ABSTRACT
Background And Aims: S100A8 and S100A9 alarmins and their heterodimer calprotectin are diversely involved in myeloid neoplasm pathophysiology as well as infectious and inflammatory diseases. In the context of COVID-19, circulating calprotectin was identified as a powerful biomarker of disease severity. Calprotectin impact on CD34+ hematopoietic stem and progenitor cells remains poorly understood. Method(s): Calprotectin effects on healthy donor and chronic myeloid neoplasm-derived CD34-positive hematopoietic stem and progenitor cells were tested in liquid culture for up to 7 days. The pro-inflammatory cytokine IL-6 was used as a control. Cytokine effects alone or in combination were explored by the use of bulk and single cell RNA sequencing, Assay for Transposase-Accessible Chromatin with high-throughput sequencing, cytokine secretion analyses and semi-solid cultures. Result(s): CD34+ cells exposed to IL-6 generate monocytic cells that overproduce calprotectin. Calprotectin inhibits erythroid differentiation of healthy CD34+ cells, possibly through CD36 receptor. Chronic myeloid neoplasm CD34+ cells over-react to calprotectin, with large transcriptomic rewiring of erythro-megakarocytic and granulo-monocytic populations. Calprotectin-induced inhibition of erythroid progenitor proliferation correlates with increased synthesis of ribosomal subunits and p53 pathway activation, while the cytokine impact on granulo-monocytic cells indicates an autocrine or paracrine amplification loop. Conclusion(s): Calprotectin secreted by monocytes generated by CD34+ cells upon IL-6 stimulation may be a pathophysiological component of inflammatory anemia, a role that is amplified in the context of myeloid neoplasms in which calprotectin effects extend to the granulo-monocytic lineage.Copyright © 2023 Elsevier Ltd. All rights reserved.
ABSTRACT
In recent years, acceleration of development timelines has become a major focus within the biopharmaceutical industry to bring innovative therapies faster to patients. However, in order to address a high unmet medical need even faster further acceleration potential has to be identified to transform "speed-to-clinic" concepts into "warp-speed" development programs. Recombinant Chinese hamster ovary (CHO) cell lines are the predominant expression system for monoclonal antibodies (mAbs) and are routinely generated by random transgene integration (RTI) of the genetic information into the host cell genome. This process, however, exhibits considerable challenges such as the requirement for a time-consuming clone screening process to identify a suitable clonally derived manufacturing cell line. Hence, RTI represents an error prone and tedious method leading to long development timelines until availability of Good Manufacturing Practice (GMP)-grade drug substance (DS). Transposase-mediated semi-targeted transgene integration (STI) has been recently identified as a promising alternative to RTI as it allows for a more rapid generation of high-performing and stable production cell lines. In this report, we demonstrate how a STI technology was leveraged to develop a very robust DS manufacturing process based on a stable pool cell line at unprecedented pace. Application of the novel strategy resulted in the manufacturing of GMP-grade DS at 2,000 L scale in less than three months paving the way for a start of Phase I clinical trials only six months after transfection. Finally, using a clonally derived production cell line, which was established from the parental stable pool, we were able to successfully implement a process with an increased mAb titer of up to 5 g per liter at the envisioned commercial scale (12,000 L) within eight months.