A novel monoclonal antibody cross-reactive with both human and mouse α9 integrin useful for therapy against rheumatoid arthritis.

This study introduces a novel monoclonal anti-α9 integrin antibody (MA9-413) with human variable regions, isolated by phage display technology. MA9-413 specifically binds to both human and mouse α9 integrin by recognizing a conserved loop region designated as L1 (amino acids 104-122 of human α9 integrin). MA9-413 inhibits human and mouse α9 integrin-dependent cell adhesion to ligands and suppresses synovial inflammation and osteoclast activation in a mouse model of arthritis. This is the first monoclonal anti-α9 integrin antibody that can react with and functionally inhibit both human and mouse α9 integrin. MA9-413 allows data acquisition both in animal and human pharmacological studies without resorting to surrogate antibodies. Since MA9-413 showed certain therapeutic effects in the mouse arthritis model, it can be considered as a useful therapy against rheumatoid arthritis and other α9 integrin-associated diseases.

AS2762900-00, a potent anti-human IL-23 receptor monoclonal antibody, prevents epidermal hyperplasia in a psoriatic human skin xenograft model.

Interleukin (IL)-23 is thought to be critical in the pathogenesis of psoriasis, and anti-IL-23 monoclonal antibodies (mAbs) have been approved for the treatment of psoriasis. We speculated that an anti-IL-23 receptor mAb might have greater efficacy than an anti-IL-23 mAb in the treatment of local inflamed lesions with high IL-23 levels. We previously generated an anti-human IL-23 receptor mAb, AS2762900-00, which potently blocked IL-23-induced cell proliferation, regardless of the concentration of IL-23. Here, we evaluated the therapeutic potential of AS2762900-00 in the treatment of psoriasis. Compared with untreated control, AS2762900-00 significantly reduced the epidermal thickness of lesions in a clinically relevant psoriatic human skin xenograft model. The expression of inflammatory genes including genes downstream of IL-23 signaling in the lesion tended to be lower in the AS2762900-00 group than the untreated group, suggesting that the inhibitory effects of AS2762900-00 in the psoriatic human skin xenograft model might occur via blockade of IL-23 signaling pathways. Further, AS2762900-00 showed an inhibitory effect on signal transducer and activator of transcription 3 (STAT3) phosphorylation as a downstream signal of IL-23 receptor activation in whole blood from patients with psoriasis. We also confirmed that AS2762900-00 inhibited IL-23-induced STAT3 phosphorylation in a concentration-dependent manner using whole blood from healthy donors. These data suggest that AS2762900-00 is a promising drug candidate for the treatment of psoriasis. In addition, STAT3 phosphorylation in whole blood may be a useful biomarker for the evaluation of the pharmacodynamic effects of AS2762900-00 in healthy volunteers in clinical development.

Generation and characterization of a potent fully human monoclonal antibody against the interleukin-23 receptor.

Interleukin (IL)-12 and IL-23 share a common subunit (p40) and function in T-helper (Th) 1 and Th17 immunity, respectively. Anti-IL-12/23p40 and specific anti-IL-23 antibodies are currently in clinical use for psoriasis and undergoing trials for autoimmune diseases. Since expression levels of the IL-23 receptor are likely to be much lower than those of IL-23, an anti-IL-23 receptor antibody might offer greater promise in inhibiting the IL-23-IL-17 pathways involved in inflammatory disorders. To our knowledge, no anti-IL-23 receptor antibody has been trialed in clinical studies to date. This study describes the generation and characterization of AS2762900-00, a fully human monoclonal antibody against the IL-23 receptor. AS2762900-00 bound both human and cynomolgus monkey IL-23 receptors. AS2762900-00 showed potent inhibitory effects on IL-23-induced Kit-225 cell proliferation compared to the existing anti-IL-12/23p40 antibody, ustekinumab. In a single dose administration pharmacodynamics study in cynomolgus monkeys, 1 mg/kg of AS2762900-00 significantly inhibited (> 85%) IL-23-induced STAT3 phosphorylation in blood for up to 84 days. Therefore, AS2762900-00 represents a potent novel IL-23-IL-17 pathway inhibitor with the potential to be developed into a new therapy for the treatment of autoimmune diseases.

Anti-IL-23 receptor monoclonal antibody prevents CD4+ T cell-mediated colitis in association with decreased systemic Th1 and Th17 responses.

Experimental colitis studies, including T cell-mediated colitis, indicate that IL-23 rather than IL-12 orchestrates intestinal inflammation in inflammatory bowel disease (IBD). Previous studies have identified the roles of IL-12 and IL-23 using mice deficient for their specific subunits, p35 and p19, respectively. However, these studies do not completely reflect the difference in roles between IL-12 and IL-23, especially since the discovery of novel IL-12 family cytokines, which also include p35 or p19 subunits. Here, to clarify the contribution of IL-12 and IL-23 in T cell-mediated colitis, we compared the efficacy of a monoclonal antibody (mAb) to an IL-23-specific receptor subunit with that of an anti-IL-12/23p40 mAb in a naive CD4+ T cell transfer model of experimental colitis, which is associated with enhanced Th1 and Th17 responses. Both antibodies almost completely prevented the development of colitis and showed reduced associated histological changes, including mucosal hyperplasia, infiltration of inflammatory cells and loss of goblet cells. The anti-IL-23 receptor mAb inhibited not only the systemic Th17-response but also the Th1-response, both of which were up-regulated in this model. These results suggest that IL-23, but not IL-12, signaling is critical for the development of colitis. Blockade of IL-23 signaling is a promising therapeutic approach for IBD.

Tamsulosin potently and selectively antagonizes human recombinant α(1A/1D)-adrenoceptors: slow dissociation from the α(1A)-adrenoceptor may account for selectivity for α(1A)-adrenoceptor over α(1B)-adrenoceptor subtype.

We determined the binding affinity of tamsulosin, a selective α(1)-adrenoceptor antagonist, for human α(1)-adrenoceptor subtypes in comparison with those of other α(1)-adrenoceptor antagonists including silodosin, prazosin, 5-methylurapidil, terazosin, alfuzosin, nafopidil, urapidil and BMY7378. The association and dissociation kinetics of [(3)H]tamsulosin for recombinant human α(1)-adrenoceptor subtypes were compared with those of [(3)H]prazosin. Tamsulosin competitively inhibited [(3)H]prazosin binding to human α(1A)-, α(1B)- and α(1D)-adrenoceptors (pK(i) values were 10.38, 9.33, 9.85) indicating 11 and 3.4-fold higher affinities for human α(1A)-adrenoceptor than those for α(1B)- and α(1D)-adrenoceptors, respectively. The affinity of tamsulosin for the human α(1A)-adrenoceptor was, respectively, 5, 9.9, 38, 120, 280, 400, 1200 and 10000 fold higher than those of silodosin, prazosin, 5-methylurapidil, terazosin, alfuzosin, naftopidil, urapidil and BMY7378, respectively. [(3)H]Tamsulosin dissociated from the α(1A)-adrenoceptor slower than from the α(1B)- and α(1D)-adrenoceptors (α(1B)>α(1D)>α(1A)). Moreover, [(3)H]tamsulosin dissociated slower than [(3)H]prazosin from the α(1A)-adrenoceptor and faster from the α(1B)- and α(1D)-adrenoceptors. In conclusion, tamsulosin potently and selectively antagonized α(1A/1D)-adrenoceptor ligand binding, and slowly dissociated from the α(1A)-adrenoceptor subtype.

A novel, selective, and orally available antagonist for CC chemokine receptor 3.

CC chemokine ligand 11 (CCL11/eotaxin) and other CC chemokine receptor 3 (CCR3) ligands (CCL24/eotaxin-2, CCL26/eotaxin-3, CCL13/monocyte chemotactic protein-4, etc.) play important roles in the chemotaxis and activation of eosinophils and other CCR3-expressing cells (basophils, mast cells, and CD4(+) T helper 2 cells) in allergic inflammation incidents, including asthma and rhinitis. A newly synthesized compound, N-{(3R)-1-[(6-fluoro-2-naphthyl)methyl]pyrrolidin-3-yl}-2-{1-[(5-hydroxy-3-methylpyridin-2-yl)carbonyl]piperidin-4-ylidene}-acetamide hemifumarate (YM-355179), inhibited the binding of CCL11 and CCL5/regulated on activation normal T cell expressed and secreted to CCR3-expressing B300-19 cells with IC(50) values of 7.6 and 24 nM, respectively. In contrast, YM-355179 did not affect the binding of CCL5 to CCR1 or CCR5. In functional assays, YM-355179 inhibited CCL11-induced, intracellular Ca(2+) influx, chemotaxis, and eosinophil degranulation with IC(50) values of 8.0, 24, and 29 nM, respectively. YM-355179 did not, however, affect any CC chemokine receptor (CCR1, CCR2, CCR4, or CCR5)-mediated Ca(2+) influx signals. Furthermore, oral administration of YM-355179 (1 mg/kg) inhibited CCL11-induced shape change of whole blood eosinophils in cynomolgus monkeys. Intravenous injection of YM-355179 (1 mg/kg) also inhibited eosinophil infiltration into airways of cynomolgus monkeys after segmental bronchoprovocation with CCL11. These results indicate that YM-355179 is a novel, selective, and orally available CCR3 antagonist with therapeutic potential for treating eosinophil-related allergic inflammatory diseases.

Effects of interleukin-11 on the hematopoietic action of granulocyte colony-stimulating factor.

Interleukin-11 (IL-11, CAS 145941-26-0) is a cytokine that ameliorates thrombocytopenia induced by chemotherapy. Granulocyte colony-stimulating factor (G-CSF) is frequently used clinically as an adjuvant therapy to ameliorate neutropenia. In this study, it has been investigated whether IL-11 influences the hematopoietic action of G-CSF in vitro. IL-11 alone did not stimulate CFU-Meg colony formation in the absence of interleukin-3 (IL-3), but did in the presence of IL-3. However, IL-11 alone stimulated the formation of CFU-E, BFU-E and CFU-GM colonies, which were further enhanced by IL-3. G-CSF alone stimulated in a concentration dependent manner colony formation of CFU-GM and CFU-E, but not BFU-E or CFU-Meg. The addition of IL-11 enhanced the stimulatory effect of G-CSF on CFU-GM colony formation, and enabled G-CSF to stimulate colony formation of BFU-E, but not CFU-E. The addition of IL-3 further enhanced the stimulatory effect of G-CSF on CFU-E, BFU-E, and CFU-GM colony formation. However, G-CSF was unable to stimulate CFU-Meg colony formation for any of the cytokine combinations tested. These studies demonstrate that IL-11 has significant stimulatory effects on G-CSF-induced CFU-GM colony formation, suggesting that the therapeutic combination of the two growth factors could be beneficial for the treatment of myelosuppression induced by chemotherapy.

Recombinant human interleukin-11 improved carboplatin-induced thrombocytopenia without affecting antitumor activities in mice bearing Lewis lung carcinoma cells.

PURPOSE: Interleukin-11 (IL-11) is a stromal cell derived multifunctional cytokine, which plays important roles in the hematopoietic and nonhematopoietic systems. Recombinant human IL-11 (rhIL-11) is used in the treatment of chemotherapy-induced thrombocytopenia. We have investigated the effects of rhIL-11 on the antitumor activity of chemotherapeutic agents and on thrombocytopenia in myelosuppressed mice bearing tumor cells. METHODS: We tested the effect of rhIL-11 on Lewis lung carcinoma (LLC) cell proliferation when used alone or in combination with three antitumor agents in vitro. Also, a newly developed chemotherapy-induced myelosuppressed mice model bearing LLC cells was used to study the effects of rhIL-11 on the antitumor activity and on thrombocytopenia. RESULTS: On its own, rhIL-11 (1-100 ng/ml) did not stimulate cell proliferation, and did not alter the antitumor activities of carboplatin, mitomycin C, or etoposide in vitro. In mice implanted with LLC cells (1 x 10(4)), carboplatin (50 mg/kg/day for 2 consecutive days, i.p.) inhibited tumor growth and caused thrombocytopenia. Treatment with rhIL-11 (500 microg/kg/day, from the day following the last dosing with carboplatin for 14 days, s.c.) successfully prevented thrombocytopenia without affecting the antitumor activity of carboplatin. With rhIL-11 there was no obvious effect on the red blood cell count, white blood cell count, or body weight. CONCLUSION: These results support the assertion that rhIL-11 may be a significant therapeutic agent for thrombocytopenia following cancer chemotherapy, and that it need be associated with little fear of tumor proliferation.

Fertilization Membrane Formation in Sea Urchin Eggs Induced by Drugs Known to Cause Ca2+ Release from Isolated Sarcoplasmic Reticulum: (sea urchin egg/fertilization membrane/ryanodine/micronazole/procaine).

Ryanodine, miconazole, clotrimazole, doxorubicin, quercetin, halothane, caffeine and chloroform, which activate Ca2+ -induced Ca2+ release from Ca2+ stores, induced Ca2+ release from a particulate fraction isolated from sea urchin eggs, Ca2+ influx into eggs and formation of a fertilization membrane in an appreciable number of eggs. Their minimum effective concentrations for inducing a fertilization membrane increased in the order of these drugs listed above, and this order was also the same as that of their minimum effective concentrations for inducing Ca2+ release from the isolated particulate fraction. Their effect in inducing a fertilization membrane was blocked by ruthenium red and procaine, which inhibit Ca2+ release from Ca2+ stores. Thus these drugs probably induced sufficient Ca2+ release to make the cytosolic Ca2+ level high enough in many eggs for formation of a fertilization membrane. In the absence of external Ca2+ , fewer eggs treated with these drugs formed a fertilization membrane and more eggs did so on further treatment with either A23187 or carbonylcyanide-p-trifluoromethoxy-phenylhydrazone (FCCP). Thus, a high level of Ca2+ is probably derived from Ca2+ release through Ca2+ releasing channels (by A23187), from mitochondria (by FCCP) and its transport from the external medium.