Natural and adoptive T-cell immunity against herpes family viruses after allogeneic hematopoietic stem cell transplantation.

2011

Reactivated infections with herpes family-related cytomegalovirus, Epstein–Barr virus and varicella zoster virus are serious and sometimes life-threatening complications for patients undergoing allogeneic hematopoietic stem cell transplantation. The pathogenesis of these infections critically involves the slow and inefficient recovery of antiviral T-cell immunity after transplantation. Although efficient drugs to decrease viral load during this vulnerable period have been developed, long-term control of herpes viruses and protection from associated diseases require the sufficient reconstitution of virus-specific memory T cells. To heal the deficiency by immunotherapeutic means, numerous re…

Strong and sustained effector function of memory- versus naïve-derived T cells upon T-cell receptor RNA transfer: Implications for cellular therapy

2012

Current protocols used to select CMV-specific T cells for adoptive immunotherapy focus on virus-specific memory T cells from seropositive donors. However, this strategy is not feasible in patients undergoing allogeneic haematopoietic stem-cell transplantation (HSCT) from CMV-seronegative donors. Here, we redirected T cells of CMV-seronegative donors with a human genetically engineered TCR recognizing an HLA-A*0201-binding peptide epitope of CMVpp65. To facilitate clinical translation of this approach, we used a non-viral expression system based on in vitro transcribed RNA and electroporation. Although memory and naive-derived T-cell subsets were both efficiently transfected by TCR-RNA, memo…

HLA-DPB1 mismatch alleles represent powerful leukemia rejection antigens in CD4 T-cell immunotherapy after allogeneic stem-cell transplantation.

2016

Refractory or relapsed acute myeloid leukemia (AML) represents a frequent complication after allogeneic hematopoietic stem-cell transplantation (HSCT). We show herein that primary in vitro stimulation of CD45RA-selected CD4 T cells of stem-cell donors with 10/10 HLA-matched AML blasts results in expansion of cytolytic T-lymphocytes (CTL) that almost all recognize HLA-DPB1 mismatch alleles, which clinically occur in up to 80% of donor-patient pairs. Primary AML blasts were found to strongly express HLA-DPB1, whereas fibroblasts and keratinocytes used as surrogate target cells for graft-versus-host disease did express HLA-DPB1 only upon IFN-γ pre-treatment. Since patients' AML blasts are rare…

Alloreactive and leukemia-reactive T cells are preferentially derived from naive precursors in healthy donors: implications for immunotherapy with me…

2011

Background HLA mismatch antigens are major targets of alloreactive T cells in HLA-incompatible stem-cell transplantation, which can trigger severe graft- versus -host disease and reduce survival in transplant recipients. Our objective was to identify T-cell subsets with reduced in vitro reactivity to allogeneic HLA antigens. Design and Methods We sorted CD4 and CD8 T-cell subsets from peripheral blood by flow cytometry according to their expression of naive and memory markers CD45RA, CD45RO, CD62L, and CCR7. Subsets were defined by a single marker to facilitate future establishment of a clinical-grade procedure for reducing alloreactive T-cell precursors and graft- versus -host disease. T c…

Late Non-Relapse Mortality (NRM) after Standard-of-Care (SOC) CAR-T Cell Therapy for Large B-Cell Lymphoma (LBCL): Frequency, Causes, and Risk Factor…

2021

Abstract Introduction Although the labeled CD19 targeting CAR-T cell constructs axi-cel and tisa-cel are generally associated with an acceptable safety profile, non-relapse deaths can occur. Little is known about timing, causes and predictors of NRM following SOC CAR-T cell therapy for LBCL. Here, we analyzed frequency, causes, and risk factors of non-relapse deaths with focus on late NRM (beyond 4 weeks after dosing) using registry data provided by the DRST, the national partner of the EBMT. Methods Patients were selected from 356 consecutive patients who received SOC CAR-T treatment of LBCL between November 2018 and April 2021 at 21 German centers and were registered with the DRST/EBMT. B…

Adoptive Transfer of T-Cell-Receptor Engineered Human T Cells Specifically Reduces Viral Titers in HLA-Transgenic NSG Mice Infected with a Humanized …

2014

Abstract Reactivation of latent human cytomegalovirus (HCMV) infection is a frequent complication in patients after allogeneic hematopoietic stem cell transplantation (HSCT). Preclinical research in murine models as well as clinical phase I/II trials have shown that the adoptive transfer of virus-specific CD8+ T cells is a therapeutic option for preventing HCMV disease. However, the feasibility of HCMV-specific immunotherapy is currently limited in clinical routine due to technical restrictions. It has also limitations, if the donor is HCMV-seronegative or carries only low numbers of HCMV-specific memory T cells. In this situation, grafting non-reactive T cells by virus-antigen specific T-c…

Nanoparticles and antigen-specific T-cell therapeutics: A comprehensive study on uptake and release

2015

Aim: T lymphocytes are used as cellular therapeutics in many disease entities including cancer. We investigated the uptake and retention of nanoparticles (NPs) by these nonphagocytic cells. Materials & methods: Uptake, release and toxicity of various polymeric NP preparations were analyzed by flow cytometry, confocal laser scanning microscopy and transmission electron microscopy. T-cell effector functions were measured using IFN-γ-ELISPOT and 51Chromium-release assays. Results: Amino-functionalized NPs were efficiently ingested by antigen-specific T cells without adversely influencing effector functions. NPs were stored in membrane-surrounded vesicles, with major proportions released e…

Efficient Delivery of Human Cytomegalovirus T Cell Antigens by Attenuated Sendai Virus Vectors.

2018

ABSTRACT Human cytomegalovirus (HCMV) represents a major cause of clinical complications during pregnancy as well as immunosuppression, and the licensing of a protective HCMV vaccine remains an unmet global need. Here, we designed and validated novel Sendai virus (SeV) vectors delivering the T cell immunogens IE-1 and pp65. To enhance vector safety, we used a replication-deficient strain (rdSeV) that infects target cells in a nonproductive manner while retaining viral gene expression. In this study, we explored the impact that transduction with rdSeV has on human dendritic cells (DCs) by comparing it to the parental, replication-competent Sendai virus strain (rcSeV) as well as the poxvirus …

Playing the Game Together: Coexpression of a Single Chain T Cell Receptor and a T Cell Receptor Constant-Alpha Domain Triggers Tumor Reactivity.

2006

Abstract Grafting T cells by tumor-antigen specific T cell receptors (TCR) could trigger the initiation of effector function and redirect T cell cytotoxicity towards tumors. We utilized various HLA-A2.1 transgenic mice to bypass human MDM2- and p53-specific self-tolerance. In contrast to the use of HuCD8×A2Kb transgenic mice to generate an MDM2-specific CD8-dependent TCR, we generated a high-affinity, CD8-independent p53-specific TCR in single human A2.1 transgenic mice. The efficiency of double chain (dc) TCR modified T cells could be affected by the incorrect TCR α/β chain pairing between endogenous and transgenic TCR constructs to form hybrid TCR potentially leading to autoimmunity. To a…

Evaluating Human T-Cell Therapy of Cytomegalovirus Organ Disease in HLA-Transgenic Mice

2015

Reactivation of human cytomegalovirus (HCMV) can cause severe disease in recipients of hematopoietic stem cell transplantation. Although preclinical research in murine models as well as clinical trials have provided 'proof of concept' for infection control by pre-emptive CD8 T-cell immunotherapy, there exists no predictive model to experimentally evaluate parameters that determine antiviral efficacy of human T cells in terms of virus control in functional organs, prevention of organ disease, and host survival benefit. We here introduce a novel mouse model for testing HCMV epitope-specific human T cells. The HCMV UL83/pp65-derived NLV-peptide was presented by transgenic HLA-A2.1 in the conte…

2004

Depletion of naive T cells using clinical grade magnetic CD45RA beads: a new approach for GVHD prophylaxis

2013

Depletion of naive T cells from donor leukapheresis products (LPs) aims at the reduction of alloreactivity, while preserving memory T-cell reactivity (for example, to pathogens). This study established the immunomagnetic depletion procedure under clean room conditions using CD45RA beads and analyzed LPs of six donors for cell composition and functional immune responses. CD45RA depletion resulted in 3.4-4.7 log (median 4.4) reduction of CD45RA(+) T cells, thereby eliminating naive and late effector T cells. B cells were also completely removed, whereas significant proportions of NK cells, monocytes and granulocytes persisted. CD45RA-depleted LPs contained effector and central memory CD4(+) a…

Subviral Dense Bodies of Human Cytomegalovirus Stimulate Maturation and Activation of Monocyte-Derived Immature Dendritic Cells

2013

ABSTRACT Dendritic cells play a central role in the immune control of human cytomegalovirus (HCMV) infection. This work aimed at investigating the impact of noninfectious, subviral dense bodies of HCMV on the maturation and activation of dendritic cells (DC). Treatment of immature DC with dense bodies led to the maturation of these cells and significantly increased their capacity for cytokine release and antigen presentation. Dense body-activated DC may thereby contribute to the development of antiviral immunity.

Standard of Care CAR-T Cell Therapy for Large B-Cell Lymphoma (LBCL): Does Bridging Efficacy Matter? a German GLA/DRST Real World Analysis

2021

Abstract Introduction The CD19 targeting CAR-T cell constructs axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel) have become an accepted standard salvage treatment of LBCL beyond the second line. Patients scheduled for approved CAR-T cell therapies usually have 4-8 weeks wait time for CAR-T cell infusion, thus often requiring bridging strategies in rapidly progressing patients to achieve disease control until start of lymphodepletion. It is still unclear, however, if the adverse impact of active progressive lymphoma can be overcome by successful bridging. We have addressed this question using registry data provided by the German Registry for Stem Cell Transplantation (DRST),…

Human CD8+ memory and EBV-specific T cells show low alloreactivity in vitro and in CD34+ stem cell–engrafted NOD/SCID/IL-2Rγcnull mice

2013

Current strategies in cellular immunotherapy of cancer and viral infections include the adoptive transfer of T cell receptor (TCR) and chimeric antigen receptor engineered T cells. When using transient RNA expression systems in clinical studies, multiple infusions with receptor-redirected T cells appear necessary. However, in allogeneic hematopoietic stem-cell transplantation, repeated transfer of donor-derived T cells increases the risk of alloreactive graft-versus-host disease. We investigated naive-derived (T N ), memory-derived (T M ), and Epstein Barr virus-specific (T EBV ) CD8 + T cell subsets for alloreactivity upon redirection with RNA encoding a cytomegalovirus-specific model TCR.…

Graft-Versus-Host Disease or Infection: Rapid Detection of HLA Mismatch-Reactive T Cells Ex Vivo Can Facilitate Diagnosis and Guide Therapy after All…

2007

Abstract Diagnosis of graft-versus-host disease (GVHD) is mainly based on clinical features and on tissue biopsies. However, clinicians and pathologists are well aware of cases, in which GVHD cannot be distinguished from infections arising from severe immunodeficiency after allogeneic stem-cell transplantation (SCT). This may pose a deep therapeutic dilemma of whether to modify immunosuppressive treatment or to use donor lymphocyte infusion (DLI) for promoting anti-microbial immunity. We observed a 68-year-old patient with myelodysplastic syndrome who developed acute GVHD grade II of skin and gut at d+16 after T-cell depleted reduced-intensity SCT (Fig. 1). GVHD was confirmed by histology a…