Process data of allogeneic ex vivo-expanded ABCB5+ mesenchymal stromal cells for human use: off-the-shelf GMP-manufactured donor-independent ATMP

Abstract

Background Human dermal mesenchymal stromal cells (MSCs) expressing the ATP-binding cassette (ABC) efflux transporter ABCB5 represent an easily accessible MSC population that, based on preclinical and first-in-human data, holds significant promise to treat a broad spectrum of conditions associated not only with skin-related but also systemic inflammatory and/or degenerative processes. Methods We have developed a validated Good Manufacturing Practice-compliant expansion and manufacturing process by which ABCB5+ MSCs derived from surgical discard skin tissues are processed to an advanced-therapy medicinal product (ATMP) for clinical use. Enrichment for ABCB5+ MSCs is achieved in a three-step process involving plastic adherence selection, expansion in a highly efficient MSC-selecting medium, and immunomagnetic isolation of the ABCB5+ cells from the mixed culture. Results Product Quality Review data covering 324 cell expansions, 728 ABCB5+ MSC isolations, 66 ABCB5+ MSC batches, and 85 final drug products reveal high process robustness and reproducible, reliable quality of the manufactured cell therapy product. Conclusion We have successfully established an expansion and manufacturing process that enables the generation of homogenous ABCB5+ MSC populations of proven biological activity manufactured as a standardized, donor-independent, highly pure, and highly functional off-the-shelf available ATMP, which is currently tested in multiple clinical trials.

Therapeutic Use of Mesenchymal Stromal Cells: The Need for Inclusive Characterization Guidelines to Accommodate All Tissue Sources and Species

“…Other markers, such as Stro-1, CD271, CD362, and ABCB5, are also considered as MSC markers by some researchers and even used for MSC flow sorting (Ning et al, 2011 ; Álvarez-Viejo et al, 2015 ; Ballikaya et al, 2020 ; Gonzalez et al, 2020 ). However, in our review we did not find these antibodies to be as available for other species or as well-demonstrated in the literature as CD29 and CD44.…”

Process development and safety evaluation of ABCB5+ limbal stem cells as advanced-therapy medicinal product to treat limbal stem cell deficiency

“…4 b). Regarding the cells’ biological activity, it had to be ruled out that the fibrin gel could create a hypoxic environment that, in turn, would stimulate the LSCs to secrete proangiogenic factors such as VEGF, as is known, e.g., for ABCB5 + mesenchymal stem cells [ 31 ]. Such adaptive secretion of proangiogenic factors would facilitate angiogenesis and thus jeopardize therapeutic success.…”

“…Nuclei were counterstained with DAPI (10–12 min). For positive control, human corneal epithelial cells (Life Technologies, Darmstadt, Germany; for ΔNp63, CK3/CK12, PAX6), human skin-derived mesenchymal stem cells (TICEBA [ 31 ]; for vimentin, connexin 43) and human skin malignant melanoma cells (SK-MEL-28, ATCC® HTB-72™, LGC Standards, Wesel, Germany; for MART-1) were used. Stains were evaluated microscopically (Leica DMi8 microscope, Leica Microsystems, Wetzlar, Germany; or Floid™ cell imaging station, Life Technologies, Darmstadt, Germany).…”

ABCB5+ Dermal Mesenchymal Stromal Cells with Favorable Skin Homing and Local Immunomodulation for Recessive Dystrophic Epidermolysis Bullosa Treatment

“…Human ABCB5+ DSCs (>95% ABCB5+ expression) and donor-matched ABCB5− cell fractions (<2% ABCB5+ expression) were isolated by TICEBA (Heidelberg, Germany). ABCB5+ DSCs were enriched and isolated from reticular dermis primary cell cultures of healthy skin donors as previously described, 21,22 whereas the remaining negative…”

“…ABCB5+ DSCs have shown promise in the field of regenerative medicine, which makes them of interest in treatment for RDEB. [20][21][22] Intradermal injections of ABCB5+ DSCs promoted healing in a chronic venous ulcer murine model, with an increase in M2 macrophages in the wound bed. 16 Our group has shown that neonatal injections of ABCB5+ DSCs in a Col7a1 −/− RDEB murine model significantly prolonged survival compared to phosphate buffered saline (PBS) control injected animals, with ABCB5+ DSC-treated mice showing decreased M1 macrophage skin infiltration.…”