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1.
Kidney Int ; 105(1): 84-98, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37839695

ABSTRACT

Clinical verification of adoptively transferred regulatory T cell (Treg) efficacy in transplantation remains challenging. Here, we examined the influence of autologous ex vivo-expanded polyclonal Tregs on kidney graft survival in a clinically relevant non-human primate model. Peripheral blood Tregs were isolated and expanded using artificial antigen presenting cells. Immunosuppression was comprised of tapered tacrolimus and CTLA4 immunoglobulin, in five animals each without or with Treg infusions. Escalating Treg doses were administered 6, 10, 13, 16, 20, 23, 27 and 30 days after transplant. Infused Tregs were monitored for Treg signature, anti-apoptotic (Bcl-2) and proliferation (Ki67) marker expression. Treg infusions prolonged median graft survival time significantly from 35 to 70 days. Treg marker (Ki67 and Bcl-2) expression by infused Tregs diminished after their infusion but remained comparable to that of circulating native Tregs. No major changes in circulating donor-reactive T cell responses or total Treg percentages, or in graft-infiltrating T cell subsets were observed with Treg infusion. However, Treg infusion was associated with significant increases in CD163 expression by circulating HLA-DR+ myeloid cells and elevated levels of circulating soluble CD163. Further, graft-infiltrating CD163+ cells were increased with Treg infusion. Thus, multiple Treg infusions were associated with M2-like myeloid cell enhancement that may mediate immunomodulatory, anti-inflammatory and graft reparative effects.


Subject(s)
Primates , T-Lymphocytes, Regulatory , Animals , Ki-67 Antigen/metabolism , Kidney , Allografts , Myeloid Cells , Proto-Oncogene Proteins c-bcl-2/metabolism
2.
J Hepatocell Carcinoma ; 10: 1547-1571, 2023.
Article in English | MEDLINE | ID: mdl-37744303

ABSTRACT

Globally, hepatocellular carcinoma (HCC) is the fourth most common cause of death from cancer. The prevalence of this pathology, which has been on the rise in the last 30 years, has been predicted to continue increasing. HCC is the most common cause of cancer-related morbidity and mortality in Egypt and is also the most common cancer in males. Chronic liver diseases, including chronic hepatitis C, which is a primary health concern in Egypt, are considered major risk factors for HCC. However, HCC surveillance is recommended for patients with chronic hepatitis B virus (HBV) and liver cirrhosis; those above 40 with HBV but without cirrhosis; individuals with hepatitis D co-infection or a family history of HCC; and Nonalcoholic fatty liver disease (NAFLD) patients exhibiting significant fibrosis or cirrhosis. Several international guidelines aid physicians in the management of HCC. However, the availability and cost of diagnostic modalities and treatment options vary from one country to another. Therefore, the current guidelines aim to standardize the management of HCC in Egypt. The recommendations presented in this report represent the current management strategy at HCC treatment centers in Egypt. Recommendations were developed by an expert panel consisting of hepatologists, oncologists, gastroenterologists, surgeons, pathologists, and radiologists working under the umbrella of the Egyptian Society of Liver Cancer. The recommendations, which are based on the currently available local diagnostic aids and treatments in the country, include recommendations for future prospects.

4.
Transplantation ; 107(5): 1079-1088, 2023 05 01.
Article in English | MEDLINE | ID: mdl-36814087

ABSTRACT

BACKGROUND: Generation of donor-specific human leukocyte antigen antibody (DSA) via indirect allorecognition is detrimental to long-term survival of transplant organs. The detection of such immune responses would make it possible to define patients with high risk of sensitization. In this study, we established a novel method for evaluating indirect allorecognition to assess sensitization in kidney transplant recipients. METHODS: Recipient CD14 + monocytes were mixed with donor peripheral blood mononuclear cells; cultured in the presence of IL-4, GM-CSF, IL-1ß, and TNFα; and used as pulsed dendritic cells (DCs). Cell proliferation and cytokine production were evaluated by carboxyfluorescein diacetate succinimidyl ester-based T cell proliferation assay and Enzyme-Linked ImmunoSpot assay, respectively. RESULTS: CD4 + T cell proliferation was strongly observed in following coculture with allogeneic antigen-pulsed DC leading to interferon-γ and IL-21 production. About 1% of CD4 + T cells exhibited Tfh-like phenotype (PD-1 high CXCR5 + ICOS + CD40L + ). Recipient DC pulsed with donor peripheral blood mononuclear cells was cocultured with recipient CD45RA+CD4+ and CD45RA-CD4+ (generally defined as naive and memory in humans, respectively) T cells. Irrespective of preformed or de novo DSA status, CD45RA + CD4 + T cells constantly produced IL-21. In contrast, IL-21-produced CD45RA - CD4 + T cells were significantly higher in preformed DSA-positive patients than those in negative patients (80.8 ± 51.2 versus 14.8 ± 20.4, P < 0.001). In de novo DSA-positive patients, IL-21-produced CD45RA - CD4 + T cells were significantly increased after transplantation compared with before transplantation (9.23 ± 9.08 versus 43.9 ± 29.1, P < 0.001). CONCLUSIONS: Assessment of indirect pathway CD4 + T cell response could provide new insights into the underlying mechanism of de novo DSA production, leading to the development of effective strategies against antibody-mediated rejection.


Subject(s)
Kidney Transplantation , Humans , Kidney Transplantation/adverse effects , Leukocytes, Mononuclear , CD4-Positive T-Lymphocytes , Interferon-gamma/metabolism , Dendritic Cells
5.
Transpl Immunol ; 75: 101696, 2022 12.
Article in English | MEDLINE | ID: mdl-35987329

ABSTRACT

BACKGROUND: We evaluated the outcome of vertical rectus abdominus myocutaneous flap (VRAM) allotransplantation in a mini-pig model, using a combined co-stimulation blockade (Co-SB) and mechanistic target of rapamycin inhibition (mTORi)-based regimen, with or without preceding calcineurin inhibition (CNI). MATERIALS AND METHODS: VRAM allotransplants were performed between SLA-mismatched MGH miniature swine. Group A (n = 2) was treated continuously with the mTOR inhibitor rapamycin from day -1 in combination with the Co-SB agent cytotoxic T lymphocyte antigen 4-Ig (CTLA4-Ig) from post-operative day (POD) 0. In group B (n = 3), animals received tacrolimus daily from POD 0 to POD 13, followed by rapamycin daily from POD 7 and CTLA4-Ig weekly from POD 7-28. Graft rejection was determined by Banff criteria and host cellular and humoral immunity monitored. RESULTS: In group A, allografts developed grade-I acute rejection by POD 2 and POD 7, and reached grade-IV by POD 17 and POD 20, respectively. By contrast, in group B, two allografts demonstrated grade-I rejection on POD 30 and grade-IV on POD 74, while the third exhibited grade-I rejection starting on POD 50, though this animal had to be euthanized on POD 58 due to Pneumocystis jirovecii infection. Time-to-event incidence of grade-I rejection was significantly lower in group A compared to group B. During the first 3 weeks post-transplant, no significant differences in anti-donor immunity were observed between the groups. CONCLUSION: A short course of CNI, followed by combined Co-SB and mTORi significantly delays acute rejection of VRAM allografts in SLA-mismatched miniature swine.


Subject(s)
Composite Tissue Allografts , Tacrolimus , Animals , Swine , Tacrolimus/therapeutic use , Swine, Miniature , Sirolimus/therapeutic use , Graft Survival , Abatacept/therapeutic use , Graft Rejection , Immunosuppressive Agents/therapeutic use , Immunosuppressive Agents/pharmacology
6.
Ann Transplant ; 27: e935338, 2022 Jul 05.
Article in English | MEDLINE | ID: mdl-35789146

ABSTRACT

BACKGROUND Although improving, survival after pig orthotopic heart transplantation (OHTx) in baboons has been mixed and largely poor. The causes for the high incidence of early failure remain uncertain. MATERIAL AND METHODS We have carried out pig OHTx in 4 baboons. Two died or were euthanized within hours, and 2 survived for 3 and 8 months, respectively. There was evidence of a significant 'cytokine storm' in the immediate post-OHTx period with the elevations in IL-6 correlating closely with the final outcome. RESULTS All 4 baboons demonstrated features suggestive of respiratory dysfunction, including increased airway resistance, hypoxia, and tachypnea. Histopathological observations of pulmonary infiltration by neutrophils and, notably, eosinophils within vessels and in the perivascular and peribronchiolar space, with minimal cardiac pathology, suggested a role for early lung acute inflammation. In one, features suggestive of transfusion-related acute lung injury were present. The 2 longer-term survivors died of (i) a cardiac dysrhythmia with cellular infiltration around the conducting tissue (at 3 months), and (ii) mixed cellular and antibody-mediated rejection (at 8 months). CONCLUSIONS These initial findings indicate a potential role of acute lung injury early after OHTx. If this response can be prevented, increased survival may result, providing an opportunity to evaluate the factors affecting long-term survival.


Subject(s)
Heart Transplantation , Animals , Antibodies , Heart Transplantation/adverse effects , Heart Transplantation/methods , Lung , Papio , Swine , Transplantation, Heterologous/methods
7.
Front Immunol ; 12: 788949, 2021.
Article in English | MEDLINE | ID: mdl-34956220

ABSTRACT

Background: In pig-to-baboon transplantation models, there is increasing evidence of systemic inflammation in xenograft recipients (SIXR) associated with pig xenograft failure. We evaluated the relationship between systemic inflammatory factors and pig kidney xenograft failure. Methods: Baboons received kidney transplants from genetically engineered pigs (n=9), and received an anti-CD40mAb-based (n=4) or conventional (n=5) immunosuppressive regimen. The pig kidney grafts were monitored by measurements of serum creatinine, serum amyloid A (SAA), white blood cell (WBC) and platelet counts, plasma fibrinogen, and pro-inflammatory cytokines (baboon and pig IL-6, TNF-α, IL-1ß). Results: Six baboons were euthanized or died from rejection, and 3 were euthanized for infection. Changes in serum creatinine correlated with those of SAA (r=0.56, p<0.01). Serum baboon IL-6 was increased significantly on day 1 after transplantation and at euthanasia (both p<0.05) and correlated with serum creatinine and SAA (r=0.59, p<0.001, r=0.58, p<0.01; respectively). but no difference was observed between rejection and infection. Levels of serum pig IL-6, TNF-α, IL-1ß were also significantly increased on day 1 and at euthanasia, and serum pig IL-6 and IL-1ß correlated with serum creatinine and SAA. The level of serum baboon IL-6 correlated with the expression of IL-6 and amyloid A in the baboon liver (r=0.93, p<0.01, r=0.79, p<0.05; respectively). Conclusion: Early upregulation of SAA and serum IL-6 may indicate the development of rejection or infection, and are associated with impaired kidney graft function. Detection and prevention of systemic inflammation may be required to prevent pig kidney xenograft failure after xenotransplantation.


Subject(s)
Graft Rejection/immunology , Inflammation Mediators/blood , Inflammation/immunology , Interleukin-6/blood , Kidney Transplantation/adverse effects , Animals , Animals, Genetically Modified , Disease Models, Animal , Graft Rejection/blood , Immunosuppressive Agents/pharmacology , Inflammation/blood , Interleukin-1beta/blood , Liver/immunology , Liver/metabolism , Papio , Serum Amyloid A Protein/metabolism , Signal Transduction , Sus scrofa/genetics , Transplantation, Heterologous/adverse effects , Up-Regulation
8.
Xenotransplantation ; 28(6): e12715, 2021 11.
Article in English | MEDLINE | ID: mdl-34644438

ABSTRACT

INTRODUCTION: Pigs deficient in three glycosyltransferase enzymes (triple-knockout [TKO] pigs, that is, not expressing the three known carbohydrate xenoantigens) and expressing 'protective' human transgenes are considered a likely source of organs for transplantation into human recipients. Some human sera have no or minimal natural antibody binding to red blood cells (RBCs) and peripheral blood mononuclear cells (PBMCs) from TKO pigs. However, all Old World monkeys exhibit natural antibody binding to TKO pig cells. The xenoantigen targets of Old World monkey natural antibodies are postulated to be carbohydrate moieties exposed when the expression of the carbohydrate N-glycolylneuraminic acid (Neu5Gc) is deleted. The aim of this study was to compare the survival in baboons and histopathology of renal grafts from pigs that either (a) expressed Neu5Gc (GTKO pigs; Group 1) or (b) did not express Neu5Gc (GTKO/CMAHKO [DKO] or TKO pigs; Group 2). METHODS: Life-supporting renal transplants were carried out using GTKO (n = 5) or DKO/TKO (n = 5) pig kidneys under an anti-CD40mAb-based immunosuppressive regimen. RESULTS: Group 1 baboons survived longer than Group 2 baboons (median 237 vs. 35 days; mean 196 vs. 57 days; p < 0.07) and exhibited histopathological features of antibody-mediated rejection in only two kidneys. Group 2 exhibited histopathological features of antibody-mediated rejection in all five grafts, with IgM and IgG binding to renal interstitial arteries and peritubular capillaries. Rejection-free survival was significantly longer in Group 1 (p < 0.05). CONCLUSIONS: The absence of expression of Neu5Gc on pig kidney grafts is associated with increased binding of baboon antibodies to pig endothelium and reduced graft survival.


Subject(s)
Kidney , Leukocytes, Mononuclear , Animals , Animals, Genetically Modified , Carbohydrates , Graft Rejection , Papio , Swine , Transplantation, Heterologous
9.
Front Cell Dev Biol ; 9: 666959, 2021.
Article in English | MEDLINE | ID: mdl-34211972

ABSTRACT

Non-human primates (NHP) are an important resource for addressing key issues regarding the immunobiology of regulatory T cells (Treg), their in vivo manipulation and the translation of adoptive Treg therapy to clinical application. In addition to their phenotypic and functional characterization, particularly in cynomolgus and rhesus macaques, NHP Treg have been isolated and expanded successfully ex vivo. Their numbers can be enhanced in vivo by administration of IL-2 and other cytokines. Both polyclonal and donor antigen (Ag) alloreactive NHP Treg have been expanded ex vivo and their potential to improve long-term outcomes in organ transplantation assessed following their adoptive transfer in combination with various cytoreductive, immunosuppressive and "Treg permissive" agents. In addition, important insights have been gained into the in vivo fate/biodistribution, functional stability, replicative capacity and longevity of adoptively-transferred Treg in monkeys. We discuss current knowledge of NHP Treg immunobiology, methods for their in vivo expansion and functional validation, and results obtained testing their safety and efficacy in organ and pancreatic islet transplantation models. We compare and contrast results obtained in NHP and mice and also consider prospects for future, clinically relevant studies in NHP aimed at improved understanding of Treg biology, and innovative approaches to promote and evaluate their therapeutic potential.

10.
Xenotransplantation ; 28(4): e12700, 2021 07.
Article in English | MEDLINE | ID: mdl-34036638

ABSTRACT

Pigs deficient in three glycosyltransferase enzymes (triple-knockout [TKO] pigs) and expressing "protective" human transgenes are likely sources of organs for transplantation into human recipients. Testing of human sera against red blood cells (RBCs) and peripheral blood mononuclear cells (PBMCs) from TKO pigs has revealed minimal evidence of natural antibody binding. However, unlike humans, baboons exhibit natural antibody binding to TKO pig cells. The xenoantigen specificities of these natural antibodies are postulated to be one or more carbohydrate moieties exposed when N-glycolylneuraminic acid (Neu5Gc) is deleted. The aim of this study was to compare the survival of renal grafts in baboons from pigs that either expressed Neu5Gc (GTKO pigs; Group1, n = 5) or did not express Neu5Gc (GTKO/CMAHKO [DKO] or TKO pigs; Group2, n = 5). An anti-CD40mAb-based immunosuppressive regimen was administered in both groups. Group1 kidneys functioned for 90-260 days (median 237, mean 196 days), with histopathological features of antibody-mediated rejection in two kidneys. Group2 kidneys functioned for 0-183 days (median 35, mean 57), with all of the grafts exhibiting histologic features of antibody-mediated rejection. These findings suggest that the absence of expression of Neu5Gc on pig kidneys impacts graft survival in baboon recipients.


Subject(s)
Kidney Transplantation , Animals , Animals, Genetically Modified , Graft Rejection , Leukocytes, Mononuclear , Neuraminic Acids , Papio , Swine , Transplantation, Heterologous
11.
Transplantation ; 105(6): 1143-1155, 2021 06 01.
Article in English | MEDLINE | ID: mdl-33534529

ABSTRACT

We discuss what therapeutic regimen might be acceptable/successful in the first clinical trial of genetically engineered pig kidney or heart transplantation. As regimens based on a calcineurin inhibitor or CTLA4-Ig have proved unsuccessful, the regimen we administer to baboons is based on induction therapy with antithymocyte globulin, an anti-CD20 mAb (Rituximab), and cobra venom factor, with maintenance therapy based on blockade of the CD40/CD154 costimulation pathway (with an anti-CD40 mAb), with rapamycin, and a corticosteroid. An anti-inflammatory agent (etanercept) is administered for the first 2 wk, and adjuvant therapy includes prophylaxis against thrombotic complications, anemia, cytomegalovirus, and pneumocystis. Using this regimen, although antibody-mediated rejection certainly can occur, we have documented no definite evidence of an adaptive immune response to the pig xenograft. This regimen could also form the basis for the first clinical trial, except that cobra venom factor will be replaced by a clinically approved agent, for example, a C1-esterase inhibitor. However, none of the agents that block the CD40/CD154 pathway are yet approved for clinical use, and so this hurdle remains to be overcome. The role of anti-inflammatory agents remains unproven. The major difference between this suggested regimen and those used in allotransplantation is the replacement of a calcineurin inhibitor with a costimulation blockade agent, but this does not appear to increase the complications of the regimen.


Subject(s)
Graft Rejection/prevention & control , Graft Survival/drug effects , Histocompatibility , Immunosuppressive Agents/pharmacology , Transplantation, Heterologous , Adrenal Cortex Hormones/pharmacology , Animals , Anti-Inflammatory Agents/pharmacology , Antibodies, Heterophile/metabolism , Antilymphocyte Serum/pharmacology , CD40 Antigens/antagonists & inhibitors , CD40 Antigens/immunology , CD40 Antigens/metabolism , Drug Therapy, Combination , Elapid Venoms/pharmacology , Graft Rejection/immunology , Graft Rejection/metabolism , Heterografts , Humans , Immunosuppressive Agents/toxicity , Papio , Risk Assessment , Risk Factors , Rituximab/pharmacology , Sirolimus/pharmacology , Sus scrofa , Transplantation, Heterologous/adverse effects
12.
Transplantation ; 105(9): 1965-1979, 2021 09 01.
Article in English | MEDLINE | ID: mdl-33587433

ABSTRACT

BACKGROUND: Regulatory T cell (Treg) therapy is a promising approach to amelioration of allograft rejection and promotion of organ transplant tolerance. However, the fate of infused Treg, and how this relates to their therapeutic efficacy using different immunosuppressive regimens is poorly understood. Our aim was to analyze the tissue distribution, persistence, replicative activity and phenotypic stability of autologous, donor antigen alloreactive Treg (darTreg) in anti-thymocyte globulin (ATG)-lymphodepleted, heart-allografted cynomolgus monkeys. METHODS: darTreg were expanded ex vivo from flow-sorted, circulating Treg using activated donor B cells and infused posttransplant into recipients of major histocompatibility complex-mismatched heart allografts. Fluorochrome-labeled darTreg were identified and characterized in peripheral blood, lymphoid, and nonlymphoid tissues and the graft by flow cytometric analysis. RESULTS: darTreg selectively suppressed autologous T cell responses to donor antigens in vitro. However, following their adoptive transfer after transplantation, graft survival was not prolonged. Early (within 2 wk posttransplant; under ATG, tacrolimus, and anti-IL-6R) or delayed (6-8 wk posttransplant; under rapamycin) darTreg infusion resulted in a rapid decline in transferred darTreg in peripheral blood. Following their early or delayed infusion, labeled cells were evident in lymphoid and nonlymphoid organs and the graft at low percentages (<4% CD4+ T cells). Notably, infused darTreg showed reduced expression of immunoregulatory molecules (Foxp3 and CTLA4), Helios, the proliferative marker Ki67 and antiapoptotic Bcl2, compared with preinfusion darTreg and endogenous CD4+CD25hi Treg. CONCLUSIONS: Lack of therapeutic efficacy of infused darTreg in lymphodepleted heart graft recipients appears to reflect loss of a regulatory signature and proliferative and survival capacity shortly after infusion.


Subject(s)
Adoptive Transfer , Antilymphocyte Serum/pharmacology , Apoptosis Regulatory Proteins/metabolism , Apoptosis , Cell Proliferation , Graft Rejection/prevention & control , Graft Survival , Heart Transplantation , Lymphocyte Activation , Lymphocyte Depletion , T-Lymphocytes, Regulatory/transplantation , Animals , Cells, Cultured , Disease Models, Animal , Graft Rejection/immunology , Graft Rejection/metabolism , Heart Transplantation/adverse effects , Macaca fascicularis , Male , Phenotype , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/metabolism , Time Factors
13.
Cell Immunol ; 351: 104087, 2020 05.
Article in English | MEDLINE | ID: mdl-32197811

ABSTRACT

Nonhuman primates (NHP) are important pre-clinical models for evaluation of the safety and efficacy of the most promising potential therapeutic advances in organ transplantation based on rodent studies. Although rare, dendritic cells (DC) play important roles in preservation of self tolerance and DC with immunoregulatory properties (regulatory DC; DCreg) can promote transplant tolerance in rodents when adoptively transferred to allograft recipients. NHP DCreg can be generated ex vivo from bone marrow precursors or blood monocytes of cynomolgus or rhesus macaques or baboons. NHP DCreg generated in the presence of anti-inflammatory factors that confer stability and resistance to maturation, subvert alloreactive T cell responses. When infused into rhesus renal allograft recipients before transplant, they safely prolong MHC mis-matched graft survival, associated with attenuation of anti-donor immune reactivity. In this concise review we describe the properties of NHP DCreg and discuss their influence on T cell responses, alloimmunity and organ transplant survival.


Subject(s)
Dendritic Cells/immunology , Disease Models, Animal , Kidney Transplantation , Transplantation Tolerance/immunology , Animals , Macaca fascicularis , Macaca mulatta , Papio , Primates , Transplantation, Homologous
14.
Am J Transplant ; 20(6): 1691-1702, 2020 06.
Article in English | MEDLINE | ID: mdl-31883190

ABSTRACT

Early phase clinical trials are evaluating the feasibility, safety, and therapeutic potential of ex vivo expanded regulatory T cells (Treg) in transplantation. A limitation is the paucity of naturally occurring Treg numbers in peripheral blood. Hence, protracted ex vivo expansion is required to obtain sufficient Treg in order to meet target cell doses. Because cytokine administration has been used successfully to mobilize immune cells to the peripheral blood in experimental and clinical studies, we hypothesized that granulocyte macrophage-colony-stimulating factor (GM-CSF) and granulocyte-CSF (G-CSF) administration would enhance Treg percentages in leukapheresis products of rhesus monkeys. Following combined GM-CSF and G-CSF administration, the incidence of Treg in peripheral blood and leukapheresis products was elevated significantly, where approximately 3.7 × 106 /kg CD4+ CD25hi Foxp3hi or 6.8 × 106 /kg CD4+ CD25hi CD127lo Treg can be collected from individual products. Mobilized Treg expressed a comparable repertoire of surface markers, chemokine receptors, and transcription factors to naïve monkey peripheral blood Treg. Furthermore, when expanded ex vivo, mobilized leukapheresis product and peripheral blood Treg exhibited similar ability to suppress autologous CD4+ and CD8+ T cell proliferation. These observations indicate that leukapheresis products from combined GM-CSF- and G-CSF-mobilized individuals are a comparatively rich source of Treg and may circumvent long-term ex vivo expansion required for therapeutic application.


Subject(s)
Granulocyte-Macrophage Colony-Stimulating Factor , T-Lymphocytes, Regulatory , Animals , Granulocyte Colony-Stimulating Factor , Leukapheresis , Macaca mulatta , Transcription Factors
16.
Transpl Immunol ; 56: 101225, 2019 10.
Article in English | MEDLINE | ID: mdl-31330261

ABSTRACT

Myeloid-derived suppressor cells (MDSC) are a heterogenous population of immunosuppressive myeloid cells now considered important immune regulatory cells in diverse clinical conditions, including cancer, chronic inflammatory disorders and transplantation. In rodents, MDSC administration can inhibit graft-versus-host disease lethality and enhance organ or pancreatic islet allograft survival. There is also evidence, however, that under systemic inflammatory conditions, adoptively-transferred MDSC can rapidly lose their suppressive function. To our knowledge, there are no reports of autologous MDSC administration to either human or clinically-relevant non-human primate (NHP) transplant recipients. Monocytic (m) MDSC have been shown to be more potent suppressors of T cell responses than other subsets of MDSC. Following their characterization in rhesus macaques, we have conducted a preliminary analysis of the feasibility and preliminary efficacy of purified mMDSC infusion into MHC-mismatched rhesus kidney allograft recipients. The graft recipients were treated with rapamycin and the high affinity variant of the T cell co-stimulation blocking agent cytotoxic T lymphocyte antigen 4 Ig (Belatacept) that targets the B7-CD28 pathway. Graft survival and histology were not affected by infusions of autologous, leukapheresis product-derived mMDSC on days 7 and 14 post-transplant (cumulative totals of 3.19 and 1.98 × 106 cells/kg in n = 2 recipients) compared with control monkeys that did not receive MDSC (n = 2). Sequential analyses of effector T cell populations revealed no differences between the groups. While these initial findings do not provide evidence of efficacy under the conditions adopted, further studies in NHP, designed to ascertain the appropriate mMDSC source and dose, timing and anti-inflammatory/immunosuppressive agent support are likely to prove instructive regarding the therapeutic potential of MDSC in organ transplantation.


Subject(s)
Cell Transplantation/methods , Graft Rejection/prevention & control , Kidney Transplantation , Myeloid-Derived Suppressor Cells/transplantation , T-Lymphocytes/immunology , Abatacept/therapeutic use , Animals , Cells, Cultured , Disease Models, Animal , Feasibility Studies , Graft Rejection/immunology , Histocompatibility Antigens/immunology , Humans , Immune Tolerance , Immunosuppressive Agents/therapeutic use , Macaca mulatta , Sirolimus/therapeutic use , Transplantation, Autologous , Transplantation, Homologous
17.
Transplantation ; 103(10): 2090-2104, 2019 10.
Article in English | MEDLINE | ID: mdl-31283686

ABSTRACT

BACKGROUND: The aims of this study were to evaluate the efficacy of US Food and Drug Administration-approved drugs in genetically engineered pig-to-baboon kidney xenotransplantation and compare the results with those using an anti-CD40 monoclonal antibody (mAb)-based regimen. METHODS: Ten life-supporting kidney transplants were carried out in baboons using α1,3-galactosyltransferase gene-knockout/CD46 pigs with various other genetic manipulations aimed at controlling coagulation dysregulation. Eight transplants resulted in informative data. Immunosuppressive therapy consisted of induction with antithymocyte globulin and anti-CD20mAb, and maintenance based on either (1) CTLA4-Ig and/or tacrolimus (+rapamycin or mycophenolate mofetil) (GroupA [US Food and Drug Administration-approved regimens], n = 4) or (2) anti-CD40mAb + rapamycin (GroupB, n = 4). All baboons received corticosteroids, interleukin-6R blockade, and tumor necrosis factor-α blockade. Baboons were followed by clinical and laboratory monitoring of kidney function, coagulation, and immune parameters. At euthanasia, morphological and immunohistochemical studies were performed on the kidney grafts. RESULTS: The median survival in GroupB was 186 days (range 90-260), which was significantly longer than in GroupA; median 14 days (range 12-32) (P < 0.01). Only GroupA baboons developed consumptive coagulopathy and the histopathological features of thrombotic microangiopathic glomerulopathy and interstitial arterial vasculitis. CONCLUSIONS: Recognizing that the pig donors in each group differed in some genetic modifications, these data indicate that maintenance immunosuppression including anti-CD40mAb may be important to prevent pig kidney graft failure.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Graft Rejection/prevention & control , Immunosuppressive Agents/administration & dosage , Kidney Transplantation/adverse effects , Life Support Care/methods , Animals , Animals, Genetically Modified , CD40 Antigens/antagonists & inhibitors , CD40 Antigens/immunology , Disease Models, Animal , Galactosyltransferases/genetics , Gene Knockout Techniques , Graft Rejection/immunology , Graft Rejection/mortality , Graft Survival/drug effects , Graft Survival/immunology , Heterografts/drug effects , Heterografts/immunology , Humans , Kidney/drug effects , Kidney/immunology , Kidney Transplantation/methods , Membrane Cofactor Protein/genetics , Papio , Swine/genetics , Transplantation, Heterologous/adverse effects , Transplants/drug effects , Transplants/immunology
18.
Transplant Rev (Orlando) ; 33(3): 130-136, 2019 07.
Article in English | MEDLINE | ID: mdl-31130302

ABSTRACT

Current immunosuppressive (IS) regimens used to prevent organ allograft rejection have well-recognized side effects, that include enhanced risk of infection and certain types of cancer, metabolic disorders, cardiovascular disease, renal complications and failure to control chronic allograft rejection. The life-long dependency of patients on these IS agents reflects their inability to induce donor-specific tolerance. Extensive studies in rodent and non-human primate models have demonstrated the ability of adoptively-transferred regulatory immune cells (either regulatory myeloid cells or regulatory T cells) to promote transplant tolerance. Consequently, there is considerable interest in the potential of regulatory immune cell therapy to allow safe minimization/complete withdrawal of immunosuppression and the promotion of organ transplant tolerance in the clinic. Here, we review the properties of regulatory dendritic cells (DCreg) with a focus on the approaches being taken to generate human DCreg for clinical testing. We also document the early phase clinical trials that are underway to assess DCreg therapy in clinical organ transplantation as well as in autoimmune disorders.


Subject(s)
Dendritic Cells , Organ Transplantation , Transplantation Immunology , Biomedical Research , Humans
19.
Xenotransplantation ; 26(4): e12516, 2019 07.
Article in English | MEDLINE | ID: mdl-30989742

ABSTRACT

Xenotransplantation research has made considerable progress in recent years, largely through the increasing availability of pigs with multiple genetic modifications. We suggest that a pig with nine genetic modifications (ie, currently available) will provide organs (initially kidneys and hearts) that would function for a clinically valuable period of time, for example, >12 months, after transplantation into patients with end-stage organ failure. The national regulatory authorities, however, will likely require evidence, based on in vitro and/or in vivo experimental data, to justify the inclusion of each individual genetic modification in the pig. We provide data both from our own experience and that of others on the advantages of pigs in which (a) all three known carbohydrate xenoantigens have been deleted (triple-knockout pigs), (b) two human complement-regulatory proteins (CD46, CD55) and two human coagulation-regulatory proteins (thrombomodulin, endothelial cell protein C receptor) are expressed, (c) the anti-apoptotic and "anti-inflammatory" molecule, human hemeoxygenase-1 is expressed, and (d) human CD47 is expressed to suppress elements of the macrophage and T-cell responses. Although many alternative genetic modifications could be made to an organ-source pig, we suggest that the genetic manipulations we identify above will all contribute to the success of the initial clinical pig kidney or heart transplants, and that the beneficial contribution of each individual manipulation is supported by considerable experimental evidence.


Subject(s)
Animals, Genetically Modified/genetics , Graft Rejection/prevention & control , Swine/genetics , Transplantation, Heterologous , Animals , Animals, Genetically Modified/immunology , CD47 Antigen/genetics , CD47 Antigen/immunology , CD55 Antigens/genetics , CD55 Antigens/immunology , Endothelial Protein C Receptor/genetics , Endothelial Protein C Receptor/immunology , Galactosyltransferases/deficiency , Galactosyltransferases/genetics , Galactosyltransferases/immunology , Gene Knock-In Techniques , Gene Knockout Techniques , Graft Rejection/immunology , Heme Oxygenase-1/genetics , Heme Oxygenase-1/immunology , Humans , Membrane Cofactor Protein/genetics , Membrane Cofactor Protein/immunology , Mixed Function Oxygenases/deficiency , Mixed Function Oxygenases/genetics , Mixed Function Oxygenases/immunology , N-Acetylgalactosaminyltransferases/deficiency , N-Acetylgalactosaminyltransferases/genetics , N-Acetylgalactosaminyltransferases/immunology , Swine/immunology , Thrombomodulin/genetics , Thrombomodulin/immunology
20.
J Hepatocell Carcinoma ; 5: 109-119, 2018.
Article in English | MEDLINE | ID: mdl-30510922

ABSTRACT

BACKGROUND: Phase II trials found that tegafur-uracil (UFT) is an effective drug in hepatocellular carcinoma (HCC), while preclinical data suggested that its combination with sorafenib may have a promising activity. Our Phase II randomized trial aimed to evaluate efficacy and tolerability of sorafenib plus UFT vs sorafenib in advanced HCC. METHODS: Patients with advanced HCC, with no prior systemic therapy, were randomized to receive either UFT at 125 mg/m2 twice daily for 4 out of 5 weeks plus sorafenib at 400 mg twice daily (arm 1) or single agent sorafenib at 400 mg twice daily (arm 2). Primary end point was time to progression (TTP). RESULTS: Between March 2012 and March 2014, 76 eligible patients - out of 143 preplanned - were randomized. The study was terminated early because of futility. This is the final analysis of the study, after a median follow-up of 10.2 months and death of 86% of randomized patients (n=64). Median TTP was 7.5 months and 8.2 months in arms 1 and 2 respectively (HR: 1.07; 95% CI, 0.52-2.22; P=0.855), while the median overall survival was 8.2 months and 10.5 months respectively (HR: 1.58; 95% CI: 0.90-2.76, P=0.112). Nine patients (25%) in the combination arm discontinued treatment because of toxicity vs eight patients (21.1%) in the sorafenib monotherapy arm (P=0.899). CONCLUSION: In patients with advanced HCC, adding UFT to sorafenib is feasible, but it did not improve efficacy outcome over sorafenib monotherapy.

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