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1.

Background aims

Multiple steps are required to produce chimeric antigen receptor (CAR)-T cells, involving subset enrichment or depletion, activation, gene transduction and expansion. Open processing steps that increase risk of contamination and production failure are required. This complex process requires skilled personnel and costly clean-room facilities and infrastructure. Simplified, reproducible CAR-T-cell manufacturing with reduced labor intensity within a closed-system is highly desirable for increased availability for patients.

Methods

The CliniMACS Prodigy with TCT process software and the TS520 tubing set that allows closed-system processing for cell enrichment, transduction, washing and expansion was used. We used MACS-CD4 and CD8-MicroBeads for enrichment, TransAct CD3/CD28 reagent for activation, lentiviral CD8 TM-41BB-CD3 ζ-cfrag vectors expressing scFv for CD19 or CD20/CD19 antigens for transduction, TexMACS medium-3%-HS-IL2 for culture and phosphate-buffered saline/ethylenediaminetetraacetic acid buffer for washing. Processing time was 13 days.

Results

Enrichment (N?=?7) resulted in CD4/CD8 purity of 98?±?4.0%, 55?±?6% recovery and CD3+ T-cell purity of 89?±?10%. Vectors at multiplicity of infection 5–10 resulted in transduction averaging 37%. An average 30-fold expansion of 108 CD4/CD8-enriched cells resulted in sufficient transduced T cells for clinical use. CAR-T cells were 82–100% CD3+ with a mix of CD4+ and CD8+ cells that primarily expressed an effector-memory or central-memory phenotype. Functional testing demonstrated recognition of B-cells and for the CAR-20/19 T cells, CD19 and CD20 single transfectants were recognized in cytotoxic T lymphocyte and interferon-γ production assays.

Discussion

The CliniMACS Prodigy device, tubing set TS520 and TCT software allow CAR-T cells to be manufactured in a closed system at the treatment site without need for clean-room facilities and related infrastructure.  相似文献   

2.

Background

The use of CD19 chimeric antigen receptor (CAR) T cells to treat B-cell malignancies has proven beneficial. Several groups use serum to produce CD19 CAR T cells. Today, ready-to-use serum-free media that require no addition of serum are commercially available. Therefore, it becomes important to evaluate the production of CD19 CAR T cells with and without the addition of serum.

Methods

T cells from buffy coats were cultured in AIM-V and TexMACS (TM) supplemented with 5% human serum (A5% and TM5%, respectively), and in TM without serum. Cells were activated with OKT3 and expanded in interleukin (IL)-2. Viral transduction was performed in RetroNectin-coated plates using the spinoculation method. CD19 CAR T cells were tested for their viability, expansion, transduction efficacy, phenotype and cytotoxicity.

Results

CD19 CAR T cells expanded in A5% and TM5% showed significantly better viability and higher fold expansion than cells expanded in TM. TM promoted the expansion of CD8+ T cells and effector phenotype of CD19 CAR T cells. The transduction efficacy and the cytotoxic function were comparable between the different media. Higher CD107a+ cells were detected in TM and TM5%, whereas higher IL-2+ and IL-17+ cells were detected in A5%. CD19 CAR exhibited co-expression of inhibitory receptors such as TIM-3+LAG-3+ and/or TIM-3+PD-1+.

Conclusion

Our results indicate that serum supplementation promotes better CD19 CAR T-cell expansion and viability in vitro. CD19 CAR T cells produced in TM medium showed lower CD4/CD8 ratio, which warrants further evaluation in clinical settings. Overall, the choice of culture medium impacts CD19 CAR T-cell end product.  相似文献   

3.
4.

Background aims

The immunomodulatory property of mesenchymal stromal cell (MSC) exosomes is well documented. On the basis of our previous report that MSC exosomes increased regulatory T-cell (Treg) production in mice with allogenic skin graft but not in ungrafted mice, we hypothesize that an activated immune system is key to exosome-mediated Treg production.

Methods

To test our hypothesis, MSC exosomes were incubated with mouse spleen CD4+ T cells that were activated with either anti-CD3/CD28 mAbs or allogenic antigen-presenting cell (APC)-enriched spleen CD11c+ cells to determine whether production of mouse CD4+CD25+ T cells or CD4+CD25+Foxp3+ Tregs could be induced. MSC exosomes were also administered to the lethal chimeric human-SCID mouse model of graft-versus-host disease (GVHD) in which human peripheral blood mononuclear cells were infused into irradiated NSG mice to induce GVHD.

Results

We report here that MSC exosome–induced production of CD4+CD25+ T cells or CD4+CD25+Foxp3+ Tregs from CD4+ T cells activated by allogeneic APC-enriched CD11C+ cells but not those activated by anti-CD3/CD28 mAbs. This induction was exosome- and APC dose–dependent. In the mouse GVHD model in which GVHD was induced by transplanted human APC-stimulated human anti-mouse CD4+ T cell effectors, MSC exosome alleviated GVHD symptoms and increased survival. Surviving exosome-treated mice had a significantly higher level of human CD4+CD25+CD127low/– Tregs than surviving mice treated with Etanercept, a tumor necrosis factor inhibitor.

Conclusions

MSC exosome enhanced Treg production in vitro and in vivo through an APC-mediated pathway.  相似文献   

5.

Background aims

This study aimed to determine the prognostic value of circulating CD8+CD28? T lymphocytes among breast cancer patients treated with adoptive T-lymphocyte immunotherapy after chemotherapy.

Methods

Two hundred and thirty-two breast cancer patients underwent adoptive T-cell immunotherapy. Circulating CD8+CD28? proportion was measured by flow cytometry. Median proportion of CD8+CD28? was 24.2% and set as the categorical cutoff value for further analysis. The median survival was estimated by Kaplan-Meier curve, with difference detection and hazard ratio estimation by log-rank test and Cox hazard proportion regression model.

Results

With adoptive T-cell therapy, patients with higher CD8+CD28? levels experienced median progression-free and overall survival of 7.1 months and 26.9 months, respectively—significantly shorter than patients with lower levels (11.8 and 36.2 months). CD8+CD28? proportion >24.2% demonstrated a hazard ratio (HR) of 2.06 (95% confidence interval [CI] 1.31–3.12) for progression and an HR of 1.97 (95% CI 1.06–3.67) for death. Among patients who had received previous first-line chemotherapy, CD8+CD28? proportion >24.2% demonstrated an HR of 2.66 (95% CI 1.45–4.88) for progression. Among patients exposed to previous second-line or higher chemotherapy, CD8+CD28? proportion >24.2% demonstrated a 486% higher risk for death (HR?=?5.86, 95% CI 1.77–19.39). A 1% increase in suppressive T cells was associated with a 5% increased risk of death.

Discussion

Elevated peripheral blood CD8+CD28? was associated with poorer prognosis for metastatic breast cancer, especially for higher risk of progression among patients with first-line chemotherapy and higher risk of death among patients with more than second-line chemotherapy.  相似文献   

6.

Background

Adoptive transfer of donor-derived T cells can be applied to improve immune reconstitution in immune-compromised patients after allogeneic stem cell transplantation. The separation of beneficial T cells from potentially harmful T cells can be achieved by using the major histocompatibility complex (MHC) I-Streptamer isolation technology, which has proven its feasibility for the fast and pure isolation of T-cell populations with a single specificity. We have analyzed the feasibility of the simultaneous isolation of multiple antigen-specific T-cell populations in one procedure by combining different MHC I-Streptamers.

Methods

First, the effect of combining different amounts of MHC I-Streptamers used in the isolation procedure on the isolation efficacy of target antigen-specific T cells and on the number of off-target co-isolated contaminating cells was assessed. The feasibility of this approach was demonstrated in large-scale validation procedures targeting both high and low frequent T-cell populations using the Good Manufacturing Practice (GMP)-compliant CliniMACS Plus device.

Results

T-cell products targeting up to 24 different T-cell populations could be isolated in one, simultaneous MHC I-Streptamer procedure, by adjusting the amount of MHC I- Streptamers per target antigen-specific T-cell population. Concurrently, the co-isolation of potentially harmful contaminating T cells remained below our safety limit. This technology allows the reproducible isolation of high and low frequent T-cell populations. However, the expected therapeutic relevance of direct clinical application without in vitro expansion of these low frequent T-cell populations is questionable.

Discussion

This study provides a feasible, fast and safe method for the generation of highly personalized MHC I-Streptamer isolated T-cell products for adoptive immunotherapy.  相似文献   

7.

Background aims

Clinical-grade chimeric antigenic receptor (CAR)19 T cells are routinely manufactured by lentiviral/retroviral (LV/RV) transduction of an anti-CD3/CD28 activated T cells, which are then propagated in a culture medium supplemented with interleukin (IL)-2. The use of LV/RVs for T-cell modification represents a manufacturing challenge due to the complexity of the transduction approach and the necessity of thorough quality control.

Methods

We present here a significantly improved protocol for CAR19 T-cell manufacture that is based on the electroporation of peripheral blood mononuclear cells with plasmid DNA encoding the piggyBac transposon/transposase vectors and their cultivation in the presence of cytokines IL-4, IL-7 and IL-21.

Results

We found that activation of the CAR receptor by either its cognate ligand (i.e., CD19 expressed on the surface of B cells) or anti-CAR antibody, followed by cultivation in the presence of cytokines IL-4 and IL-7, enables strong and highly selective expansion of functional CAR19 T cells, resulting in >90% CAR+ T cells. Addition of cytokine IL-21 to the mixture of IL-4 and IL-7 supported development of immature CAR19 T cells with central memory and stem cell memory phenotypes and expressing very low amounts of inhibitory receptors PD-1, LAG-3 and TIM-3.

Conclusions

Our protocol provides a simple and cost-effective method for engineering high-quality T cells for adoptive therapies.  相似文献   

8.

Background

CD4+ T cells are of great importance in the pathogenesis of systemic lupus erythematosus (SLE), as an imbalance between CD4+ regulatory T cells (Tregs) and CD4+ responder T cells (Tresps) causes flares of active disease in SLE patients. In this study, we aimed to find the role of aberrant Treg/Tresp cell differentiation for maintaining Treg/Tresp cell balance and Treg functionality.

Methods

To determine differences in the differentiation of Tregs/Tresps we calculated the percentages of CD45RA+CD31+ recent thymic emigrant (RTE) Tregs/Tresps and CD45RA+CD31? mature naive (MN) Tregs/Tresps, as well as CD45RA?CD31+ and CD45RA?CD31? memory Tregs/Tresps (CD31+ and CD31? memory Tregs/Tresps) within the total Treg/Tresp pool of 78 SLE remission patients compared with 94 healthy controls of different ages. The proliferation capacity of each Treg/Tresp subset was determined by staining the cells with anti-Ki67 monoclonal antibodies. Differences in the autologous or allogeneic Treg function between SLE remission patients and healthy controls were determined using suppression assays.

Results

With age, we found an increased differentiation of RTE Tregs via CD31+ memory Tregs and of RTE Tresps via MN Tresps into CD31? memory Tregs/Tresp in healthy volunteers. This opposite differentiation of RTE Tregs and Tresps was associated with an age-dependent increase in the suppressive activity of both naive and memory Tregs. SLE patients showed similar age-dependent Treg cell differentiation. However, in these patients RTE Tresps differentiated increasingly via CD31+ memory Tresps, whereby CD31? memory Tresps arose that were much more difficult to inhibit for Tregs than those that emerged through differentiation via MN Tresps. Consequently, the increase in the suppressive activity of Tregs with age could not be maintained in SLE patients. Testing the Tregs of healthy volunteers and SLE patients with autologous and nonautologous Tresps revealed that the significantly decreased Treg function in SLE patients was not exclusively attributed to an age-dependent diminished sensitivity of the Tresps for Treg suppression. The immunosuppressive therapy reduced the accelerated age-dependent Tresp cell proliferation to normal levels, but simultaneously inhibited Treg cell proliferation below normal levels.

Conclusions

Our data reveal that the currently used immunosuppressive therapy has a favorable effect on the differentiation and proliferation of Tresps but has a rather unfavorable effect on the proliferation of Tregs. Newer substances with more specific effects on the immune system would be desirable.
  相似文献   

9.

Background aims

Adoptive cell therapy employing natural killer group 2D (NKG2D) chimeric antigen receptor (CAR)-modified T cells has demonstrated preclinical efficacy in several model systems, including hematological and solid tumors. We present comprehensive data on manufacturing development and clinical production of autologous NKG2D CAR T cells for treatment of acute myeloid leukemia and multiple myeloma (ClinicalTrials.gov Identifier: NCT02203825). An NKG2D CAR was generated by fusing native full-length human NKG2D to the human CD3ζ cytoplasmic signaling domain. NKG2D naturally associates with native costimulatory molecule DAP10, effectively generating a second-generation CAR against multiple ligands upregulated during malignant transformation including MIC-A, MIC-B and the UL-16 binding proteins.

Methods

CAR T cells were infused fresh after a 9-day process wherein OKT3-activated T cells were genetically modified with replication-defective gamma-retroviral vector and expanded ex vivo for 5 days with recombinant human interleukin-2.

Results

Despite sizable interpatient variation in originally collected cells, release criteria, including T-cell expansion and purity (median 98%), T-cell transduction (median 66% CD8+ T cells), and functional activity against NKG2D ligand-positive cells, were met for 100% of healthy donors and patients enrolled and collected. There was minimal carryover of non–T cells, particularly malignant cells; both effector memory and central memory cells were generated, and inflammatory cytokines such as granulocyte colony-stimulating factor, RANTES, interferon-γ and tumor necrosis factor-α were selectively up-regulated.

Conclusions

The process resulted in production of required cell doses for the first-in-human phase I NKG2D CAR T clinical trial and provides a robust, flexible base for further optimization of NKG2D CAR T-cell manufacturing.  相似文献   

10.

Background

Cytokine-induced killer cells (CIKs) are an advanced therapeutic medicinal product (ATMP) that has shown therapeutic activity in clinical trials but needs optimization. We developed a novel strategy using CIKs from banked cryopreserved cord blood units (CBUs) combined with bispecific antibody (BsAb) blinatumomab to treat CD19+ malignancies.

Methods

CB-CIKs were expanded in vitro and fully characterized in comparison with peripheral blood (PB)–derived CIKs.

Results

CB-CIKs, like PB-CIKs, were mostly CD3+ T cells with mean 45% CD3+CD56+ and expressing mostly TCR(T cell receptor)αβ with a TH1 phenotype. CB-CIK cultures had, however, a larger proportion of CD4+ cells, mostly CD56?, as well as a greater proportion of naïve CCR7+CD45RA+ and a lower percentage of effector memory cells, compared with PB-CIKs. CB-CIKs were very similar to PB-CIKs in their expression of a large panel of co-stimulatory and inhibitory/exhaustion markers, except for higher CD28 expression among CD8+ cells. Like PB-CIKs, CB-CIKs were highly cytotoxic in vitro against natural killer (NK) cell targets and efficiently lysed CD19+ tumor cells in the presence of blinatumomab, with 30–60% lysis of target cells at very low effector:target ratios. Finally, both CB-CIKs and PB-CIKs, combined with blinatumomab, showed significant therapeutic activity in an aggressive PDX Ph+ CD19+ acute lymphoblastic leukemia model in NOD-SCID mice, without sign of toxicity or graft-versus-host disease. The improved expansion protocol was finally validated in good manufacturing practice conditions, showing reproducible expansion of CIKs from cryopreserved cord blood units with a median of 28.8?×?106 CIK/kg.

Discussion

We conclude that CB-CIKs, combined with bispecific T-cell–engaging antibodies, offer a novel, effective treatment strategy for leukemia.  相似文献   

11.

Background

Declining telomere length (TL) is associated with T cell senescence. While TL in naïve and memory T cells declines with increasing age, there is limited data on TL dynamics in virus-specific memory CD4+ T cells in healthy adults. We combined BrdU-labeling of virus-stimulated T cells followed with flow cytometry-fluorescent in situ hybridization for TL determination. We analyzed TL in T cells specific for several virus infections: non-recurring acute (vaccinia virus, VACV), recurring-acute (influenza A virus, IAV), and reactivating viruses (varicella-zoster virus, VZV, and cytomegalovirus, CMV) in 10 healthy subjects. Additionally, five subjects provided multiple blood samples separated by up to 10 years.

Results

VACV- and CMV-specific T cells had longer average TL than IAV-specific CD4+ T cells. Although most virus-specific cells were CD45RA-, we observed a minor population of BrdU+ CD45RA+ T cells characterized by long telomeres. Longitudinal analysis demonstrated a slow decline in average TL in virus-specific T cells. However, in one subject, VZV reactivation led to an increase in average TL in VZV-specific memory T cells, suggesting a conversion of longer TL cells from the naïve T cell repertoire.

Conclusions

TLs in memory CD4+ T cells in otherwise healthy adults are heterogeneous and follow distinct virus-specific kinetics. These findings suggests that the distribution of TL and the creation and maintenance of long TL memory T cells could be important for the persistence of long-lived T cell memory.
  相似文献   

12.

Background aims

To produce an anti-leukemic effect after hematopoietic stem cell transplantation we have long considered the theoretical possibility of using banks of HLA-DP specific T-cell clones transduced with a suicide gene. For that application as for any others, a clonal strategy is constrained by the population doubling (PD) potential of T cells, which has been rarely explored or exploited.

Methods

We used clinical-grade conditions and two donors who were homozygous and identical for all HLA-alleles except HLA-DP. After mixed lymphocyte culture and transduction, we obtained 14 HLA-DP–specific T-cell clones transduced with the HSV-TK suicide gene. Clones were then selected on the basis of their specificity and functional characteristics and evaluated for their doubling potential.

Results

After these steps of selection the clone NAT-DP4(TK), specific for HLA-DPB1*04:01/04:02, which produced high levels of interferon-γ (IFNγ), tumor necrosis factor (TNF), interleukin-2 (IL-2) and granulocyte-macrophage colony-stimulating factor (GM-CSF), was fully sequenced. It has two copies of the HSV-TK suicide transgene whose localizations were determined. Four billion NAT-DP4(TK) cells were frozen after 50 PDs. Thawed NAT-DP4(TK) cells retain the potential to undergo 50 additional PDs, a potential very far beyond that required to produce a biological effect. This PD potential was confirmed on 6/16 additional different T-cell clones. This type of well-defined clone can also support a second genetic modification with CAR constructs.

Conclusion

The possibility of choosing rare donors and exploiting the natural proliferative potential of T lymphocytes may dramatically reduce the clinical and immunologic complexity of adoptive transfer protocols that rely on the use of third-party T-cell populations.  相似文献   

13.

Purpose

CD4+CD25+ regulatory T (Treg) cells are present in increased numbers in patients with advanced cancer and CD25+ T cell depletion potentiates tumour immunity in animal models. The aim of this study was to assess the feasibility and safety of adoptive transfer of CD25+ depleted autologous T cells in patients with advanced renal cell carcinoma and to examine resulting changes in lymphocyte subsets.

Patients and methods

Six patients with advanced renal cell carcinoma underwent leukapheresis followed by conditioning chemotherapy with cyclophosphamide and fludarabine. The autologous leukapheresis product was depleted of CD25+ cells using CliniMACS® System then re-infused into the patient.

Results

Efficient CD25+ depletion from all leukapheresis products was achieved and 0.55–5.87 × 107/kg CD3+ cells were re-infused. Chemotherapy related haematological toxicity was observed, but blood counts recovered in all patients allowing discharge after a mean inpatient stay of 21 days. One patient subsequently developed a rapidly progressive neurological syndrome. A transient reduction in CD25+ subset was noted in the peripheral blood of 5 out of 6 patients with evidence of increased T cell responses to PHA in 4 out of 6 patients. One patient showed increased specific proliferative responses to the tumour associated antigen h5T4 coinciding with the nadir of Treg cells.

Conclusions

Given the transient nature of the reduction in CD25+ subset and the observed toxicity there is a need to explore further strategies to improve the safety and efficacy of this approach. Nevertheless, the results provide proof of concept in potentiation of tumour antigen T cell responses when Treg cell levels are depleted.
  相似文献   

14.

Objective

Immune imbalance between regulatory T (Treg) and Th17 cells is a characteristic of systemic sclerosis (SSc). The functional heterogeneity among Treg can be elucidated by separating Treg into different subsets based on the expression of FoxP3 and CD45RA. The aim of this study was to investigate the role of Treg subsets in the immune imbalance in naïve SSc.

Methods

Peripheral blood mononuclear cells (PBMCs) of 31 SSc patients and 33 healthy controls were analyzed for the expression of CD4, CD25, CD45RA, CTLA-4, FoxP3, and IL-17 using flow cytometry. Treg immunesuppression capacity was measured in co-culture experiments. The expression of FoxP3, CTLA-4, IL-17A, and RORC mRNA was measured by real-time PCR.

Results

The frequency of CD4+CD25+FoxP3+ Treg cells was significantly elevated in patients with SSc (3.62±1.14 vs 1.97±0.75, p<0.001) with diminished immunosuppression capacity. In SSc, the proportion of FoxP3highCD45RA activated Treg cells (aTreg) was decreased, the proportion of FoxP3lowCD45RA T cells was increased, and the proportion of FoxP3lowCD45RA+ resting Treg cells (rTreg) was decreased. The immune suppression capacity of aTreg and rTreg was diminished, while FoxP3lowCD45RA T cells exhibited a lack of suppression capacity. The immune dysfunction of aTreg was accompanied by the abnormal expression of CTLA-4. Th17 cell numbers were elevated in SSc, FoxP3lowCD45RA T cells produced IL-17, confirming their Th17 potential, which was consistent with the elevated levels of FoxP3+IL-17+ cells in SSc.

Conclusion

A decrease in aTreg levels, along with functional deficiency, and an increase in the proportion of FoxP3lowCD45RA T cells, was the reason for the increase in dysfunctional Treg in SSc patients, potentially causing the immune imbalance between Treg and Th17 cells.  相似文献   

15.

Background aims

Although intra-articular injection of platelet products is increasingly used for joint regenerative approaches, there are few data on their biological effects on joint-resident multipotential stromal cells (MSCs), which are directly exposed to the effects of these therapeutic strategies. Therefore, this study investigated the effect of platelet lysate (PL) on synovial fluid–derived MSCs (SF-MSCs), which in vivo have direct access to sites of cartilage injury.

Methods

SF-MSCs were obtained during knee arthroscopic procedures (N?=?7). Colony forming unit–fibroblast (CFU-F), flow-cytometric phenotyping, carboxyfluorescein succinimidyl ester-based immunomodulation for T-cell and trilineage differentiation assays were performed using PL and compared with standard conditions.

Results

PL-enhanced SF-MSC (PL-MSC) proliferation as CFU-F colonies was 1.4-fold larger, and growing cultures had shorter population-doubling times. PL-MSCs and fetal calf serum (FCS)-MSCs had the same immunophenotype and similar immunomodulation activities. In chondrogenic and osteogenic differentiation assays, PL-MSCs produced 10% more sulfated-glycosaminoglycan (sGAG) and 45% less Ca++ compared with FCS-MSCs, respectively. Replacing chondrogenic medium transforming growth factor-β3 with 20% or 50% PL further increased sGAG production of PL-MSCs by 69% and 95%, respectively, compared with complete chondrogenic medium. Also, Dulbecco's Modified Eagle's Medium high glucose (HG-DMEM) plus 50% PL induced more chondrogenesis compared with HG-DMEM plus 10% FCS and was comparable to complete chondrogenic medium.

Conclusions

This is the first study to assess SF-MSC responses to PL and provides biological support to the hypothesis that PL may be capable of modulating multiple functional aspects of joint resident MSCs with direct access to injured cartilage.  相似文献   

16.

Background

Menstrual blood is only recently and still poorly studied, but it is an abundant and noninvasive source of highly proliferative mesenchymal stromal cells (MSCs). However, no appropriate isolation method has been reported due to its high viscosity and high content of clots and desquamated epithelium.

Methods

We studied three different isolation approaches and their combinations: ammonium-containing lysing buffer, distilled water and gradient-density centrifugation. We tested the proliferative capacity, morphology, surface markers and pluripotency of the resulting cells.

Results

Our isolation method yields up to four million nucleated cells per milliliter of initial blood, of which about 0.2–0.3% are colony-forming cells expressing standard mesenchymal markers CD90, CD105 and CD73, but not expressing CD45, CD34, CD117, CD133 or HLA-G. The cells have high proliferative potential (doubling in 26?h) and the ability to differentiate into adipocytes and osteocytes. Early endometrial MSCs (eMSCs) express epithelial marker cytokeratin 7 (CK7). CK7 is easily induced in later passages in a prohepatic environment. We show for the first time that a satisfactory and stable yield of eMSCs is observed throughout the whole menstrual period (5 consecutive days) of a healthy woman.

Discussion

The new cost/yield adequate method allows isolation from menstrual blood a relatively homogenous pool of highly proliferative MSCs, which seem to be the best candidates for internal organ therapy due to their proepithelial background (early expression of CK7 and its easy induction in later passages) and for mass cryobanking due to their high yield and availability.  相似文献   

17.

Background aims

Umbilical cord blood (UCB) provides an alternative source for hematopoietic stem/progenitor cells (HSPCs) in the treatment of hematological malignancies. However, clinical usage is limited due to the low quantity of HSPCs in each unit of cord blood and defects in bone marrow homing. Hyperbaric oxygen (HBO) is among the more recently explored methods used to improve UCB homing and engraftment. HBO works by lowering the host erythropoietin before UCB infusion to facilitate UCB HSPC homing, because such UCB cells are not directly exposed to HBO. In this study, we examined how direct treatment of UCB-CD34+ cells with HBO influences their differentiation, proliferation and in vitro transmigration.

Methods

Using a locally designed HBO chamber, freshly enriched UCB-CD34+ cells were exposed to 100% oxygen at 2.5 atmospheres absolute pressure for 2?h before evaluation of proliferative capacity, migration toward a stromal cell–derived factor 1 gradient and lineage differentiation.

Results

Our results showed that HBO treatment diminishes proliferation and in vitro transmigration of UCB-CD34+ cells. Treatment was also shown to limit the ultimate differentiation of these cells toward an erythrocyte lineage. As a potential mechanism for these findings, we also investigated HBO effects on the relative concentration of cytoplasmic and nucleic reactive oxygen species (ROS) and on erythropoietin receptor (Epo-R) and CXCR4 expression. HBO-treated cells showed a relative increase in nucleic ROS but no detectable differences in the level of Epo-R nor CXCR4 expression were established compared with non-treated cells.

Discussion

In summary, HBO amplifies the formation of ROS in DNA of UCB-CD34+ cells, potentially explaining their reduced proliferation, migration and erythrocytic differentiation.  相似文献   

18.

Background aims

CD1d-restricted invariant natural killer (iNK) T cells are rare regulatory T cells that may contribute to the immune-regulation in allogeneic stem cell transplantation (ASCT). Here, we sought to develop an effective strategy to expand human iNK T cells for use in cell therapy to prevent graft-versus-host disease (GVHD) in ASCT.

Methods

Human iNK T cells were first enriched from peripheral blood mononuclear cells (PBMCs) using magnetic-activated cell sorting separation, then co-cultured with dendritic cells in the presence of agonist glycolipids, alpha-galactosylceramide, for 2 weeks.

Results

The single antigenic stimulation reliably expanded iNK T cells to an average of 2.8?×?107 per 5?×?108 PBMCs in an average purity of 98.8% in 2 weeks (N?=?24). The expanded iNK T cells contained a significantly higher level of CD4+ and central memory phenotype (CD45RA?CD62L+) compared with freshly isolated iNK T cells, and maintained their ability to produce both Th-1 (interferon [IFN]γ and tumor necrosis factor [TNF]α) and Th-2 type cytokines (interleukin [IL]-4, IL-5 and IL-13) upon antigenic stimulation or stimulation with Phorbol 12-myristate 13-acetate/ionomycin. Interestingly, expanded iNK T cells were highly autoreactive and produced a Th-2 polarized cytokine production profile after being co-cultured with dendritic cells alone without exogenous agonist glycolipid antigen. Lastly, expanded iNK T cells suppressed conventional T-cell proliferation and ameliorated xenograft GVHD (hazard ratio, 0.1266; P < 0.0001).

Conclusion

We have demonstrated a feasible approach for obtaining ex vivo expanded, highly enriched human iNK T cells for use in adoptive cell therapy to prevent GVHD in ASCT.  相似文献   

19.

Background aims

Chimeric antigen receptors (CARs) offer great potential toward a functional cure of human immunodeficiency virus (HIV) infection. To achieve the necessary long-term virus suppression, we believe that CARs must be designed for optimal potency and anti-HIV specificity, and also for minimal probability of virus escape and CAR immunogenicity. CARs containing antibody-based motifs are problematic in the latter regard due to epitope mutation and anti-idiotypic immune responses against the variable regions.

Methods

We designed bispecific CARs, each containing a segment of human CD4 linked to the carbohydrate recognition domain of a human C-type lectin. These CARs target two independent regions on HIV-1 gp120 that presumably must be conserved on clinically significant virus variants (i.e., the primary receptor binding site and the dense oligomannose patch). Functionality and specificity of these bispecific CARs were analyzed in assays of CAR-T cell activation and spreading HIV-1 suppression.

Results

T cells expressing a CD4-dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DCSIGN) CAR displayed robust stimulation upon encounter with Env-expressing targets, but negligible activity against intercellular adhesion molecule (ICAM)-2 and ICAM-3, the natural dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin ligands. Moreover, the presence of the lectin moiety prevented the CD4 from acting as an entry receptor on CCR5-expressing cells, including CD8+ T cells. However, in HIV suppression assays, the CD4-DCSIGN CAR and the related CD4-liver/lymph node-specific intercellular adhesion molecule-3-grabbing non-integrin CAR displayed only minimally increased potency compared with the CD4 CAR against some HIV-1 isolates and reduced potency against others. By contrast, the CD4-langerin and CD4-mannose binding lectin (MBL) CARs uniformly displayed enhanced potency compared with the CD4 CAR against all the genetically diverse HIV-1 isolates examined. Further experimental data, coupled with known biological features, suggest particular advantages of the CD4-MBL CAR.

Discussion

These studies highlight features of bispecific CD4-lectin CARs that achieve potency enhancement by targeting two distinct highly conserved Env determinants while lacking immunogenicity-prone antibody-based motifs.  相似文献   

20.

Background

Patients with end-stage renal disease (ESRD) have an impaired immune response with a prematurely aged T-cell system. Mitogen-activated protein kinases (MAPKs) including extracellular signal-regulated kinase (ERK) and p38, regulate diverse cellular programs by transferring extracellular signals into an intracellular response. T cell receptor (TCR)-induced phosphorylation of ERK (pERK) may show an age-associated decline, which can be reversed by inhibiting dual specific phosphatase (DUSP) 6, a cytoplasmic phosphatase with substrate specificity to dephosphorylate pERK. The aim of this study was to assess whether ESRD affects TCR-mediated signaling and explore possibilities for intervening in ESRD-associated defective T-cell mediated immunity.

Results

An age-associated decline in TCR-induced pERK-levels was observed in the different CD4+ (P < 0.05), but not CD8+, T-cell subsets from healthy individuals (HI). Interestingly, pERK-levels of CD4+ T-cell subsets from young ESRD patients were in between young and elderly HI. A differentiation-associated decline in TCR-induced ERK and p38 phosphorylation was observed in T cells, although TCR-induced p38 phosphorylation was not significantly affected by age and/or ESRD. Frequencies of TCR-induced CD69-expressing CD4+ T cells declined with age and were positively associated with pERK. In addition, an age-associated tendency of increased expression of DUSP6 was observed in CD4+ T cells of HI and DUSP6 expression in young ESRD patients was similar to old HI. Inhibition of DUSP6 significantly increased TCR-induced pERK-levels of CD4+ T cells in young and elderly ESRD patients, and elderly HI.

Conclusions

TCR-mediated phosphorylation of ERK is affected in young ESRD patients consistent with the concept of premature immunological T cell ageing. Inhibition of DUSP6 specific for pERK might be a potential intervention enhancing T-cell mediated immunity in ESRD patients.
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