Separation of oxidized variants of a monoclonal antibody by anion-exchange.

Monoclonal antibodies are subject to a variety of degradation mechanisms, therefore orthogonal techniques are required to demonstrate product quality. In this study, the three individual antibodies comprising a multi-antibody drug product, XOMA 3AB were evaluated by both cation-exchange (CEX) and anion-exchange chromatography (AEX). In contrast to CEX analysis which showed only a single, broad peak for the force-oxidized antibodies, AEX analysis of Ab-A (pI=7.

Polymyxin B enhances ISS-mediated immune responses across multiple species.

The immunostimulatory effects of bacterial DNA on mammalian cells have been localized to unmethylated CpG motifs, and synthetic CpG-containing oligodeoxynucleotides that mimic these effects are known as immunostimulatory sequences (ISS). We have found that the polycationic antibiotic, polymyxin B (PMXB), associates with ISS and serum albumin in vitro and forms microparticles that greatly increase the activity of ISS on plasmacytoid dendritic cells (PDCs). Specifically, ISS/PMXB greatly enhanced IFN-alpha production from PDCs and other activities downstream of IFN-alpha, including IFN-gamma secretion, NK lytic activity, and the expression of genes dependent upon IFN-alpha/IFN-gamma.

A minimal human immunostimulatory CpG motif that potently induces IFN-gamma and IFN-alpha production.

Recent reports have shown that immunostimulatory sequences (ISS) containing CpG motifs have minimal length requirements (>/=12 bases) for the exertion of immune-enhancing function upon mammalian cells. Herein we demonstrate that short ISS (5-7 bases), which exhibit no activity on their own, induce IFN-gamma and IFN-alpha secretion from human peripheral blood mononuclear cells when adsorbed to the surface of cationic poly(D,L-lactide-co-glycolide) microparticles (cPLGA). Utilizing this technique, we discovered a minimal ISS sequence for induction of IFN-gamma and IFN-alpha from human cells: 5'-TCGXX-3'.