A Novel Fusion of IL-10 Engineered to Traffic across Intestinal Epithelium to Treat Colitis.

IL-10 is a potent anti-inflammatory cytokine capable of suppressing a number of proinflammatory signals associated with intestinal inflammatory diseases, such as ulcerative colitis and Crohn's disease. Clinical use of human IL-10 (hIL-10) has been limited by anemia and thrombocytopenia following systemic injection, side effects that might be eliminated by a gut-restricted distribution. We have identified a transcytosis pathway used by cholix, an exotoxin secreted by nonpandemic forms of the intestinal pathogen A nontoxic fragment of the first 386 aa of cholix was genetically fused to hIL-10 to produce recombinant AMT-101.

Protein effects on surfactant adsorption suggest the dominant mode of surfactant-mediated stabilization of protein.

Surfactants stabilize proteins through two major mechanisms: (1) their preferential location at nearby interfaces, in this way precluding protein adsorption; and/or (2) their association with protein into "complexes" that prevent proteins from interacting with surfaces as well as each other. However, selection of surfactants for protein stabilization currently is not typically made with benefit of any quantitative, predictive information to ensure that either mechanism will be enforced. We compared surface tension depression by poloxamer 188, polysorbate (PS) 80, and PS 20 in the presence and absence of lysozyme or a recombinant protein.

Modulation of protein adsorption by poloxamer 188 in relation to polysorbates 80 and 20 at solid surfaces.

Poloxamer 188 (BASF Pluronic® F68) is widely used as a shear-protective excipient to enhance cell yield in agitated cultures and reduce cell adhesion in stationary cultures. However, little is known in any quantitative sense of its effect on protein adsorption and aggregation. Optical waveguide lightmode spectroscopy was used here to compare the adsorption kinetics exhibited by poloxamer 188, and polysorbates 80 and 20, in the presence and absence of a model protein (chicken egg white lysozyme) and in separate experiments, a recombinant protein (human granulocyte colony-stimulating factor) at hydrophilic, silica-titania surfaces.