| 1. |
- Arruda, Lucas C. M., et al.
(författare)
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A novel CD34-specific T-cell engager efficiently depletes acute myeloid leukemia and leukemic stem cells in vitro and in vivo
- 2022
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 107:8, s. 1786-1795
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Tidskriftsartikel (refereegranskat)abstract
- Less than a third of patients with acute myeloid leukemia (AML) are cured by chemotherapy and/or hematopoietic stem cell transplantation, highlighting the need to develop more efficient drugs. The low efficacy of standard treatments is associated with inadequate depletion of CD34(+) blasts and leukemic stem cells, the latter a drug-resistant subpopulation of leukemia cells characterized by the CD34(+)CD38(-) phenotype. To target these drug-resistant primitive leukemic cells better, we have designed a CD34/CD3 bi-specific T-cell engager (BTE) and characterized its anti-leukemia potential in vitro, ex vivo and in vivo. Our results show that this CD34-specific BTE induces CD34-dependent T-cell activation and subsequent leukemia cell killing in a dose-dependent manner, further corroborated by enhanced T-cell-mediated killing at the singlecell level. Additionally, the BTE triggered efficient T-cell-mediated depletion of CD34(+) hematopoietic stem cells from peripheral blood stem cell grafts and CD34(+) blasts from AML patients. Using a humanized AML xenograft model, we confirmed that the CD34-specific BTE had in vivo efficacy by depleting CD34(+) blasts and leukemic stem cells without side effects. Taken together, these data demonstrate that the CD34-specific BTE has robust antitumor effects, supporting development of a novel treatment modality with the aim of improving outcomes of patients with AML and myelodysplastic syndromes.
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| 2. |
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| 3. |
- Gaballa, Ahmed, et al.
(författare)
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Revisiting the Role of gamma delta T Cells in Anti-CMV Immune Response after Transplantation
- 2021
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Ingår i: Viruses. - : MDPI AG. - 1999-4915. ; 13:6, s. 1031-
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Forskningsöversikt (refereegranskat)abstract
- Gamma delta (gamma delta) T cells form an unconventional subset of T lymphocytes that express a T cell receptor (TCR) consisting of gamma and delta chains. Unlike conventional alpha beta T cells, gamma delta T cells share the immune signature of both the innate and the adaptive immunity. These features allow gamma delta T cells to act in front-line defense against infections and tumors, rendering them an attractive target for immunotherapy. The role of gamma delta T cells in the immune response to cytomegalovirus (CMV) has been the focus of intense research for several years, particularly in the context of transplantation, as CMV reactivation remains a major cause of transplant-related morbidity and mortality. Therefore, a better understanding of the mechanisms that underlie CMV immune responses could enable the design of novel gamma delta T cell-based therapeutic approaches. In this regard, the advent of next-generation sequencing (NGS) and single-cell TCR sequencing have allowed in-depth characterization of CMV-induced TCR repertoire changes. In this review, we try to shed light on recent findings addressing the adaptive role of gamma delta T cells in CMV immunosurveillance and revisit CMV-induced TCR reshaping in the era of NGS. Finally, we will demonstrate the favorable and unfavorable effects of CMV reactive gamma delta T cells post-transplantation.
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| 4. |
- Gaballa, Ahmed, et al.
(författare)
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T-cell frequencies of CD8(+) gamma delta and CD27(+) gamma delta cells in the stem cell graft predict the outcome after allogeneic hematopoietic cell transplantation
- 2019
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Ingår i: Bone Marrow Transplantation. - : NATURE PUBLISHING GROUP. - 0268-3369 .- 1476-5365. ; 54:10, s. 1562-1574
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Tidskriftsartikel (refereegranskat)abstract
- The impact of intra-graft T cells on the clinical outcome after allogeneic hematopoietic cell transplantation has been investigated. Most previous studies have focused on the role of alpha beta cells while gamma delta cells have received less attention. It has been an open question whether gamma delta cells are beneficial or not for patient outcome, especially with regards to graft versus host disease. In this study, graft composition of.d cell subsets was analyzed and correlated to clinical outcome in 105 recipients who underwent allogeneic hematopoietic cell transplantation between 2013 and 2016. We demonstrate for the first time that grafts containing higher T-cell proportions of CD8(+) gamma delta cells were associated with increased cumulative incidence of acute graft versus host disease grade II-III (50% vs 22.6%; P = 0.008). Additionally, graft T-cell frequency of CD27(+) gamma delta cells was inversely correlated with relapse (P = 0.006) and CMV reactivation (P = 0.05). We conclude that clinical outcome after allogeneic hematopoietic cell transplantation is influenced by the proportions of distinct gamma delta cell subsets in the stem cell graft. We also provide evidence that CD8(+) gamma delta cells are potentially alloreactive and may play a role in acute graft versus host disease. This study illustrates the importance of better understanding of the role of distinct subsets of.d cells in allogeneic hematopoietic cell transplantation.
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| 5. |
- Guldevall, Karolin, 1981-, et al.
(författare)
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Microchip screening platform for assessment of cytotoxic effector cells
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Here we report a screening platform for assessment of the cytotoxic potential of individual natural killer (NK) or T cells within larger populations. Human primary NK cells or human Epstein-Barr virus (EBV)- specific T cells were distributed across a silicon-glass microchip containing 32 400 individual microwells loaded with target cells. Through fluorescence screening and automated image analysis the numbers of effector and live or dead target cells in each well could be assessed at different time-points after initial mixing. Cytotoxicity was also studied by time-lapse live-cell imaging in microwells quantifying the killing potential of individual NK cells. Although most resting NK cells (≈75%) were non-cytotoxic to the leukemia cell line K562, some NK cells were able to kill several (≥3) target cells within the 12 hours long experiment. We demonstrate that this assay can be used to enumerate and characterize cytotoxic cells, something that could find clinical applications, e.g. in the selection of donors for stem cell transplantation or generation of highly specific and cytotoxic cells for adoptive immunotherapy.
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| 6. |
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| 7. |
- Radestad, Emelie, et al.
(författare)
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Immune profiling and identification of prognostic immune-related risk factors in human ovarian cancer
- 2019
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Ingår i: Oncoimmunology. - : TAYLOR & FRANCIS INC. - 2162-4011 .- 2162-402X. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- Suppression of immune reactivity by increased expression of co-inhibitory receptors has been discussed as a major reason as to why the immune system fails to control tumor development. Elucidating the co-inhibitory expression pattern of tumor-infiltrating lymphocytes in different cancer types will help to develop future treatment strategies. We characterized markers reflecting and affecting T-cell functionality by flow cytometry on lymphocytes isolated from blood, ascites and tumor from advanced ovarian cancer patients (n = 35). Significantly higher proportions of CD4+ and CD8+ T-cells expressed coinhibitory receptors LAG-3, PD-1 and TIM-3 in tumor and ascites compared to blood. Co-expression was predominantly observed among intratumoral CD8+ T-cells and the most common combination was PD-1 and TIM-3. Analysis of 26 soluble factors revealed highest concentrations of IP-10 and MCP-1 in both ascites and tumor. Correlating these results with clinical outcome revealed the proportion of CD8+ T-cells without expression of LAG-3, PD-1 and TIM-3 to be beneficial for overall survival. In total we identified eight immune-related risk factors associated with reduced survival. Ex vivo activation showed tumor-derived CD4+ and CD8+ T-cells to be functionally active, assessed by the production of IFN-gamma, IL-2, TNF-alpha, IL-17 and CD107a. Blocking the PD-1 receptor resulted in significantly increased release of IFN-. suggesting potential reinvigoration. The ovarian tumor environment exhibits an inflammatory milieu with abundant presence of infiltrating immune cells expressing inhibitory checkpoints. Importantly, we found subsets of CD8+ T-cells with double and triple expression of co-inhibitory receptors, supporting the need for multiple checkpoint-targeting agents to overcome T-cell dysfunction in ovarian cancer.
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| 8. |
- Stikvoort, Arwen, et al.
(författare)
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Combining Flow and Mass Cytometry in the Search for Biomarkers in Chronic Graft-versus-Host Disease
- 2017
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Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Chronic graft-versus-host disease (cGVHD) is a debilitating complication arising in around half of all patients treated with an allogeneic hematopoietic stem cell transplantation. Even though treatment of severe cGVHD has improved during recent years, it remains one of the main causes of morbidity and mortality in affected patients. Biomarkers in blood that could aid in the diagnosis and classification of cGVHD severity are needed for the development of novel treatment strategies that can alleviate symptoms and reduce the need for painful and sometimes complicated tissue biopsies. Methods that comprehensively profile complex biological systems such as the immune system can reveal unanticipated markers when used with the appropriate methods of data analysis. Here, we used mass cytometry, flow cytometry, enzyme-linked immunosorbent assay, and multiplex assays to systematically profile immune cell populations in 68 patients with varying grades of cGVHD. We identified multiple subpopulations across T, B, and NK-cell lineages that distinguished patients with cGVHD from those without cGVHD and which were associated in varying ways with severity of cGVHD. Specifically, initial flow cytometry demonstrated that patients with more severe cGVHD had lower mucosal-associated T cell frequencies, with a concomitant higher level of CD38 expression on T cells. Mass cytometry could identify unique subpopulations specific for cGVHD severity albeit with some seemingly conflicting results. For instance, patients with severe cGVHD had an increased frequency of activated B cells compared to patients with moderate cGVHD while activated B cells were found at a reduced frequency in patients with mild cGVHD compared to patients without cGVHD. Moreover, results indicate it may be possible to validate mass cytometry results with clinically viable, smaller flow cytometry panels. Finally, no differences in levels of blood soluble markers could be identified, with the exception for the semi-soluble combined marker B-cell activating factor/B cell ratio, which was increased in patients with mild cGVHD compared to patients without cGVHD. These findings suggest that interdependencies between such perturbed subpopulations of cells play a role in cGVHD pathogenesis and can serve as future diagnostic and therapeutic targets.
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| 9. |
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| 10. |
- Stikvoort, Arwen, et al.
(författare)
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Risk Factors for Severe Acute Graft-versus-Host Disease in Donor Graft Composition
- 2018
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Ingår i: Biology of blood and marrow transplantation. - : ELSEVIER SCIENCE INC. - 1083-8791 .- 1523-6536. ; 24:3, s. 467-477
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Tidskriftsartikel (refereegranskat)abstract
- Acute graft-versus-host disease (aGVHD) is 1 of the main major complications of post-hematopoietic stem cell transplantation (HSCT). Identifying patients at risk of severe aGVHD may lead to earlier intervention and treatment, resulting in increased survival and a better quality of life. We aimed to identify biomarkers in donor grafts and patient plasma around the time of transplantation that might be predictive of aGVHD development. We build on our previously published methods by using multiplex assays and multicolor flow cytometry. We identified 5 easily assessable cellular markers in donor grafts that combined could potentially be used to calculate risk for severe aGVHD development. Most noteworthy are the T cell subsets expressing IL-7 receptor-a (CD127) and PD-1. Additionally, we identified a potential role for elevated tumor necrosis factor-a levels in both graft and patient before HSCT in development of aGVHD.
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