CD16+CD56− NK Cells in the Peripheral Blood of Cord Blood Transplant Recipients: A Unique Subset of Immature NK Cells Possibly Associated with Graft-Versus-Leukemia Effect.

Abstract NK cells play a major role in the activity of graft-versus-host (GVL) effect after an HLA-mismatched stem cell transplantation. In unrelated cord blood transplantation (CBT) where there is often an HLA mismatch between the donor and recipient, NK cells may also play a vital role, though their roles have not been extensively studied. Cord blood (CB) is known to have a unique subset of NK cells characterized by a CD16+CD56− phenotype. CD16+CD56− NK cells in CB are thought to be progenitors of CD16+CD56+ NK cells because CD16+CD56− NK cells acquires CD56 expression after in vitro culture in the presence of IL-2. However, the function of this immature NK cell subset after CBT remains unknown. A marked increase in the number of CD16+CD56- NK cells in the peripheral blood of an HLA-mismatched CBT recipient with acute myeloid leukemia (AML) was recently observed. A 56-year old male, who received a reduced intensity CBT following a full relapse after allogeneic stem cell transplantation from an HLA-matched sibling donor, showed an increase in the copy number of WT-1 mRNA in the peripheral blood around day 80 after the CBT, but the WT-1 copy number decreased from 1500/microliter RNA to 230/microliter RNA in association with the increase in the number of CD16+CD56- NK cells, and his molecular remission lasted more than 1.5 years thereafter. This case prompted an investigation of CD16+CD56− NK cells in the peripheral blood after allogeneic stem cell transplantation. A similar increase in the proportion of CD16+CD56− NK cells (20% or more) in the peripheral blood CD16+ NK cells was observed in 64% (7/11) of CBT recipients, all of whom maintained remission, but in none of the 11 bone marrow and 8 peripheral blood stem cell transplant recipients examined (Figure 1). CD16+CD56− NK cells in CBT recipients expressed receptors specific to NK cells such as NKp30 and NKp46 same level as CD16+CD56− NK cells of fresh CB cells. CD16+CD56− NK cells isolated from CBT recipients became CD56+ when they were cultured in the presence of IL-2 with or without K562-mb15-4-1BBL. When cultured NK cells derived from the CD16+CD56− NK cells were separated into CD158b+ and CD158b− cells, CD158b+ cells failed to kill 721–221 cells transfected with HLA-C*0301 while they killed untransfected or HLA-C*0401-transfected 221 cells. Despite the presence of the corresponding KIR ligand (C*0304), cultured CD16+CD56− NK cells showed cytotoxicity against the patient’s leukemic cells. These findings suggest that an increase in the proportion of CD16+CD56− NK cells is unique to recipients of CBT and that this immature NK-cell subset in CBT recipients may undergo differentiation into mature NK cells in vivo capable of killing residual leukemic cells, thereby contributing to the GVL effect regardless of the presence of the KIR ligand. Figure 1 Flow cytometric analysis of CD3-CD16+CD56-cells in peripheral blood of SCT recipients and healthy individual.Examples of three-flourescence cytofluorometric analysis of fresh isolated PBMC stained with CD3,CD56 and CD16 in different SCT patients and health individuals. The characterization of the unusual CD56-CD16+ cell subset expend only in the CBT individual(a). Presenting cellware gated on CD3-cells Figure 1. Flow cytometric analysis of CD3-CD16+CD56-cells in peripheral blood of SCT recipients and healthy individual.Examples of three-flourescence cytofluorometric analysis of fresh isolated PBMC stained with CD3,CD56 and CD16 in different SCT patients and health individuals. The characterization of the unusual CD56-CD16+ cell subset expend only in the CBT individual(a). Presenting cellware gated on CD3-cells

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The Studies on the T-Cell Receptor Repertoire Diversity and Flow Cytometric Analysis in a Patient with MAS/HPS after Unrelated Peripheral Blood Stem Cell Transplantation.

Blood ◽

10.1182/blood.v110.11.4970.4970 ◽

2007 ◽

Vol 110 (11) ◽

pp. 4970-4970

Author(s):

Xin Du ◽

Yangqiu Li ◽

Suxia Geng ◽

Jianyu Weng ◽

Zesheng Lu ◽

...

Keyword(s):

T Cells ◽

Stem Cell ◽

Stem Cell Transplantation ◽

Cell Transplantation ◽

Peripheral Blood ◽

Peripheral Blood Stem Cell ◽

Nk Cell ◽

Flow Cytometric Analysis ◽

Blood Stem Cell ◽

Flow Cytometric

Abstract Macrophage activation syndrome (MAS) /Hemophagocytic syndrome (HPS) is characterized by proliferation of activated macrophages under conditions such as infection(C Clin Infect Dis 2004)lymphoma(Aouba A Am J Hematol 2004), autoimmune disease(Kaneko K Clin Rheumatol 2005), solid organ transplantation(Akamatsu N,Transplant Proc 2006;). There have been several reports of MAS /HPS after hematopoietic stem cell transplantation, involving not only allogeneic,but also autologous transplantation(Sreedharan A Bone Marrow Transplantation,2006). Generally, MAS /HPS is a cytokine-related disorder.But at present, its clinical characteristics remain unknown. We firstly study here the T-cell receptor repertoire diversity and flow cytometric analysis in MAS /HPS after unrelated peripheral blood stem cell transplantation. The CDR3 of TCR Vα and Vβ subfamily genes were amplified in peripheral blood mononuclear cells from the patient with MAS/HPS after unrelated peripheral blood stem cell using RT-PCR for detection of the distribution of TCR Vα and Vβ repertoire, the PCR products were further analyzed by genescan technique for the CDR3 size, to evaluating clonality of the detectable TCR Vα and VβT cells. Lymphocyte subsets in the peripheral blood were detected by monoclone antibody and flow cytometry including T lymphocyte subsets and NK cells. Flow-cytometric analysis showed CD56+ CD16+ cell 68.65% and CD3+ cell 11.79% in the lymphocyte population;CD16+CD69+ cell 68.51% and CD25+CD16+ cell 31.59% in NK cell. In the T lymphocytic subsets, CD25 + CD3+ cell 62%; CD69+CD3+ cell 75.81%; CD25CD4+ cell 0.81%,CD25CD8+ cell 3.48%; CD69CD4+ cell 0.31%, CD69+CD8+ cell 16.86%.The results show that the main activated lymphocytes is NK cell in patient at diagnosed with MAS/HPS. Of interest, it was only after the addition of high-dose IVIG 1g/kg/d for two days (Ostronoff et al BMT2006) to the treatment that MAS remitted. There are 23 Vα and 15Vβ subfamily T cells could be identified in this time, and the clonal expansion T cells could be found in TCR Vα5, 13, 20; TCR Vβ4, 11, 15 and 21subfamilies. Billiau et al (Blood 2005)describes the immunohistochemical findings on liver tissues from 5 children with MAS in the context of a different type of hemophagocytic syndrome (HPS) in liver transplantation. This study is the first directly to substantiates the presumed immunopathogenesis of MAS by documenting in situ expression of IFN-γ+ by activated CD8+ lymphocytes, and of IL-6 and TNF-α+ by hemophagocytosing macrophages, on liver tissues of patients with MAS. We found no evidence of potential infectious, autoimmune or malignant triggers of R-HPS in our patient, despite extensive investigations. We conclued that the skew distribution and clonal expansion of TCR Vα and Vβ subfamily T cells underscore the primary role of T cells in the pathogenesis of MAS/HPS.

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NK Cytotoxicity Is Decreased During the Early Posttransplant Period Following Pediatric Allogeneic Transplantation From Unrelated Donors Using CD3/CD19-Depleted Graft.

Blood ◽

10.1182/blood.v114.22.2434.2434 ◽

2009 ◽

Vol 114 (22) ◽

pp. 2434-2434

Author(s):

Antonio Pérez-Martínez ◽

Manuel Ramírez ◽

María Ruiz-Salmerón ◽

Marta Gonzalez-Vicent ◽

S. Grande ◽

...

Keyword(s):

Stem Cell ◽

Stem Cell Transplantation ◽

Nk Cells ◽

Cell Transplantation ◽

Nk Cell ◽

Cell Subset ◽

Median Number ◽

Hematopoietic Stem ◽

Unrelated Donors ◽

Nk Cytotoxicity

Abstract Abstract 2434 Poster Board II-411 Introduction and objectives: Unrelated donors, match unrelated (MUD) and haploidentical donors (HSCT), have been described as a therapeutic option for high-risk childhood acute leukemia. CD3/CD19 depleted graft has been used in order to decrease the incidence of graft versus host disease (GvHD) and post-transplant lymphoproliferative disease, in the unrelated transplantation setting. Donor-derived NK cell alloreactivity has been reported to mediate early graft-versus-leukemia (GvL) effect after allogeneic hematopoietic stem cell transplantation. NK cells are components of the innate immunity playing an important role in the surveillance of human tumors. NK cell recognition of malignant cells depends on a dynamic balance between activating and inhibitory receptors. NK cell alloreactivity can be predicted by donor Killer Immunoglobulin like Receptors (KIRs), Natural Killer Receptors (NCRs), C-type Lectin receptors (NKG2D), Toll Like Receptors (TLRs) and recipient human leukocyte antigen (HLA) class I alleles as ligands. Reduced risk of relapsed has been described in malignant cancer after haploidentical stem cell transplantation when HLA ligands against the inhibitory KIRs present in the donor were absent in the recipient (KIR–HLA receptor–ligand mismatch). We prospectively investigated NK function and NK reconstitution in 18 CD3/CD19 depleted graft unrelated hematopoietic stem cell transplantation (7 MUD and 11 HSCT) using fludarabine-based reduced intensity conditioning regimen. Results: NK cells peaked around day 30 after transplantation. The median number of NK cells on day +30 was 403±88/μL . On day 100 after transplantation the median number of NK cells/μL was 221±58. While the CD56bright NK cell subset was above normal during the first 100 days post-transplant, the “effector” NK cell subset, CD56dim CD16bright, was significantly reduced early after transplantation. The median percentage of CD56bright cells among NK cells in peripheral blood was 25.8±4.6% at day +30, and it was 24.5±5.7 at day +100. The decreased in CD56dim CD16bright NK cell subset was correlated with the decreased of the inhibitory KIR receptors (KIR2DL1, KIR2DL2, KIR3DL1) expression. We also observed a lower expression than donors of the activating receptors NKG2D, TLR4 at day +30, NKp46, TLR 9 at day 60 and NKp46, NKp30 at day +100. Although absolute NK-cell counts rapidly increased after transplant, their cytotoxicity against K562 was much lower compared to that of their donors. At day 100 after transplantation, patients NK cytotoxicity was lower than donor values. These results suggest that the low NK cell cytotoxicity could be related to an “immature” NK phenotype during the early period after HSCT. As other authors have published, activating receptors can be significantly upregulated in cytokine-stimulated NK cells. In our experience, overnight incubation with IL-15 overcomes this limitation, enhancing three times NK cytotoxicity, in vitro. Conclusion: The phenotype of NK cells and NK cytotoxicity ability are significantly altered early after allogeneic transplantation from unrelated donors using CD3/CD19-depleted graft. NK repertoire observed in patients was associated with the imbalance between CD56bright and CD56dim NK subsets and the expression of KIRs and NCRs. These data suggest a pattern consistent with an ongoing NK maturation after MUD and HSCT transplantation. In our experience, the phenotype and functional pattern of NK cells observed is suggestive of a cytokine-driven process. IL-15 stimulated NK cells could be helpful to optimize adoptive antitumor NK immunotherapy to enhance GvL effect as early as possible after transplantation. Disclosures: No relevant conflicts of interest to declare.

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Treatment of Myeloid and Lymphoid Malignancies with Highly Purified Alloreactive CD56+CD3− NK-Cells and Haploidentical Stem Cell Transplantation: Promising Results of a Phase I Study.

Blood ◽

10.1182/blood.v106.11.2906.2906 ◽

2005 ◽

Vol 106 (11) ◽

pp. 2906-2906 ◽

Cited By ~ 1

Author(s):

Chiara Gentilini ◽

Urte Hilbers ◽

Goetz Hartung ◽

Thoralf Lange ◽

Constanze Kliem ◽

...

Keyword(s):

Stem Cell ◽

Stem Cell Transplantation ◽

Nk Cells ◽

Cell Transplantation ◽

Nk Cell ◽

Good Condition ◽

Leukemic Cells ◽

Hematopoietic Stem ◽

Technical Problems

Abstract NK cell alloreactivity can mediate strong graft versus leukemia (GvL) effects following haploidentical hematopoietic stem cell transplantation (HSCT). In an attempt to further improve the antileukemic effectiveness of this approach, we have adoptively transferred high numbers of alloreactive donor NK cells during the early phase after transplantation. Method: In a phase-II study, 10 patients (6 AML, 1 MDS, 1 HD, 1 CML, 1 ALL, median age 38 yrs, range 17–48 yrs) were transplanted in late phases of their disease (5 pts. as 2nd transplantation) and received purified NK cells from their haploidentical donors at day +2 after HSCT. Conditioning consisted of 12 Gy fTBI, Thiotepa (10mg/kg), Fludarabine (5 x 30 mg/qm) and OKT3 (day −4 to +2). Two patients received a reduced conditioning with Fludarabine and OKT3 alone. NK cells were isolated from the CD34- fraction using an automated two-step procedure of CD3+ depletion and subsequent CD56+ selection. Results: No severe technical problems occurred and a mean of 12,1 x 10E8 (16,74 x10E6/kg, range 6,12 to 27,2 x10E6/kg) CD34+ cells was selected in high purity (95,9 %) with a very low T-cell content (mean 1,83 x10E4/kg CD3+ cells, 4,5 Log depletion). A mean of 5,7 x10E8 (6,7 x 10E6/kg) CD56+CD3− NK cells was transferred (yield 70,36%, purity 70%). The mean number of contaminating CD3+ cells was 3,2 x10E4/kg (3,6 Log depletion).No severe acute toxicity attributable to NK cell infusion was observed. Hematopoietic recovery was fast with leukocytes > 1/nl between day 5 and 11. Seven patients developed early grade II GvHD of the skin which promptly resolved after CSA and steroids. One patient developed late graft rejection five months after reduced conditioning, received a 2nd graft from a different donor, engrafted but unfortunately died due to pneumonia one month after the second transplantation. One pt with CML died due to adenovirus infection at day 140. One pt. with HD in 5th CR died due to pneumonia at day 85. One patient showed a relapse of the AML three months after transplant. She received a DLI with NK cells form the donor but died due to disease progression one month after. Interestingly, leukemic cells from this patient proved to be resistant to donor NK cell mediated lysis. Five of 9 patients are alive and in CCR with a median follow up of 192 days, the two patients with the longest follow up are in very good condition and free of GvHD at day +1271 and +1019. Our data show for the first time that the early adoptive transfer of high numbers of HLA-mismatched NK cells is safe and feasible.

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Human NK Cells in Autologous Hematopoietic Stem Cell Transplantation for Cancer Treatment

Cancers ◽

10.3390/cancers13071589 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1589

Author(s):

Ane Orrantia ◽

Iñigo Terrén ◽

Gabirel Astarloa-Pando ◽

Olatz Zenarruzabeitia ◽

Francisco Borrego

Keyword(s):

Stem Cell ◽

Hematopoietic Stem Cell Transplantation ◽

Stem Cell Transplantation ◽

Nk Cells ◽

Cell Transplantation ◽

Hematopoietic Stem Cell ◽

Cell Biology ◽

Nk Cell ◽

Hematopoietic Stem ◽

Autologous Hsct

Natural killer (NK) cells are phenotypically and functionally diverse lymphocytes with the ability to recognize and kill malignant cells without prior sensitization, and therefore, they have a relevant role in tumor immunosurveillance. NK cells constitute the main lymphocyte subset in peripheral blood in the first week after hematopoietic stem cell transplantation (HSCT). Although the role that NK cells play in allogenic HSCT settings has been documented for years, their significance and beneficial effects associated with the outcome after autologous HSCT are less recognized. In this review, we have summarized fundamental aspects of NK cell biology, such as, NK cell subset diversity, their effector functions, and differentiation. Moreover, we have reviewed the factors that affect autologous HSCT outcome, with particular attention to the role played by NK cells and their receptor repertoire in this regard.

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Donor and host coexpressing KIR ligands promote NK education after allogeneic hematopoietic stem cell transplantation

Blood Advances ◽

10.1182/bloodadvances.2019000242 ◽

2019 ◽

Vol 3 (24) ◽

pp. 4312-4325 ◽

Cited By ~ 4

Author(s):

Xiang-Yu Zhao ◽

Xing-Xing Yu ◽

Zheng-Li Xu ◽

Xun-Hong Cao ◽

Ming-Rui Huo ◽

...

Keyword(s):

Stem Cell ◽

Hematopoietic Stem Cell Transplantation ◽

Stem Cell Transplantation ◽

Nk Cells ◽

Cell Transplantation ◽

Hematopoietic Stem Cell ◽

Nk Cell ◽

K562 Cells ◽

Inhibitory Receptors ◽

Hematopoietic Stem

Abstract The rate and extent of natural killer (NK)–cell education after hematopoietic cell transplantation correlates with leukemia control. To study the effect of donor and host HLA on NK-cell reconstitution, single killer-cell immunoglobulin-like receptor (KIR)+ NK cells (exhibiting KIR2DL1, KIR2DL2/KIR2DL3, or KIR3DL1 as their sole receptor) were grouped into 4 groups based on the interaction between donor/host HLA and donor inhibitory KIR in 2 cohorts (n = 114 and n = 276, respectively). On days 90 to 180 after transplantation, the absolute number and responsiveness against K562 cells (CD107a or interferon-γ expression) of single-KIR+ NK cells were higher in pairs where donor and host HLA both expressed ligands for donor inhibitory KIRs than in pairs where 1 or both of the donor and recipient HLA lacked at least 1 KIR ligand. NK-cell responsiveness was tuned commensurate with the number of inhibitory receptors from the donor. When both donor and host expressed the 3 major KIR ligands (HLA-C1, HLA-C2, and HLA-Bw4), NK cells expressing 3 inhibitory receptors (KIR2DL1/2DL3/3DL1) reached the maximum responsiveness against K562 cells compared with those NK cells expressing only 1 or 2 inhibitory receptors. When donor and host HLA both expressed all ligands for donor inhibitory KIRs, patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) showed the lowest recurrence rate after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). In conclusion, this study demonstrates that when both donors and hosts present all the KIR ligands for donor KIRs, reconstituted NK cells achieve better functional education and contribute to least relapse among patients. This observation study was registered at www.clinicaltrials.gov as #NCT02978274.

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IL-2 and Anti-TGF-β Promote NK Cell Reconstitution and Anti-tumor Effects after Syngeneic Hematopoietic Stem Cell Transplantation

Cancers ◽

10.3390/cancers12113189 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3189 ◽

Cited By ~ 1

Author(s):

Maite Alvarez ◽

Cordelia Dunai ◽

Lam T. Khuat ◽

Ethan G. Aguilar ◽

Isabel Barao ◽

...

Keyword(s):

Stem Cell ◽

Hematopoietic Stem Cell Transplantation ◽

Stem Cell Transplantation ◽

Nk Cells ◽

Cell Transplantation ◽

Hematopoietic Stem Cell ◽

Immune Cells ◽

Nk Cell ◽

Continuous Treatment ◽

Hematopoietic Stem

The failure of autologous hematopoietic stem cell transplantation (HSCT) has been associated with a profound immunodeficiency that follows shortly after treatment, which renders patients susceptible to opportunistic infections and/or cancer relapse. Thus, given the additional immunosuppressive pathways involved in immune evasion in cancer, strategies that induce a faster reconstitution of key immune effector cells are needed. Natural killer (NK) cells mediate potent anti-tumor effector functions and are the first immune cells to repopulate after HSCT. TGF-β is a potent immunosuppressive cytokine that can impede both the development and function of immune cells. Here, we evaluated the use of an immunotherapeutic regimen that combines low dose of IL-2, an NK cell stimulatory signal, with TGF-β neutralization, in order to accelerate NK cell reconstitution following congenic HSCT in mice by providing stimulatory signals yet also abrogating inhibitory ones. This therapy led to a marked expansion of NK cells and accelerated NK cell maturation. Following HSCT, mature NK cells from the treated recipients displayed an activated phenotype and enhanced anti-tumor responses both in vitro and in vivo. No overt toxicities or adverse effects were observed in the treated recipients. However, these stimulatory effects on NK cell recovery were predicated upon continuous treatment as cessation of treatment led to return to baseline levels and to no improvement of overall immune recovery when assessed at later time-points, indicating strict regulatory control of the NK cell compartment. Overall, this study still demonstrates that therapies that combine positive and negative signals can be plausible strategies to accelerate NK cell reconstitution following HSCT and augment anti-tumor efficacy.

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Mobilization with cyclophosphamide reduces the number of lymphocyte subpopulations in the leukapheresis product and delays their reconstitution after autologous hematopoietic stem cell transplantation in patients with multiple myeloma

Radiology and Oncology ◽

10.1515/raon-2016-0028 ◽

2016 ◽

Vol 50 (4) ◽

pp. 402-408 ◽

Cited By ~ 1

Author(s):

Matevz Skerget ◽

Barbara Skopec ◽

Darja Zontar ◽

Peter Cernelc

Keyword(s):

Stem Cell ◽

Hematopoietic Stem Cell Transplantation ◽

Stem Cell Transplantation ◽

Nk Cells ◽

Cell Transplantation ◽

Hematopoietic Stem Cell ◽

T Regulatory Cells ◽

Nk Cell ◽

Hematopoietic Stem ◽

Cell Counts

Abstract Background Autologous hematopoietic stem cell transplantation is considered the standard of care for younger patients with multiple myeloma. Several mobilization regimens are currently used, most commonly growth factors alone or in combination with chemotherapy. The aim of our study was to investigate the differences in lymphocyte subpopulation counts between three different mobilization regimens on collection day, in the leukapheresis product and on day 15 after autologous hematopoietic stem cell transplantation. Patients and methods In total 48 patients were prospectively enrolled in three different mobilization regimens; (i) filgrastim (20), (ii) pegfilgrastim (19) and (iii) cyclophosphamide + filgrastim (9). Lymphocytes, CD16+/56+ natural killer and CD4+/CD25high T regulatory cells were determined by flow cytometry. Results We found a statistically significant difference between the mobilization regimens. Cyclophosphamide reduced lymphocyte and natural killer (NK) cell counts on collection day (lymphocytes 1.08 × 109/L; NK cells 0.07 × 109/L) compared to filgrastim (lymphocytes 3.08 × 109/L; NK cells 0.52 × 109/L) and pegfilgrastim (lymphocytes 3 × 109/L; NK cells 0.42 × 109/L). As a consequence lymphocyte and NK cell counts were also lower in the leukapheresis products following cyclophosphamide mobilization regimen (lymphocytes 50.1 × 109/L; NK cells 4.18 × 109/L) compared to filgrastim (lymphocytes 112 × 109/L; NK cells 17.5 × 109/L) and pegfilgrastim (lymphocytes 112 × 109/L; NK cells 14.3 × 109/L). In all mobilization regimens T regulatory cells increased 2-fold on collection day, regarding the base line value before mobilization. There was no difference in T regulatory cell counts between the regimens. Conclusions Mobilization with cyclophophamide reduces the number of mobilized and collected lymphocytes and NK cells as compared to mobilization with growth factors only and results in their delayed reconstitution following autologous hematopoietic stem cell transplantation. We found no difference between filgrastim and pegfilgrastim mobilization.

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Dynamic Changes of Inhibitory Killer-Immunoglobulin-Like Receptors on NK Cells after Allogeneic Hematopoietic Stem Cell Transplantation: An Initial Study

Journal of Clinical Medicine ◽

10.3390/jcm9113502 ◽

2020 ◽

Vol 9 (11) ◽

pp. 3502

Author(s):

Tereza Dekojová ◽

Lucie Houdová ◽

Jiří Fatka ◽

Pavel Pitule ◽

Pavel Ostašov ◽

...

Keyword(s):

Stem Cell ◽

Hematopoietic Stem Cell Transplantation ◽

Stem Cell Transplantation ◽

Nk Cells ◽

Cell Transplantation ◽

Hematopoietic Stem Cell ◽

Nk Cell ◽

Ex Vivo ◽

Post Transplantation ◽

Hematopoietic Stem

Killer-immunoglobulin-like receptors (KIRs) are critical natural killer (NK) cell regulators. The expression of KIRs is a dynamic process influenced by many factors. Their ligands—HLA(Human Leukocyte Antigen) class I molecules—are expressed on all nucleated cells that keep NK cells under control. In hematopoietic stem cell transplantation (HSCT), NK cells play an essential role in relapse protection. In the presented pilot study, we characterized the dynamic expression of inhibitory KIRS (iKIRs), which protect cells against untoward lysis, in donors and patients during the first three months after HSCT using flow cytometry. The expression of all iKIRs was highly variable and sometimes correlated with patients’ clinical presentation and therapy regiment. Cyclophosphamide (Cy) in the graft-versus-host disease (GvHD) prevention protocol downregulated KIR2DL1 to just 25% of the original donor value, and the FEAM (Fludarabine + Etoposid + Ara-C + Melphalan) conditioning protocol reduced KIR2DL3. In lymphoid neoplasms, there was a slightly increased KIR2DL3 expression compared to myeloid malignancies. Additionally, we showed that the ex vivo activation of NK cells did not alter the level of iKIRs. Our study shows the influence of pre- and post-transplantation protocols on iKIR expression on the surface of NK cells and the importance of monitoring their cell surface.

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Granulocyte Colony-Stimulating Factor Effectively Mobilizes TCR γδ and NK Cells Providing an Allograft Potentially Enhanced for the Graft-Versus-Leukemia Effect for Allogeneic Stem Cell Transplantation

Frontiers in Immunology ◽

10.3389/fimmu.2021.625165 ◽

2021 ◽

Vol 12 ◽

Author(s):

Lia Minculescu ◽

Henrik Sengelov ◽

Hanne Vibeke Marquart ◽

Lars Peter Ryder ◽

Anne Fischer-Nielsen ◽

...

Keyword(s):

T Cells ◽

Stem Cell ◽

Stem Cell Transplantation ◽

Nk Cells ◽

Peripheral Blood ◽

Nk Cell ◽

Cell Compartment ◽

Effector Cells ◽

Graft Versus Leukemia ◽

Hla Dr

Allogeneic hematopoietic stem cell transplantation (HSCT) is a potential cure for patients with hematological malignancies but substantial risks of recurrence of the malignant disease remain. TCR γδ and NK cells are perceived as potent innate effector cells in HSCT and have been associated with post-transplant protection from relapse in clinical studies. Immunocompetent cells from the donor are crucial for patient outcomes and peripheral blood stem cells (PBSC) are being increasingly applied as graft source. G-CSF is the preferential mobilizing agent in healthy donors for PBSC grafts, yet effects of G-CSF on TCR γδ and NK cells are scarcely uncovered and could influence the graft composition and potency of these cells. Therefore, we analyzed T and NK cell subsets and activation markers in peripheral blood samples of 49 donors before and after G-CSF mobilization and—for a subset of donors—also in the corresponding graft samples using multicolor flowcytometry with staining for CD3, CD4, CD8, TCRαβ, TCRγδ, Vδ1, Vδ2, HLA-DR, CD45RA, CD197, CD45RO, HLA-DR, CD16, CD56, and CD314. We found that TCR γδ cells were mobilized and harvested with an efficiency corresponding that of TCR αβ cells. For TCR γδ as well as for TCR αβ cells, G-CSF preferentially mobilized naïve and terminally differentiated effector (TEMRA) cells over memory cells. In the TCR γδ cell compartment, G-CSF preferentially mobilized cells of the nonVδ2 types and increased the fraction of HLA-DR positive TCR γδ cells. For NK cells, mobilization by G-CSF was increased compared to that of T cells, yet NK cells appeared to be less efficiently harvested than T cells. In the NK cell compartment, G-CSF-stimulation preserved the proportion of CD56dim NK effector cells which have been associated with relapse protection. The expression of the activating receptor NKG2D implied in anti-leukemic responses, was significantly increased in both CD56dim and CD56bright NK cells after G-CSF stimulation. These results indicate differentiated mobilization and altering properties of G-CSF which could improve the effects of donor TCR γδ and NK cells in the processes of graft-versus-leukemia for relapse prevention after HSCT.

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NK Cell Reconstitution After Autologous Hematopoietic Stem Cell Transplantation: Association Between NK Cell Maturation Stage and Outcome in Multiple Myeloma

Frontiers in Immunology ◽

10.3389/fimmu.2021.748207 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ane Orrantia ◽

Iñigo Terrén ◽

Gabirel Astarloa-Pando ◽

Carmen González ◽

Alasne Uranga ◽

...

Keyword(s):

Multiple Myeloma ◽

Stem Cell ◽

Hematopoietic Stem Cell Transplantation ◽

Stem Cell Transplantation ◽

Nk Cells ◽

Cell Transplantation ◽

Hematopoietic Stem Cell ◽

Nk Cell ◽

Cell Maturation ◽

Hematopoietic Stem

Autologous hematopoietic stem cell transplantation (autoHSCT) is a standard of care for transplant-eligible patients with multiple myeloma (MM). Among factors that influence outcome after autoHSCT, it has been suggested that the number of natural killer (NK) cells plays an important role. However, the impact that different NK cell subsets and their phenotype could have in disease progression after autoHSCT are less clear. For this reason, we have phenotypically and functionally characterized NK cells during immune system reconstitution after autoHSCT in 54 MM patients. Shortly after leukocyte recovery, an extensive redistribution of NK cell subsets occurs in these patients. In addition, NK cells undergo a profound phenotypic change characterized, among others, by their increased proliferative capacity and immature phenotype. Importantly, MM patients who showed lower frequencies of the mature highly differentiated NKG2A-CD57+ NK cell subset at +30 and +100 days after autoHSCT experienced superior progression-free survival and had a longer time to the next treatment than those with higher frequencies. Our results provide significant insights into NK cell reconstitution after autoHSCT and suggest that the degree of NK cell maturation after autoHSCT affects the clinical outcome of MM patients treated with this therapeutic strategy.

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