RESUMO
Provoked by sterile/nonsterile insults, prolonged monocyte mobilization and uncontrolled monocyte/macrophage activation can pose imminent or impending harm to the affected organs. Curiously, folate receptor beta (FRß), with subnanomolar affinity for the vitamin folic acid (FA), is upregulated during immune activation in hematopoietic cells of the myeloid lineage. This phenomenon has inspired a strong interest in exploring FRß-directed diagnostics/therapeutics. Previously, we have reported that FA-targeted aminopterin (AMT) therapy can modulate macrophage function and effectively treat animal models of inflammation. Our current investigation of a lead compound (EC2319) leads to discovery of a highly FR-specific mechanism of action independent of the root causes against inflammatory monocytes. We further show that EC2319 suppresses interleukin-6/interleukin-1ß release by FRß+ monocytes in a triple co-culture leukemic model of cytokine release syndrome with anti-CD19 chimeric antigen receptor T cells. Because of its chemical stability and metabolically activated linker, EC2319 demonstrates favorable pharmacokinetic characteristics and cross-species translatability to support future pre-clinical and clinical development.
Assuntos
Aminopterina/farmacologia , Síndrome da Liberação de Citocina/prevenção & controle , Receptor 2 de Folato/genética , Antagonistas do Ácido Fólico/farmacologia , Ácido Fólico/metabolismo , Macrófagos/efeitos dos fármacos , Animais , Antígenos CD19/genética , Antígenos CD19/imunologia , Células CHO , Cricetulus , Síndrome da Liberação de Citocina/genética , Síndrome da Liberação de Citocina/imunologia , Síndrome da Liberação de Citocina/patologia , Feminino , Receptor 1 de Folato/antagonistas & inibidores , Receptor 1 de Folato/genética , Receptor 1 de Folato/imunologia , Receptor 2 de Folato/antagonistas & inibidores , Receptor 2 de Folato/imunologia , Humanos , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Modelos Biológicos , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Monócitos/patologia , Células RAW 264.7 , Ratos , Ratos Endogâmicos Lew , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/patologiaRESUMO
Arsenic trioxide (ATO, As2 O3 ) is currently used to treat acute promyelocytic leukemia. However, expanding its use to include high-dose treatment of other cancers is severely hampered by serious side effects on healthy organs. To address these limitations, we loaded ATO onto folate (FA)-labeled human serum albumin (HSA) pretreated with glutathione (GSH) based on the low pH- and GSH-sensitive arsenic-sulfur bond, and we termed the resulting smart nanodrug as FA-HSA-ATO. FA-HSA-ATO could specifically recognize folate receptor-ß-positive (FRß+) chronic myeloid leukemia (CML) cells, resulting in more intracellular accumulation of ATO. Furthermore, the nanodrug could upregulate FRß expression in CML cancer cells and xenograft tumor model, facilitating even more recruitment and uptake of FRß-targeting drugs. Inâ vitro and inâ vivo experiments indicate that the nanodrug significantly alleviates side effects and improves therapeutic efficacy of ATO on CML and xenograft tumor model.
Assuntos
Antineoplásicos/farmacologia , Trióxido de Arsênio/farmacologia , Receptor 2 de Folato/antagonistas & inibidores , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Nanopartículas/química , Albumina Sérica Humana/química , Animais , Antineoplásicos/química , Trióxido de Arsênio/química , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Receptor 2 de Folato/metabolismo , Humanos , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Camundongos , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Relação Estrutura-AtividadeRESUMO
INTRODUCTION: We previously demonstrated that synovial sublining macrophages express folate receptor beta (FRß). The aim of this study was to evaluate the efficacy of intra-articular administration of a recombinant immunotoxin to FRß for treating rat antigen-induced arthritis. METHODS: A monoclonal antibody (mAb) to rat FRß was produced by immunizing mice with B300-19 cells (murine pre-B cells) transfected with the rat FRß gene. Recombinant immunotoxin was prepared by conjugating the Fv portion of the anti-rat FRß mAb heavy chain with a truncated Pseudomonas exotoxin A and the Fv portion of the anti-rat FRß mAb light chain. Antigen-induced arthritis was induced through intra-articular injection of methylated bovine serum albumin (mBSA) after two subcutaneous injections of mBSA and complete Freund's adjuvant. Immunotoxin was intra-articularly injected into the arthritis joint every other day for seven days after arthritis onset. Joint swelling was measured and histological scores of inflammation, synovial thickness, cartilage, and bone destruction were determined. Immunohistochemistry was performed to detect osteoclast and osteoclast precursor FRß-expressing macrophages and cathepsin K-positive cells on day 21. RESULTS: Intra-articular administration of the immunotoxin attenuated joint swelling (61% suppression; P < 0.01 compared to the control on day 21) and improved histological findings, particularly cartilage and bone destruction (scores of rats treated with control versus the immunotoxin: 2.2 versus 0.5; P < 0.01), by reducing the number of FRß-expressing macrophages and cathepsin K-positive cells. CONCLUSIONS: Intra-articular administration of an immunotoxin to FRß is effective for improving rat antigen-induced arthritis.