GMP-grade neural progenitor derivation and differentiation from clinical-grade human embryonic stem cells.

BACKGROUND: A major challenge for the clinical use of human pluripotent stem cells is the development of safe, robust and controlled differentiation protocols. Adaptation of research protocols using reagents designated as research-only to those which are suitable for clinical use, often referred to as good manufacturing practice (GMP) reagents, is a crucial and laborious step in the translational pipeline. However, published protocols to assist this process remain very limited. METHODS: We adapted research-grade protocols for the derivation and differentiation of long-term neuroepithelial stem cell progenitors (lt-NES) to GMP-grade reagents and factors suitable for clinical applications. We screened the robustness of the protocol with six clinical-grade hESC lines deposited in the UK Stem Cell Bank. RESULTS: Here, we present a new GMP-compliant protocol to derive lt-NES, which are multipotent, bankable and karyotypically stable. This protocol resulted in robust and reproducible differentiation of several clinical-grade embryonic stem cells from which we derived lt-NES. Furthermore, GMP-derived lt-NES demonstrated a high neurogenic potential while retaining the ability to be redirected to several neuronal sub-types. CONCLUSIONS: Overall, we report the feasibility of derivation and differentiation of clinical-grade embryonic stem cell lines into lt-NES under GMP-compliant conditions. Our protocols could be used as a flexible tool to speed up translation-to-clinic of pluripotent stem cells for a variety of neurological therapies or regenerative medicine studies.

Extracellular HMGB1 promotes differentiation of nurse-like cells in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is a disease of an accumulation of mature B cells that are highly dependent on the microenvironment for maintenance and expansion. However, little is known regarding the mechanisms whereby CLL cells create their favorable microenvironment for survival. High-mobility group protein B-1 (HMGB1) is a highly conserved nuclear protein that can be actively secreted by innate immune cells and passively released by injured or dying cells. We found significantly increased HMGB1 levels in the plasma of CLL patients compared with healthy controls, and HMGB1 concentration is associated with absolute lymphocyte count. We therefore sought to determine potential roles of HMGB1 in modulating the CLL microenvironment. CLL cells passively released HMGB1, and the timing and concentrations of HMGB1 in the medium were associated with differentiation of nurse-like cells (NLCs). Higher CD68 expression in CLL lymph nodes, one of the markers for NLCs, was associated with shorter overall survival of CLL patients. HMGB1-mediated NLC differentiation involved internalization of both receptor for advanced glycation end products (RAGE) and Toll-like receptor-9 (TLR9). Differentiation of NLCs can be prevented by blocking the HMGB1-RAGE-TLR9 pathway. In conclusion, this study demonstrates for the first time that CLL cells might modulate their microenvironment by releasing HMGB1.