RESUMO
Costimulatory receptors such as glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) play key roles in regulating the effector functions of T cells. In human clinical trials, however, GITR agonist antibodies have shown limited therapeutic effect, which may be due to suboptimal receptor clustering-mediated signaling. To overcome this potential limitation, a rational protein engineering approach is needed to optimize GITR agonist-based immunotherapies. Here we show a bispecific molecule consisting of an anti-PD-1 antibody fused with a multimeric GITR ligand (GITR-L) that induces PD-1-dependent and FcγR-independent GITR clustering, resulting in enhanced activation, proliferation and memory differentiation of primed antigen-specific GITR+PD-1+ T cells. The anti-PD-1-GITR-L bispecific is a PD-1-directed GITR-L construct that demonstrated dose-dependent, immunologically driven tumor growth inhibition in syngeneic, genetically engineered and xenograft humanized mouse tumor models, with a dose-dependent correlation between target saturation and Ki67 and TIGIT upregulation on memory T cells. Anti-PD-1-GITR-L thus represents a bispecific approach to directing GITR agonism for cancer immunotherapy.
Assuntos
Neoplasias , Receptor de Morte Celular Programada 1 , Animais , Análise por Conglomerados , Modelos Animais de Doenças , Proteína Relacionada a TNFR Induzida por Glucocorticoide/agonistas , Humanos , Imunoterapia/métodos , Camundongos , Neoplasias/tratamento farmacológico , Receptores do Fator de Necrose Tumoral/agonistas , Linfócitos TRESUMO
CD137 (TNFRSF9, 4-1BB) agonist antibodies (mAb) have demonstrated potent antitumor activity with memory response while causing hepatotoxicity in mouse models. In clinical trials, the degrees of liver toxicity of anti-CD137 vary from grade 4 transaminitis (urelumab) to nonexistent (utomilumab). To exploit the antitumor potential of CD137 signaling, we identified a new class of CD137 agonist mAbs with strong antitumor potency without significant transaminitis in vivo compared with CD137 agonists previously reported. These mAbs are cross-reactive to mouse and cynomolgus monkey and showed cross-linking-dependent T-cell costimulation activity in vitro Antitumor efficacy was maintained in Fc gamma receptor (FcγR) III-deficient mice but diminished in FcγRIIB-deficient mice, suggesting the critical role for FcγRIIB to provide cross-linking in vivo Interestingly, a single dose of an affinity-reduced variant was sufficient to control tumor growth, but a higher affinity variant did not improve efficacy. These observations suggest that binding epitope and FcγR interaction, but not necessarily high affinity, are important for antitumor efficacy and reduced liver toxicity of CD137 mAb. Our study suggests the possibility of CD137 agonist therapy with improved safety profile in humans.
Assuntos
Anticorpos Monoclonais/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Neoplasias do Colo/tratamento farmacológico , Reagentes de Ligações Cruzadas/química , Epitopos/imunologia , Melanoma Experimental/tratamento farmacológico , Receptores de IgG/fisiologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Animais , Apoptose , Proliferação de Células , Neoplasias do Colo/imunologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Reagentes de Ligações Cruzadas/metabolismo , Feminino , Humanos , Melanoma Experimental/imunologia , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Tumorais CultivadasRESUMO
Agonistic CD40 monoclonal antibodies (mAb) have demonstrated some clinical activity, but with dose-limiting toxicity. To reduce systemic toxicity, we developed a bispecific molecule that was maximally active in the presence of a tumor antigen and had limited activity in the absence of the tumor antigen. LB-1 is a bispecific molecule containing single-chain Fv domains targeting mouse CD40 and the tumor antigen mesothelin. LB-1 exhibited enhanced activity upon binding to cell-surface mesothelin but was less potent in the absence of mesothelin binding. In a mouse model implanted with syngeneic 4T1 tumors expressing cell-surface mesothelin, LB-1 demonstrated comparable antitumor activity as an agonistic CD40 mAb but did not cause elevation of serum cytokines and liver enzymes, as was observed in anti-CD40-treated mice. The results from our study of LB-1 were used to develop a human cross-reactive bispecific molecule (ABBV-428) that targeted human CD40 and mesothelin. ABBV-428 demonstrated enhanced activation of antigen-presenting cells and T cells upon binding to cell-surface mesothelin, and inhibition of cultured or implanted PC3 tumor cell growth after immune activation. Although expression of cell-surface mesothelin is necessary, the bispecific molecules induced immune-mediated antitumor activity against both mesothelin+ and mesothelin- tumor cells. ABBV-428 represents a class of bispecific molecules with conditional activity dependent on the binding of a tumor-specific antigen, and such activity could potentially maximize antitumor potency while limiting systemic toxicity in clinical studies.
Assuntos
Anticorpos Biespecíficos/imunologia , Antígenos de Neoplasias/imunologia , Antineoplásicos Imunológicos/imunologia , Antígenos CD40/imunologia , Proteínas Ligadas por GPI/imunologia , Animais , Anticorpos Biespecíficos/química , Anticorpos Biespecíficos/farmacologia , Anticorpos Biespecíficos/uso terapêutico , Células Apresentadoras de Antígenos/efeitos dos fármacos , Células Apresentadoras de Antígenos/imunologia , Antígenos de Neoplasias/metabolismo , Antineoplásicos Imunológicos/química , Antineoplásicos Imunológicos/farmacologia , Antineoplásicos Imunológicos/uso terapêutico , Antígenos CD40/agonistas , Linhagem Celular Tumoral , Proteínas Ligadas por GPI/metabolismo , Humanos , Ativação Linfocitária/efeitos dos fármacos , Mesotelina , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Mutantes , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologiaRESUMO
Progress in understanding tumor stromal biology has been constrained in part because cancer-associated fibroblasts (CAF) are a heterogeneous population with limited cell-type-specific protein markers. Using RNA expression profiling, we identified the membrane protein leucine-rich repeat containing 15 (LRRC15) as highly expressed in multiple solid tumor indications with limited normal tissue expression. LRRC15 was expressed on stromal fibroblasts in many solid tumors (e.g., breast, head and neck, lung, pancreatic) as well as directly on a subset of cancer cells of mesenchymal origin (e.g., sarcoma, melanoma, glioblastoma). LRRC15 expression was induced by TGFß on activated fibroblasts (αSMA+) and on mesenchymal stem cells. These collective findings suggested LRRC15 as a novel CAF and mesenchymal marker with utility as a therapeutic target for the treatment of cancers with LRRC15-positive stromal desmoplasia or cancers of mesenchymal origin. ABBV-085 is a monomethyl auristatin E (MMAE)-containing antibody-drug conjugate (ADC) directed against LRRC15, and it demonstrated robust preclinical efficacy against LRRC15 stromal-positive/cancer-negative, and LRRC15 cancer-positive models as a monotherapy, or in combination with standard-of-care therapies. ABBV-085's unique mechanism of action relied upon the cell-permeable properties of MMAE to preferentially kill cancer cells over LRRC15-positive CAF while also increasing immune infiltrate (e.g., F4/80+ macrophages) in the tumor microenvironment. In summary, these findings validate LRRC15 as a novel therapeutic target in multiple solid tumor indications and support the ongoing clinical development of the LRRC15-targeted ADC ABBV-085.Significance: These findings identify LRRC15 as a new marker of cancer-associated fibroblasts and cancers of mesenchymal origin and provide preclinical evidence for the efficacy of an antibody-drug conjugate targeting the tumor stroma. Cancer Res; 78(14); 4059-72. ©2018 AACR.
Assuntos
Anticorpos Monoclonais/farmacologia , Imunoconjugados/farmacologia , Proteínas de Membrana/metabolismo , Neoplasias/tratamento farmacológico , Células Estromais/efeitos dos fármacos , Animais , Linhagem Celular , Linhagem Celular Tumoral , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Células HCT116 , Humanos , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos SCID , Neoplasias/metabolismo , Oligopeptídeos/farmacologia , Ratos , Ratos Sprague-Dawley , Sarcoma/tratamento farmacológico , Sarcoma/metabolismo , Células Estromais/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto/métodosRESUMO
Recent advances in immuno-oncology have shown that the immune system can be activated to induce long-term, durable antitumor responses. For immuno-oncology drug development, immune activation is often explored using rat Abs in immunocompetent mouse models. Although these models can be used to show efficacy, antidrug immune responses to experimental protein-based therapeutics can arise. Immunogenicity of surrogate Abs may therefore represent an important obstacle to the evaluation of the antitumor efficacy of immunomodulator Abs in syngeneic models. A recent publication has shown that anti-glucocorticoid-induced TNFR family-related protein agonistic Ab DTA-1 (rat or murinized IgG2a) can induce the development of anaphylaxis in C57BL/6 mice upon repeated i.p. dosing because of an anti-idiotypic anti-drug Ab immune response. This study was undertaken to address the impact of the immunogenicity derived from the Fc and variable domains. To this end, chimerized (rat V domains/mouse constant regions) and murinized (95% mouse sequence) DTA-1-based surrogate Abs with a murine IgG2c H chain isotype were created. Chimerization and murinization of DTA-1 did not affect receptor binding and glucocorticoid-induced TNFR family-related protein-induced T cell agonistic properties. Similar in vivo antitumor efficacy and intratumoral CD8+/regulatory T cells were also observed. Finally, treatment of C57BL/6 mice with the chimerized and murinized DTA-1 Abs on a C57BL/6-matched IgG2c isotype resulted in reduced development and severity of anaphylaxis as measured by decline of body temperature, behavioral effects, serum IL-4, IgE, and anti-drug Ab levels. These results suggest that careful murinization and selection of a strain-matched H chain isotype are critical to generate ideal surrogate Abs for testing immuno-oncology mechanisms in vivo.
Assuntos
Anafilaxia/imunologia , Proteína Relacionada a TNFR Induzida por Glucocorticoide/imunologia , Isotipos de Imunoglobulinas/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Interleucina-4/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Receptores de IgG/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
The fibroblast growth factor (FGF) pathway promotes tumor growth and angiogenesis in many solid tumors. Although there has long been interest in FGF pathway inhibitors, development has been complicated: An effective FGF inhibitor must block the activity of multiple mitogenic FGF ligands but must spare the metabolic hormone FGFs (FGF-19, FGF-21, and FGF-23) to avoid unacceptable toxicity. To achieve these design requirements, we engineered a soluble FGF receptor 1 Fc fusion protein, FP-1039. FP-1039 binds tightly to all of the mitogenic FGF ligands, inhibits FGF-stimulated cell proliferation in vitro, blocks FGF- and vascular endothelial growth factor (VEGF)-induced angiogenesis in vivo, and inhibits in vivo growth of a broad range of tumor types. FP-1039 antitumor response is positively correlated with RNA levels of FGF2, FGF18, FGFR1c, FGFR3c, and ETV4; models with genetic aberrations in the FGF pathway, including FGFR1-amplified lung cancer and FGFR2-mutated endometrial cancer, are particularly sensitive to FP-1039-mediated tumor inhibition. FP-1039 does not appreciably bind the hormonal FGFs, because these ligands require a cell surface co-receptor, klotho or ß-klotho, for high-affinity binding and signaling. Serum calcium and phosphate levels, which are regulated by FGF-23, are not altered by administration of FP-1039. By selectively blocking nonhormonal FGFs, FP-1039 treatment confers antitumor efficacy without the toxicities associated with other FGF pathway inhibitors.
Assuntos
Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Imunoglobulina G/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Proteínas de Fusão Oncogênica/uso terapêutico , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/uso terapêutico , Cálcio/sangue , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/metabolismo , Humanos , Fosfatos/sangue , Proteínas Recombinantes de FusãoAssuntos
Antígenos CD28/imunologia , Antígenos CD40/antagonistas & inibidores , Sobrevivência de Enxerto/imunologia , Transplante de Coração/imunologia , Transplante de Pele/imunologia , Animais , Antígenos CD28/fisiologia , Antígenos CD40/fisiologia , Células Cultivadas , Facilitação Imunológica de Enxerto/métodos , Facilitação Imunológica de Enxerto/tendências , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Rejeição de Enxerto/terapia , Transplante de Coração/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Transgênicos , Transdução de Sinais/imunologia , Transplante de Pele/patologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Subpopulações de Linfócitos T/transplanteRESUMO
Blockade of the CD40/CD154 signaling pathway using anti-CD154 Abs has shown promise in attenuating the alloimmune response and promoting long-term graft survival in murine model systems, although side effects observed in humans have hampered its progression through clinical trials. Appropriately designed anti-CD40 Abs may provide a suitable alternative. We investigated two isoforms of a novel monoclonal rat anti-mouse CD40 Ab (7E1) for characteristics and effects mirroring those of anti-CD154: 7E1-G1 (an IgG1 isotype); and 7E1-G2b (an IgG2b isotype). In vitro proliferation assays to measure the agonist properties of the two anti-CD40 Abs revealed similar responses when plate bound. However, when present as a soluble stimulus, 7E1-G1 but not 7E1-G2b led to proliferation. 7E1-G2b was as effective as anti-CD154 when administered in vivo in concert with CTLA4-Ig in promoting both allogeneic bone marrow chimerism and skin graft survival, whereas 7E1-G1 was not. The protection observed with 7E1-G2b was not due to depletion of CD40-bearing APCs. These data suggest that an appropriately designed anti-CD40 Ab can promote graft survival as well as anti-CD154, making 7E1-G2b an attractive substitute in mouse models of costimulation blockade-based tolerance regimens.
Assuntos
Anticorpos Monoclonais/farmacologia , Antígenos CD/imunologia , Antígenos CD40/imunologia , Sobrevivência de Enxerto/efeitos dos fármacos , Imunoglobulinas/farmacologia , Transplante Homólogo/imunologia , Animais , Anticorpos Monoclonais/uso terapêutico , Transplante de Medula Óssea/imunologia , Antígeno CTLA-4 , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Tolerância Imunológica/efeitos dos fármacos , Imunoglobulinas/uso terapêutico , Camundongos , Modelos Animais , Transplante de Pele/imunologia , Transplante Homólogo/métodosRESUMO
To understand the system of secreted proteins and receptors involved in cell-cell signaling, we produced a comprehensive set of recombinant secreted proteins and the extracellular domains of transmembrane proteins, which constitute most of the protein components of the extracellular space. Each protein was tested in a suite of assays that measured metabolic, growth, or transcriptional responses in diverse cell types. The pattern of responses across assays was analyzed for the degree of functional selectivity of each protein. One of the highly selective proteins was a previously undescribed ligand, designated interleukin-34 (IL-34), which stimulates monocyte viability but does not affect responses in a wide spectrum of other assays. In a separate functional screen, we used a collection of extracellular domains of transmembrane proteins to discover the receptor for IL-34, which was a known cytokine receptor, colony-stimulating factor 1 (also called macrophage colony-stimulating factor) receptor. This systematic approach is thus useful for discovering new ligands and receptors and assessing the functional selectivity of extracellular regulatory proteins.
Assuntos
Espaço Extracelular/química , Interleucinas/isolamento & purificação , Receptores de Interleucina/isolamento & purificação , Animais , Clonagem Molecular , DNA Complementar , Humanos , Interleucinas/metabolismo , Interleucinas/fisiologia , Proteínas de Membrana/isolamento & purificação , Proteínas de Membrana/fisiologia , Estrutura Terciária de Proteína , Proteoma , Receptores de Interleucina/fisiologiaRESUMO
LFA-1 (leukocyte function-associated antigen-1), is a member of the beta(2)-integrin family and is expressed on all leukocytes. The LFA-1/ICAM interaction promotes tight adhesion between activated leukocytes and the endothelium, as well as between T cells and antigen-presenting cells. Evidence from both animal models and clinical trials provides support for LFA-1 as a target in several different inflammatory diseases. This paper describes the de novo design, synthesis and in vitro activity of LFA-1 antagonists based on a bicyclic[5.5]hydantoin scaffold.
Assuntos
Hidantoínas/síntese química , Antígeno-1 Associado à Função Linfocitária/efeitos dos fármacos , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Desenho de Fármacos , Células HeLa , Humanos , Hidantoínas/farmacologia , Inflamação/tratamento farmacológico , Concentração Inibidora 50 , Molécula 1 de Adesão Intercelular/química , Antígeno-1 Associado à Função Linfocitária/química , Conformação Molecular , Ligação Proteica/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
A series of novel small molecule inhibitors of inosine monophosphate dehydrogenase (IMPDH), based upon a 3-cyanoindole core, were explored. IMPDH catalyzes the rate determining step in guanine nucleotide biosynthesis and is a target for anticancer, immunosuppressive and antiviral therapy. The synthesis and the structure-activity relationships (SAR), derived from in vitro studies, for this new series of inhibitors is given.
Assuntos
Inibidores Enzimáticos/farmacologia , IMP Desidrogenase/antagonistas & inibidores , Indóis/farmacologia , Catálise , Cinética , Relação Estrutura-AtividadeRESUMO
The first reported structure-activity relationships (SARs) about the N-[3-methoxy-4-(5-oxazolyl)phenyl moiety for a series of recently disclosed inosine monophosphate dehydrogenase (IMPDH) inhibitors are described. The syntheses and in vitro inhibitory values for IMPDH II, and T-cell proliferation (for select analogues) are given.
Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , IMP Desidrogenase/antagonistas & inibidores , Oxazóis/química , Oxazóis/farmacologia , Animais , Carbamatos/química , Carbamatos/farmacologia , Linhagem Celular , Cricetinae , Cricetulus , Concentração Inibidora 50 , Ativação Linfocitária/efeitos dos fármacos , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/farmacologia , Oxazóis/síntese química , Compostos de Fenilureia/química , Compostos de Fenilureia/farmacologia , Relação Estrutura-Atividade , Linfócitos T/efeitos dos fármacos , Linfócitos T/fisiologiaRESUMO
The development of a series of novel indole-based inhibitors of 5'-inosine monophosphate dehydrogenase (IMPDH) is described. Various hydrogen bond acceptors at C-3 of the indole were explored. The synthesis and the structure-activity relationships (SARs) derived from in vitro studies are outlined.
Assuntos
Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , IMP Desidrogenase/antagonistas & inibidores , Indóis/química , Divisão Celular/efeitos dos fármacos , Inibidores Enzimáticos/química , Glucuronídeos/metabolismo , Humanos , Ligação de Hidrogênio , Sistema Imunitário/efeitos dos fármacos , Isoenzimas/antagonistas & inibidores , Mitógenos/farmacologia , Quinolonas/síntese química , Quinolonas/farmacologia , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Screening of our in-house compound collection led to the discovery of 5-bromo-6-amino-2-isoquinoline 1 as a weak inhibitor of IMPDH. Subsequent optimization of 1 afforded a series of novel 2-isoquinolinoaminooxazole-based inhibitors, represented by 17, with single-digit nanomolar potency against the enzyme.
Assuntos
Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , IMP Desidrogenase/antagonistas & inibidores , Isoquinolinas/síntese química , Isoquinolinas/farmacologia , Oxazóis/síntese química , Oxazóis/farmacologia , Avaliação Pré-Clínica de Medicamentos , Escherichia coli/enzimologia , Humanos , NAD/metabolismo , Relação Estrutura-AtividadeRESUMO
A series of novel quinolone-based small molecule inhibitors of inosine monophosphate dehydrogenase (IMPDH) was explored. The synthesis and the structure-activity relationships (SARs) derived from in vitro studies are described.
Assuntos
Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , IMP Desidrogenase/antagonistas & inibidores , Quinolonas/síntese química , Quinolonas/farmacologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Fenômenos Químicos , Físico-Química , Cristalografia por Raios X , Humanos , Relação Estrutura-Atividade , Linfócitos T/efeitos dos fármacos , Linfócitos T/enzimologiaRESUMO
The synthesis and the structure-activity relationships (SAR) of analogues derived from the introduction of basic residues on ring D of quinolone-based inhibitors of IMPDH are described. This led to the identification of compound 27 as a potent inhibitor of IMPDH with significantly improved aqueous solubility over the lead compound 1.
Assuntos
Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , IMP Desidrogenase/antagonistas & inibidores , Quinolonas/síntese química , Quinolonas/farmacologia , Humanos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
This unit details the use of transient expression in mammalian cells to screen cDNA libraries with monoclonal antibodies (MAb) to isolate cDNA clones encoding cell-surface and intracellular proteins. The first protocol in this unit describes the cloning of cDNAs encoding cell-surface antigens. Several steps in this protocol involve transfection procedures that are described in greater detail elsewhere in this volume. The second protocol is a modification that facilitates isolation of cDNAs encoding antigens that are expressed intracellularly. Both protocols are designed for use with the expression vector CDM8, which contains a polylinker for subcloning double-stranded cDNA.
Assuntos
Anticorpos Monoclonais/imunologia , Antígenos de Superfície/genética , Antígenos/genética , Clonagem Molecular/métodos , Expressão Gênica , Biblioteca Gênica , Animais , Antígenos/imunologia , Antígenos de Superfície/imunologia , Células COS , Chlorocebus aethiops , DEAE-Dextrano , DNA Complementar/genética , Escherichia coli/genética , Vetores Genéticos/genética , Técnicas de Imunoadsorção/instrumentação , Espaço Intracelular , Mamíferos , Cloreto de Polivinila/análogos & derivados , Esferoplastos/metabolismo , Transfecção/métodosRESUMO
BACKGROUND: Organ transplant recipients currently require lifetime immunosuppressive therapy, with its accompanying side effects. Biological agents that block T-cell costimulatory pathways are important components of strategies being developed to induce transplantation tolerance. The aim of this study was to test the effect of a novel chimeric anti-human CD40 monoclonal antibody (Chi 220), either alone or in combination with CTLA4-Ig, on the survival of renal allografts in a nonhuman primate model. METHODS: Captive-bred adolescent male rhesus monkeys (Macaca mulatta) (4-10 kg) were used as recipients and donors. Four treatment protocols were tested: Chi220 monotherapy, CTLA4-Ig monotherapy, Chi220 combined with CTLA4-Ig, and H106 (anti-CD40L) combined with CTLA4-Ig. Control animals received human albumin. Recipients were followed for survival, renal allograft function as determined by measurement of serum blood urea nitrogen (BUN) and creatinine, chemistries (sodium, potassium, chloride, and bicarbonate), complete blood cell count (CBC) with differential, and the development of donor-specific alloantibody. RESULTS: Treatment with Chi220 for 14 days prolonged renal allograft survival (MST 38.5 vs. 7 days in untreated controls). Notably, simultaneous blockade of the CD28/B7 pathway did not further augment graft survival but did suppress the development of donor-specific antibodies, an effect not achieved with Chi220 alone, despite peripheral B cell depletion. Finally, treatment with Chi220 suppressed the primary immune response to cytomegalovirus, resulting in severe systemic manifestations. CONCLUSIONS: Blockade of the CD40 pathway with anti-CD40 mAb is immunosuppressive in a large animal, preclinical renal transplant model. The potential effect of this therapy on viral immune responses will be important to consider for the design of safe clinical trials.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antígenos de Diferenciação/uso terapêutico , Antígenos CD40/imunologia , Sobrevivência de Enxerto/efeitos dos fármacos , Imunoconjugados , Transplante de Rim , Abatacepte , Animais , Anticorpos/uso terapêutico , Anticorpos Monoclonais/efeitos adversos , Formação de Anticorpos/efeitos dos fármacos , Antígenos CD , Antígenos de Diferenciação/efeitos adversos , Linfócitos B/efeitos dos fármacos , Linfócitos B/patologia , Antígenos CD28/efeitos dos fármacos , Ligante de CD40/imunologia , Antígeno CTLA-4 , Infecções por Citomegalovirus/induzido quimicamente , Infecções por Citomegalovirus/patologia , Quimioterapia Combinada , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Isoanticorpos/imunologia , Rim/patologia , Macaca mulatta , Masculino , Doadores de Tecidos , Transplante HomólogoRESUMO
A series of heterocyclic replacements for the central diamide moiety of 1, a potent small molecule inhibitor of inosine monophosphate dehydrogenase (IMPDH) were explored The synthesis and the structure-activity relationships (SARs), derived from in vitro studies, for these new series of inhibitors is given.
Assuntos
Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/farmacologia , IMP Desidrogenase/antagonistas & inibidores , Humanos , Técnicas In Vitro , Indicadores e Reagentes , Ligantes , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Modelos Moleculares , Conformação Molecular , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
A modified approach to the synthesis of 3-(oxazolyl-5-yl) indoles is reported. This method was applied to the synthesis of series of novel indole based inhibitors of inosine monophosphate dehydrogenase (IMPDH). The synthesis and the structure-activity relationships (SARs), derived from in vitro studies, for this new series of inhibitors is given.