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A7398 - Therapeutic Effects of the Generated Antibodies Targeting Human Resistin in Pulmonary Hypertension
Author Block: Q. Lin1, C. Fan1, J. Skinner1, D. Bedja2, K. Van Raemdonck3, M. Nakahara1, K. Kegan1, R. A. Johns1; 1Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Rheumatology, University of Illinois at Chicago, Chicago, IL, United States.
Rationale: Pulmonary arterial hypertension (PH) is a complex and multifactorial disease with poor clinical outcome. The resistin-like molecule (RELM) family proteins are critically involved in the pathogenesis of PH. Our previously rodent work strongly suggested that human resistin (hResistin) is mechanistically important to the etiology of human PH and constitutes a therapeutic target for this disease. In this study, we aimed to develop human antibodies (Abs) against hResistin with target validation, and investigate the therapeutic effects of these generated Abs on pulmonary vascular remodeling and PH development.
Methods: The monoclonal antibody approach was applied for the anti-hResistin Ab production. The in vivo rat model of the hypoxia-induced PH, and the in vitro cell culture with the hResistin-treated human bronchial smooth muscle cells (BSMCs), were employed for testing the biological neutralizing activities and therapeutic effects of the generated Abs.
Results: Screening of the resulting hybridoma cell lines were conducted by direct ELISA with the original target peptides and recombinant proteins. The short-listed prepared candidate Abs were further validated and ranked for their in vitro efficacy against the potent mitogenic activities of hResistin in the human BSMCs measured by BrdU assay. The human lead Abs also exhibited the capability of blocking rodent RELM actions in the same human cell assays, and the duration of their in vivo administration was demonstrated, This formed the basis for in vivo experiments to determine if application of these anti-hResistin Abs could be therapeutically efficacious in the chronic hypoxia-induced rodent PH model—a critical step in moving these antibodies toward human use. Each of the lead Abs were found effective at reducing vascular wall thickness, decreasing right ventricular pressure, and ameliorating right ventricular hypertrophy. Echocardiography assessment further showed the attenuated cardiac hypertrophy, diminished right ventricle thickness and improved PAT/PET ratios in the Ab-treated hypoxic rats.
Conclusion: We successfully established the monoclonal anti-hResistin human Abs as a novel therapy for PH. Using hResistin-treated human SMC cells and a hypoxic rat PH model, the in vitro anti-proliferative activities and in vivo anti-PH effects of these Abs were demonstrated. This supports a potential role in human PH and warrants more functional PH efficacy studies to further evaluate and optimize the preparation and regimen of these Abs before their clinical toxicology, manufacturing and application in human trials.