Interferon alpha 2a

The hematopoietic progenitor cells generated from modified iPSCs at 5 × 10⁴ cells/ml were cultured in the absence or presence of drugs which had potentials to treat MPN patients, 0.5 µg/ml interferon alpha-2a (Roche, New Jersey, USA) and/or 250 nM arsenic trioxide (M&B, London, United Kingdom)^{40 (link),41 (link)}.
The yields of total erythroid cells were enumerated as above. The percentage and relative changes of cell deaths were determined using FITC-conjugated anti-human Glycophorin A (Clone HI264, BioLegend) and propidium iodide (#421301, BioLegend). The results were compared between with vs. without doxycycline to determine the differential effects on mutated vs. normal cells, respectively.

Five antibodies IgG1s (PPI02, PPI03, PPI04, PPI10, PPI13), one bispecific antibody (PPI08), one IgG2 (PPI17), and one HSA-fusion protein (PPI18) were provided by AstraZeneca (Cambridge, UK). Interferon alpha-2a (PPI30) was provided from Roche Diagnostics GmbH. A summary of the protein’s physical properties is listed in Table 1. The proteins were dialyzed overnight using Slide-A-Lyzer™ cassettes (Thermo Fisher Scientific, Waltham, USA) with suitable membrane cut-off against excess of 10 mM of histidine HCl buffer with pH 5.0, 5.5, 6.0, 6.5, 7.0, 7.5. The excipient (e.g. NaCl) stock solutions were prepared in the respective buffers. Protein concentration was measured on a Nanodrop 2000 (Thermo Fisher Scientific, Waltham, USA) using the protein extinction coefficient calculated from the primary sequence. All conditions were prepared in 1.5 mL non-coated PP Eppendorf tubes. Finally, the formulations were sterile-filtered with 0.22 μm cellulose acetate filters from VWR International (Darmstadt, Germany). The purity of the proteins was studied by SEC and cEIF (SI 5).