FcRn binding is not sufficient for achieving systemic therapeutic levels of immunoglobulin G after oral delivery of enteric-coated capsules in cynomolgus macaques.

Although much speculation has surrounded intestinally expressed FcRn as a means for systemic uptake of orally administered immunoglobulin G (IgG), this has not been validated in translational models beyond neonates or in FcRn-expressing cells in vitro. Recently, IgG1 intestinal infusion acutely in anesthetized cynomolgus resulted in detectable serum monoclonal antibody (mAb) levels. In this study, we show that IgG2 has greater protease resistance to intestinal enzymes in vitro and mice in vivo, due to protease resistance in the hinge region.

The contribution of cell surface FcRn in monoclonal antibody serum uptake from the intestine in suckling rat pups.

The neonatal Fc receptor (FcRn) in intestinal epithelium is the primary mechanism for transfer of maternal immunoglobulin G (IgG) from suckled milk to serum; but the factors contributing to the rapid uptake of IgG are poorly understood. These studies help to determine the contribution of cell surface FcRn in IgG uptake in 2-week-old rat pups by varying local pH and binding conditions. Variants of a human wild-type (WT) IgG monoclonal antibody (mAb WT) were assessed for binding affinity (KD) to rat (r)FcRn at pH 6.

EGF potentiation of VEGF production is cell density dependent in H292 EGFR wild type NSCLC cell line.

Non-small cell lung cancer (NSCLC) affects millions of patients each year worldwide. Existing therapies include epidermal growth factor receptor (EGFR) inhibition using small molecules or antibodies with good efficacy. Unfortunately, intrinsic and acquired resistance to EGFR therapy remains a persistent complication for disease treatment.

Human and non-human primate intestinal FcRn expression and immunoglobulin G transcytosis.

Purpose: To evaluate transcytosis of immunoglobulin G (IgG) by the neonatal Fc receptor (FcRn) in adult primate intestine to determine whether this is a means for oral delivery of monoclonal antibodies (mAbs).

Methods: Relative regional expression of FcRn and localization in human intestinal mucosa by RT-PCR, ELISA & immunohistochemistry. Transcytosis of full-length mAbs (sandwich ELISA-based detection) across human intestinal segments mounted in Ussing-type chambers, human intestinal (caco-2) cell monolayers grown in transwells, and serum levels after regional intestinal delivery in isoflurane-anesthetized cynomolgus monkeys.

Alternative functional in vitro models of human intestinal epithelia.

Physiologically relevant sources of absorptive intestinal epithelial cells are crucial for human drug transport studies. Human adenocarcinoma-derived intestinal cell lines, such as Caco-2, offer conveniences of easy culture maintenance and scalability, but do not fully recapitulate in vivo intestinal phenotypes. Additional sources of renewable physiologically relevant human intestinal cells would provide a much needed tool for drug discovery and intestinal physiology.

Dynamic mass redistribution as a means to measure and differentiate signaling via opioid and cannabinoid receptors.

Classically, G protein-coupled receptor activation by a ligand has been viewed as producing a defined response such as activation of a G protein, activation or inhibition of adenylyl cyclase, or stimulation of phospholipase C and/or alteration in calcium flux. Newer concepts of ligand-directed signaling recognize that different ligands, ostensibly acting at the same receptors, may induce different downstream effects, complicating the selection of a screening assay. Dynamic mass redistribution (DMR), a label-free technology that uses light to measure ligand-induced changes in the mass of cells proximate to the biosensor, provides an integrated cellular response comprising multiple pathways and cellular events.

Diabetogenic effect of a series of tricyclic delta opioid agonists structurally related to cyproheptadine.

The unexpected observation of a hyperglycemic effect of some tricycle-based delta opioid receptor (DOR) agonists led to a series of studies to better understand the finding. Single administration of two novel tricyclic DOR agonists dose dependently elevated rat plasma glucose levels; 4-week toxicology studies confirmed the hyperglycemic finding and further revealed pancreatic β-cell hypertrophy, including vacuole formation, as well as bone dysplasia and Harderian gland degeneration with regeneration. Similar diabetogenic effects were observed in dog.

Triazinediones as prokineticin 1 receptor antagonists. Part 1: SAR, synthesis and biological evaluation.

A series of guanidine triazinediones were identified as potent PK1 receptor antagonists. A compound in this series inhibited the PK1 invoked prosecretory response in rat ileum tissue.