scholarly journals Generation of BCR-ABL Reactive CD4+ T Helper Cells By Reprograming and Redifferentiation

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3424-3424
Author(s):  
Norihiro Ueda ◽  
Yasusi Uemura ◽  
Rhong Zhang ◽  
Shuichi Kitayama ◽  
Yutaka Yasui ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Tyrosine Kinase ◽  
Research Funding ◽  
T Helper ◽  
Th Cells ◽  
Hematopoietic Stem ◽  
Chugai Pharmaceutical ◽  
Dc Maturation

Abstract Chronic myeloid leukemia (CML) is a clonal hematopoietic stem cell disorder caused by BCR-ABL fusion protein that has constitutively active tyrosine kinase activity. Although the prognosis of the patient with CML in chronic phase has markedly improved by the advent of tyrosine kinase inhibiters, the management of the patients with CML in advanced phase remains to be the major challenge. Immunotherapy is considered to be one of the promising treatment strategies for refractory CML. BCR-ABL fusion region, b3a2 peptide, represents a neo-epitope that can induce CML-specific immune responses. The activation of b3a2 peptide-specific CD4+ T helper (Th) cells and their interaction with dendritic cells (DCs) can induce a robust cytotoxic T lymphocyte (CTL)-mediated anti-leukemic immunity through epitope spreading. However, current vaccination strategies cannot effectively induce the proliferation of antigen-specific Th cells in vivo, presumably due to the tumor-induced immunosuppressive milieu. In addition, ex vivo expansion of antigen-specific Th cells attenuates their effector functions by expansion-related cell senescence, and the procedure to establish antigen-specific Th cells for each patient's treatment is too complicated for the clinical application. The purpose of the present study is to establish a method to generate large amounts of functional b3a2-specific CD4+ Th cells enough for the treatment of the patients with refractory CML by using induced pluripotent stem cell (iPSC) technology. First, we established b3a2-specific CD4+ Th clone from peripheral blood mononuclear cells of a healthy donor positive for HLA-DRB1*09:01 and HLA-A*24:02. The Th clone recognized b3a2 peptide in the context of HLA-DR9 and exhibited a Th1 profile. Second, we established iPSCs from the Th clone and differentiated them into T cell lineage by coculture with OP9 stromal cells expressing Notch ligand Delta-like 1. The iPSC-derived T cells (b3a2-iPS-T cells) expressed the same T cell antigen receptor (TCR) as the original Th clone but not CD4 molecule. Because CD4 acts as a co-receptor in the TCR-mediated Th responses, we transduced b3a2-iPS-T cells with CD4 gene. The CD4-expressing b3a2-iPS-T cells (CD4+ b3a2-iPS-T cells) recognized b3a2 peptide in the context of HLA-DR9 as the original Th clone. Moreover, CD4+ b3a2-iPS-T cells activated by b3a2 peptide induced DC maturation, as indicated by the upregulation of CD86 on DCs. In the additional presence of HLA-A24-restricted Wilms tumor 1 (WT1) peptide, the mature DCs stimulated primary expansion of WT1-specific CTLs. The CTLs exerted cytotoxicity against WT1 peptide-loaded HLA-A24 positive cell lines. These data suggest that the CD4+ b3a2-iPS-T cells have a potential to induce effective anti-leukemic immunity via DC maturation and subsequent CTL responses. The current approach enable to provide large amounts of b3a2 specific CD4+ Th-like cells that would augment CTL-mediated anti-leukemic responses via DC maturation, which may contribute to the treatment of patients with refractory CML. Disclosures Kiyoi: Yakult Honsha Co.,Ltd.: Research Funding; FUJIFILM Corporation: Patents & Royalties, Research Funding; Eisai Co., Ltd.: Research Funding; Kyowa Hakko Kirin Co., Ltd.: Consultancy, Research Funding; Sumitomo Dainippon Pharma Co., Ltd.: Research Funding; Zenyaku Kogyo Co., Ltd.: Research Funding; Novartis Pharma K.K.: Research Funding; Mochida Pharmaceutical Co., Ltd.: Research Funding; Astellas Pharma Inc.: Consultancy, Research Funding; Nippon Shinyaku Co., Ltd.: Research Funding; FUJIFILM RI Pharma Co.,Ltd.: Research Funding; Nippon Boehringer Ingelheim Co., Ltd.: Research Funding; Alexion Pharmaceuticals: Research Funding; MSD K.K.: Research Funding; Japan Blood Products Organization: Research Funding; Takeda Pharmaceutical Co., Ltd.: Research Funding; Pfizer Inc.: Research Funding; Bristol-Myers Squibb: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding; Taisho Toyama Pharmaceutical Co., Ltd.: Research Funding; Teijin Ltd.: Research Funding. Naoe:Celgene K.K.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding; Toyama Chemical CO., LTD.: Research Funding; Kyowa Hakko Kirin Co., Ltd.: Patents & Royalties, Research Funding; Chugai Pharmaceutical Co., Ltd.: Patents & Royalties; FUJIFILM Corporation: Patents & Royalties, Research Funding; Nippon Boehringer Ingelheim Co., Ltd.: Research Funding; Pfizer Inc.: Research Funding; Astellas Pharma Inc.: Research Funding. Kaneko:AsTlym Co., Ltd: Other: founder, shareholder and scientific adviser.

scholarly journals Prior Use of Mogamulizumab to Allogenic Hematopoietic Stem Cell Transplantation Induces Severe Acute Graft-Versus-Host Disease

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1940-1940 ◽  
Author(s):  
Takeshi Sugio ◽  
Koji Kato ◽  
Takatoshi Aoki ◽  
Takanori Ota ◽  
Noriyuki Saito ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Regulatory T Cells ◽  
Research Funding ◽  
Acute Gvhd ◽  
Cell Lymphoma ◽  
Hematopoietic Stem ◽  
Graft Versus Host

Abstract [Introduction] Adult T-cell leukemia/lymphoma (ATL) is an aggressive peripheral T-cell lymphoma (PTCL) with a dismal prognosis. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative treatment in ATL patients. Mogamulizumab, a humanized anti-CC chemokine receptor 4 (CCR4) monoclonal antibody, is a novel immunotherapeutic agent, effective in treating patients with PTCL such as ATL, PTCL-not specified, and cutaneous T-cell lymphoma. However, in allo-HSCT setting, we should be careful to use mogamulizumab because CCR4 is expressed in regulatory T cells: The mogamulizumab treatment may accelerate GVHD by eradicating regulatory T cells in allo-HSCT patients. Here, we retrospectively analyzed the effect of mogamulizumab on GVHD development in ATL patients treated with mogamulizumab prior to allo-HSCT. [Patients and Methods] Data from the Fukuoka Bone Marrow Transplantation Group were retrospectively analyzed after the approval of mogamulizumab use in Japan. [Results] A total of 24 patients with ATL received mogamulizumab prior to allo-HSCT between April 2012 and April 2015 in our group. The median age at allo-HSCT was 58.5 years (range, 32-72). The median intervals from the last administration of mogamulizumab to allo-HSCT were 25 days (range, 9-126). The median total dose of mogamulizumab was 3 mg/kg (range, 1-8 mg/kg). After treatment with mogamulizumab, 18 patients (75%) had achieved in remission (CR in 4 patients and PR in 14) at allo-HSCT. Ten patients received unrelated bone marrow, 5 received related peripheral blood, and 9 received cord blood as stem cell sources. Eleven patients were treated with full-intensity conditioning and 13 received reduced-intensity conditioning. Graft-versus-host disease (GVHD) prophylaxis consisted of calcineurin inhibitors (cyclosporine or tacrolimus) with short-term methotrexate in 14 patients and mycophenolate mofetil in 9. The cumulative incidence (CI) of acute GVHD at 100 days was 66.6% in grade 2-4 and 33.3% in grade 3-4. The involved organs of acute GVHD were skin in 14 patients, gut in 10, and liver in 4. Among 14 patients who developed grade 2-4 acute GVHD, 5 had severe fluid retention such as pleural effusion or ascites associated with GVHD. Chronic GVHD was observed in 6 patients, and 5 of them were extensive disease. The CI of transplant-related mortality (TRM) and relapse at 1-year were 53.2% (95%CI, 29.3-72.3%) and 29.6% (95%CI, 12.6-48.9%), respectively. The leading cause of death was GVHD (n = 7). The 1-year overall survival and progression-free survival were 19.2% (95%CI, 5.7-38.8%) and 17.2% (95%CI, 4.9-35.7%), respectively. [Discussion] Use of mogamulizumab prior to transplantation in allo-HSCT patients has a merit to decrease the burden of ATL cells. However, it was associated with an increase of TRM due to severe GVHD. Although most of ATL patients achieved better disease status at allo-HSCT through mogamulizumab and the survival rate was expected to be 50% based on the previous data, the survival in the present study was ~20%. These data suggest that mogamulizumab administered before transplantation may have retained until an early phase of post-transplantation, and the donor or host-derived regulatory T cells might be eliminated, allowing the GVHD T-cell clone to expand. Since mogalizumab is a potent anti-ATL agent, we need to develop new treatment protocols integrating mogalizumab at a suitable dose or administration timing, to minimize the unwanted GVHD development in future studies. Disclosures Akashi: Asahi Kasei: Research Funding, Speakers Bureau; Shionogi: Research Funding, Speakers Bureau; Astellas: Research Funding, Speakers Bureau; Celgene: Research Funding, Speakers Bureau; Chugai: Research Funding, Speakers Bureau; Bristol-Myers Squibb: Research Funding, Speakers Bureau; Novartis Pharma K.K.: Consultancy, Research Funding, Speakers Bureau; Kyowa Hakko Kirin Co., Ltd.: Consultancy, Research Funding, Speakers Bureau.

scholarly journals T Helper Cell Lineage-Defining Transcription Factors: Potent Targets for Specific GVHD Therapy?

2022 ◽  
Vol 12 ◽  
Author(s):  
Julia Campe ◽  
Evelyn Ullrich
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Acute Gvhd ◽  
Cell Subset ◽  
Cell Transplant ◽  
T Helper ◽  
Hematopoietic Stem ◽  
Th Cell ◽  
Th17 Differentiation

Allogenic hematopoietic stem cell transplantation (allo-HSCT) represents a potent and potentially curative treatment for many hematopoietic malignancies and hematologic disorders in adults and children. The donor-derived immunity, elicited by the stem cell transplant, can prevent disease relapse but is also responsible for the induction of graft-versus-host disease (GVHD). The pathophysiology of acute GVHD is not completely understood yet. In general, acute GVHD is driven by the inflammatory and cytotoxic effect of alloreactive donor T cells. Since several experimental approaches indicate that CD4 T cells play an important role in initiation and progression of acute GVHD, the contribution of the different CD4 T helper (Th) cell subtypes in the pathomechanism and regulation of the disease is a central point of current research. Th lineages derive from naïve CD4 T cell progenitors and lineage commitment is initiated by the surrounding cytokine milieu and subsequent changes in the transcription factor (TF) profile. Each T cell subtype has its own effector characteristics, immunologic function, and lineage specific cytokine profile, leading to the association with different immune responses and diseases. Acute GVHD is thought to be mainly driven by the Th1/Th17 axis, whereas Treg cells are attributed to attenuate GVHD effects. As the differentiation of each Th subset highly depends on the specific composition of activating and repressing TFs, these present a potent target to alter the Th cell landscape towards a GVHD-ameliorating direction, e.g. by inhibiting Th1 and Th17 differentiation. The finding, that targeting of Th1 and Th17 differentiation appears more effective for GVHD-prevention than a strategy to inhibit Th1 and Th17 cytokines supports this concept. In this review, we shed light on the current advances of potent TF inhibitors to alter Th cell differentiation and consecutively attenuate GVHD. We will focus especially on preclinical studies and outcomes of TF inhibition in murine GVHD models. Finally, we will point out the possible impact of a Th cell subset-specific immune modulation in context of GVHD.

scholarly journals Results of a Phase II Study of PD-1 Inhibition in Advanced Myeloproliferative Neoplasms

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 14-15
Author(s):  
Gabriela S. Hobbs ◽  
Cansu Cimen Bozkus ◽  
Martha Wadleigh ◽  
Lonette Sandy ◽  
Mikaela Doughtery ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Hematopoietic Stem Cell ◽  
Peripheral Blood ◽  
Research Funding ◽  
Post Treatment ◽  
Phase 2 ◽  
Hematopoietic Stem ◽  
Grade 3

Background: Myelofibrosis (MF) is a hematopoietic stem cell neoplasm characterized by abnormal JAK-STAT signaling, increased inflammation, and evolution to acute myeloid leukemia. Most patients harbor a phenotypic driver mutation- JAK2, CALR or MPL. In the last decade, two JAK2 inhibitors have been approved, however, outside of hematopoietic stem cell transplantation (HSCT), there are no medications that meaningfully modify MF disease biology. Thus, additional treatments are needed. We previously demonstrated the presence of multiple immunosuppressive mechanisms in MPN patients, including expanded myeloid derived suppressor cell (MDSC) populations and elevated expression of immune checkpoint receptors, particularly PD1, on T cells from MPN patients compared to healthy donors (Cimen Bozkus, Cancer Discovery 2019). Therefore, we conducted a multi-center, open-label, phase 2, single-arm study of pembrolizumab in patients with primary, post-essential thrombocythemia or post-polycythemia vera myelofibrosis (MF) (NCT03065400). Methods: Patients with intermediate-2/high DIPSS MF, ineligible for or previously failed ruxolitinib were eligible. Pembrolizumab was administered at the FDA-approved dose of 200 mg every 3 weeks for 6 cycles. The study was a Simon two-stage design, 9 patients enrolled in the first arm. The study was terminated after completion of this arm due to the lack of responses. Response assessment was conducted after 6 cycles utilizing the International Working Group (IWG-MRT) criteria. In addition, patients with accelerated or blast phase (MPN-AP/BP) could enroll as a separate, ten patient, exploratory cohort. Results: 9 patients enrolled in the MF cohort and 1 in the BP cohort between 6/2017 and 3/2020. Baseline characteristics are summarized in Table 1. Median weeks on treatment were 14.7 (range 4-20). All 9 MF patients were evaluable for response as they received at least 1 dose of pembrolizumab. Of the 9 patients who were evaluable for response, all had SD, 4 (44%) patients discontinued therapy prior to the end of cycle 6. Reasons for discontinuation were adverse events (n=1), patient decision (n=1), physician decision (n=2). Grade 3/4 AEs included anemia (n=3), thrombocytopenia (n=2), leukopenia (n=1), hyperglycemia (n=2), hyperuricemia (n=1), dyspnea (n=1), headache (n=1). No grade 3/4 immune related AEs occurred (Table 2). The effects of pembrolizumab on the immune suppressive milieu observed in MPN were analyzed. PD-1 was detected on peripheral blood T cells by flow cytometry at baseline, but not post-treatment, likely due to receptor occupancy by pembrolizumab. In all patients analyzed, the levels of soluble PD1 in the plasma by Olink assay were significantly higher post-treatment. Other soluble factors associated with T cell activation such as class I-restricted T cell-associated molecule (CRTAM) and CD27 were also elevated after pembrolizumab administration. Furthermore, ARG1, a molecule that mediates T-cell suppression by MDSC, was significantly reduced in the plasma of treated patients. An increase in peripheral blood T cell frequencies was observed in a subset of patients after two cycles. Discussion: Pembrolizumab did not demonstrate clinical activity in this phase 2 trial. The relevance of the preliminary correlative findings will be further confirmed by in situ gene profiling of immune cells and their microenvironment. The complete results will be available at the meeting. These results suggest that pembrolizumab may promote a phenotypical and soluble signature suggestive of a restored immune response. The fact that these molecular changes were not associated with clinical responses indicate that pembrolizumab alone may not be sufficient to reverse the multifactorial causes of immune tolerance in MPN. Disclosures Hobbs: Constellation: Honoraria, Research Funding; Bayer: Research Funding; Jazz: Honoraria; Incyte: Research Funding; Novartis: Honoraria; Merck: Research Funding; Celgene/BMS: Honoraria. Stone:Syndax: Consultancy, Research Funding; Daiichi-Sankyo: Consultancy; Astellas: Consultancy; Takeda: Other: DSMB; Syntrix: Other: DSMB; Arog: Consultancy, Research Funding; Jazz: Consultancy; Trovagene: Consultancy; Syros: Consultancy; Abbvie: Consultancy, Research Funding; Biolinerx: Consultancy; Argenix: Other; Novartis: Consultancy, Research Funding; Celgene: Consultancy, Other; Agios: Consultancy, Research Funding; Gemoab: Consultancy; Janssen: Consultancy; Stemline: Consultancy; Pfizer: Consultancy; Aztra-Zeneca: Consultancy; Macrogenics: Consultancy; Actinium: Consultancy, Membership on an entity's Board of Directors or advisory committees. Mascarenhas:Incyte, Kartos, Roche, Promedior, Merck, Merus, Arog, CTI Biopharma, Janssen, and PharmaEssentia: Other: Research funding (institution); Celgene, Prelude, Galecto, Promedior, Geron, Constellation, and Incyte: Consultancy.

scholarly journals Predicting Immune Pathology after Hematopoietic Stem Cell Transplant with Transcriptomics: Naïve CD4 T Cell Expansion at Day 100 Predicts Patients with De Novo Chronic Gvhd

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 38-39
Author(s):  
Ben Watkins ◽  
James Kaminski ◽  
Muna Qayed ◽  
Kayla Betz ◽  
Yvonne Suessmuth ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Cd4 T Cells ◽  
Research Funding ◽  
De Novo ◽  
Cd4 T Cell ◽  
Unrelated Donor ◽  
Cell Transplant ◽  
Hematopoietic Stem

Background: Chronic graft-versus-host disease (CGVHD) is the leading cause of long-term morbidity and mortality following hematopoietic stem cell transplant (HCT) and occurs in over 50% of patients undergoing unrelated donor HCT. Despite its frequency, the mechanisms driving this disease remain incompletely understood, making its prevention and successful treatment challenging. To address this issue, we have undertaken a transcriptomic analysis of T cell reconstitution after unrelated donor HCT, to dissect mechanisms driving CGVHD. Methods: The patients studied were enrolled on a Phase 2, randomized, placebo-controlled trial of abatacept for GVHD prevention in patients receiving 8/8 unrelated-donor HCT for hematologic malignancies (NCT01743131). All immune analyses in the current study were performed on patients randomized to standard GVHD prophylaxis with calcineurin inhibition + methotrexate alone (placebo cohort, n =69), and thus provide insights into the drivers of CGVHD during standard unrelated donor HCT. On Day +100, CD4+ T cells were purified from the peripheral blood of these patients, and then analyzed by RNASeq. To determine the transcriptomic drivers of CGVHD without the confounder of significant prior acute GVHD (AGVHD) or exposure to steroids, we focused on profiling the CD4+ transcriptome of de novo CGVHD (CGVHD which develops in the absence of prior grade II-IV AGVHD, n = 7) and compared these patients to those who were 'operationally tolerant' and never developed either grade II-IV AGVHD or any CGVHD (n= 4). Gene expression from the resulting transcriptomes was quantified using kallisto. Differentially expressed (DE) genes were identified using DESeq2 (threshold for DE, adjusted (for multiple testing) p <0.05). Gene Set Enrichment Analysis (GSEA) was also performed, with genes ranked by Log2FC/std_error (Log2FC), and gene signatures with an adjusted p <0.05 considered significantly enriched. Results: DE analysis identified 101 genes that were significantly upregulated in CD4+ T cells from de novo CGVHD group and 54 genes that were significantly upregulated in the 'operationally tolerant' group (Figure 1A). GSEA identified that the mostly highly enriched signatures in patients with de novo CGVHD encompassed naïve CD4+ transcriptional programing (Figure 1B-C), in agreement with flow cytometric analysis, which also demonstrated expansion of CD4+ naïve T cells at Day +100 in patients developing de novo CGVHD compared to those demonstrating operational tolerance (Figure 1D). Importantly, the naïve CD4+ T cell signatures that were identified were distinct from those defining CD4+ stem cell memory T cells (which did not enrich in the de novo CGVHD cohort). In contrast, the gene signature of the operationally tolerant patients were enriched for regulatory gene sets (Figure 1C), consistent with a large body of evidence demonstrating that Treg expansion can be protective against CGVHD. Discussion: This study represents, to our knowledge, the first interrogation of the transcriptomic features of patients developing de novo CGVHD versus those operationally tolerant patients who develop neither significant AGVHD nor CGVHD after HCT. These patients may represent a particularly effective cohort in which to study immunologic drivers of CGVHD, given their freedom from prior treatment with corticosteroids, which can confound downstream transcriptomic analyses. Our data provide compelling evidence for a prominent naïve CD4+ T cell signature in patients who develop moderate-to-severe CGVHD despite their lack of antecedent AGVHD. These results are provocative, as they implicate a cell subset that is often considered more quiescent (naïve T cells) as associated with patients who develop immune pathology associated with CGVHD. These results suggest that naïve CD4+ T cells may represent a potent reservoir for alloreactivity, that, once activated, can cause significant disease. This would be in agreement with the implications of previously reported trials of naïve T cell depletion, which resulted in significant control of CGVHD. These results suggest that strategies to restrain naïve T cell pathogenic activation after Day +100 may improve CGVHD outcomes, and that the CD4+ T cell transcriptomic signature at this timepoint could be developed into a robust immunologic biomarker for the risk of developing CGVHD versus operational tolerance after HCT. Figure 1 Disclosures Watkins: Bristol Myers Squib: Honoraria. Qayed:Novartis: Consultancy; Mesoblast: Consultancy. Blazar:Tmunity: Other: Co-founder; KidsFirst Fund: Research Funding; BlueRock Therapeutics: Research Funding; Childrens' Cancer Research Fund: Research Funding; BlueRock Therapeuetic: Consultancy; Magenta Therapeutics: Consultancy; Fate Therapeutics Inc.: Research Funding. Horan:Bristol Myers Squib: Honoraria, Research Funding. Langston:Kadmon Corporation: Research Funding; Astellas Pharmaceuticals: Research Funding; Jazz Pharmaceuticals: Research Funding; Incyte: Research Funding; Bristol Myers Squib: Research Funding; Chimerix: Research Funding; Takeda: Research Funding. Kean:fortyseven: Consultancy; regeneron: Research Funding; hifibio: Consultancy; kymab: Consultancy; Bristol Meyers Squibb: Research Funding; gilead: Research Funding; novartis: Consultancy; bluebird bio: Research Funding; magenta: Research Funding.

scholarly journals Dissecting the Immune Cell Progeny of CAR-Expressing Hematopoietic Stem Cells in a Humanized Mouse Model

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4640-4640
Author(s):  
Heng-Yi Liu ◽  
Nezia Rahman ◽  
Tzu-Ting Chiou ◽  
Satiro N. De Oliveira
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
T Cell ◽  
Hematopoietic Stem Cells ◽  
Cell Lines ◽  
Immune Cells ◽  
Research Funding ◽  
Humanized Mice ◽  
Tumor Challenge ◽  
Hematopoietic Stem

Background: Chemotherapy-refractory or recurrent B-lineage leukemias and lymphomas yield less than 50% of chance of cure. Therapy with autologous T-cells expressing chimeric antigen receptors (CAR) have led to complete remissions, but the effector cells may not persist, limiting clinical efficacy. Our hypothesis is the modification of hematopoietic stem cells (HSC) with anti-CD19 CAR will lead to persistent generation of multilineage target-specific immune cells, enhancing graft-versus-cancer activity and leading to development of immunological memory. Design/Methods: We generated second-generation CD28- and 4-1BB-costimulated CD19-specific CAR constructs using third-generation lentiviral vectors for modification of human HSC for assessment in vivo in NSG mice engrafted neonatally with human CD34-positive cells. Cells were harvested from bone marrows, spleens, thymus and peripheral blood at different time points for evaluation by flow cytometry and ddPCR for vector copy numbers. Cohorts of mice received tumor challenge with subcutaneous injection of lymphoma cell lines. Results: Gene modification of HSC with CD19-specific CAR did not impair differentiation or proliferation in humanized mice, leading to CAR-expressing cell progeny in myeloid, NK and T-cells. Humanized NSG engrafted with CAR-modified HSC presented similar humanization rates to non-modified HSC, with multilineage CAR-expressing cells present in all tissues with stable levels up to 44 weeks post-transplant. No animals engrafted with CAR-modified HSC presented autoimmunity or inflammation. T-cell populations were identified at higher rates in humanized mice with CAR-modified HSC in comparison to mice engrafted with non-modified HSC. CAR-modified HSC led to development of T-cell effector memory and T-cell central memory phenotypes, confirming the development of long-lasting phenotypes due to directed antigen specificity. Mice engrafted with CAR-modified HSC successfully presented tumor growth inhibition and survival advantage at tumor challenge with lymphoma cell lines, with no difference between both constructs (62.5% survival for CD28-costimulated CAR and 66.6% for 41BB-costimulated CAR). In mice sacrificed due to tumor development, survival post-tumor injection was directly correlated with tumor infiltration by CAR T-cells. Conclusions: CAR modification of human HSC for cancer immunotherapy is feasible and continuously generates CAR-bearing cells in multiple lineages of immune cells. Targeting of different malignancies can be achieved by adjusting target specificity, and this approach can augment the anti-lymphoma activity in autologous HSC recipients. It bears decreased morbidity and mortality and offers alternative therapeutic approach for patients with no available sources for allogeneic transplantation, benefiting ethnic minorities. Disclosures De Oliveira: National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust and University College London: Research Funding; NIAID, NHI: Research Funding; Medical Research Council: Research Funding; CIRM: Research Funding; National Gene Vector Repository: Research Funding.

scholarly journals CD34+ Hematopoietic Stem Cells Exert Accessory Function in Lipopolysaccharide-induced  T Cell Stimulation and CD80 Expression on Monocytes

1999 ◽  
Vol 189 (4) ◽  
pp. 693-700 ◽  
Author(s):  
Taila Mattern ◽  
Gundolf Girroleit ◽  
Hans-Dieter Flad ◽  
Ernst T. Rietschel ◽  
Artur J. Ulmer
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Hematopoietic Stem Cells ◽  
Cell Stimulation ◽  
Hematopoietic Stem ◽  
Accessory Function ◽  
T Cell Stimulation ◽  
Blood Stem Cells

CD34+ hematopoietic stem cells, which circulate in peripheral blood with very low frequency, exert essential accessory function during lipopolysaccharide (LPS)-induced human T lymphocyte activation, resulting in interferon γ production and proliferation. In contrast, stimulation of T cells by “conventional” recall antigens is not controlled by blood stem cells. These conclusions are based on the observation that depletion of CD34+ blood stem cells results in a loss of LPS-induced T cell stimulation as well as reduced expression of CD80 antigen on monocytes. The addition of CD34-enriched blood stem cells resulted in a recovery of reactivity of T cells and monocytes to LPS. Blood stem cells could be replaced by the hematopoietic stem cell line KG-1a. These findings may be of relevance for high risk patients treated with stem cells or stem cell recruiting compounds and for patients suffering from endotoxin-mediated diseases.

Abstract P285: Hydralazine Attenuates the Development of Hypertension in the Female Dahl Salt-sensitive Rat in a T Cell-independent Manner

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Amrita V Pai ◽  
Crystal A West ◽  
Aline Souza ◽  
Parnika S Kadam ◽  
Emma J Pollner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Rat Kidney ◽  
T Helper ◽  
Independent Manner ◽  
Th Cells ◽  
Time Treatment ◽  
Salt Sensitive Hypertension ◽  
Cell Profile

Introduction: Several studies in Dahl salt-sensitive ( DS ) rats suggest that T cells play a role in salt-sensitive hypertension. To further investigate the role of T cells, we compared T cell profiles in hypertensive DS and normotensive Dahl salt-resistant ( DR ) rats as well as in DS rats treated with hydralazine ( HYD ) to attenuate the development of hypertension. Methods: Mean arterial pressure ( MAP ) was measured by telemetry in DS rats (n=13) from 1 to 4.5 months ( mo ) of age. At 1.5 mo, all of the DR (n=8) and half of the DS rats were treated with vehicle (VEH, n=7). The other half of the DS rats (n=6) received HYD (25 mg/kg/day) in the drinking water. At 4.5 mo, renal T helper ( Th ) and cytotoxic ( Tc ) cells were assessed by multicolor flow cytometry. Results: In the DS kidney, the frequency of CD4 + Th cells [(%): DS-VEH, 76±1.2* vs. DR-VEH, 55±0.7; *p<0.0001; n=7-8/group] was higher while the frequency of CD8 + Tc cells [(%): DS-VEH, 14±1.2* vs. DR-VEH, 35±1; *p<0.0001; n=7-8/group] was lower compared to DR rats. 10 weeks of HYD treatment attenuated the age-associated increase in MAP observed in DS rats [p<0.0001, Two-Way ANOVA (time, treatment); MAP (mmHg): DS-VEH, 157±4 vs. DS-HYD, 133±3; *p<0.0004; n=6-7/group]. HYD had no effect on the frequency of CD4 + [(%):77±1.5] or CD8 + [(%):15.5±0.9] T cells in the kidney of DS rats [(CD4 + ): DS-VEH vs. DS-HYD, p=0.83; (CD8 + ): DS-VEH vs. DS-HYD, p=0.5; n=7-8/group]. In summary, the ratio of Th (CD4 + ) to Tc (CD8 + ) cells is higher in the kidney of DS compared to DR rats and HYD had no effect on the T cell profile in the DS rat kidney under conditions in which the MAP was attenuated by 20 mm Hg. Conclusions: These findings indicate the DS rat has more active Th cells in the kidney compared to the DR rat. Our study also suggests that vasodilators can attenuate the development of hypertension in the DS rat in a Th- and Tc-independent manner.

scholarly journals Direct evidence for new T-cell generation by patients after either T-cell–depleted or unmodified allogeneic hematopoietic stem cell transplantations

Blood ◽  
2002 ◽  
Vol 100 (6) ◽  
pp. 2235-2242 ◽  
Author(s):  
Sharon R. Lewin ◽  
Glenn Heller ◽  
Linqi Zhang ◽  
Elaine Rodrigues ◽  
Eva Skulsky ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Hematopoietic Stem Cell ◽  
Opportunistic Infections ◽  
Cell Receptor ◽  
Hematopoietic Stem ◽  
Cell Immunity ◽  
The Difference ◽  
T Cell Phenotypes

Abstract Successful allogeneic hematopoietic stem cell transplantation (HSCT) requires reconstitution of normal T-cell immunity. Recipient thymic activity, biologic features of the allograft, and preparative regimens all contribute to immune reconstitution. We evaluated circulating T-cell phenotypes and T-cell receptor rearrangement excision circles (TRECs) in 331 blood samples from 158 patients who had undergone allogeneic HSCTs. All patients had received myeloablative conditioning regimens and were full donor chimeras in remission. Younger patients exhibited more rapid recovery and higher TRECs (P = .02). Recipients of T-cell–depleted allografts initially had lower TRECs than unmodified allograft recipients (P < .01), but the difference abated beyond 9 months. TREC level disparities did not achieve significance among adults with respect to type of allograft. Measurable, albeit low, TREC values correlated strongly with severe opportunistic infections (P < .01). This finding was most notable during the first 6 months after transplantation, when patients are at greatest risk but before cytofluorography can detect circulating CD45RA+ T cells. Low TRECs also correlated strongly with extensive chronic graft-versus-host disease (P < .01). Recipients of all ages of either unmodified or T-cell–depleted allografts therefore actively generate new T cells. This generation is most notable among adult recipients of T-cell–depleted allografts, most of whom had also received antithymocyte globulin for rejection prophylaxis. Low TREC values are significantly associated with morbidity and mortality after transplantation. T-cell neogenesis, appropriate to age but delayed in adult recipients of T-cell– depleted allografts, justifies interventions to hasten this process and to stimulate desirable cellular immune responses.

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