Publications by authors named "Taewoong Choi"

13 Publications

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A phase 2 trial of the somatostatin analog pasireotide to prevent GI toxicity and acute GVHD in allogeneic hematopoietic stem cell transplant.

PLoS One 2021 25;16(6):e0252995. Epub 2021 Jun 25.

Division of Hematologic Malignancies and Cellular Therapy, Duke University School of Medicine, Durham, NC, United States of America.

Background: Allogeneic hematopoietic stem cell transplantation (HCT) is an often curative intent treatment, however it is associated with significant gastrointestinal (GI) toxicity and treatment related mortality. Graft-versus-host disease is a significant contributor to transplant-related mortality. We performed a phase 2 trial of the somatostatin analog pasireotide to prevent gastrointestinal toxicity and GVHD after myeloablative allogeneic HCT.

Methods: Patients received 0.9mg pasireotide every 12 hours from the day prior to conditioning through day +4 after HCT (or a maximum of 14 days). The primary outcomes were grade 3-4 gastrointestinal toxicity through day 30 and acute GVHD. Secondary outcomes were chronic GVHD, overall survival and relapse free survival at one year. Stool and blood samples were collected from before and after HCT for analyses of stool microbiome, local inflammatory markers, and systemic inflammatory and metabolic markers. Results were compared with matched controls.

Results: Twenty-six patients received pasireotide and were compared to 52 matched contemporaneous controls using a 1-2 match. Grade 3-4 GI toxicity occurred in 21 (81%) patients who received pasireotide and 35 (67%) controls (p = 0.33). Acute GVHD occurred in 15 (58%) patients in the pasireotide group and 28 (54%) controls (p = 0.94). Chronic GVHD occurred in 16 patients in the pasireotide group (64%) versus 22 patients in the control group (42%) (p = 0.12). Overall survival at 1 year in the pasireotide group was 63% (95% CI: 47%,86%) versus 82% (95% CI: 72%, 93%) in controls (log-rank p = 0.006). Relapse-free survival rate at one year was 40% (95% CI: 25%, 65%) in the pasireotide group versus 78% (95% CI: 68%, 91%) in controls (log-rank p = 0.002). After controlling for the effect of relevant covariates, patients in the pasireotide group had attenuated post-HCT loss of microbial diversity. Analysis of systemic inflammatory markers and metabolomics demonstrated feasibility of such analyses in patients undergoing allogeneic HCT. Baseline level and pre-to-post transplant changes in several inflammatory markers (including MIP1a, MIP1b, TNFa, IL8Pro, and IL6) correlated with likelihood of survival.

Conclusions: Pasireotide did not prevent gastrointestinal toxicity or acute GVHD compared to contemporaneous controls. Pasireotide was associated with numerically higher chronic GVHD and significantly decreased OS and RFS compared to contemporaneous controls. Pasireotide may provide a locally protective effect in the stool microbiome and in local inflammation as measured by stool calprotectin, stool beta-defensin, and stool diversity index.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0252995PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8232534PMC
June 2021

Female Sex Is Associated with Improved Long-Term Survival Following Allogeneic Hematopoietic Stem Cell Transplantation.

Transplant Cell Ther 2021 Sep 17;27(9):784.e1-784.e7. Epub 2021 Jun 17.

Division of Hematologic Malignancies and Cellular Therapy, Duke University Medical Center, Durham, North Carolina. Electronic address:

Life expectancy for long-term survivors of allogeneic hematopoietic stem cell transplantation (alloHSCT), defined as those living ≥5 years post-transplantation, is significantly lower compared with that of the age-matched general population despite a relatively low primary disease relapse rate at >2 years post-transplantation. Among several factors, patient sex is increasingly recognized as a prognostic indicator of long-term survival. We examined the influence of patient sex and donor-recipient sex matching on overall survival (OS) in a landmark analysis of long-term survivors. Using our institutional database supplemented with individual patient record review, we retrospectively investigated the relative influence of recipient sex and donor-recipient sex matching on outcomes of long-term survivors of alloHSCT between 1994 and 2014. Over this 20-year period, 247 met inclusion criteria for analysis; males and females had similar demographic and treatment characteristics. However, significantly more deaths after the 5-year landmark occurred in male recipients. Interestingly, donor sex did not have a significant impact on OS in multivariate analysis, and differences in OS of donor-recipient sex pairs was driven by recipient sex. In addition to recipient sex, only chronic graft-versus-host disease (cGVHD) retained significance as a covariate with an impact on OS in multivariate analysis. Men experienced slightly higher, but statistically nonsignificant, rates and increased severity of cGVHD, and had higher cGVHD-related mortality compared with females. In this long-term survival analysis of adult alloHSCT recipients, one of the only to include follow-up to 15 years, our results show that women survive significantly longer than men irrespective of their age at transplantation. This outcome is independent of other common pretransplantation prognostic indicators, such as donor sex or performance status at transplantation. The inferior survival in males is consistent with survival outcomes described in the transplantation literature. Increasing evidence suggests a biological basis for long-term sex-determined outcomes, possibly owing to differing rates or severity of cGVHD or sustained alloimmune tolerance in females. Larger studies are warranted to validate these retrospective clinical results.
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http://dx.doi.org/10.1016/j.jtct.2021.06.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8403653PMC
September 2021

Decreased Mortality in 1-Year Survivors of Umbilical Cord Blood Transplant vs. Matched Related or Matched Unrelated Donor Transplant in Patients with Hematologic Malignancies.

Transplant Cell Ther 2021 08 12;27(8):669.e1-669.e8. Epub 2021 May 12.

Division of Hematologic Malignancies and Cellular Therapy, Department of Medicine, Duke University, Durham, North Carolina. Electronic address:

Allogeneic hematopoietic stem cell transplantation (HCT) has the potential to cure hematologic malignancies but is associated with significant morbidity and mortality. Although deaths during the first year after transplantation are often attributable to treatment toxicities and complications, death after the first year may be due to sequelae of accelerated aging caused by cellular senescence. Cytotoxic therapies and radiation used in cancer treatments and conditioning regimens for HCT can induce aging at the molecular level; HCT patients experience time-dependent effects, such as frailty and aging-associated diseases, more rapidly than people who have not been exposed to these treatments. Consistent with this, recipients of younger cells tend to have decreased markers of aging and improved survival, decreased graft-versus-host disease, and lower relapse rates. Given that umbilical cord blood (UCB) is the youngest donor source available, we studied the outcomes after the first year of UCB transplantation versus matched related donor (MRD) and matched unrelated donor (MUD) transplantation in patients with hematologic malignancies over a 20-year period. In this single-center, retrospective study, we examined the outcomes of all adult patients who underwent their first allogeneic HCT through the Duke Adult Bone Marrow Transplant program from January 1, 1996, to December 31, 2015, to allow for at least 3 years of follow-up. Patients were excluded if they died or were lost to follow-up before day 365 after HCT, received an allogeneic HCT for a disease other than a hematologic malignancy, or received cells from a haploidentical or mismatched adult donor. UCB recipients experienced a better unadjusted overall survival than MRD/MUD recipients (log rank P = .03, median overall survival: UCB not reached, MRD/MUD 7.4 years). After adjusting for selected covariates, UCB recipients who survived at least 1 year after HCT had a hazard of death that was 31% lower than that of MRD/MUD recipients (hazard ratio, 0.69; 95% confidence interval, 0.47-0.99; P = .049). This trend held true in a subset analysis of subjects with acute leukemia. UCB recipients also experienced lower rates of moderate or severe chronic graft-versus-host disease (GVHD) and nonrelapse mortality, and slower time to relapse. UCB and MRD/MUD recipients experienced similar rates of grade 2-4 acute GVHD, chronic GHVD, secondary malignancy, and subsequent allogeneic HCT. UCB is already widely used as a donor source in pediatric HCT; however, adult outcomes and adoption have historically lagged behind in comparison. Recent advancements in UCB transplantation such as the implementation of lower-intensity conditioning regimens, double unit transplants, and ex vivo expansion have improved early mortality, making UCB an increasingly attractive donor source for adults; furthermore, our findings suggest that UCB may actually be a preferred donor source for mitigating late effects of HCT.
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http://dx.doi.org/10.1016/j.jtct.2021.05.002DOI Listing
August 2021

Assessing the Feasibility of a Novel mHealth App in Hematopoietic Stem Cell Transplant Patients.

Transplant Cell Ther 2021 02 13;27(2):181.e1-181.e9. Epub 2020 Dec 13.

Division of Hematologic Malignancies and Cellular Therapy, Department of Medicine, Duke University Medical Center, Durham, North Carolina. Electronic address:

Hematopoietic stem cell transplantation (HCT) is a curative treatment option for patients with hematologic conditions but presents many complications that must be managed as a complex, chronic condition. Mobile health applications (mHealth apps) may permit tracking of symptoms in HCT. In seeking strategies to manage the complexities of HCT, our team collaborated with Sicklesoft, Inc., to develop an mHealth app specifically for HCT patients to allow for daily evaluation of patient health, Technology Recordings to better Understand Bone Marrow Transplantation (TRU-BMT). The primary value of this application is that of potentially enhancing the monitoring of symptoms and general health of patients undergoing HCT, with the ultimate goal of allowing earlier detection of adverse events, earlier intervention, and improving outcomes. To first evaluate patient interest in mHealth apps, we designed and administered an interest survey to patients at the 2017 BMT-InfoNet reunion. As a follow-up to the positive feedback received, we began testing the TRU-BMT app in a Phase 1 pilot study. Thirty patients were enrolled in this single-arm study and were given the TRU-BMT mHealth app on a smartphone device in addition to a wearable activity tracker. Patients were followed for up to 180 days, all the while receiving daily app monitoring. Adherence to TRU-BMT was approximately 30% daily and 44% weekly, and greater adherence was associated with increased meal completion, decreased heart rate, and shorter hospital stay. TRU-BMT assessments of symptom severity were significantly associated with duration of hospital stay and development of chronic graft-versus-host disease. Our findings suggest that using TRU-BMT throughout HCT is feasible for patients and established a proof-of-concept for a future randomized control trial of the TRU-BMT application in HCT. © 2021 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.
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http://dx.doi.org/10.1016/j.jtct.2020.10.017DOI Listing
February 2021

Chlorhexidine Gluconate Bathing Reduces the Incidence of Bloodstream Infections in Adults Undergoing Inpatient Hematopoietic Cell Transplantation.

Transplant Cell Ther 2021 03 7;27(3):262.e1-262.e11. Epub 2021 Jan 7.

Division of Hematologic Malignancies and Cellular Therapy, Duke University Medical Center, Durham, North Carolina. Electronic address:

Bloodstream infections (BSIs) occur in 20% to 45% of inpatient autologous and allogeneic hematopoietic cell transplant (HCT) patients. Daily bathing with the antiseptic chlorhexidine gluconate (CHG) has been shown to reduce the incidence of BSIs in critically ill patients, although very few studies include HCT patients or have evaluated the impact of compliance on effectiveness. We conducted a prospective cohort study with historical controls to assess the impact of CHG bathing on the rate of BSIs and gut microbiota composition among adults undergoing inpatient HCT at the Duke University Medical Center. We present 1 year of data without CHG bathing (2016) and 2 years of data when CHG was used on the HCT unit (2017 and 2018). Because not all patients adhered to CHG, patients were grouped into four categories by rate of daily CHG usage: high (>75%), medium (50% to 75%), low (1% to 49%), and none (0%). Among 192 patients, univariate trend analysis demonstrated that increased CHG usage was associated with decreased incidence of clinically significant BSI, defined as any BSI requiring treatment by the medical team (high, 8% BSI; medium, 15.2%; low, 15.6%; no CHG, 30.3%; P = .003), laboratory-confirmed BSI (LCBI; P = .03), central line-associated BSI (P = .04), and mucosal barrier injury LCBI (MBI-LCBI; P = .002). Multivariate analysis confirmed a significant effect of CHG bathing on clinically significant BSI (P = .023) and MBI-LCBI (P = .007), without consistently impacting gut microbial diversity. Benefits of CHG bathing were most pronounced with >75% daily usage, and there were no adverse effects attributable to CHG. Adherence to daily CHG bathing significantly decreases the rate of bloodstream infection following HCT.
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http://dx.doi.org/10.1016/j.jtct.2021.01.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8010223PMC
March 2021

Lipid Level, Lipid Variability, and Risk of Multiple Myeloma: A Nationwide Population-Based Study of 3,527,776 Subjects.

Cancers (Basel) 2021 Jan 31;13(3). Epub 2021 Jan 31.

Supportive Care Center/Department of Family Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.

(1) Background: There is evidence that abnormality in lipid metabolism promotes cancer development. This study investigated whether lipid level and its variability are associated with the development of MM at a population level. (2) Methods: A retrospective cohort study included a total of 3,527,776 subjects aged 40 and above who participated in ≥3 health examinations within the previous five years, including the index year (2012-2013). Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) were measured, and visit-to-visit lipid variability were calculated by variability independent of the mean (VIM) method. The study population was followed from the health examination date in the index year until the diagnosis of MM, death, or the last follow-up date (31 December 2017). (3) Results: During a median (5-95%) 5.1 years of follow-up, 969 subjects developed MM. A lower risk of MM was observed with higher quartiles of baseline lipid levels compared to the lowest quartile group (Q4 vs. Q1: adjusted hazard ratios (aHRs) 0.51, 95% confidence interval (CI) (0.42-0.61) for TC; 0.50 (0.41-0.61) for HDL-C; 0.65 (0.54-0.77) for LDL-C; and 0.72 (0.60-0.87) for TG in model (3). Among all lipid measures, only variability in HDL-C was associated with risk of MM: aHRs (95% CI) were 1.12 (0.91-1.38), 1.19 (0.97-1.46), and 1.34 (1.09-1.65) in the Q2, Q3, and Q4, respectively, compared to the Q1 of VIM of HDL-C. (4) Conclusions: This study shows that patients with lower lipid levels and high HDL-C variability are at increased risk of developing MM.
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http://dx.doi.org/10.3390/cancers13030540DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7866996PMC
January 2021

Association between high-density lipoprotein cholesterol level and risk of hematologic malignancy.

Leukemia 2021 05 2;35(5):1356-1364. Epub 2020 Dec 2.

Supportive Care Center/Department of Family Medicine, Samsung Medical Center, Seoul, Republic of Korea.

This study investigated the relationships between HDL-C and major types of blood cancers. Competing risks regression was used to examine the hazard ratios of hematologic malignancies in 9,596,145 individuals (≥20 years) using data from the Korean National Health Insurance Service (2009-2017). The incidence of the following hematologic cancers was determined based on the International Classification of Diseases 10th revision: Multiple Myeloma (MM), Hodgkin Lymphoma (HL), Non-Hodgkin Lymphoma (NHL), Lymphoid Leukemia (LL), and Myeloid Leukemia (ML). During an average of 8.3 years of follow-up (79,179,225 person-years), 15,864 incident hematologic malignancies were identified. Compared to those in the highest HDL-C quartile, subjects in the lowest HDL-C quartile had the highest risk of all hematologic cancers combined (adjusted hazard ratio [HR], 95% confidence interval [95% CI] = 1.31, 1.25-1.37) and of each respective type of blood cancer, as follows: MM (HR 1.61, 95% CI, 1.46-1.76), HL (HR 1.35, 95% CI 1.07-1.70), NHL (HR 1.12, 95%CI 1.04-1.21), LL (HR 1.36, 95% CI 1.16-1.61), and ML (HR 1.33, 95% CI 1.22-1.45). Low HDL-C level was significantly associated with increased risk of hematologic malignancy, suggesting that a low HDL-C level is an independent risk factor and preclinical marker for hematologic malignancy.
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http://dx.doi.org/10.1038/s41375-020-01081-5DOI Listing
May 2021

Clinical and Neuroimaging Correlates of Post-Transplant Delirium.

Biol Blood Marrow Transplant 2020 12 19;26(12):2323-2328. Epub 2020 Sep 19.

Department of Medicine, Division of Hematologic Malignancies and Cellular Therapy, Duke University Medical Center, Durham, North Carolina.

Delirium is common among adults undergoing hematopoietic stem cell transplantation (HCT), although the clinical and neuroimaging correlates of post-HCT delirium have not been adequately delineated. We therefore examined the frequency of delirium and neuroimaging correlates of post-transplant delirium in a retrospective cohort of 115 adults undergoing neuroimaging after allogeneic HCT. Delirium was established using previously validated methods for retrospective identification of chart-assessed postprocedural delirium. Chart reviews were independently conducted by a multidisciplinary team with expertise in HCT, psychiatry, and psychology on consecutive allogeneic HCT patients who underwent neuroimaging assessments and transplantation at a single center between January 2009 and December 2016. Neuroimaging markers of white matter damage and brain volume loss were also recorded. In total, 115 patients were included, ranging in age from 20 to 74 years (mean [SD] age, 49 [13]). Fifty-three patients (46%) developed post-HCT delirium. In an adjusted model, delirium incidence was associated with older age (odds ratio [OR], 1.92 [1.28, 2.87] per decade, P = .002), greater severity of white matter hyperintensities (OR, 1.95 [1.06, 3.57], P = .031), and conditioning intensity (OR, 6.37 [2.20, 18.45], P < .001) but was unrelated to cortical atrophy (P = .777). Delirium was associated with fewer hospital-free days (P = .023) but was not associated with overall survival (hazard ratio, 0.95 [0.56, 1.61], P = .844). Greater incidence of delirium following HCT was associated with greater age, microvascular burden, and conditioning intensity. Pre-HCT consideration of microvascular burden and other neuroimaging biomarkers of risk may be warranted.
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http://dx.doi.org/10.1016/j.bbmt.2020.09.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7977594PMC
December 2020

Pre-transplant hepatic steatosis (fatty liver) is associated with chronic graft-vs-host disease but not mortality.

PLoS One 2020 11;15(9):e0238824. Epub 2020 Sep 11.

Division of Hematologic Malignancies and Cell Therapy, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, United States of America.

Allogeneic-HCT (allo-HCT), while potentially curative, can result in significant complications including graft versus host disease (GVHD). Prior studies suggest that metabolic syndrome may be one risk factor for GVHD. We hypothesized that hepatic steatosis on pre-HCT computed tomography (CT) scans may be a marker for development of GVHD and poor outcomes in allo-HCT. In this retrospective study, we reviewed the pre-HCT CT scans and transplant outcome data of patients who underwent allo-HCT at Duke University Medical Center from 2009 to 2017. The presence of steatosis was confirmed using CT attenuation measurements. We then assessed the association between pre-HCT hepatic steatosis and HCT-related outcomes including GVHD. 80 patients who had pre-HCT CT scans were included in the study. Pre-transplant hepatic steatosis was associated with the development of chronic GVHD (OR 4.2, p = 0.02), but was not associated with acute GVHD (OR 1.3, p = 0.7), non-relapse mortality (p = 0.81) or overall survival (p = 0.74). Based on this single center retrospective study, pre-transplant hepatic steatosis is associated with development of chronic GVHD. Further, prospective study with other imaging modalities including non-contrasted CT scans is needed to determine if this association is reproducible.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0238824PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7485815PMC
November 2020

Is autologous stem cell transplantation still relevant for multiple myeloma?

Authors:
Taewoong Choi

Curr Opin Hematol 2019 11;26(6):386-391

Division of Hematologic Malignancies and Cellular Therapy, Duke University Medical Center, Durham, North Carolina, USA.

Purpose Of Review: Autologous stem cell transplantation has been the standard of care in myeloma treatment for many years, but the availability of newer antimyeloma drugs and the emerging data from chimeric antigen receptor (CAR) T-cell clinical studies make us question the relevance of it. The purpose of this review is to go over recent data and to reassess the current status of autologous stem cell transplantation as a standard of care.

Recent Findings: Autologous stem cell transplantation can be safely performed for elderly patients and there is no absolute age limit. Recent data on BEAM (Carmustine, Etoposide, Cytarabine, and Melphalan), Busulfan/Melphalan, and Carmustine/Melphalan conditioning when compared with Melphalan showed favorable survival outcomes with manageable toxicities although we need to see data from randomized, multicenter studies. Posttransplant maintenance and consolidation can maximize the benefit of transplant by prolonging progression-free survival. Current B-cell maturation antigen CAR T-cell therapy showed remarkably high response rates, but didn't seem to provide durable response yet.

Summary: Recent advances in myeloma therapy and autologous stem cell transplantation are described. Although we've seen many new developments including CAR T-cell therapies, autologous stem cell transplantation remains as the standard of care. However, it may be replaced by or combined with newer therapies in the future.
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http://dx.doi.org/10.1097/MOH.0000000000000538DOI Listing
November 2019

Isolation of primitive mouse extraembryonic endoderm (pXEN) stem cell lines.

Stem Cell Res 2018 07 18;30:100-112. Epub 2018 May 18.

Department of Molecular & Life Science, College of Science and Technology, Hanyang University (ERICA Campus), 55 Hanyangdaehak-ro, Sangrok-gu, Ansan-si, Gyeonggi-do 15588, Republic of Korea.. Electronic address:

Mouse blastocysts contain the committed precursors of the extraembryonic endoderm (ExEn), which express the key transcription factor Oct4, depend on LIF/LIF-like factor-driven Jak/Stat signaling, and initially exhibit lineage plasticity. Previously described rat blastocyst-derived ExEn precursor-like cell lines (XENP cells/HypoSCs) also show these features, but equivalent mouse blastocyst-derived cell lines are lacking. We now present mouse blastocyst-derived cell lines, named primitive XEN (pXEN) cells, which share these and additional characteristics with the XENP cells/HypoSCs, but not with previously known mouse blastocyst-derived XEN cell lines. Otherwise, pXEN cells are highly similar to XEN cells by morphology, lineage-intrinsic differentiation potential, and multi-gene expression profile, although the pXEN cell profile correlates better with the blastocyst stage. Finally, we show that pXEN cells easily convert into XEN-like cells but not vice versa. The findings indicate that (i) pXEN cells are more representative than XEN cells of the blastocyst stage; (ii) mouse pXEN, rather than XEN, cells are homologs of rat XENP cells/HypoSCs, which we propose to call rat pXEN cells.
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http://dx.doi.org/10.1016/j.scr.2018.05.008DOI Listing
July 2018

Ly49-dependent NK cell licensing and effector inhibition involve the same interaction site on MHC ligands.

J Immunol 2011 Apr 18;186(7):3911-7. Epub 2011 Feb 18.

Rheumatology Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.

NK cells become functionally competent to be triggered by their activation receptors through the interaction of NK cell inhibitory receptors with their cognate self-MHC ligands, an MHC-dependent educational process termed "licensing." For example, Ly49A(+) NK cells become licensed by the interaction of the Ly49A inhibitory receptor with its MHC class I ligand, H2D(d), whereas Ly49C(+) NK cells are licensed by H2K(b). Structural studies indicate that the Ly49A inhibitory receptor may interact with two sites, termed site 1 and site 2, on its H2D(d) ligand. Site 2 encompasses the α1/α2/α3 domains of the H2D(d) H chain and β(2)-microglobulin (β2m) and is the functional binding site for Ly49A in effector inhibition. Ly49C functionally interacts with a similar site in H2K(b). However, it is currently unknown whether this same site is involved in Ly49A- or Ly49C-dependent licensing. In this study, we produced transgenic C57BL/6 mice expressing wild-type or site 2 mutant H2D(d) molecules and studied whether Ly49A(+) NK cells are licensed. We also investigated Ly49A- and Ly49C-dependent NK licensing in murine β2m-deficient mice that are transgenic for human β2m, which has species-specific amino acid substitutions in β2m. Our data from these transgenic mice indicate that site 2 on self-MHC is critical for Ly49A- and Ly49C-dependent NK cell licensing. Thus, NK cell licensing through Ly49 involves specific interactions with its MHC ligand that are similar to those involved in effector inhibition.
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http://dx.doi.org/10.4049/jimmunol.1004168DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3082152PMC
April 2011

HLA alleles determine differences in human natural killer cell responsiveness and potency.

Proc Natl Acad Sci U S A 2008 Feb 19;105(8):3053-8. Epub 2008 Feb 19.

Howard Hughes Medical Institute, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.

Epidemiological studies have associated certain human disease outcomes with particular killer cell Ig-like receptor (KIR) and HLA genotypes. However, the functional explanation for these associations is poorly understood, because the KIRs were initially described as natural killer (NK) cell inhibitory receptors with specificity for HLA molecules on their cellular targets. Yet resolution of infections is often associated with genotypic pairing of inhibitory KIRs with their cognate HLA ligands. Recent studies in mice indicate a second role for MHC-specific inhibitory receptors, i.e., self-MHC recognition confers functional competence on the NK cell to be triggered through their activation receptors, a process termed licensing. As a result, licensed NK cells with self-MHC-specific receptors are more readily activated as compared with unlicensed NK cells without self-MHC-specific receptors. Such results predict that human NK cells may undergo a similar process. Here, we examined the human NK cell subset expressing KIR3DL1, the only known KIR specific for HLA-Bw4 alleles. The KIR3DL1(+) subset in normal donors with two HLA-B-Bw4 genes displayed increased responsiveness to tumor stimulation compared with the KIR3DL1(+) subset from individuals with only one or no Bw4 genes. By contrast, NK cells lacking KIR3DL1 showed no differences. Therefore, these data indicate that particular KIR and HLA alleles are associated with more responsive NK cells, strongly suggesting that human NK cells are also subjected to NK cell licensing, and providing a potential functional explanation for the influence of KIR and HLA genes in disease as well as interindividual differences in NK cell potency.
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http://dx.doi.org/10.1073/pnas.0712229105DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2268583PMC
February 2008
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