Regeneration of immunocompetent B lymphopoiesis from pluripotent stem cells guided by transcription factors

Regeneration of functional B lymphopoiesis from pluripotent stem cells(PSCs)is challenging,and reliable methods have not been developed.Here,we unveiled the guiding role of three essential factors,Lhx2,Hoxa9,and Runx1,the simultaneous expression of which preferentially drives B lineage fate commitment and in vivo B lymphopoiesis using PSCs as a cell source.In the presence of Lhx2,Hoxa9,and Runx1 expression,PSC-derived induced hematopoietic progenitors(iHPCs)immediately gave rise to pro/pre-B cells in recipient bone marrow,which were able to further differentiate into entire B cell lineages,including innate B-1a,B-1b,and marginal zone B cells,as well as adaptive follicular B cells.In particular,the regenerative B cells produced adaptive humoral immune responses,sustained antigen-specific antibody production,and formed immune memory in response to antigen challenges.The regenerative B cells showed natural B cell development patterns of immunoglobulin chain switching and hypermutation via cross-talk with host T follicular helper cells,which eventually formed T cell-dependent humoral responses.This study exhibits de novo evidence that B lymphopoiesis can be regenerated from PSCs via an HSC-independent approach,which provides insights into treating B cell-related deficiencies using PSCs as an unlimited cell resource.

Two-step protocol for regeneration of immunocompetent T cells from mouse pluripotent stem cells

Numerous efforts have been attempted to regenerate T cells in culture dish from pluripotent stem cells(PSCs).However,in vitro generated T cells exhibited extremely low activity and compromised immunocompetency in vivo.Here,we describe a two-step protocol for regenerating functional T cells using an inducible Runx1-Hoxa9-PSC(iR9-PSCs)line.The procedure mainly includes generation of induced hematopoietic progenitor cells(iHPCs)in vitro,transplantation,and development of functional induced T cells(iT)in vivo via transplantation.The entire induction process in vitro requires 21 days before iHPCs transplantation.The development of mature T cells in vivo takes 4 to 6 weeks post-transplantation.We provide a simple and reproducible approach for functional T cell regeneration from iR9-PSCs for research purpose.

Pluripotent stem cell-derived CD 19-CAR iT cells effectively eradicate B-cell lymphoma in vivo

Chimeric antigen receptor T cell(CAR-T)therapy is one of the most promising approaches in cancer treatment.1 However,the limited availability of patient-derived T cells narrows its universal applicability.Thus,it is necessary to invent new methods to obtain alternative T-cell sources.Pluripotent stem cells(PSCs),which have unlimited culture potential and are amenable to gene editing,are ideal for generating induced T(iT)cells.