RESUMO
FMS-related tyrosine kinase 3 ligand (FLT3L), encoded by FLT3LG, is a hematopoietic factor essential for the development of natural killer (NK) cells, B cells, and dendritic cells (DCs) in mice. We describe three humans homozygous for a loss-of-function FLT3LG variant with a history of various recurrent infections, including severe cutaneous warts. The patients' bone marrow (BM) was hypoplastic, with low levels of hematopoietic progenitors, particularly myeloid and B cell precursors. Counts of B cells, monocytes, and DCs were low in the patients' blood, whereas the other blood subsets, including NK cells, were affected only moderately, if at all. The patients had normal counts of Langerhans cells (LCs) and dermal macrophages in the skin but lacked dermal DCs. Thus, FLT3L is required for B cell and DC development in mice and humans. However, unlike its murine counterpart, human FLT3L is required for the development of monocytes but not NK cells.
Assuntos
Células Matadoras Naturais , Proteínas de Membrana , Animais , Feminino , Humanos , Masculino , Camundongos , Linfócitos B/metabolismo , Linfócitos B/citologia , Medula Óssea/metabolismo , Linhagem da Célula , Células Dendríticas/metabolismo , Hematopoese , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/citologia , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/imunologia , Células de Langerhans/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Monócitos/metabolismo , Pele/metabolismo , Camundongos Endogâmicos C57BLRESUMO
X-linked chronic granulomatous disease (CGD) is associated with defective phagocytosis, life-threatening infections, and inflammatory complications. We performed a clinical trial of lentivirus-based gene therapy in four patients (NCT02757911). Two patients show stable engraftment and clinical benefits, whereas the other two have progressively lost gene-corrected cells. Single-cell transcriptomic analysis reveals a significantly lower frequency of hematopoietic stem cells (HSCs) in CGD patients, especially in the two patients with defective engraftment. These two present a profound change in HSC status, a high interferon score, and elevated myeloid progenitor frequency. We use elastic-net logistic regression to identify a set of 51 interferon genes and transcription factors that predict the failure of HSC engraftment. In one patient, an aberrant HSC state with elevated CEBPß expression drives HSC exhaustion, as demonstrated by low repopulation in a xenotransplantation model. Targeted treatments to protect HSCs, coupled to targeted gene expression screening, might improve clinical outcomes in CGD.
Assuntos
Doença Granulomatosa Crônica , Transplante de Células-Tronco Hematopoéticas , Humanos , Terapia Genética/efeitos adversos , Doença Granulomatosa Crônica/diagnóstico , Doença Granulomatosa Crônica/genética , Doença Granulomatosa Crônica/terapia , Células-Tronco Hematopoéticas/metabolismo , Inflamação/metabolismo , Interferons/metabolismoRESUMO
Long-term multilineage hematopoietic donor chimerism occurs sporadically in patients who receive a transplanted solid organ enriched in lymphoid tissues such as the intestine or liver. There is currently no evidence for the presence of kidney-resident hematopoietic stem cells in any mammal species. Graft-versus-host-reactive donor T cells promote engraftment of graft-derived hematopoietic stem cells by making space in the bone marrow. Here, we report full (over 99%) multilineage, donor-derived hematopoietic chimerism in a pediatric kidney transplant recipient with syndromic combined immune deficiency that leads to transplant tolerance. Interestingly, we found that the human kidney-derived hematopoietic stem cells took up long-term residence in the recipient's bone marrow and gradually replaced their host counterparts, leading to blood type conversion and full donor chimerism of both lymphoid and myeloid lineages. Thus, our findings highlight the existence of human kidney-derived hematopoietic stem cells with a self-renewal ability able to support multilineage hematopoiesis.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas , Animais , Humanos , Criança , Medula Óssea , Linfócitos T , Hematopoese , Rim , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Medula Óssea , MamíferosRESUMO
In gene therapy with human hematopoietic stem and progenitor cells (HSPCs), each gene-corrected cell and its progeny are marked in a unique way by the integrating vector. This feature enables lineages to be tracked by sampling blood cells and using DNA sequencing to identify the vector integration sites. Here, we studied 5 cell lineages (granulocytes, monocytes, T cells, B cells, and natural killer cells) in patients having undergone HSPC gene therapy for Wiskott-Aldrich syndrome or ß hemoglobinopathies. We found that the estimated minimum number of active, repopulating HSPCs (which ranged from 2000 to 50 000) was correlated with the number of HSPCs per kilogram infused. We sought to quantify the lineage output and dynamics of gene-modified clones; this is usually challenging because of sparse sampling of the various cell types during the analytical procedure, contamination during cell isolation, and different levels of vector marking in the various lineages. We therefore measured the residual contamination and corrected our statistical models accordingly to provide a rigorous analysis of the HSPC lineage output. A cluster analysis of the HSPC lineage output highlighted the existence of several stable, distinct differentiation programs, including myeloid-dominant, lymphoid-dominant, and balanced cell subsets. Our study evidenced the heterogeneous nature of the cell lineage output from HSPCs and provided methods for analyzing these complex data.
Assuntos
Células Clonais/citologia , Terapia Genética , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/citologia , Hemoglobinopatias/terapia , Síndrome de Wiskott-Aldrich/terapia , Diferenciação Celular , Rastreamento de Células , Células Clonais/metabolismo , Técnicas de Transferência de Genes , Terapia Genética/métodos , Vetores Genéticos/genética , Transplante de Células-Tronco Hematopoéticas/métodos , Células-Tronco Hematopoéticas/metabolismo , Hemoglobinopatias/genética , Humanos , Síndrome de Wiskott-Aldrich/genéticaRESUMO
Lentiviral vectors have emerged as an efficient, safe therapeutic tool for gene therapy based on hematopoietic stem cells (HSCs) or T cells. However, the monitoring of transduced cells in preclinical models remains challenging because of the inefficient transduction of murine primary T cells with lentiviral vectors, in contrast to gammaretroviral vectors. The use of this later in preclinical proof of concept is not considered as relevant when a lentiviral vector will be used in a clinical trial. Hence, there is an urgent need to develop an efficient transduction protocol for murine cells with lentiviral vectors. Here, we describe an optimized protocol in which a nontoxic transduction enhancer (Lentiboost) enables the efficient transduction of primary murine T cells with lentiviral vectors. The optimized protocol combines low toxicity and high transduction efficiency. We achieved a high-level transduction of murine CD4+ and CD8+ T cells with a VSV-G-pseudotyped lentiviral vector with no changes in the phenotypes of transduced T cells, which were stable and long-lived in culture. This enhancer also increased the transduction of murine HSCs. Hence, use of this new transduction enhancer overcomes the limitations of lentiviral vectors in preclinical experiments and should facilitate the translation of strategies based on lentiviral vectors from the bench to the clinic.