Survivors of acute radiation exposure suffer from the delayed effects of acute radiation exposure... more Survivors of acute radiation exposure suffer from the delayed effects of acute radiation exposure (DEARE), a chronic condition affecting multiple organs, including lung, kidney, heart, gastrointestinal tract, eyes, and brain, and often causing cancer. While effective medical countermeasures (MCM) for the hematopoietic-acute radiation syndrome (H-ARS) have been identified and approved by the FDA, development of MCM for DEARE has not yet been successful. We previously documented residual bone marrow damage (RBMD) and progressive renal and cardiovascular DEARE in murine survivors of H-ARS, and significant survival efficacy of 16,16-dimethyl prostaglandin E2 (dmPGE2) given as a radioprotectant or radiomitigator for H-ARS. We now describe additional DEARE (physiological and neural function, progressive fur graying, ocular inflammation, and malignancy) developing after sub-threshold doses in our H-ARS model, and detailed analysis of the effects of dmPGE2 administered before (PGE-pre) or a...
The Center for Cellular Therapy and Hematopoietic Stem Cell Transplantation for Cancer was establ... more The Center for Cellular Therapy and Hematopoietic Stem Cell Transplantation for Cancer was established in July 2007 to promote translational and clinical research in cellular therapy for cancer. The primary goal of the Center is translate discoveries from bench-to-clinic through phase I and early phase II cellular therapy clinical trials. To achieve this objective, the Center has brought together the unique expertise in hematopoiesis, immunology, gene therapy, graft engineering, and clinical hematopoietic stem cell transplantation (HCT) available at IUPUI. Since its establishment, we have completed two phase I clinical trials developing novel preparative regimens for allogeneic and autologous stem cell transplantation for patients with refractory leukemia and lymphoma, respectively. In addition, we have also initiated 5 additional early phase clinical trials that directly translate IUPUI laboratory discoveries to patients with hematological cancers. The Center has successfully compe...
It has been reported that the granulocyte-derived hematoregulatory pentapeptide, HP-5, and its di... more It has been reported that the granulocyte-derived hematoregulatory pentapeptide, HP-5, and its dimer (HP-5b) have potent hematoregulatory properties. The proposed mechanism of action for HP-5b is synergy with colony-stimulating activity (CSA) resulting in enhanced myeloid colony formation in vitro. We now demonstrate that the effects of HP-5b on enhanced colony formation are indirect and mediated by an effect on CSA production by bone marrow stromal cells. Bone marrow stromal cell culture systems from mice, rats, and humans were used as target cells for the action of HP-5 monomer and dimer. Cell-free supernatants from these cultures were assayed for CSA in a murine granulocyte-macrophage colony-forming unit (CFU-GM) assay. Supernatants from stromal cell cultures pulsed for 1 h with HP-5b resulted in increased murine CFU-GM colony proliferation with an estimated half-maximal effective concentration (EC50) of 1-5 ng/ml. This increase in CFU-GM proliferation was neutralized by anti-mac...
Aging of human hematopoiesis is associated with increased frequency and clonality of hematopoieti... more Aging of human hematopoiesis is associated with increased frequency and clonality of hematopoietic stem cells (HSC), along with functional compromise and myeloid bias, and donor age is a significant variable in survival after HSC transplantation. No clinical methods exist to enhance aged HSC function, and little is known regarding how aging affects molecular responses of HSC to biological stimuli. Exposure of young fish, mouse, nonhuman primate and human HSC to 16,16-dimethyl prostaglandin E2 (dmPGE2) can enhance transplantation, but the effect of dmPGE2 on aged HSC has not yet been tested. Bone marrow cells from young (3 mo) and aged (25 mo) C57BL/6J mice were pulsed ex vivo with dmPGE2 or vehicle prior to competitive transplantation. DmPGE2 enhanced long-term repopulation of aged grafts in primary and secondary transplantation, increasing final chimerism an average of 27%, similar to the average increase of 21% for young grafts (both p
dmPGE2 stabilizes the transcription factor HIF1a in stem and progenitor cells. Pharmacologic stab... more dmPGE2 stabilizes the transcription factor HIF1a in stem and progenitor cells. Pharmacologic stabilization of HIF1a increases CXCR4 and enhances stem and progenitor homing and engraftment. Hematopoietic stem cell (HSC) transplantation is a lifesaving therapy for a number of immunologic disorders. For effective transplant, HSCs must traffic from the peripheral blood to supportive bone marrow niches. We previously showed that HSC trafficking can be enhanced by ex vivo treatment of hematopoietic grafts with 16-16 dimethyl pros-taglandin E2 (dmPGE2). While exploring regulatory molecules involved in dmPGE2 enhancement, we found that transiently increasing the transcription factor hypoxia-inducible factor 1-a (HIF1a) is required for dmPGE2-enhanced CXCR4 upregulation and enhanced migration and homing of stem and progenitor cells and that pharmacologic manipulation of HIF1a is also capable of enhancing homing and engraftment. We also now identify the specific hypoxia response element requi...
The bone marrow (BM) microenvironment/niche plays a key role in regulating hematopoietic stem and... more The bone marrow (BM) microenvironment/niche plays a key role in regulating hematopoietic stem and progenitor cell (HSPC) activities; however, mechanisms regulating niche cell function are not well understood. In this study, we show that niche intrinsic expression of the CXCR4 chemokine receptor critically regulates HSPC maintenance during steady state, and promotes early hematopoietic regeneration after myeloablative irradiation. At steady state, chimeric mice with wild-type (WT) HSPC and marrow stroma that lack CXCR4 show decreased HSPC quiescence, and their repopulation capacity was markedly reduced. Mesenchymal stromal cells (MSC) were significantly reduced in the BM of CXCR4 deficient mice, which was accompanied by decreased levels of the HSPC supporting factors stromal cell-derived factor-1 (SDF-1) and stem cell factor (SCF). CXCR4 also plays a crucial role in survival and restoration of BM stromal cells after myeloablative irradiation, where the loss of BM stromal cells was mo...
Hematopoietic stem cells (HSCs) reside in hypoxic niches within the bone marrow (BM). Yet, all HS... more Hematopoietic stem cells (HSCs) reside in hypoxic niches within the bone marrow (BM). Yet, all HSC studies have been performed to date with cells immediately isolated in non-physiologic ambient air, whether or not they are subsequently processed in low oxygen tension. By collecting/manipulating BM in physiologically native conditions of hypoxia where all procedures are performed inside a hypoxic chamber, we demonstrate that brief exposure of mouse BM or human cord blood (CB) to ambient oxygen decreases recovery of phenotypically-defined and functional self-renewing long-term repopulating HSC and concomitantly increases numbers of progenitor cells, a phenomenon we term Extra Physiologic Oxygen Shock/Stress (EPHOSS). This new phenomenon is exquisitely sensitive to oxygen and great care must be taken to ensure all reagents, solutions, plastics, and anything that will come into contact with the cell suspension, is extensively pre-equilibrated in hypoxia. Up to 5-fold greater numbers of ...
The relationship between major histocompatibility complex class II antigens (MHC class II, eg, HL... more The relationship between major histocompatibility complex class II antigens (MHC class II, eg, HLA-DR, Ia), T lymphocytes, and the enhancement of erythroid colony formation from BFU-E by prostaglandin E was analyzed using normal bone marrow cells. In primary methylcellulose culture, the addition of prostaglandin E1 (PGE1) to unseparated buffy coat, low-density, or nonadherent low-density (NAL) marrow cells resulted in an enhancement of the total number of erythroid (BFU-E) colonies observed. Treatment of bone marrow cells with a monoclonal antihuman MHC class II antibody plus complement (C') resulted in a reduction of the total number of colonies by approximately 50% and abrogation of the enhancing effect of PGE1. Analysis of accessory cell requirements by depletion of both adherent cells and sheep erythrocyte rosetting lymphocytes (E+ cells) and reconstitution using C' or anti- MHC class II antibody plus C'-treated T cell-depleted NAL (NALT-) marrow cells and E+ cell po...
Marrow cytogenetic and granulocyte-macrophage colony formation (CFU-GM) studies were performed on... more Marrow cytogenetic and granulocyte-macrophage colony formation (CFU-GM) studies were performed on 34 previously untreated patients with documented myelodysplastic syndromes seen between January 1978 and June 1982. All patients were managed without chemotherapy until progression to acute leukemia was observed. All 10 patients with exclusively abnormal marrow metaphases developed acute leukemia (100%) while only one (7%) of 14 patients with solely normal marrow metaphases subsequently developed leukemia (p less than 0.001). Three (42%) of the seven patients with both normal and abnormal marrow metaphases developed acute leukemia. Fifteen (86%) of the 19 patients with either large cluster or no growth patterns developed acute leukemia while only two (13%) of 15 patients with either small cluster or colony forming growth patterns developed acute leukemia (p less than 0.001). Abnormal marrow cytogenetic status correlated with abnormal marrow CFU-GM growth pattern (p less than 0.05). Anal...
Bone marrow and peripheral blood cells of patients with non-leukemic neutropenia contain and elab... more Bone marrow and peripheral blood cells of patients with non-leukemic neutropenia contain and elaborate a granulocyte-progenitor cell inhibitory activity. The inhibitory activity is common to the neutropenias of the various etiologies studied, which included congenital, idiopathic, autoimmune, cyclical, common variable immuno-deficiency with hypogammaglobulinemia and drug induced states. It derives from non-adherent, low density, slowly sedimenting and non-E-rosetting cells and appears to require RNA and protein synthesis, but not cell division, for its production. The material is not species specific, inhibits autologous and allogeneic normal CFUgm and leukemic CFUgm, is not cell-cycle specific in action and is most effective against granulocyte colony forming cells (CFUg), less effective against mixed granulocyte-macrophage colony forming cells (CFUgm) and least or non-effective against macrophage colony forming cells (CFUm). This inhibitory activity has no influence on cells which...
Survivors of acute radiation exposure suffer from the delayed effects of acute radiation exposure... more Survivors of acute radiation exposure suffer from the delayed effects of acute radiation exposure (DEARE), a chronic condition affecting multiple organs, including lung, kidney, heart, gastrointestinal tract, eyes, and brain, and often causing cancer. While effective medical countermeasures (MCM) for the hematopoietic-acute radiation syndrome (H-ARS) have been identified and approved by the FDA, development of MCM for DEARE has not yet been successful. We previously documented residual bone marrow damage (RBMD) and progressive renal and cardiovascular DEARE in murine survivors of H-ARS, and significant survival efficacy of 16,16-dimethyl prostaglandin E2 (dmPGE2) given as a radioprotectant or radiomitigator for H-ARS. We now describe additional DEARE (physiological and neural function, progressive fur graying, ocular inflammation, and malignancy) developing after sub-threshold doses in our H-ARS model, and detailed analysis of the effects of dmPGE2 administered before (PGE-pre) or a...
The Center for Cellular Therapy and Hematopoietic Stem Cell Transplantation for Cancer was establ... more The Center for Cellular Therapy and Hematopoietic Stem Cell Transplantation for Cancer was established in July 2007 to promote translational and clinical research in cellular therapy for cancer. The primary goal of the Center is translate discoveries from bench-to-clinic through phase I and early phase II cellular therapy clinical trials. To achieve this objective, the Center has brought together the unique expertise in hematopoiesis, immunology, gene therapy, graft engineering, and clinical hematopoietic stem cell transplantation (HCT) available at IUPUI. Since its establishment, we have completed two phase I clinical trials developing novel preparative regimens for allogeneic and autologous stem cell transplantation for patients with refractory leukemia and lymphoma, respectively. In addition, we have also initiated 5 additional early phase clinical trials that directly translate IUPUI laboratory discoveries to patients with hematological cancers. The Center has successfully compe...
It has been reported that the granulocyte-derived hematoregulatory pentapeptide, HP-5, and its di... more It has been reported that the granulocyte-derived hematoregulatory pentapeptide, HP-5, and its dimer (HP-5b) have potent hematoregulatory properties. The proposed mechanism of action for HP-5b is synergy with colony-stimulating activity (CSA) resulting in enhanced myeloid colony formation in vitro. We now demonstrate that the effects of HP-5b on enhanced colony formation are indirect and mediated by an effect on CSA production by bone marrow stromal cells. Bone marrow stromal cell culture systems from mice, rats, and humans were used as target cells for the action of HP-5 monomer and dimer. Cell-free supernatants from these cultures were assayed for CSA in a murine granulocyte-macrophage colony-forming unit (CFU-GM) assay. Supernatants from stromal cell cultures pulsed for 1 h with HP-5b resulted in increased murine CFU-GM colony proliferation with an estimated half-maximal effective concentration (EC50) of 1-5 ng/ml. This increase in CFU-GM proliferation was neutralized by anti-mac...
Aging of human hematopoiesis is associated with increased frequency and clonality of hematopoieti... more Aging of human hematopoiesis is associated with increased frequency and clonality of hematopoietic stem cells (HSC), along with functional compromise and myeloid bias, and donor age is a significant variable in survival after HSC transplantation. No clinical methods exist to enhance aged HSC function, and little is known regarding how aging affects molecular responses of HSC to biological stimuli. Exposure of young fish, mouse, nonhuman primate and human HSC to 16,16-dimethyl prostaglandin E2 (dmPGE2) can enhance transplantation, but the effect of dmPGE2 on aged HSC has not yet been tested. Bone marrow cells from young (3 mo) and aged (25 mo) C57BL/6J mice were pulsed ex vivo with dmPGE2 or vehicle prior to competitive transplantation. DmPGE2 enhanced long-term repopulation of aged grafts in primary and secondary transplantation, increasing final chimerism an average of 27%, similar to the average increase of 21% for young grafts (both p
dmPGE2 stabilizes the transcription factor HIF1a in stem and progenitor cells. Pharmacologic stab... more dmPGE2 stabilizes the transcription factor HIF1a in stem and progenitor cells. Pharmacologic stabilization of HIF1a increases CXCR4 and enhances stem and progenitor homing and engraftment. Hematopoietic stem cell (HSC) transplantation is a lifesaving therapy for a number of immunologic disorders. For effective transplant, HSCs must traffic from the peripheral blood to supportive bone marrow niches. We previously showed that HSC trafficking can be enhanced by ex vivo treatment of hematopoietic grafts with 16-16 dimethyl pros-taglandin E2 (dmPGE2). While exploring regulatory molecules involved in dmPGE2 enhancement, we found that transiently increasing the transcription factor hypoxia-inducible factor 1-a (HIF1a) is required for dmPGE2-enhanced CXCR4 upregulation and enhanced migration and homing of stem and progenitor cells and that pharmacologic manipulation of HIF1a is also capable of enhancing homing and engraftment. We also now identify the specific hypoxia response element requi...
The bone marrow (BM) microenvironment/niche plays a key role in regulating hematopoietic stem and... more The bone marrow (BM) microenvironment/niche plays a key role in regulating hematopoietic stem and progenitor cell (HSPC) activities; however, mechanisms regulating niche cell function are not well understood. In this study, we show that niche intrinsic expression of the CXCR4 chemokine receptor critically regulates HSPC maintenance during steady state, and promotes early hematopoietic regeneration after myeloablative irradiation. At steady state, chimeric mice with wild-type (WT) HSPC and marrow stroma that lack CXCR4 show decreased HSPC quiescence, and their repopulation capacity was markedly reduced. Mesenchymal stromal cells (MSC) were significantly reduced in the BM of CXCR4 deficient mice, which was accompanied by decreased levels of the HSPC supporting factors stromal cell-derived factor-1 (SDF-1) and stem cell factor (SCF). CXCR4 also plays a crucial role in survival and restoration of BM stromal cells after myeloablative irradiation, where the loss of BM stromal cells was mo...
Hematopoietic stem cells (HSCs) reside in hypoxic niches within the bone marrow (BM). Yet, all HS... more Hematopoietic stem cells (HSCs) reside in hypoxic niches within the bone marrow (BM). Yet, all HSC studies have been performed to date with cells immediately isolated in non-physiologic ambient air, whether or not they are subsequently processed in low oxygen tension. By collecting/manipulating BM in physiologically native conditions of hypoxia where all procedures are performed inside a hypoxic chamber, we demonstrate that brief exposure of mouse BM or human cord blood (CB) to ambient oxygen decreases recovery of phenotypically-defined and functional self-renewing long-term repopulating HSC and concomitantly increases numbers of progenitor cells, a phenomenon we term Extra Physiologic Oxygen Shock/Stress (EPHOSS). This new phenomenon is exquisitely sensitive to oxygen and great care must be taken to ensure all reagents, solutions, plastics, and anything that will come into contact with the cell suspension, is extensively pre-equilibrated in hypoxia. Up to 5-fold greater numbers of ...
The relationship between major histocompatibility complex class II antigens (MHC class II, eg, HL... more The relationship between major histocompatibility complex class II antigens (MHC class II, eg, HLA-DR, Ia), T lymphocytes, and the enhancement of erythroid colony formation from BFU-E by prostaglandin E was analyzed using normal bone marrow cells. In primary methylcellulose culture, the addition of prostaglandin E1 (PGE1) to unseparated buffy coat, low-density, or nonadherent low-density (NAL) marrow cells resulted in an enhancement of the total number of erythroid (BFU-E) colonies observed. Treatment of bone marrow cells with a monoclonal antihuman MHC class II antibody plus complement (C') resulted in a reduction of the total number of colonies by approximately 50% and abrogation of the enhancing effect of PGE1. Analysis of accessory cell requirements by depletion of both adherent cells and sheep erythrocyte rosetting lymphocytes (E+ cells) and reconstitution using C' or anti- MHC class II antibody plus C'-treated T cell-depleted NAL (NALT-) marrow cells and E+ cell po...
Marrow cytogenetic and granulocyte-macrophage colony formation (CFU-GM) studies were performed on... more Marrow cytogenetic and granulocyte-macrophage colony formation (CFU-GM) studies were performed on 34 previously untreated patients with documented myelodysplastic syndromes seen between January 1978 and June 1982. All patients were managed without chemotherapy until progression to acute leukemia was observed. All 10 patients with exclusively abnormal marrow metaphases developed acute leukemia (100%) while only one (7%) of 14 patients with solely normal marrow metaphases subsequently developed leukemia (p less than 0.001). Three (42%) of the seven patients with both normal and abnormal marrow metaphases developed acute leukemia. Fifteen (86%) of the 19 patients with either large cluster or no growth patterns developed acute leukemia while only two (13%) of 15 patients with either small cluster or colony forming growth patterns developed acute leukemia (p less than 0.001). Abnormal marrow cytogenetic status correlated with abnormal marrow CFU-GM growth pattern (p less than 0.05). Anal...
Bone marrow and peripheral blood cells of patients with non-leukemic neutropenia contain and elab... more Bone marrow and peripheral blood cells of patients with non-leukemic neutropenia contain and elaborate a granulocyte-progenitor cell inhibitory activity. The inhibitory activity is common to the neutropenias of the various etiologies studied, which included congenital, idiopathic, autoimmune, cyclical, common variable immuno-deficiency with hypogammaglobulinemia and drug induced states. It derives from non-adherent, low density, slowly sedimenting and non-E-rosetting cells and appears to require RNA and protein synthesis, but not cell division, for its production. The material is not species specific, inhibits autologous and allogeneic normal CFUgm and leukemic CFUgm, is not cell-cycle specific in action and is most effective against granulocyte colony forming cells (CFUg), less effective against mixed granulocyte-macrophage colony forming cells (CFUgm) and least or non-effective against macrophage colony forming cells (CFUm). This inhibitory activity has no influence on cells which...
Uploads
Papers by Louis Pelus