Abstract: CTLA-4, an Ig superfamily molecule with homology to CD28, is one of the most potent negative regulators of T-cell responses. In vivo blockade of CTLA-4 exacerbates autoimmunity, enhances tumor-specific T-cell responses, and may inhibit the induction of T-cell anergy. Clinical trials of CTLA-4–blocking antibodies to augment T-cell responses to malignant melanoma are at an advanced stage; however, little is known about the effects of CTLA-4 blockade on memory CD8+ T-cell responses and the formation and maintenance of long-term CD8+ T-cell memory. In our studies, we show that during in vivo memory CD8+ T-cell responses to Listeria monocytogenes infection, CTLA-4 blockade enhances bacterial clearance and increases memory CD8+ T-cell expansion. This is followed by an accumulation of memory cells that are capable of producing the effector cytokines IFN-γ and TNF-α. We also demonstrate that in a vaccination setting, blocking CTLA-4 during CD8+ T-cell priming leads to increased expansion and maintenance of antigen-specific memory CD8+ T cells without adversely affecting the overall T-cell repertoire. This leads to an increase in memory cell effector function and improved protective immunity against further bacterial challenges. These results indicate that transient blockade of CTLA-4 enhances memory CD8+ T-cell responses and support the possible use of CTLA-4–blocking antibodies during vaccination to augment memory formation and maintenance.

Abstract: Rationale Orexin-1 receptor antagonists have been shown to block the reinforcing effects of drugs of abuse and food. However, whether blockade of orexin-2 receptor has similar effects has not been determined. We have recently described the in vitro and in vivo effects of JNJ-10397049, a selective and brain penetrant orexin-2 receptor antagonist.

Abstract: The role of chemokines in the pathogenesis of lung cancer has been increasingly appreciated. Monocyte chemoattractant protein-1 (MCP-1, also known as CCL2) is secreted from tumor cells and associated tumor stromal cells. The blockade of CCL2, as mediated by neutralizing antibodies, was shown to reduce tumorigenesis in several solid tumors, but the role of CCL2 in lung cancer remains controversial, with evidence of both protumorigenic and antitumorigenic effects. We evaluated the effects and mechanisms of CCL2 blockade in several animal models of non-small-cell lung cancer (NSCLC). Anti-murine-CCL2 monoclonal antibodies were administered in syngeneic flank and orthotopic models of NSCLC. CCL2 blockade significantly slowed the growth of primary tumors in all models studied, and inhibited lung metastases in a model of spontaneous lung metastases of NSCLC. In contrast to expectations, no significant effect of treatment was evident in the number of tumor-associated macrophages recruited into the tumor after CCL2 blockade. However, a change occurred in the polarization of tumor-associated macrophages to a more antitumor phenotype after CCL2 blockade. This was associated with the activation of cytotoxic CD8(+) T lymphocytes (CTLs). The antitumor effects of CCL2 blockade were completely lost in CB-17 severe combined immunodeficient mice or after CD8 T-cell depletion. Our data from NSCLC models show that CCL2 blockade can inhibit the tumor growth of primary and metastatic disease. The mechanisms of CCL2 blockade include an alteration of the tumor macrophage phenotype and the activation of CTLs. Our work supports further evaluation of CCL2 blockade in thoracic malignancies.

Abstract: The programmed death ligand 1 (PDL1)/programmed death 1 (PD1) costimulatory pathway plays an important role in the inhibition of alloimmune responses as well as in the induction and maintenance of peripheral tolerance. It has been demonstrated recently that PDL1 also can bind B7.1 to inhibit T cell responses in vitro. Using the bm12 into B6 heart transplant model, we investigated the functional significance of this interaction in alloimmune responses in vivo. PD1 blockade unlike PDL1 blockade failed to accelerate bm12 allograft rejection, suggesting a role for an additional binding partner for PDL1 other than PD1 in transplant rejection. PDL1 blockade was able to accelerate allograft rejection in B7.2-deficient recipients but not B7.1-deficient recipients, indicating that PDL1 interaction with B7.1 was important in inhibiting rejection. Administration of the novel 2H11 anti-PDL1 mAb, which only blocks the PDL1-B7.1 interaction, aggravated chronic injury of bm12 allografts in B6 recipients. Aggravated chronic injury was associated with an increased frequency of alloreactive IFN-γ-, IL-4-, and IL-6-producing splenocytes and a decreased percentage of regulatory T cells in the recipients. Using an in vitro cell culture assay, blockade of the interaction of PDL1 on dendritic cells with B7.1 on T cells increased IFN-γ production from alloreactive CD4(+) T cells, whereas blockade of dendritic cell B7.1 interaction with T cell PDL1 did not. These data indicate that PDL1 interaction with B7.1 plays an important role in the inhibition of alloimmune responses in vivo and suggests a dominant direction for PDL1 and B7.1 interaction.

Abstract: Previous studies have identified the inhibitory role that the programmed death 1 (PD-1) pathway plays during chronic infection. Blockade of this pathway results in rescue of viral-specific CD8 T cells, as well as reduction of viral loads in mice chronically infected with lymphocytic choriomeningitis virus (LCMV). We tested the effect of combining PD ligand 1 (PD-L1) blockade with an agonistic regimen that induces 4-1BB costimulation during chronic LCMV infection. There is a boosting effect in the rescue of LCMV-specific CD8 T cell responses after dual treatment with PD-L1 blockade and 4-1BB agonistic Abs when the amount and timing of 4-1BB costimulation are carefully controlled. When PD-L1–blocking Abs are given together with a single low dose of anti–4-1BB agonistic Abs, there is an enhanced and stable expansion of viral-specific CD8 T cells. Conversely, when blocking Abs to PD-L1 are given with a repetitive high dose of anti–4-1BB, there is an initial synergistic expansion of viral-specific CD8 T cells by day 7, followed by dramatic apoptosis by day 14. Viral control paralleled CD8 T cell kinetics after dual treatment. By day 7 posttreatment, viral titers were lower in both of the combined regimens (compared with PD-L1 blockade alone). However, whereas the high dose of anti–4-1BB plus PD-L1 blockade resulted in rebound of viral titers to original levels, the low dose of anti–4-1BB plus PD-L1 blockade resulted in a stable reduction of viral loads. These findings demonstrate the importance of carefully manipulating the balance between activating and inhibitory signals to enhance T cell responses during chronic infection.

Abstract: The aim of this study was to provide more insight into the question as to why blockade of CCR1, CCR2, and CCR5 may have failed in clinical trials in rheumatoid arthritis (RA) patients, using an in vitro monocyte migration system model. Monocytes from healthy donors (HD; n = 8) or from RA patients (for CCR2 and CCR5 antibody n = 8; for CCR1 blockade n = 13) were isolated from peripheral blood and pre-incubated with different concentrations of either anti-CCR1, anti-CCR2, or anti-CCR5 blocking antibodies (or medium or isotype controls). In addition, a small molecule CCR1 antagonist (BX471) was tested. Chemotaxis was induced by CCL2/MCP-1 (CCR2 ligand), CCL5/RANTES (CCR1 and CCR5 ligand), or by a mix of 5 RA synovial fluids (SFs), and cellular responses compared to chemotaxis in the presence of medium alone. Anti-CCR2 antibody treatment blocked CCL2/MCP-1-induced chemotaxis of both HD and RA monocytes compared to isotype control. Similarly, anti-CCR5 antibody treatment blocked CCL5/RANTES-induced chemotaxis of RA monocytes. While neither CCR2 nor CCR5 blocking antibodies were able to inhibit SF-induced monocyte chemotaxis, even when both receptors were blocked simultaneously, both anti-CCR1 antibodies and the CCR1 antagonist were able to inhibit SF-induced monocyte chemotaxis. The RA synovial compartment contains several ligands for CCR1, CCR2, and CCR5 as well as other chemokines and receptors involved in monocyte recruitment to the site of inflammation. The results suggest that CCR2 and CCR5 are not critical for the migration of monocytes towards the synovial compartment in RA. In contrast, blockade of CCR1 may be effective. Conceivably, CCR1 blockade failed in clinical trials, not because CCR1 is not a good target, but because very high levels of receptor occupancy at all times may be needed to inhibit monocyte migration in vivo

Abstract: Blockade of the CD40/CD154 pathway potently attenuates T-cell responses in models of autoimmunity, inflammation, and transplantation. Indeed, CD40 pathway blockade remains one of the most powerful methods of prolonging graft survival in models of transplantation. But despite this effectiveness, the cellular and molecular mechanisms underlying the protective effects of CD40 pathway blockade are incompletely understood. Furthermore, the relative contributions of deletion, anergy, and regulation have not been measured in a model in which donor-reactive CD4+ and CD8+ T-cell responses can be assessed simultaneously. To investigate the impact of CD40/CD154 pathway blockade on graft-specific T-cell responses, a transgenic mouse model was used in which recipients containing ovalbumin-specific CD4+ and CD8+ TCR transgenic T cells were grafted with skin expressing ovalbumin in the presence or absence of anti-CD154 and donor-specific transfusion. The results indicated that CD154 blockade altered the kinetics of donor-reactive CD8+ T-cell expansion, delaying differentiation into IFN-γ+ TNF+ multifunctional cytokine producers. The eventual differentiation of cytokine-producing effectors in tolerant animals coincided with the emergence of an antigen-specific CD4+ CD25hi Foxp3+ T-cell population, which did not arise from endogenous natural Treg but rather were peripherally generated from naive Foxp3− precursors.

Abstract: High-mobility group box 1 (HMGB1), a non-histone nuclear protein, has been implicated in cardiovascular diseases. Dilated cardiomyopathy (DCM), one of the leading causes of heart failure, is often caused by coxsackievirus B3-triggered myocarditis and promoted by the post-infectious autoimmune process. Th17 cells, a novel CD4(+) T subset, may be important in the pathogenesis of autoimmune myocarditis. In the present study, we attempted to block HMGB1 function with a monoclonal antibody specific for HMGB1 B box and investigated the effects of the blockade on Th17 cells and experimental autoimmune myocarditis (EAM). After induction of EAM, HMGB1 protein levels were significantly elevated both in the heart and blood. Administration of an anti-HMGB1 B box mAb attenuated cardiac pathological changes and reduced the number of infiltrating inflammatory cells in the heart during EAM. These protective effects of HMGB1 blockade correlated with a reduced number of Th17 cells in local tissues and lower levels of IL-17 in the serum. Furthermore, in vitro, studies demonstrated that HMGB1 promoted Th17-cell expansion. Therefore, we speculate that HMGB1 blockade ameliorates cardiac pathological changes in EAM by suppressing Th17 cells.

Abstract: Background Anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) antibodies, such as ipilimumab, have generated measurable immune responses to Melan-A, NY-ESO-1, and gp100 antigens in metastatic melanoma. Vaccination against such targets has potential for immunogenicity and may produce an effector-memory T-cell response. Methods To determine the effect of CTLA-4 blockade on antigen-specific responses following vaccination, in-depth immune monitoring was performed on three ipilimumabtreated patients prevaccinated with gp100 DNA (IMF-24), gp100 209‐217 and tyrosinase peptides plus GM-CSF DNA

Abstract: Most antihistamines are known to induce sedative side but the mechanism remains unclear (Pollard et a1 1973). Such an impairment of central nervous function possibly be attributed to a blockade of the brain’s H~ receptors, recently shown biochemically (Chang et a1 1978; Hill et al1978; Tran et all978). Even if the role of histamine as putative neurotransmitter (Schwartz 1975 ; Schwartz et a1 1976) appears somewhat difficult to evaluate, both the presence of histaminergic fibres innerving the telencephalon via the lateral hypothalamic area (Dropp 1972) and the fact that brain histamine concentration or histamine turnover exhibited cirw d i a n variations (Orr & Quay 1975; Friedman & Walker 1968), might suggest a role of histamine on wakefulness and sleep (Verdiere et a1 1977). Recently, a new phenothiazine derivative, mequitazine or (10-[3-quinuclidinylmethyl]-phenothiazine) has * Correspondence.

Abstract: Serotonin (5-HT)-selective reuptake inhibitors (SSRIs) are widely administered for the treatment of depression, anxiety, and other neuropsychiatric disorders, but response rates are low, and side effects often lead to discontinuation. Side effect profiles suggest that SSRIs inhibit dopaminergic activity, but mechanistic insight remains scarce. Here we show that in mice, chronic 5-HT transporter (5-HTT) blockade during adulthood but not during development impairs basal ganglia-dependent behaviors in a dose-dependent and reversible fashion. Furthermore, chronic 5-HTT blockade reduces striatal dopamine (DA) content and metabolism. A causal relationship between reduced DA signaling and impaired basal ganglia-dependent behavior is indicated by the reversal of behavioral deficits through l-DOPA administration. Our data suggest that augmentation of DA signaling would reduce side effects and increase efficacies of SSRI-based therapy.

Abstract: ESTLER, C.-J. & AMMON, H. P. T. (1969). JULOU, L. (1956), cited by COURVOISIER, S. (1956). LESZKOVSKY, G.& TARDOS, L. (1965). LISH, P. M., WEIKEL, J. H. &DUNGAN, K. W. (1965). MURMANN, W., ALMIRANTE, L. & SACCANI-GUELFI, M. (1966). J. Pharm. Pharmac., 21, 554-555. J. clin. exp. Psychopath., 17, 25. J. Pharm. Pharmac., 17, 518-519. J. Pharm. exp. Ther., 149, 161-173. J. Pharm. Pharmac., 18,317-318.

Abstract: Adult-onset Still's disease (AOSD) is a systemic inflammatory disorder of unknown aetiology1 Based on the substantial acute phase responses observed in AOSD, we hypothesised that blockade of the interleukin 6R (IL-6R), neutralising the induction of the acute phase response by IL-6, could be a useful treatment in multidrug-resistant AOSD We here report on three patients with AOSD who were refractory to standard treatment and cytokine blockade with anakinra and tumour necrosis factor (TNF) blockers and were subjected to treatment with tocilizumab The characteristics of these three patients are summarised in table 1 View this table: Table 1 Characteristics of patients A 19-year-old woman was first diagnosed with AOSD in July 2006 Prednisone therapy was started, but multiple relapses occurred during the following 2 years requiring …

Abstract: Aim:To investigate whether and how COS inhibited IL-8 production in LPS-induced human umbilical vein endothelial cells (HUVECs).Methods:RT-PCR, enzyme-linked immunosorbent assays (ELISA) and Western blotting were used to study IL-8 expression and related signaling pathway. Wound healing migration assays and monocytic cell adhesion analysis were used to explore the chemotactic and adhesive activities of HUVECs.ResultsCOS 50–200 μg/mL exerted a significant inhibitory effect on LPS 100 ng/mL-induced IL-8 expression in HUVECs at both the transcriptional and translational levels. In addition, COS 50–200 μg/mL inhibited LPS-induced HUVEC migration and U937 monocyte adhesion to HUVECs in a concentration-dependent manner. Signal transduction studies suggest that COS blocked LPS-induced activation of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) as well as phosphorylation of p38 mitogen-activated protein kinase (MAPK) and phosphokinase Akt. Further, the over-expression of LPS-induced IL-8 mRNA in HUVECs was suppressed by a p38 MAPK inhibitor (SB203580, 25 μmol/L) or a phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002, 50 μmol/L).Conclusion:COS inhibited LPS-induced IL-8 expression in HUVECs through the blockade of the p38 MAPK and PI3K/Akt signaling pathways.

Abstract: Aldosterone, a steroid hormone with mineralocorticoid activity, is far more than merely a salt-and-water hormone. Aldosterone has a number of non-classical, mineralocorticoid receptor (MR)-mediated actions, including tissue remodeling, modulation of vascular tone and stimulating inflammation and fibrosis, which may fuel progression of end organ damage. Aldosterone breakthrough during blockade of the renin-angiotensin aldosterone system (RAAS) may explain why this treatment regimen only confers partial cardiovascular and renal protection. Of major interest, aldosterone is deleterious only if inappropriately high for its sodium status i.e. high aldosterone and high sodium. The mechanism of sodium dependence of aldosterone-induced renal and cardiovascular damage continues to fascinate. Aldosterone excess increases sodium and fluid retention and consequently increases blood pressure, which, in turn, mediates target organ damage. Moreover, blood pressure independent effects play a role with dissociation of low circulating and high tissue aldosterone levels during high sodium intake and possibly enhanced MR signaling. MR blockade is a valuable strategy, which has potency to halt the progressive end organ damage as observed during current treatments. In heart failure, MR blockade on top of RAAS blockade reduces hard clinical endpoints. Despite encouraging results on the intermediate endpoint proteinuria, long-term data on the efficacy and safety of MR blockade in preventing dialysis and/or cardiovascular endpoints in chronic kidney disease are still lacking. It is obligatory that future clinical studies on the effects of MR blockade on end-organ damage take into account the sodium status.

Abstract: PURPOSE. To analyze whether insulin receptor substrate (IRS-1) is involved in lymphatic vessel development and whether IRS-1 blockade can inhibit lymphangiogenesis in vivo. METHODS. The impact of IRS-1 blockade by GS-101 (Aganirsen), an antisense oligonucleotide against IRS-1, on lymphatic endothelial cell (LEC) proliferation was assessed by ELISA. Furthermore, the effect of IRS-1 blockade on prolymphangiogenic growth factor expression by LECs and macrophages (peritoneal exudate cells) was tested by real-time PCR. The mouse model of inflammatory corneal neovascularization was used to analyze the effect of IRS-1 blockade in vivo: after corneal suture placement, mice were treated with GS-101 eye drops (twice daily afterwards for 1 week, 5 L per drop; 50, 100, or 200 M). Afterward, corneal wholemounts were prepared and stained for blood and lymphatic vessels. RESULTS. Blockade of IRS-1 by GS-101 inhibited LEC proliferation dose dependently. GS-101 led to decreased VEGF-A expression levels in LECs, whereas VEGF-C, VEGF-D, and VEGFR3 showed no significant change. In macrophages, VEGF-A expression levels were also inhibited by IRS-1 blockade. Additionally, GS-101 strongly inhibited macrophage-derived VEGF-C, VEGF-D, and VEGFR3 expression. In vivo, corneal hemangiogenesis was significantly inhibited when used at a concentration of 200 M (by 17%; P 0.01). Corneal lymphangiogenesis was significantly inhibited when used at a dose of 100 M (by 21%; P 0.01), and the highest used dose (200 M) showed an even stronger inhibition (by 28%; P 0.001). CONCLUSIONS. Blockade of IRS-1 inhibits not only hemangiogenesis but also lymphangiogenesis. To the authors’ knowledge, this is the first evidence that IRS-1 is involved in the molecular pathway leading to lymphangiogenesis. (Invest Ophthalmol Vis Sci. 2011;52:5778‐5785) DOI:10.1167/iovs.10-6816

Abstract: The inhibition of the pressor effects of noradrenaline by phenoxybenzamine was reduced by propranolol and sotalol in the normal and acutely adrenalectomized, but not in the chronically adrenalectomized, rat. The administration of a glucocorticoid, but not a mineralocorticoid, to the chronically adrenalectomized rat, produced a preparation in which the phenoxybenzamine-produced α-adrenoceptor blockade was reduced by the β-adrenoceptor blocking agents, demonstrating that this action is glucocorticoid-dependent.

Abstract: Although accumulating evidence supports a role for cytokines in the pathophysiology of depression, the cytokine hypothesis of depression is debatable. It has been suggested that neuroendocrine and immune systems acting in concert may have roles in the development and the maintenance of the disease. Glucocorticoid receptor (GR) is the key element which exerts both anti-inflammatory and cytokine-inhibiting effects. Whether functional changes of GR are involved in the pathophysiology of cytokine-induced depression remains elusive. In the present study, the effects of both acute and chronic GR blockade on depressive-like behaviour and cytokine production induced by lipopolysaccharides (LPS), cytokine inducer, were investigated in rats. Acute or chronic blockade of GR was achieved by a single administration or repeated administrations, respectively, of the GR antagonist RU486 (RU). Behavioural measurements, including saccharin preference, locomotor activity, and immobility time, were assessed. The serum levels of proinflammatory cytokines (TNFα, IL-1β, and IFNγ) were determined by ELISA. The results showed that LPS induced significant but transient depressive-like behaviour. Repeated, but not single, administration of RU significantly enhanced and prolonged LPS-induced depressive-like behaviour and an increase in the serum production of TNFα and IFNγ. These results indicate that the effective blockade of GR enhanced the depressive-like behaviour induced by cytokines. Findings from this study suggest that GR dysfunction may be an important contributing factor to the development of cytokine-related depression. These findings add to the growing evidence of mechanisms by which cytokines influence depression.

Abstract: For malignant growth, solid cancers must stimulate the formation of new blood vessels by producing vascular endothelial growth factor (VEGF-A), which is required for the survival of tumor-associated vessels. Novel anticancer agents that block VEGF-A signaling trigger endothelial cell (EC) apoptosis and vascular regression preferentially within tumors, but how the ECs die is not understood. In this study, we demonstrate that VEGF-A deprivation, provoked either by drug-induced tumor shrinkage or direct VEGF-A blockade, up-regulates the proapoptotic BH3 (Bcl-2 homology 3)-only Bcl-2 family member Bim in ECs. Importantly, the tumor growth inhibitory activity of a VEGF-A antagonist required Bim-induced apoptosis of ECs. These findings thus reveal the mechanism by which VEGF-A blockade induces EC apoptosis and impairs tumor growth. They also indicate that drugs mimicking BH3-only proteins may be exploited to kill tumor cells not only directly but also indirectly by ablating the tumor vasculature.

Abstract: Peterson, Hardinge & Tilton (1 964) suggested that death from amphetamine may follow neuromuscular blockade. With in vitro studies they showed that the neuromuscular blocking action of amphetamine was enhanced by the addition of lactic acid to the bath. The concentration of lactate used by these investigators was based upon the report by Fletcher & Hopkins (1917) that, in fatigued muscle, lactate may reach a level of 0.25% (approximately equivalent to 28 pmoles/g). The relevance of these in vitro findings to the death of aggregated mice is questionable since, as shown here by direct measurement, the lactic acid content of skeletal muscle does not increase in the exhausted mice and is only one quarter of that used in the in vitro studies. However, as reported previously and substantiated here, the (+)-amphetamine treated mice which become depressed also develop a marked hypoglycaemia. This hypoglycaemia may be an important factor leading to the death of the aggregated mice (Moore & others, 1965). Acknowledgement. This work was supported by Grant AM 06275 from the National Institute of Arthritis and Metabolic Diseases.