scholarly journals NK cells expressing inhibitory KIR for non–self-ligands remain tolerant in HLA-matched sibling stem cell transplantation

Blood ◽  
2010 ◽  
Vol 115 (13) ◽  
pp. 2686-2694 ◽  
Author(s):  
Andreas T. Björklund ◽  
Marie Schaffer ◽  
Cyril Fauriat ◽  
Olle Ringdén ◽  
Mats Remberger ◽  
...  

Abstract Natural killer (NK)–cell alloreactivity in recipients of hematopoietic stem cell grafts from HLA-identical siblings is intriguing and has suggested breaking of NK-cell tolerance during the posttransplantation period. To examine this possibility, we analyzed clinical outcomes in a cohort of 105 patients with myeloid malignancies who received T cell–replete grafts from HLA-matched sibling donors. Presence of inhibitory killer cell immunoglobulin-like receptors (KIRs) for nonself HLA class I ligands had no effect on disease-free survival, incidence of relapse, or graft-versus-host disease. A longitudinal analysis of the NK-cell repertoire and function revealed a global hyporesponsiveness of NK cells early after transplantation. Functional responses recovered at approximately 6 months after transplantation. Importantly, NKG2A− NK cells expressing KIRs for nonself HLA class I ligands remained tolerant at all time points. Furthermore, a direct comparison of NK-cell reconstitution in T cell–replete and T cell–depleted HLA-matched sibling stem cell transplantation (SCT) revealed that NKG2A+ NK cells dominated the functional repertoire early after transplantation, with intact tolerance of NKG2A− NK cells expressing KIRs for nonself ligands in both settings. Our results provide evidence against the emergence of alloreactive NK cells in HLA-identical allogeneic SCT.

Blood ◽  
2011 ◽  
Vol 117 (3) ◽  
pp. 764-771 ◽  
Author(s):  
Lorenzo Moretta ◽  
Franco Locatelli ◽  
Daniela Pende ◽  
Emanuela Marcenaro ◽  
Maria Cristina Mingari ◽  
...  

Abstract Natural killer (NK) cells are key members of the innate immune system. In a self-environment, they sense and kill target cells lacking major histocompatibility complex class I molecules and release various cytokines on activation. The discovery of human leukocyte antigen (HLA) class I specific inhibitory receptors (including the allotype-specific killer immunoglobulin-like receptors), and of various activating receptors and their ligands, provided the basis for understanding the molecular mechanism of NK-cell activation and function, mainly resulting from the balance between activating and inhibitory signals. In an allogeneic setting, such as T cell–depleted haploidentical hematopoietic stem cell transplantation, NK cells may express inhibitory killer immunoglobulin-like receptors that are not engaged by any of the HLA class I alleles present on allogeneic cells. Such “alloreactive” NK cells greatly contribute both to eradication of leukemia blasts escaping the preparative regimen and to clearance of residual host dendritic cells and T lymphocytes (thus preventing graft-versus-host disease and graft rejection, respectively). Improved prevention of graft-versus-host disease might be achieved by redirecting to lymph nodes adoptively transferred, alloreactive NK cells by inducing CCR7-uptake in vitro. Recent studies suggested that, after immune-suppressive therapy, alloreactive NK cells from an HLA-haploidentical donor may prevent leukemia recurrence also in patients who have not received allogeneic hematopoietic stem cell transplantation.


2019 ◽  
Vol 8 (11) ◽  
pp. 1904 ◽  
Author(s):  
Helena Stabile ◽  
Paolo Nisti ◽  
Cinzia Fionda ◽  
Daria Pagliara ◽  
Stefania Gaspari ◽  
...  

T-cell-depleted (TCD) human leukocyte antigen (HLA) haploidentical (haplo) hematopoietic stem cell transplantation (HSCT) (TCD-haplo-HSCT) has had a huge impact on the treatment of many haematological diseases. The adoptive transfer of a titrated number of T cells genetically modified with a gene suicide can improve immune reconstitution and represents an interesting strategy to enhance the success of haplo-HSCT. Natural killer (NK) cells are the first donor-derived lymphocyte population to reconstitute following transplantation, and play a pivotal role in mediating graft-versus-leukaemia (GvL). We recently described a CD56lowCD16low NK cell subset that mediates both cytotoxic activity and cytokine production. Given the multifunctional properties of this subset, we studied its functional recovery in a cohort of children given α/βT-cell-depleted haplo-HSCT followed by the infusion of a titrated number of iCasp-9-modified T cells (iCasp-9 HSCT). The data obtained indicate that multifunctional CD56lowCD16low NK cell frequency is similar to that of healthy donors (HD) at all time points analysed, showing enrichment in the bone marrow (BM). Interestingly, with regard to functional acquisition, we identified two groups of patients, namely those whose NK cells did (responder) or did not (non responder) degranulate or produce cytokines. Moreover, in patients analysed for both functions, we observed that the acquisition of degranulation capacity was not associated with the ability to produce interferon-gamma (IFN-γ Intriguingly, we found a higher BM and peripheral blood (PB) frequency of iCas9 donor T cells only in patients characterized by the ability of CD56lowCD16low NK cells to degranulate. Collectively, these findings suggest that donor iCasp9-T lymphocytes do not have a significant influence on NK cell reconstitution, even if they may positively affect the acquisition of target-induced degranulation of CD56lowCD16low NK cells in the T-cell-depleted haplo-HSC transplanted patients.


Hematology ◽  
2016 ◽  
Vol 2016 (1) ◽  
pp. 106-118 ◽  
Author(s):  
Rohtesh S. Mehta ◽  
Katayoun Rezvani

Abstract Natural killer (NK) cell function is regulated by a fine balance between numerous activating and inhibitory receptors, of which killer-cell immunoglobulin-like receptors (KIRs) are among the most polymorphic and comprehensively studied. KIRs allow NK cells to recognize downregulation or the absence of HLA class I molecules on target cells (known as missing-self), a phenomenon that is commonly observed in virally infected cells or cancer cells. Because KIR and HLA genes are located on different chromosomes, in an allogeneic environment such as after hematopoietic stem cell transplantation, donor NK cells that express an inhibitory KIR for an HLA class I molecule that is absent on recipient targets (KIR/KIR-ligand mismatch), can recognize and react to this missing self and mediate cytotoxicity. Accumulating data indicate that epistatic interactions between KIR and HLA influence outcomes in several clinical conditions. Herein, we discuss the genetic and functional features of KIR/KIR-ligand interactions in hematopoietic stem cell transplantation and how these data can guide donor selection. We will also review clinical studies of adoptive NK cell therapy in leukemia and emerging data on the use of genetically modified NK cells that could broaden the scope of cancer immunotherapy.


Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1589
Author(s):  
Ane Orrantia ◽  
Iñigo Terrén ◽  
Gabirel Astarloa-Pando ◽  
Olatz Zenarruzabeitia ◽  
Francisco Borrego

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.


2019 ◽  
Vol 3 (24) ◽  
pp. 4312-4325 ◽  
Author(s):  
Xiang-Yu Zhao ◽  
Xing-Xing Yu ◽  
Zheng-Li Xu ◽  
Xun-Hong Cao ◽  
Ming-Rui Huo ◽  
...  

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.


Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3189 ◽  
Author(s):  
Maite Alvarez ◽  
Cordelia Dunai ◽  
Lam T. Khuat ◽  
Ethan G. Aguilar ◽  
Isabel Barao ◽  
...  

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.


2016 ◽  
Vol 50 (4) ◽  
pp. 402-408 ◽  
Author(s):  
Matevz Skerget ◽  
Barbara Skopec ◽  
Darja Zontar ◽  
Peter Cernelc

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.


2020 ◽  
Vol 9 (11) ◽  
pp. 3502
Author(s):  
Tereza Dekojová ◽  
Lucie Houdová ◽  
Jiří Fatka ◽  
Pavel Pitule ◽  
Pavel Ostašov ◽  
...  

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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