RESUMO
Little is known about the maintenance of intestinal stem cells (ISCs) and progenitors during immune-mediated tissue damage or about the susceptibility of transplant recipients to tissue damage mediated by the donor immune system during graft versus host disease (GVHD). We demonstrate here that deficiency of recipient-derived IL-22 increased acute GVHD tissue damage and mortality, that ISCs were eliminated during GVHD, and that ISCs as well as their downstream progenitors expressed the IL-22 receptor. Intestinal IL-22 was produced after bone marrow transplant by IL-23-responsive innate lymphoid cells (ILCs) from the transplant recipients, and intestinal IL-22 increased in response to pretransplant conditioning. However, ILC frequency and IL-22 amounts were decreased by GVHD. Recipient IL-22 deficiency led to increased crypt apoptosis, depletion of ISCs, and loss of epithelial integrity. Our findings reveal IL-22 as a critical regulator of tissue sensitivity to GVHD and a protective factor for ISCs during inflammatory intestinal damage.
Assuntos
Transplante de Medula Óssea/imunologia , Doença Enxerto-Hospedeiro/imunologia , Interleucinas/metabolismo , Intestino Delgado/imunologia , Células-Tronco/metabolismo , Animais , Transplante de Medula Óssea/efeitos adversos , Modelos Animais de Doenças , Citometria de Fluxo , Doença Enxerto-Hospedeiro/mortalidade , Imuno-Histoquímica , Interleucina-23/metabolismo , Interleucinas/genética , Interleucinas/imunologia , Intestino Delgado/citologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Interleucina/metabolismo , Interleucina 22RESUMO
Epithelial regeneration is critical for barrier maintenance and organ function after intestinal injury. The intestinal stem cell (ISC) niche provides Wnt, Notch and epidermal growth factor (EGF) signals supporting Lgr5(+) crypt base columnar ISCs for normal epithelial maintenance. However, little is known about the regulation of the ISC compartment after tissue damage. Using ex vivo organoid cultures, here we show that innate lymphoid cells (ILCs), potent producers of interleukin-22 (IL-22) after intestinal injury, increase the growth of mouse small intestine organoids in an IL-22-dependent fashion. Recombinant IL-22 directly targeted ISCs, augmenting the growth of both mouse and human intestinal organoids, increasing proliferation and promoting ISC expansion. IL-22 induced STAT3 phosphorylation in Lgr5(+) ISCs, and STAT3 was crucial for both organoid formation and IL-22-mediated regeneration. Treatment with IL-22 in vivo after mouse allogeneic bone marrow transplantation enhanced the recovery of ISCs, increased epithelial regeneration and reduced intestinal pathology and mortality from graft-versus-host disease. ATOH1-deficient organoid culture demonstrated that IL-22 induced epithelial regeneration independently of the Paneth cell niche. Our findings reveal a fundamental mechanism by which the immune system is able to support the intestinal epithelium, activating ISCs to promote regeneration.
Assuntos
Células Epiteliais/citologia , Interleucinas/imunologia , Mucosa Intestinal/citologia , Intestino Delgado/citologia , Regeneração , Células-Tronco/citologia , Células-Tronco/metabolismo , Animais , Células Epiteliais/imunologia , Células Epiteliais/patologia , Feminino , Doença Enxerto-Hospedeiro/patologia , Humanos , Imunidade nas Mucosas , Interleucinas/deficiência , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Intestino Delgado/imunologia , Intestino Delgado/patologia , Camundongos , Organoides/citologia , Organoides/crescimento & desenvolvimento , Organoides/imunologia , Celulas de Paneth/citologia , Fosforilação , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Nicho de Células-Tronco , Interleucina 22RESUMO
Nuclear factor erythroid-derived 2-like 2 (Nrf2) is a ubiquitously expressed transcription factor that is well known for its role in regulating the cellular redox pathway. Although there is mounting evidence suggesting a critical role for Nrf2 in hematopoietic stem cells and innate leukocytes, little is known about its involvement in T-cell biology. In this study, we identified a novel role for Nrf2 in regulating alloreactive T-cell function during allogeneic hematopoietic cell transplantation (allo-HCT). We observed increased expression and nuclear translocation of Nrf2 upon T-cell activation in vitro, especially in CD4+ donor T cells after allo-HCT. Allo-HCT recipients of Nrf2 -/- donor T cells had significantly less acute graft-versus-host disease (GVHD)-induced mortality, morbidity, and pathology. This reduction in GVHD was associated with the persistence of Helios+ donor regulatory T cells in the allograft, as well as defective upregulation of the gut-homing receptor LPAM-1 on alloreactive CD8+ T cells. Additionally, Nrf2 -/- donor CD8+ T cells demonstrated intact cytotoxicity against allogeneic target cells. Tumor-bearing allo-HCT recipients of Nrf2 -/- donor T cells had overall improved survival as a result of preserved graft-versus-tumor activity and reduced GVHD activity. Our findings characterized a previously unrecognized role for Nrf2 in T-cell function, as well as revealed a novel therapeutic target to improve the outcomes of allo-HCT.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Doença Enxerto-Hospedeiro/imunologia , Transplante de Células-Tronco Hematopoéticas , Ativação Linfocitária , Fator 2 Relacionado a NF-E2/imunologia , Neoplasias Experimentais/imunologia , Doença Aguda , Aloenxertos , Animais , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/patologia , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapiaRESUMO
Graft-versus-host disease (GVHD) and posttransplant immunodeficiency are frequently related complications of allogeneic hematopoietic transplantation. Alloreactive donor T cells can damage thymic epithelium, thus limiting new T-cell development. Although the thymus has a remarkable capacity to regenerate after injury, endogenous thymic regeneration is impaired in GVHD. The mechanisms leading to this regenerative failure are largely unknown. Here we demonstrate in experimental mouse models that GVHD results in depletion of intrathymic group 3 innate lymphoid cells (ILC3s) necessary for thymic regeneration. Loss of thymic ILC3s resulted in deficiency of intrathymic interleukin-22 (IL-22) compared with transplant recipients without GVHD, thereby inhibiting IL-22-mediated protection of thymic epithelial cells (TECs) and impairing recovery of thymopoiesis. Conversely, abrogating IL-21 receptor signaling in donor T cells and inhibiting the elimination of thymic ILCs improved thymopoiesis in an IL-22-dependent fashion. We found that the thymopoietic impairment in GVHD associated with loss of ILCs could be improved by restoration of IL-22 signaling. Despite uninhibited alloreactivity, exogenous IL-22 administration posttransplant resulted in increased recovery of thymopoiesis and development of new thymus-derived peripheral T cells. Our study highlights the role of innate immune function in thymic regeneration and restoration of adaptive immunity posttransplant. Manipulation of the ILC-IL-22-TEC axis may be useful for augmenting immune reconstitution after clinical hematopoietic transplantation and other settings of T-cell deficiency.
Assuntos
Doença Enxerto-Hospedeiro/imunologia , Imunidade Inata , Linfócitos/imunologia , Timo/imunologia , Animais , Transplante de Medula Óssea , Interleucinas/deficiência , Interleucinas/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Transdução de Sinais , Linfócitos T Reguladores/imunologia , Interleucina 22RESUMO
T-cell deficiency related to disease, medical treatment, or aging represents a major clinical challenge and is associated with significant morbidity and mortality in cancer and bone marrow transplantation recipients. This study describes several innovative and clinically relevant strategies to manipulate thymic function based on an interventional radiology technique for intrathymic injection of cells or drugs. We show that intrathymic injection of multipotent hematopoietic stem/progenitor cells into irradiated syngeneic or allogeneic young or aged recipients resulted in efficient and long-lasting generation of functional donor T cells. Persistence of intrathymic donor cells was associated with intrathymic presence of cells resembling long-term hematopoietic stem cells, suggesting a self-renewal capacity of the intrathymically injected cells. Furthermore, our approach enabled the induction of long-term antigen-specific T-cell-mediated antitumor immunity following intrathymic injection of progenitor cells harboring a transgenic T-cell receptor gene. The intrathymic injection of interleukin-7 prior to irradiation conferred radioprotection. In addition, thymopoiesis of aged mice improved with a single intrathymic administration of low-dose keratinocyte growth factor, an effect that was sustained even in the setting of radiation-induced injury. Taken together, we established a preclinical framework for the development of novel clinical protocols to establish lifelong antigen-specific T-cell immunity.
Assuntos
Imunidade Celular , Imunoterapia , Células-Tronco Multipotentes/citologia , Transplante de Células-Tronco , Linfócitos T/imunologia , Timo/imunologia , Fatores Etários , Animais , Antígenos/imunologia , Transplante de Medula Óssea , Modelos Animais de Doenças , Feminino , Células-Tronco Hematopoéticas/citologia , Imunofenotipagem , Linfopoese/efeitos dos fármacos , Linfopoese/imunologia , Linfopoese/efeitos da radiação , Camundongos , Células-Tronco Multipotentes/metabolismo , Neoplasias/imunologia , Neoplasias/terapia , Fenótipo , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/metabolismo , Irradiação Corporal TotalRESUMO
Despite significant advances in prevention and management, graft versus host disease (GVHD) is still a leading complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Although skin, gut, liver, thymus, and lung are GVHD targets, neurological complications (NC) have also been reported following allo-HSCT. We demonstrate that the central nervous system (CNS) can be a direct target of alloreactive T cells following allo-HSCT in mice. We found significant infiltration of the CNS with donor T lymphocytes and cell death of neurons and neuroglia in allo-HSCT recipients with GVHD. We also found that allo-HSCT recipients with GVHD had deficits in spatial learning/memory and demonstrated increased anxious behavior. These findings highlight CNS sensitivity to damage caused by alloreactive donor T cells and represent the first characterization of target cell subsets and NC during GVHD. Therefore, these clinically relevant studies offer a novel and rational explanation for the well-described neurological symptoms observed after allo-HSCT.
Assuntos
Doenças do Sistema Nervoso Central/etiologia , Doença Enxerto-Hospedeiro/complicações , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Complicações Pós-Operatórias , Linfócitos T/patologia , Doença Aguda , Animais , Comportamento Animal , Medula Óssea/metabolismo , Medula Óssea/patologia , Doenças do Sistema Nervoso Central/patologia , Citometria de Fluxo , Depleção Linfocítica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Transplante HomólogoRESUMO
IL-21 is a proinflammatory cytokine produced by Th17 cells. Abrogation of IL-21 signaling has recently been shown to reduce GVHD while retaining graft-versus-leukemia/lymphoma (GVL) responses. However, the mechanisms by which IL-21 may lead to a separation of GVHD and GVL remain incompletely understood. In a murine MHC-mismatched BM transplantation model, we observed that IL-21 receptor knockout (IL-21R KO) donor T cells mediate decreased systemic and gastrointestinal GVHD in recipients of a transplant. This reduction in GVHD was associated with expansion of transplanted donor regulatory T cells and with tissue-specific modulation of Th-cell function. IL-21R KO and wild-type donor T cells showed equivalent alloactivation, but IL-21R KO T cells showed decreased infiltration and inflammatory cytokine production within the mesenteric lymph nodes. However, Th-cell cytokine production was maintained peripherally, and IL-21R KO T cells mediated equivalent immunity against A20 and P815 hematopoietic tumors. In summary, abrogation of IL-21 signaling in donor T cells leads to tissue-specific modulation of immunity, such that gastrointestinal GVHD is reduced, but peripheral T-cell function and GVL capacity are retained. IL-21 is thus an exciting target for therapeutic intervention and improvement of clinical transplantation outcomes.
Assuntos
Doença Enxerto-Hospedeiro/genética , Efeito Enxerto vs Leucemia/genética , Imunidade Inata/genética , Interleucinas/fisiologia , Linfócitos T/metabolismo , Doadores de Tecidos , Animais , Técnicas de Silenciamento de Genes , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/metabolismo , Humanos , Imunidade Inata/fisiologia , Subunidade alfa de Receptor de Interleucina-21/genética , Subunidade alfa de Receptor de Interleucina-21/metabolismo , Subunidade alfa de Receptor de Interleucina-21/fisiologia , Interleucinas/genética , Interleucinas/metabolismo , Linfócitos do Interstício Tumoral/metabolismo , Linfócitos do Interstício Tumoral/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Especificidade de Órgãos/genética , Especificidade de Órgãos/imunologia , Transdução de Sinais/genética , Linfócitos T/fisiologia , Imunologia de TransplantesRESUMO
Immunoincompetence after allogeneic hematopoietic stem cell transplantation (HSCT) affects in particular the T-cell lineage and is associated with an increased risk for infections, graft failure and malignant relapse. To generate large numbers of T-cell precursors for adoptive therapy, we cultured mouse hematopoietic stem cells (HSCs) in vitro on OP9 mouse stromal cells expressing the Notch-1 ligand Delta-like-1 (OP9-DL1). We infused these cells, together with T-cell-depleted mouse bone marrow or purified HSCs, into lethally irradiated allogeneic recipients and determined their effect on T-cell reconstitution after transplantation. Recipients of OP9-DL1-derived T-cell precursors showed increased thymic cellularity and substantially improved donor T-cell chimerism (versus recipients of bone marrow or HSCs only). OP9-DL1-derived T-cell precursors gave rise to host-tolerant CD4+ and CD8+ populations with normal T-cell antigen receptor repertoires, cytokine secretion and proliferative responses to antigen. Administration of OP9-DL1-derived T-cell precursors increased resistance to infection with Listeria monocytogenes and mediated significant graft-versus-tumor (GVT) activity but not graft-versus-host disease (GVHD). We conclude that the adoptive transfer of OP9-DL1-derived T-cell precursors markedly enhances T-cell reconstitution after transplantation, resulting in GVT activity without GVHD.
Assuntos
Transferência Adotiva , Transplante de Células-Tronco Hematopoéticas , Células-Tronco/fisiologia , Linfócitos T/imunologia , Linfócitos T/fisiologia , Animais , Técnicas de Cocultura , Fator 7 de Crescimento de Fibroblastos/farmacologia , Doença Enxerto-Hospedeiro/imunologia , Efeito Enxerto vs Tumor/imunologia , Listeriose/imunologia , Depleção Linfocítica , Camundongos , Regeneração , Linfócitos T/efeitos dos fármacosRESUMO
Alloreactive T cells are crucial for graft-versus-host disease (GVHD) pathophysiology, and modulating their trafficking patterns has been efficacious in ameliorating experimental disease. We report in this paper that P-selectin, a glycoprotein found on resting and inflamed endothelium, is important for donor alloreactive T cells trafficking into GVHD target organs, such as the intestines and skin. Compared with wild-type (WT) recipients of allogeneic bone marrow transplantation, P-selectin(-/-) recipients exhibit decreased GVHD mortality and decreased GVHD of the skin, liver, and small bowels. This was associated with diminished infiltration of alloactivated T cells into the Peyer's patches and small bowels, coupled with increased numbers of donor T cells in the spleen and secondary lymphoid organs (SLOs). Surprisingly, however, donor T cells deficient for P-selectin glycoprotein ligand 1, the most well described P-selectin ligand, mediated GVHD similar to WT T cells and accumulated in SLO and target organs in similar numbers as WT T cells. This suggests that P-selectin may be required for trafficking into inflamed tissues but not SLO and that donor T cells may use multiple P-selectin ligands apart from P-selectin glycoprotein ligand 1 to interact with P-selectin and traffic into inflamed tissues during GVHD. We conclude that targeting P-selectin may be a viable strategy for GVHD prophylaxis or treatment.
Assuntos
Transplante de Medula Óssea/imunologia , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/terapia , Selectina-P/genética , Animais , Modelos Animais de Doenças , Endotélio Vascular/imunologia , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Doença Enxerto-Hospedeiro/fisiopatologia , Mediadores da Inflamação/metabolismo , Mediadores da Inflamação/fisiologia , Ligantes , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Selectina-P/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Subpopulações de Linfócitos T/transplante , Transplante HomólogoRESUMO
CD4(+) interleukin-17 (IL-17)(+) T cells (Th17 cells) have been implicated in allograft rejection of solid organs and several autoimmune diseases. However, the functional role of Th17 cells in the development of acute graft-versus-host disease (GVHD) has not been well-characterized. We detected significant numbers of alloreactive CD4(+) donor T cells expressing IL-17, IL-17F, or IL-22 in the lymphoid organs of recipients of an allogeneic bone marrow transplant. We found no differences in GVHD mortality or graft-versus-tumor (GVT) activity between wild type (WT) and IL-17(-/-) T-cell recipients. However, upon transfer of murine IL-17(-/-) CD4(+) T cells in an allogeneic BMT model, GVHD development was significantly delayed behind recipients of WT CD4(+) T cells, yet overall GVHD mortality was unaffected. Moreover, recipients of IL-17(-/-) CD4(+) T cells had significantly fewer Th1 cells during the early stages of GVHD. Furthermore, we observed a decrease in the number of IFN-gamma-secreting macrophages and granulocytes and decreased production of proinflammatory cytokines (interferon [IFN]-gamma, IL-4, and IL-6) in recipients of IL-17(-/-) CD4(+) T cells. We conclude that IL-17 is dispensable for GVHD and GVT activity by whole T cells, but contributes to the early development of CD4-mediated GVHD by promoting production of proinflammatory cytokines.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Doença Enxerto-Hospedeiro/imunologia , Interleucina-17/imunologia , Animais , Transplante de Medula Óssea/imunologia , Linfócitos T CD4-Positivos/metabolismo , Proliferação de Células , Feminino , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/metabolismo , Interferon gama/sangue , Interleucina-17/deficiência , Interleucina-17/genética , Interleucina-17/metabolismo , Interleucinas/imunologia , Linfócitos/imunologia , Camundongos , Camundongos Knockout , Baço/citologia , Baço/imunologia , Transplante Homólogo/imunologia , Interleucina 22RESUMO
Keratinocyte growth factor (KGF), which is given exogenously to allogeneic bone marrow transplantation (allo-BMT) recipients, supports thymic epithelial cells and increases thymic output of naive T cells. Here, we demonstrate that this improved T-cell reconstitution leads to enhanced responses to DNA plasmid tumor vaccination. Tumor-bearing mice treated with KGF and DNA vaccination have improved long-term survival and decreased tumor burden after allo-BMT. When assayed before vaccination, KGF-treated allo-BMT recipients have increased numbers of peripheral T cells, including CD8(+) T cells with vaccine-recognition potential. In response to vaccination, KGF-treated allo-BMT recipients, compared with control subjects, generate increased numbers of tumor-specific CD8(+) cells, as well as increased numbers of CD8(+) cells producing interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha). We also found unanticipated benefits to antitumor immunity with the administration of KGF. KGF-treated allo-BMT recipients have an improved ratio of T effector cells to regulatory T cells, a larger fraction of effector cells that display a central memory phenotype, and effector cells that are derived from a broader T-cell-receptor repertoire. In conclusion, our data suggest that KGF can function as a potent vaccine adjuvant after allo-BMT through its effects on posttransplantation T-cell reconstitution.
Assuntos
Transplante de Medula Óssea/imunologia , Vacinas Anticâncer/imunologia , Fator 7 de Crescimento de Fibroblastos/farmacologia , Timo/efeitos dos fármacos , Vacinas de DNA/imunologia , Animais , Transplante de Medula Óssea/métodos , Transplante de Medula Óssea/mortalidade , Antígenos CD4/metabolismo , Linfócitos T CD8-Positivos/citologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/imunologia , Feminino , Fatores de Transcrição Forkhead/metabolismo , Memória Imunológica/efeitos dos fármacos , Memória Imunológica/imunologia , Contagem de Linfócitos , Camundongos , Camundongos Endogâmicos C57BL , Plasmídeos , Taxa de Sobrevida , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/metabolismo , Timo/citologia , Timo/imunologia , Quimeras de Transplante , Transplante HomólogoRESUMO
Posttransplant immunodeficiency, specifically a lack of T cell reconstitution, is a major complication of allogeneic bone marrow transplantation. This immunosuppression results in an increase in morbidity and mortality from infections and very likely contributes to relapse. In this study, we demonstrate that sex steroid ablation using leuprolide acetate, a luteinizing hormone-releasing hormone agonist (LHRHa), increases the number of lymphoid and myeloid progenitor cells in the bone marrow and developing thymocytes in the thymus. Although few differences are observed in the peripheral myeloid compartments, the enhanced thymic reconstitution following LHRHa treatment and allogeneic bone marrow transplantation leads to enhanced peripheral T cell recovery, predominantly in the naive T cell compartment. This results in an increase in T cell function in vivo and in vitro. Graft-versus-host-disease is not exacerbated by LHRHa treatment and graft-versus-tumor activity is maintained. Because LHRHa allows for reversible (and temporary) sex steroid ablation, has a strong safety profile, and has been clinically approved for diseases such as prostate and breast cancer, this drug treatment represents a novel therapeutic approach to reversal of thymic atrophy and enhancement of immunity following immunosuppression.
Assuntos
Transplante de Medula Óssea/imunologia , Hormônio Liberador de Gonadotropina/administração & dosagem , Linfócitos T/efeitos dos fármacos , Linfócitos T/transplante , Animais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/imunologia , Transplante de Medula Óssea/patologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/imunologia , Feminino , Hormônio Liberador de Gonadotropina/agonistas , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/patologia , Doença Enxerto-Hospedeiro/terapia , Efeito Enxerto vs Tumor/efeitos dos fármacos , Efeito Enxerto vs Tumor/imunologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/imunologia , Células-Tronco Hematopoéticas/patologia , Humanos , Isoantígenos/administração & dosagem , Isoantígenos/genética , Leuprolida/administração & dosagem , Linfopenia/imunologia , Linfopenia/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Baço/citologia , Baço/efeitos dos fármacos , Baço/imunologia , Linfócitos T/patologia , Timo/citologia , Timo/efeitos dos fármacos , Timo/imunologiaRESUMO
Delayed T-cell recovery is an important complication of allogeneic bone marrow transplantation (BMT). We demonstrate in murine models that donor BM-derived T cells display increased apoptosis in recipients of allogeneic BMT with or without GVHD. Although this apoptosis was associated with a loss of Bcl-2 and Bcl-X(L) expression, allogeneic recipients of donor BM deficient in Fas-, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)- or Bax-, or BM-overexpressing Bcl-2 or Akt showed no decrease in apoptosis of peripheral donor-derived T cells. CD44 expression was associated with an increased percentage of BM-derived apoptotic CD4(+) and CD8(+) T cells. Transplantation of RAG-2-eGFP-transgenic BM revealed that proliferating eGFP(lo)CD44(hi) donor BM-derived mature T cells were more likely to undergo to apoptosis than nondivided eGFP(hi)CD44(lo) recent thymic emigrants in the periphery. Finally, experiments using carboxyfluorescein succinimidyl ester-labeled T cells adoptively transferred into irradiated syngeneic hosts revealed that rapid spontaneous proliferation (as opposed to slow homeostatic proliferation) and acquisition of a CD44(hi) phenotype was associated with increased apoptosis in T cells. We conclude that apoptosis of newly generated donor-derived peripheral T cells after an allogeneic BMT contributes to delayed T-cell reconstitution and is associated with CD44 expression and rapid spontaneous proliferation by donor BM-derived T cells.
Assuntos
Apoptose , Transplante de Medula Óssea , Diferenciação Celular , Proliferação de Células , Receptores de Hialuronatos/metabolismo , Linfócitos T/fisiologia , Animais , Apoptose/genética , Apoptose/imunologia , Transplante de Medula Óssea/imunologia , Transplante de Medula Óssea/reabilitação , Diferenciação Celular/fisiologia , Células Cultivadas , Feminino , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Linfócitos T/citologia , Linfócitos T/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/fisiologia , Fatores de Tempo , Transplante Homólogo , Proteína X Associada a bcl-2/genética , Receptor fas/genética , Receptor fas/fisiologiaRESUMO
Graft-versus-host disease (GVHD) is a serious complication of allogeneic bone marrow transplantation, and donor T cells are indispensable for GVHD. Current therapies have limited efficacy, selectivity, and high toxicities. We used a novel flow cytometry technique for the analysis of intracellular phosphorylation events in single cells in murine BMT models to identify and validate novel GVHD drug targets.(1-7) This method circumvents the requirement for large numbers of purified cells, unlike western blots. We defined a signaling profile for alloactivated T cells in vivo and identified the phosphorylation of ERK1/2 and STAT-3 as important events during T-cell (allo)activation in GVHD. We establish that interference with STAT-3 phosphorylation can inhibit T-cell activation and proliferation in vitro and GVHD in vivo. This suggests that phospho-specific flow cytometry is useful for the identification of promising drug targets, and ERK1/2 and STAT-3 phosphorylation in alloactivated T cells may be important for GVHD.
Assuntos
Transplante de Medula Óssea/imunologia , Doença Enxerto-Hospedeiro , Ativação Linfocitária , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fator de Transcrição STAT3/metabolismo , Linfócitos T/imunologia , Animais , Citometria de Fluxo , Camundongos , Fosforilação/imunologia , Transplante HomólogoRESUMO
This corrects the article DOI: 10.1038/nm.4470.
RESUMO
The thymus is not only extremely sensitive to damage but also has a remarkable ability to repair itself. However, the mechanisms underlying this endogenous regeneration remain poorly understood, and this capacity diminishes considerably with age. We show that thymic endothelial cells (ECs) comprise a critical pathway of regeneration via their production of bone morphogenetic protein 4 (BMP4) ECs increased their production of BMP4 after thymic damage, and abrogating BMP4 signaling or production by either pharmacologic or genetic inhibition impaired thymic repair. EC-derived BMP4 acted on thymic epithelial cells (TECs) to increase their expression of Foxn1, a key transcription factor involved in TEC development, maintenance, and regeneration, and its downstream targets such as Dll4, a key mediator of thymocyte development and regeneration. These studies demonstrate the importance of the BMP4 pathway in endogenous tissue regeneration and offer a potential clinical approach to enhance T cell immunity.
Assuntos
Proteína Morfogenética Óssea 4/metabolismo , Células Endoteliais/metabolismo , Regeneração/fisiologia , Timo/metabolismo , Timo/fisiologia , Animais , Proliferação de Células/fisiologia , Células Endoteliais/fisiologia , Células Epiteliais/metabolismo , Células Epiteliais/fisiologia , Feminino , Fatores de Transcrição Forkhead/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais/fisiologia , Células-Tronco/metabolismo , Células-Tronco/fisiologia , Linfócitos T/metabolismo , Linfócitos T/fisiologiaRESUMO
Bone marrow transplantation (BMT) offers curative potential for patients with high-risk hematologic malignancies, but the post-transplantation period is characterized by profound immunodeficiency. Recent studies indicate that the intestinal microbiota not only regulates mucosal immunity, but can also contribute to systemic immunity and hematopoiesis. Using antibiotic-mediated microbiota depletion in a syngeneic BMT mouse model, here we describe a role for the intestinal flora in hematopoietic recovery after BMT. Depletion of the intestinal microbiota resulted in impaired recovery of lymphocyte and neutrophil counts, while recovery of the hematopoietic stem and progenitor compartments and the erythroid lineage were largely unaffected. Depletion of the intestinal microbiota also reduced dietary energy uptake and visceral fat stores. Caloric supplementation through sucrose in the drinking water improved post-BMT hematopoietic recovery in mice with a depleted intestinal flora. Taken together, we show that the intestinal microbiota contribute to post-BMT hematopoietic reconstitution in mice through improved dietary energy uptake.
Assuntos
Transplante de Medula Óssea , Microbioma Gastrointestinal , Apoio Nutricional , Animais , Medula Óssea/fisiologia , Hematopoese , Camundongos , Modelos Animais , Resultado do TratamentoRESUMO
There is a substantial unmet clinical need for new strategies to protect the hematopoietic stem cell (HSC) pool and regenerate hematopoiesis after radiation injury from either cancer therapy or accidental exposure. Increasing evidence suggests that sex hormones, beyond their role in promoting sexual dimorphism, regulate HSC self-renewal, differentiation, and proliferation. We and others have previously reported that sex-steroid ablation promotes bone marrow (BM) lymphopoiesis and HSC recovery in aged and immunodepleted mice. Here we found that a luteinizing hormone (LH)-releasing hormone antagonist (LHRH-Ant), currently in wide clinical use for sex-steroid inhibition, promoted hematopoietic recovery and mouse survival when administered 24 h after an otherwise-lethal dose of total-body irradiation (L-TBI). Unexpectedly, this protective effect was independent of sex steroids and instead relied on suppression of LH levels. Human and mouse long-term self-renewing HSCs (LT-HSCs) expressed high levels of the LH/choriogonadotropin receptor (LHCGR) and expanded ex vivo when stimulated with LH. In contrast, the suppression of LH after L-TBI inhibited entry of HSCs into the cell cycle, thus promoting HSC quiescence and protecting the cells from exhaustion. These findings reveal a role of LH in regulating HSC function and offer a new therapeutic approach for hematopoietic regeneration after hematopoietic injury.
Assuntos
Autorrenovação Celular/genética , Células-Tronco Hematopoéticas/metabolismo , Hormônio Luteinizante/metabolismo , Lesões Experimentais por Radiação/tratamento farmacológico , Animais , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/efeitos da radiação , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Proliferação de Células/efeitos da radiação , Autorrenovação Celular/efeitos dos fármacos , Autorrenovação Celular/efeitos da radiação , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Hematopoese/efeitos dos fármacos , Hematopoese/genética , Hematopoese/efeitos da radiação , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/efeitos da radiação , Humanos , Hormônio Luteinizante/farmacologia , Camundongos , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Receptores do LH/genética , Regeneração/efeitos dos fármacos , Regeneração/genética , Regeneração/efeitos da radiação , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação , Irradiação Corporal TotalRESUMO
NF-κB plays a variety of roles in oncogenesis and immunity that may be beneficial for therapeutic targeting, but strategies to selectively inhibit NF-κB to exert antitumor activity have been elusive. Here, we describe IT-901, a bioactive naphthalenethiobarbiturate derivative that potently inhibits the NF-κB subunit c-Rel. IT-901 suppressed graft-versus-host disease while preserving graft-versus-lymphoma activity during allogeneic transplantation. Further preclinical assessment of IT-901 for the treatment of human B-cell lymphoma revealed antitumor properties in vitro and in vivo without restriction to NF-κB-dependent lymphoma. This nondiscriminatory, antilymphoma effect was attributed to modulation of the redox homeostasis in lymphoma cells resulting in oxidative stress. Moreover, NF-κB inhibition by IT-901 resulted in reduced stimulation of the oxidative stress response gene heme oxygenase-1, and we demonstrated that NF-κB inhibition exacerbated oxidative stress induction to inhibit growth of lymphoma cells. Notably, IT-901 did not elicit increased levels of reactive oxygen species in normal leukocytes, illustrating its cancer selective properties. Taken together, our results provide mechanistic insight and preclinical proof of concept for IT-901 as a novel therapeutic agent to treat human lymphoid tumors and ameliorate graft-versus-host disease.