RESUMO
Modeling the tumor-immune cell interactions in humanized mice is complex and limits drug development. Here, we generated easily accessible tumor models by transforming either primary skin fibroblasts or induced pluripotent stem cell-derived cell lines injected in immune-deficient mice reconstituted with human autologous immune cells. Our results showed that fibroblastic, hepatic, or neural tumors were all efficiently infiltrated and partially or totally rejected by autologous immune cells in humanized mice. Characterization of tumor-immune infiltrates revealed high expression levels of the dysfunction markers Tim3 and PD-1 in T cells and an enrichment in regulatory T cells, suggesting rapid establishment of immunomodulatory phenotypes. Inhibition of PD-1 by Nivolumab in humanized mice resulted in increased immune cell infiltration and a slight decrease in tumor growth. We expect that these versatile and accessible cancer models will facilitate preclinical studies and the evaluation of autologous cancer immunotherapies across a range of different tumor cell types.
Assuntos
Células-Tronco Pluripotentes Induzidas , Neoplasias , Camundongos , Humanos , Animais , Células-Tronco Pluripotentes Induzidas/metabolismo , Receptor de Morte Celular Programada 1 , Neoplasias/terapia , Nivolumabe , Imunoterapia/métodosRESUMO
It is still unclear if immune responses will compromise the large-scale utilization of human induced pluripotent stem cells (hiPSCs)-derived cell therapies. To answer this question, we used humanized mouse models generated by the adoptive transfer of peripheral blood mononuclear cells or the cotransplantation of hematopoietic stem cells and human thymic tissue. Using these mice, we evaluated the engraftment in skeletal muscle of myoblasts derived either directly from a muscle biopsy or differentiated from hiPSCs or fibroblasts. Our results showed that while allogeneic grafts were mostly rejected and highly infiltrated with human T cells, engraftment of autologous cells was tolerated. We also observed that hiPSC-derived myogenic progenitor cells (MPCs) are not targeted by autologous T cells and natural killer cells in vitro. These findings suggest that the reprogramming and differentiation procedures we used are not immunogenic and that hiPSC-derived MPCs will be tolerated in the presence of a competent human immune system.
Assuntos
Células-Tronco Pluripotentes Induzidas , Transferência Adotiva , Animais , Diferenciação Celular , Reprogramação Celular , Fibroblastos , Transplante de Células-Tronco Hematopoéticas , Humanos , Células-Tronco Pluripotentes Induzidas/transplante , Leucócitos Mononucleares , Camundongos , Mioblastos , Timo/citologiaRESUMO
The safe utilization of induced pluripotent stem cell (iPSC) derivatives in clinical use is attributed to the complete elimination of the risk of forming teratomas after transplantation. The extent by which such a risk exists in immune-competent hosts is mostly unknown. Here, using humanized mice reconstituted with fetal hematopoietic stem cells and autologous thymus tissue (bone-liver-thymus humanized mice [Hu-BLT]) or following the adoptive transfer of peripheral blood mononuclear cells(PBMCs) (Hu-AT), we evaluated the capacity of immune cells to prevent or eliminate teratomas derived from human iPSCs (hiPSCs). Our results showed that the injection of hiPSCs failed to form teratomas in Hu-AT mice reconstituted with allogeneic or autologous PBMCs or purified natural killer (NK) cells alone. However, teratomas were observed in Hu-AT mice reconstituted with autologous PBMCs depleted from NK cells. In line with these results, Hu-BLT, which do not have functional NK cells, could not prevent the growth of teratomas. Finally, we found that established teratomas were not targeted by NK cells and instead were efficiently rejected by allogeneic but not autologous T cells in Hu-AT mice. Overall, our findings suggest that autologous hiPSC-derived therapies are unlikely to form teratomas in the presence of NK cells.
Assuntos
Células Matadoras Naturais/imunologia , Células-Tronco Pluripotentes/imunologia , Teratoma/prevenção & controle , Transferência Adotiva/efeitos adversos , Adulto , Animais , Humanos , Leucócitos Mononucleares/transplante , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Linfócitos T/imunologia , Teratoma/etiologia , Teratoma/imunologia , Transplante HeterólogoRESUMO
Therapeutic uses of mesenchymal stromal cells (MSCs) have emerged over the past decade. Yet, their effect on tumor growth remains highly debated, particularly in an immune competent environment. In this study, we wanted to investigate the impact of human umbilical cord-derived MSCs (hUC-MSCs) on tumor growth in humanized mice generated by the human adoptive transfer of PBMCs or the cotransplantation of hematopoietic stem cells and human thymic tissue (human BLT [Hu-BLT]). Our results showed that the growth and immune rejection of engineered human fibroblastic tumors was not altered by the injection of hUC-MSCs in immune-deficient or humanized mice, respectively. This was observed whether tumor cells were injected s.c. or i.v. and independently of the injection route of the hUC-MSCs. Moreover, only in Hu-BLT mice did hUC-MSCs have some effects on the tumor-immune infiltrate, yet without altering tumor growth. These results demonstrate that hUC-MSCs do not promote fibroblastic tumor growth and neither do they prevent tumor infiltration and rejection by immune cells in humanized mice.
Assuntos
Linfócitos do Interstício Tumoral/imunologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/imunologia , Transferência Adotiva , Animais , Linhagem Celular Transformada/transplante , Fibroblastos/transplante , Vetores Genéticos , Rejeição de Enxerto/imunologia , Xenoenxertos , Humanos , Injeções Intravenosas , Injeções Subcutâneas , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Transplante de Neoplasias , Neoplasias Experimentais/imunologia , Quimera por Radiação , Organismos Livres de Patógenos Específicos , Telomerase/genética , Telomerase/fisiologia , Timo/transplante , Geleia de Wharton/citologiaRESUMO
Ischemic myocardial injury results in sterile cardiac inflammation that leads to tissue repair, two processes controlled by mononuclear phagocytes. Despite global burden of cardiovascular diseases, we do not understand the functional contribution to pathogenesis of specific cardiac mononuclear phagocyte lineages, in particular dendritic cells. To address this limitation, we used detailed lineage tracing and genetic studies to identify bona fide murine and human CD103+ conventional dendritic cell (cDC)1s, CD11b+ cDC2s, and plasmacytoid DCs (pDCs) in the heart of normal mice and immunocompromised NSG mice reconstituted with human CD34+ cells, respectively. After myocardial infarction (MI), the specific depletion of cDCs, but not pDCs, improved cardiac function and prevented adverse cardiac remodeling. Our results showed that fractional shortening measured after MI was not influenced by the absence of pDCs. Interestingly, however, depletion of cDCs significantly improved reduction in fractional shortening. Moreover, fibrosis and cell areas were reduced in infarcted zones. This correlated with reduced numbers of cardiac macrophages, neutrophils, and T cells, indicating a blunted inflammatory response. Accordingly, mRNA levels of proinflammatory cytokines IL-1ß and IFN-γ were reduced. Collectively, our results demonstrate the unequivocal pathological role of cDCs following MI.
Assuntos
Movimento Celular/imunologia , Células Dendríticas/imunologia , Infarto do Miocárdio/imunologia , Animais , Movimento Celular/genética , Células Dendríticas/patologia , Humanos , Interferon gama/genética , Interferon gama/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Camundongos Knockout , Monócitos/imunologia , Monócitos/patologia , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Neutrófilos/imunologia , Neutrófilos/patologia , Linfócitos T/imunologia , Linfócitos T/patologiaRESUMO
BACKGROUND: In patients with HIV/AIDS receiving antiretroviral therapy (ART), HIV-1 persistence in brain tissue is a vital and unanswered question. HIV-1 infects and replicates in resident microglia and trafficking macrophages within the brain although the impact of individual ART drugs on viral infection within these brain myeloid cells is unknown. Herein, the effects of contemporary ART drugs were investigated using in vitro and in vivo models of HIV-1 brain infection. RESULTS: The EC50 values for specific ART drugs in HIV-infected human microglia were significantly higher compared to bone marrow-derived macrophages and peripheral blood mononuclear cells. Intracellular ART drug concentrations in microglia were significantly lower than in human lymphocytes. In vivo brain concentrations of ART drugs in mice were 10 to 100-fold less in brain tissues compared with plasma and liver levels. In brain tissues from untreated HIV-infected BLT mice, HIV-encoded RNA, DNA and p24 were present in human leukocytes while ART eradicated viral RNA and DNA in both brain and plasma. Interruption of ART resulted in detectable viral RNA and DNA and increased human CD68 expression in brains of HIV-infected BLT mice. In aviremic HIV/AIDS patients receiving effective ART, brain tissues that were collected within hours of last ART dosing showed HIV-encoded RNA and DNA with associated neuroinflammatory responses. CONCLUSIONS: ART drugs show variable concentrations and efficacies in brain myeloid cells and tissues in drug-specific manner. Despite low drug concentrations in brain, experimental ART suppressed HIV-1 infection in brain although HIV/AIDS patients receiving effective ART had detectable HIV-1 in brain. These findings suggest that viral suppression in brain is feasible but new approaches to enhancing ART efficacy and concentrations in brain are required for sustained HIV-1 eradication from brain.
Assuntos
Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/farmacocinética , Encéfalo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1 , Latência Viral/efeitos dos fármacos , Adulto , Animais , Fármacos Anti-HIV/uso terapêutico , Encéfalo/efeitos dos fármacos , Encéfalo/virologia , Técnicas de Cultura de Células , Modelos Animais de Doenças , HIV-1/efeitos dos fármacos , HIV-1/fisiologia , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/virologia , Macrófagos/efeitos dos fármacos , Macrófagos/virologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Microglia/efeitos dos fármacos , Microglia/virologia , Pessoa de Meia-Idade , Replicação Viral/efeitos dos fármacosRESUMO
Despite progress in our comprehension of the mechanisms regulating adipose tissue development, the nature of the factors that functionally characterize adipose precursors is still elusive. Defining the early steps regulating adipocyte development is needed for the generation of tools to control adipose tissue size and function. Here, we report the discovery of V-set and transmembrane domain containing 2A (VSTM2A) as a protein expressed and secreted by committed preadipocytes. VSTM2A expression is elevated in the early phases of adipogenesis in vitro and adipose tissue development in vivo. We show that VSTM2A-producing cells associate with the vasculature and express the common surface markers of adipocyte progenitors. Overexpression of VSTM2A induces adipogenesis, whereas its depletion impairs this process. VSTM2A controls preadipocyte determination at least in part by modulating BMP signaling and PPARγ2 activation. We propose a model in which VSTM2A is produced to preserve and amplify the adipogenic capability of adipose precursors.
Assuntos
Adipogenia , Linhagem da Célula , Proteínas de Membrana/metabolismo , Receptores Imunológicos/metabolismo , Células 3T3-L1 , Adipócitos/metabolismo , Tecido Adiposo Branco/irrigação sanguínea , Tecido Adiposo Branco/citologia , Animais , Biomarcadores/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Diferenciação Celular , Técnicas de Silenciamento de Genes , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Células NIH 3T3 , Neovascularização Fisiológica , PPAR gama/metabolismo , Transdução de SinaisRESUMO
Plasmacytoid dendritic cells (pDCs) are unique bone-marrow-derived cells that produce large amounts of type I interferon in response to microbial stimulation. Furthermore, pDCs also promote T cell tolerance in sterile-inflammation conditions. However, the immunomodulatory role of aortic pDCs in atherosclerosis has been poorly understood. Here, we identified functional mouse and human pDCs in the aortic intima and showed that selective, inducible pDC depletion in mice exacerbates atherosclerosis. Aortic pDCs expressed CCR9 and indoleamine 2,3-dioxygenase 1 (IDO-1), an enzyme involved in driving the generation of regulatory T cells (Tregs). As a consequence, loss of pDCs resulted in decreased numbers of Tregs and reduced IL-10 levels in the aorta. Moreover, antigen presentation by pDCs expanded antigen-specific Tregs in the atherosclerotic aorta. Notably, Tregs ablation affected pDC homeostasis in diseased aorta. Accordingly, pDCs in human atherosclerotic aortas colocalized with Tregs. Collectively, we identified a mechanism of atheroprotection mediated by tolerogenic aortic pDCs.