cell antigen receptor in mature and immature B cells: implications for tolerance and activation.

Immature B cells display increased sensitivity to tolerance induction compared with their mature counterparts. The molecular mechanisms underlying these differences are poorly defined. In this study, we demonstrate unique maturation stage-dependent differences in B cell Ag receptor (BCR) signaling, including BCR-mediated calcium mobilization responses. Immature B cells display greater increases in intracellular calcium concentrations following Ag stimulation. This has consequences for the induction of biologically relevant responses: immature B cells require lower Ag concentrations for activation than mature B cells, as measured by induction of receptor editing and CD86 expression, respectively. BCR-induced tyrosine phosphorylation of CD79a, Lyn, B cell linker protein, and phospholipase Cgamma2 is enhanced in immature B cells and they exhibit greater capacitative calcium entry in response to Ag. Moreover, B cell linker protein, Bruton's tyrosine kinase, and phospholipase Cgamma2, which are crucial for the induction of calcium mobilization responses, are present at approximately 3-fold higher levels in immature B cells, potentially contributing to increased mobilization of calcium. Consistent with this possibility, we found that the previously reported lack of inositol-1,4,5-triphosphate production in immature B cells may be explained by enhanced inositol-1,4,5-triphosphate breakdown. These data demonstrate that multiple mechanisms guarantee increased Ag-induced mobilization of calcium in immature B cells and presumably ensure elimination of autoreactive B cells from the repertoire.

Adrenergic control of natural killer cell circulation and adhesion.

Natural killer (NK) cell circulation is subject to adrenergic regulation. Exactly how NK cells are released into the circulation is unknown. In an attempt to identify some of the mechanisms, the present report focuses on aspects of adhesion regulation of NK cells. Results demonstrate that interactions between NK and endothelial cells (EC) in vitro can be reduced by beta 2-adrenoceptor stimulation for as long as the receptor stimulation occurs. The level of soluble adhesion molecules (sICAM-1, sE-selectin, sVCAM-1) in vivo remained unchanged during adrenaline infusion. In vitro analyses further reveal the requirement for Ca2+/Mg2+ in NK-EC adhesion. Blocking studies indicate the involvement of several members of the beta 1(CD29)- and beta 2(CD18)-integrin family, reducing NK cell adhesion by 28 to 39%. Stimulation of beta 2-adrenoceptors in the presence of these blocking antibodies further reduced NK adhesion by an average of 22%. Analysis of NK cell adhesion to various extracellular matrix components demonstrates significant NK cell adhesion to fibronectin but much less to laminin or collagens I and IV. NK cell adhesion to fibronectin was reduced by 50% upon beta 2-adrenoceptor stimulation, independent of the VLA-4/VLA-5 binding site on fibronectin. Together these results contribute to understanding the influences of beta-adrenoceptor stimulation on NK cell circulation and adhesion.

Lymphocyte subsets and cellular immunity in patients with chronic pancreatitis.

BACKGROUND: An abnormal immune response may play a pathogenetic role in chronic pancreatitis. However, to date characterization of the systemic immunological changes in patients with chronic pancreatitis has not been undertaken. METHODS: Lymphocyte phenotypes and proliferation ((3)H-thymidine) after stimulation with mitogens and interleukin-2 were studied in peripheral mononuclear cells from 11 patients with chronic pancreatitis (alcohol-induced n = 6; idiopathic pancreatitis n = 5). The natural killer cell activity was investigated in a (51)Cr release cytotoxicity assay. In vitro cytokine release of stimulated mononuclear cells was measured. RESULTS: Flow cytometric studies showed a significant decrease in the percentage of circulating CD8+, CD56+ and CD25+ cells in patients with chronic pancreatitis independent of the etiology. Comparing all patients with chronic pancreatitis to controls, the proliferation rate was not significantly increased, but patients with pain (n = 5) showed increased proliferation in comparison to patients without pain (n = 6). No significant difference in natural killer cytotoxicity was observed. The in vitro release of tumor necrosis factor-alpha and interleukin-10 by stimulated mononuclear cells was increased. CONCLUSIONS: Chronic pancreatitis is accompanied by systemic immune dysregulation. The observed changes in peripheral mononuclear cells reveal additional evidence that the cell-mediated immune response may contribute to the development of pain and tissue destruction in chronic pancreatitis.

Effects of beta-adrenoceptor-blockade on stress-induced adrenocorticotrophin release in humans.

We investigated the mechanisms of stress-induced alterations in adrenocorticotrophin (ACTH) release. Tandem parachutists received either a placebo or the beta-adrenoceptor antagonist propranolol prior to a first time parachute jump. Blood samples were drawn 4 h before, immediately after, and 1 h after the jump. Cortisol and catecholamine concentrations displayed a significant stress-induced increase in both groups. The ACTH plasma concentrations significantly increased in the placebo and the propranolol group, with significantly more pronounced changes in the propranolol-treated subjects compared to the placebo group. These data demonstrated a stress-induced increase of ACTH plasma concentrations in humans that was enhanced by beta-blockade.

Experimental stress and immunological reactivity: a closer look at perceived uncontrollability.

OBJECTIVE: Although stressor uncontrollability has been shown to suppress immune responses in animals and for human subjects, the results have been inconsistent. We reanalyzed results of our previous study regarding stress-related immune deviation in man, to establish whether perceived uncontrollability of an acute stressor acts as a co-determinant in the observed changes in immunological parameters. METHOD: Three types of cognitive reactions to an acute interpersonal stressor were assessed: "motivation," "uncontrollability," and "guiltiness." Stress-induced changes in the number of several types of immune cells in peripheral blood and proliferative responses of lymphocytes to antigens and mitogens were assessed. RESULTS: In comparison with control subjects and with subjects perceiving high control over the experimental stress situation, the subject perceiving low control showed a stressor-induced decrease in the number of T helper cells. Reversely, subjects perceiving high control showed an increase in the number of B cells as opposed to the other two groups. The effects of perceived uncontrollability could not be accounted for by mood changes, but they were related to previously experienced life stress. CONCLUSIONS: Perceived uncontrollability of an acute stressor can have immuno-modulating effects over and above those of the stressor per se.

Modulation of the immunologic response to acute stress in humans by beta-blockade or benzodiazepines.

Acute stress evokes immediate responses in the cardiovascular endocrine, and immune systems. In particular, the number and activity of natural killer (NK) lymphocytes increase after stress. Here, we investigate the possibility to pharmacologically interfere with these stress-induced immunologic changes. Twenty-five healthy males were subjected to an acute stressor, a first-time tandem parachute jump. Subjects were randomly assigned to a beta-adrenoceptor antagonist (propranolol), a benzodiazepine (alprazolam), or placebo group. To analyze the role of the spleen in lymphocyte redistribution, splenectomized subjects performed a parachute jump. Propranolol, but no alprazolam, inhibited the heart rate increase during jumping. Increases in epinephrine and cortisol in the propranolol group were comparable to placebo, but were attenuated by alprazolam. The number and activity of NK cells significantly increased in the placebo group but not in the propranolol group immediately after stress. Alprazolam treatment did not alter the increase in NK cell numbers but did inhibit the increase in NK activity. In splenectomized subjects, NK cell numbers, but not NK activity, increased as in placebo subjects. We conclude that stress-induced changes in the immune system are controlled by beta-adrenergic mechanisms and only partly depend on the spleen; central interference with alprazolam differentially affects stress-induced changes in the NK cell compartment.

Catecholamines modulate human NK cell circulation and function via spleen-independent beta 2-adrenergic mechanisms.

Increases in catecholamines have been shown to induce changes in migration of lymphocytes, in particular NK cells. To analyze the mechanisms of catecholamine-induced NK cell trafficking, normal healthy male human subjects and splenectomized individuals were infused with either adrenaline (0.10 microgram/kg/min), noradrenaline (0.15 microgram/kg/min), or NaCl i.v. for 20 min. Lymphocyte subsets (CD3+, CD4+, CD8+) transiently increased after administration of both catecholamines, with most pronounced increases (up to 600%) in NK cell numbers (CD16+ or CD56+) after infusion of adrenaline. These changes in NK cell numbers and function were accompanied neither by alterations in expression of adhesion molecules (CD11a), CD11b, CD31, CD43, CD44, CD62L) on NK cells nor by changes in plasma concentrations of soluble (s) adhesion molecules (sVCAM-1, sICAM-1, sE-selectin). Comparable increases in lymphocyte subsets were observed in splenectomized subjects, suggesting lymphocyte recruitment from other sources than the spleen. Furthermore, catecholamine-induced increases in lymphocyte subsets could be inhibited by pretreatment with the nonselective beta-adrenoceptor antagonist propranolol, but not by the beta1-selective antagonist bisoprolol. These data demonstrate that adrenaline and noradrenaline modulate the migratory capacity of human NK cells via spleen-independent beta 2-adrenoceptor mechanism.

Activation and anergy in bone marrow B cells of a novel immunoglobulin transgenic mouse that is both hapten specific and autoreactive.

Available evidence indicates that B cell tolerance is attained by receptor editing, anergy, or clonal deletion. Here, we describe a p-azophenylarsonate (Ars)-specific immunoglobulin transgenic mouse in which B cells become anergic as a consequence of cross-reaction with autoantigen in the bone marrow. Developing bone marrow B cells show no evidence of receptor editing but transiently upregulate activation markers and appear to undergo accelerated development. Mature B cells are present in normal numbers but are refractory to BCR-mediated induction of calcium mobilization, tyrosine phosphorylation, and antibody responses. Activation marker expression and acquisition of the anergic phenotype is prevented in bone marrow cultures by monovalent hapten. In this model, it appears that induction of anergy in B cells can be prevented by monovalent hapten competing with autoantigen for the binding site.