| 1. |
- Gaballa, Ahmed, et al.
(författare)
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Evaluating Thymic Function After Human Hematopoietic Stem Cell Transplantation in the Personalized Medicine Era
- 2020
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 11
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Forskningsöversikt (refereegranskat)abstract
- Hematopoietic stem cell transplantation (HSCT) is an effective treatment option for several malignant and non-malignant hematological diseases. The clinical outcome of this procedure relies to a large extent on optimal recovery of adaptive immunity. In this regard, the thymus plays a central role as the primary site forde novogeneration of functional, diverse, and immunocompetent T-lymphocytes. The thymus is exquisitely sensitive to several insults during HSCT, including conditioning drugs, corticosteroids, infections, and graft-vs.-host disease. Impaired thymic recovery has been clearly associated with increased risk of opportunistic infections and poor clinical outcomes in HSCT recipients. Therefore, better understanding of thymic function can provide valuable information for improving HSCT outcomes. Recent data have shown that, besides gender and age, a specific single-nucleotide polymorphism affects thymopoiesis and may also influence thymic output post-HSCT, suggesting that the time of precision medicine of thymic function has arrived. Here, we review the current knowledge about thymic role in HSCT and the recent work of genetic control of human thymopoiesis. We also discuss different transplant-related factors that have been associated with impaired thymic recovery and the use of T-cell receptor excision circles (TREC) to assess thymic output, including its clinical significance. Finally, we present therapeutic strategies that could boost thymic recovery post-HSCT.
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| 2. |
- Guldevall, Karolin, et al.
(författare)
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Microchip screening Platform for single cell assessment of NK cell cytotoxicity
- 2016
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Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Here, we report a screening platform for assessment of the cytotoxic potential of individual natural killer (NK) cells within larger populations. Human primary NK 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 NK 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 (approximate to 75%) were non-cytotoxic against the leukemia cell line K562, some NK cells were able to kill several (>= 3) target cells within the 12-h long experiment. In addition, the screening approach was adapted to increase the chance to find and evaluate serial killing NK cells. Even if the cytotoxic potential varied between donors, it was evident that a small fraction of highly cytotoxic NK cells were responsible for a substantial portion of the killing. We demonstrate multiple assays where our platform can be used to enumerate and characterize cytotoxic cells, such as NK or T cells. This approach could find use in 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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| 3. |
- Radestad, Emelie, et al.
(författare)
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Individualization of Hematopoietic Stem Cell Transplantation Using Alpha/Beta T-Cell Depletion
- 2019
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Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Allogeneic hematopoietic stem cell transplantation (HSCT) is associated with several potentially lethal complications. Higher levels of CD3+ T-cells in the graft have been associated with increased risk of graft-versus-host disease (GVHD), but also beneficial graft-versus-leukemia effect and reduced infections. To tackle post-transplant complications, donor lymphocyte infusions have been used but with an increased risk of GVHD. To reduce this risk, we performed depletion of alpha beta T-cells and treated 12 patients post-HSCT suffering from infections and/or poor immune reconstitution. The alpha beta T-cell depleted cell products were characterized by flow cytometry. The median log depletion of alpha beta T-cells was -4.3 and the median yield of gamma delta T-cells was 73.5%. The median CD34+ cell dose was 4.4 x 10(6)/kg. All 12 patients were alive 3 months after infusion and after 1 year, two patients had died. No infusion-related side effects were reported and no severe acute GVHD (grade III-IV) developed in any patient post-infusion. Overall, 3 months after infusion 11 out of 12 patients had increased levels of platelets and/or granulocytes. In conclusion, we describe the use of alpha beta T-cell depleted products as stem cell boosters with encouraging results.
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| 4. |
- 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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| 5. |
- Tauriainen, Johanna, et al.
(författare)
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Single-cell characterization of in vitro migration and interaction dynamics of T cells expanded with IL-2 and IL-7
- 2015
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- T cells are pivotal in the immune defense against cancers and infectious agents. To mount an effector response against cancer cells, T cells need to migrate to the cancer-site, engage in contacts with cancer cells, and perform their effector functions. Adoptive T cell therapy is an effective strategy as treatment of complications such as relapse or opportunistic infections after hematopoietic stem cell transplantations. This requires a sufficient amount of cells that are able to expand and respond to tumor or viral antigens. The cytokines interleukin (IL)-2 and IL-7 drive T cell differentiation, proliferation, and survival and are commonly used to expand T cells ex vivo. Here, we have used microchip-based live-cell imaging to follow the migration of individual T cells, their interactions with allogeneic monocytes, cell division, and apoptosis for extended periods of time; something that cannot be achieved by commonly used methods. Our data indicate that cells grown in IL-7 + IL-2 had similar migration and contact dynamics as cells grown in IL-2 alone. However, the addition of IL-7 decreased cell death creating a more viable cell population, which should be beneficial when preparing cells for immunotherapy.
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