Functional Competence of NK Cells via the KIR/MHC Class I Interaction Correlates with DNAM-1 Expression.

The interaction of inhibitory receptors with self-MHC class I (MHC-I) molecules is responsible for NK cell education. The intensity of DNAM-1 expression correlates with NK cell education. However, whether DNAM-1 expression directly influences the functional competence of NK cells via the KIR/MHC-I interaction remains unclear. Based on allogeneic haploidentical hematopoietic stem cell transplantation, we investigated the intensity of DNAM-1 expression on reconstituted NK cells via the interaction of KIR with both donor HLA and recipient HLA at days 30, 90, and 180 after hematopoietic stem cell transplantation. The reconstituted NK cells educated by donor and recipient HLA molecules showed the highest DNAM-1 expression, whereas DNAM-1 expression on educated NK cells with only recipient HLA molecules was higher than that on educated NK cells with only donor HLA molecules, indicating that NK cells with donor or recipient HLA molecules regulate DNAM-1 expression and thereby affect NK cell education. Additionally, the effects of recipient cells on NK cell education were greater than those of donor cells. However, only when the DNAM-1, NKP30, and NKG2D receptors were blocked simultaneously was the function of educated and uneducated NK cells similar. Therefore, activating receptors may collaborate with DNAM-1 to induce educated NK cell hyperresponsiveness. Our data, based on in vitro and in vivo studies, demonstrate that the functional competence of NK cells via the KIR/MHC-I interaction correlates with DNAM-1 expression in human NK cells.

Interfacial Engineering of Ni/V2 O3 Heterostructure Catalyst for Boosting Hydrogen Oxidation Reaction in Alkaline Electrolytes.

Alkaline fuel cells can permit the adoption of platinum group metal-free (PGM-free) catalysts and cheap bipolar plates, thus further lowering the cost. With the exploration of PGM-free hydrogen oxidation reaction (HOR) catalysts, nickel-based compounds have been considered as the most promising HOR catalysts in alkali. Here we report an interfacial engineering through the formation of nickel-vanadium oxide (Ni/V2 O3 ) heterostructures to activate Ni for efficient HOR catalysis in alkali. The strong electron transfer from Ni to V2 O3 could modulate the electronic structure of Ni sites. The optimal Ni/V2 O3 catalyst exhibits a high intrinsic activity of 0.038 mA cm-2 and outstanding stability. Experimental and theoretical studies reveal that Ni/V2 O3 interface as the active sites can enable to optimize the hydrogen and hydroxyl bindings, as well as protect metallic Ni from extensive oxidation, thus achieving the notable activity and durability.

Donor activating killer cell immunoglobulin-like receptors genes correlated with Epstein-Barr virus reactivation after haploidentical haematopoietic stem cell transplantation.

Natural killer (NK) cells exert anti-viral effects after haematopoietic stem cell transplantation (HSCT). The balance between inhibition and activation of NK cells determined by the inherited repertoire of killer cell immunoglobulin-like receptors (KIR) genes may influence Epstein-Barr virus (EBV) reactivation after transplantation. To evaluate the relative contributions of KIR genotypes to EBV reactivation, we prospectively enrolled 300 patients with malignant haematological disease who were suitable for haploidentical HSCT. Univariate analysis showed that donors with KIR2DS1, KIR2DS3 or KIR3DS1 genes were associated with an increased risk of EBV reactivation [hazard ratio (HR) 1·86, 95% confidence interval (CI) 1·19-2·9, P = 0·0067; HR 1·78, 95% CI 1·07-2·97, P = 0·027; HR 1·86, 95% CI 1·19-2·91, P = 0·0065 respectively]. Multivariate analysis revealed that the presence of KIR2DS1, KIR2DS3 or KIR3DS1 genes was associated with increased EBV reactivation after HSCT. This effect was more evident in the absence of the cognate ligands for the corresponding activating receptors. Our present data firstly showed that donors with activating KIR genes, specifically activating KIR2DS1, KIR2DS3 and KIR3DS1, had an increased risk of EBV reactivation. Precaution for patients whose donors carry activating genes will help prevent EBV reactivation and improve patient prognosis after HSCT.

Expanded clinical-grade membrane-bound IL-21/4-1BBL NK cell products exhibit activity against acute myeloid leukemia in vivo.

BACKGROUND: Adoptive NK cell infusion is a promising immunotherapy for acute myeloid leukemia (AML) patients. The aim of this study was to test the activity of clinical-grade membrane-bound IL-21/4-1BBL-expanded NK cell products against AML in vivo. METHODS: Fresh peripheral blood mononuclear cells (PBMCs) were incubated with equal numbers of irradiated membrane-bound IL-21/4-1BBL-expressing K562 cells for 2-3 weeks to induce clinical-grade NK cell expansion. RESULTS: Expansion for 2 and 3 weeks produced ∼4 and 8 × 109 NK cells from 2 × 107 PBMCs. The production of CD107a and TNF-α in NK cell products in response to AML cell lines and primary blasts was higher than that observed in resting NK cells. The 2-week expanded NK cell products were xenografted into immunodeficient mice with leukemia and were persistently found in the BM, spleen, liver, lung, and peripheral blood for at least 13 days; furthermore, these expanded products reduced the AML burden in vivo. Compared with matched AML patients with persistent or relapsed minimal residual disease (MRD+ ) who underwent regular consolidation therapy, MRD+ patients who underwent NK treatment had better overall survival and showed no major adverse events. CONCLUSIONS: Clinical-grade mbIL-21/4-1BBL-expanded NK cells exhibited antileukemic activity against AML in vitro and in vivo.

First-line Therapy With Donor-derived Human Cytomegalovirus (HCMV)-specific T Cells Reduces Persistent HCMV Infection by Promoting Antiviral Immunity After Allogenic Stem Cell Transplantation.

BACKGROUND: Human cytomegalovirus (HCMV) infection, especially persistent HCMV infection, is an important cause of morbidity and mortality after allogenic stem cell transplantation (allo-SCT). Antiviral agents remain the first-line therapy but are limited by side effects and acquired resistance. METHODS: We evaluated the safety and efficacy of donor-derived HCMV-specific cytotoxic T cells (CTLs) as a first-line therapy for HCMV infection after allo-SCT and investigated the underlying mechanisms. RESULTS: In humanized HCMV-infected mice, first-line therapy with CTLs effectively combated systemic HCMV infection by promoting the restoration of graft-derived endogenous HCMV-specific immunity in vivo. In a clinical trial, compared with the pair-matched, high-risk control cohort, first-line therapy with CTLs significantly reduced the rate of persistent (2.9% vs 20.0%, P = .018) and late (5.7% vs 20.0%, P = .01) HCMV infection and cumulative incidence of persistent HCMV infection (hazard ratio [HR], 0.13; 95% confidence interval [CI], 0.10-0.82; P = .02), lowered 1-year treatment-related mortality (HR, 0.15. 95% CI, 0.11-0.90. P = .03), and improved 1-year overall survival (HR, 6.35; 95% CI, 1.05-9.00; P = .04). Moreover, first-line therapy with CTLs promoted the quantitative and functional recovery of CTLs in patients, which was associated with HCMV clearance. CONCLUSIONS: We provide robust support for the benefits of CTLs combined with antiviral drugs as a first-line therapy for treating HCMV infection and suggest that adoptively infused CTLs may stimulate the recovery of endogenous HCMV-specific immunity. CLINICAL TRIALS REGISTRATION: NCT02985775.

Quantity and Quality Reconstitution of NKG2A+ Natural Killer Cells Are Associated with Graft-versus-Host Disease after Allogeneic Hematopoietic Cell Transplantation.

The immune mechanism underlying graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (HSCT) remains unclear. Natural killer (NK) cells play a crucial role in mediating pathogen-specific immunity and are the first donor-derived lymphocytes reconstituted post-HSCT. However, NK cells vary at different stages after HSCT. Here, we found that the absolute NKG2A+ subset cell counts and the percentages of NKG2A+ among NK cells were significantly reduced in GVHD patients after HSCT compared with those from non-GVHD patients. Moreover, the reduction in NKG2A+ NK cells in post-HSCT GVHD patients was ascribed to increased apoptosis and a decreased proliferation capacity while retaining a strong graft-versus-leukemia effect. In vitro assays showed that co-culture of T cells with NKG2A+ NK cells significantly reduced IFN-γ secretion by T cells and increased IL-4 secretion. Moreover, the CD25 expression level was decreased, whereas the number of cells with the CD4+CD25+FOXP3+ phenotype was increased. In addition, the NKG2A+ NK cells induced T cell apoptosis and decreased T cell proliferation during the co-culture process. Importantly, NKG2A+ NK cells mainly regulated activated but not resting T cells. In vivo assays showed that the serologic IL-10 level was evidently lower in GVHD than in non-GVHD patients, whereas the IL-1ß, IFN-γ, and tumor necrosis factor-α levels were higher in GVHD patients. Furthermore, the NKG2A+ NK cell ratio from GVHD patients was markedly increased by the presence of exogenous IL-10 but not by other cytokines. In contrast, the NKG2A+ cell ratio from non-GVHD patients was not increased by IL-10. Therefore, post-HSCT GVHD may be ascribed to the reduced induction of NKG2A+ NK cells by IL-10, which further overactivates T cells.

Delay expression of NKp30 on NK cells correlates with long-term mycophenolate mofetil treatment and higher EBV viremia post allogenic hematological stem cells transplantation.

Mycophenolate mofetil (MMF) is an immunosuppressive agent that is widely used in graft-versus-host disease prophylaxis because of its inhibitory function on T cells and B cells. However, the effect of MMF on natural killer cell reconstitution after allogenic hematological transplantation is largely unknown. The present study examined the effects of different MMF administration durations after haploidentical allo-HSCT on NK cell reconstitution. Ninety patients were enrolled in this study and defined into two groups in term of MMF duration. We found that MMF patients in the long-term MMF group were associated with a poor reconstitution of NK cells and a significantly lower cytotoxicity from day 30 to day 180 post-transplantation. Especially, the long-term MMF group inhibits reconstitution of NKp30 NK subsets, which correlated with higher risk of EBV viremia. Multivariate analysis showed that a better reconstitution of NKp30 cells was associated with lower EBV viremia (HR0.957, p = .04). In vitro experiments demonstrated that the active metabolite of MMF, mycophenolic acid (MPA), inhibited the proliferation and cytotoxicity of NK cells from healthy donors or patients at day 30 post-transplantation. In summary, our findings demonstrated that long-term MMF administration delayed the quality and quantity of NK cells, especially NKp30 subpopulations, which was associated with decreased EBV viremia post allogeneic HSCT.

Effect of the in vivo application of granulocyte colony-stimulating factor on NK cells in bone marrow and peripheral blood.

Granulocyte colony-stimulating factor (G-CSF) has been widely used in the field of allogeneic haematopoietic stem cell transplantation (allo-HSCT) for priming donor stem cells from the bone marrow (BM) to peripheral blood (PB) to collect stem cells more conveniently. Donor-derived natural killer (NK) cells have important antitumour functions and immune regulatory roles post-allo-HSCT. The aim of this study was to evaluate the effect of G-CSF on donors' NK cells in BM and PB. The percentage of NK cells among nuclear cells and lymphocyte was significantly decreased and led to increased ratio of T and NK cells in BM and PB post-G-CSF in vivo application. Relative expansion of CD56bri NK cells led to a decreased ratio of CD56dim and CD56bri NK subsets in BM and PB post-G-CSF in vivo application. The expression of CD62L, CD54, CD94, NKP30 and CXCR4 on NK cells was significantly increased in PB after G-CSF treatment. G-CSF treatment decreased the IFN-γ-secreting NK population (NK1) dramatically in BM and PB, but increased the IL-13-secreting NK (NK2), TGF-ß-secreting NK (NK3) and IL-10-secreting NK (NKr) populations significantly in BM. Clinical data demonstrated that higher doses of NK1 infused into the allograft correlated with an increased incidence of chronic graft-vs-host disease post-transplantation. Taken together, our results show that the in vivo application of G-CSF can modulate NK subpopulations, leading to an increased ratio of T and NK cells and decreased ratio of CD56dim and CD56bri NK cells as well as decreased NK1 populations in both PB and BM.

Recipient-donor KIR ligand matching prevents CMV reactivation post-haploidentical T cell-replete transplantation.

Licensed natural killer (NK) cells have been demonstrated to have anti-cytomegalovirus (CMV) activity. We prospectively analysed the human leucocyte antigen typing of donor-recipient pairs and the killer cell immunoglobulin-like receptor (KIR) typing of donors for 180 leukaemia patients to assess the predictive roles of licensed NK cells on CMV reactivation post-T-cell-replete haploidentical stem cell transplantation. Multivariate analysis showed that donor-recipient KIR ligand graft-versus-host or host-versus-graft direction mismatch was associated with increased refractory CMV infection (Hazard ratio = 2·556, 95% confidence interval, 1·377-4·744, P = 0·003) post-transplantation. Donor-recipient KIR ligand matching decreased CMV reactivation [51·65% (46·67, 56·62%) vs. 75·28% (70·87, 79·69%), P = 0·012], refractory CMV infection [17·58% (13·77, 21·40%) vs. 35·96% (31·09, 40·82%), P = 0·004] and CMV disease [3·30% (1·51, 5·08%) vs. 11·24% (8·04, 14·43%), P = 0·024] by day 100 post-transplantation. In addition, the percentage of γ-interferon expression on donor-derived NK cells was significantly higher in the recipients among the recipient-donor pairs with a KIR ligand match compared with that in the recipients among the pairs with a KIR ligand graft-versus-host or host-versus-graft direction mismatch on days 30 and 100 post-transplantation (P = 0·036 and 0·047, respectively). These findings have suggested that donor-recipient KIR ligand matching might promote the NK cell licensing process, thereby increasing NK cell-mediated protection against CMV reactivation.

Treatment of bilateral developmental dysplasia of the hip joint with an improved technique: A case report.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a common osteoarticular deformity in pediatric orthopedics. A patient with bilateral DDH was diagnosed and treated using our improved technique "(powerful overturning acetabuloplasty)" combined with femoral rotational shortening osteotomy. CASE SUMMARY: A 4-year-old girl who was diagnosed with bilateral DDH could not stand normally, and sought surgical treatment to solve the problem of double hip extension and standing. As this child had high dislocation of the hip joint and the acetabular index was high, we changed the traditional acetabuloplasty to "powerful turnover acetabuloplasty" combined with femoral rotation shortening osteotomy. During the short-term postoperative follow-up (1, 3, 6, 9, 12, and 15 months), the child had no discomfort in her lower limbs. After the braces and internal fixation plates were removed, formal rehabilitation training was actively carried out. CONCLUSION: Our "powerful overturning acetabuloplasty" combined with femoral rotational shortening osteotomy is feasible in the treatment of DDH in children. This technology may be widely used in the clinic.

Expanded clinical-grade NK cells exhibit stronger effects than primary NK cells against HCMV infection.

Cytomegalovirus (CMV) reactivation remains a common complication and leads to high mortality in patients who undergo allogeneic hematopoietic stem cell transplantation (allo-HSCT). Early natural killer (NK) cell reconstitution may protect against the development of human CMV (HCMV) infection post-HSCT. Our previous data showed that ex vivo mbIL21/4-1BBL-expanded NK cells exhibited high cytotoxicity against leukemia cells. Nevertheless, whether expanded NK cells have stronger anti-HCMV function is unknown. Herein, we compared the anti-HCMV functions of ex vivo expanded NK cells and primary NK cells. Expanded NK cells showed higher expression of activating receptors, chemokine receptors and adhesion molecules; stronger cytotoxicity against HCMV-infected fibroblasts; and better inhibition of HCMV propagation in vitro than primary NK cells. In HCMV-infected humanized mice, expanded NK cell infusion resulted in higher NK cell persistence and more effective tissue HCMV elimination than primary NK cell infusion. A clinical cohort of 20 post-HSCT patients who underwent adoptive NK cell infusion had a significantly lower cumulative incidence of HCMV infection (HR = 0.54, 95% CI = 0.32-0.93, p = 0.042) and refractory HCMV infection (HR = 0.34, 95% CI = 0.18-0.65, p = 0.009) than controls and better NK cell reconstitution on day 30 post NK cell infusion. In conclusion, expanded NK cells exhibit stronger effects than primary NK cells against HCMV infection both in vivo and in vitro.

[Bryophyte diversity and microhabitat characteristics of bryophyte-dominated biological soil crusts development in water-wind erosion crisscross region of the northern Loess Plateau, China]. / é»„åœŸé«˜åŽŸåŒ—éƒ¨æ°´èš€é£Žèš€äº¤é”™åŒºè‹”è—“å¤šæ ·æ€§åŠè‹”è—“ç»“çš®å‘è‚²çš„å¾®ç”Ÿå¢ƒç‰¹å¾.

Microhabitat factors play an important role in regulating bryophyte species distribution and the development of bryophyte-dominated biological soil crusts (hereafter bryophyte crusts). We investigated the distribution and development of bryophytes in eight microhabitats in the water-wind erosion crisscross region of the Loess Pla-teau. We used the line intercept transects to explore and quantify the influencing pathways of microhabitat factors on bryophyte diversity and analyzed the influencing pathways of plant cover, slope aspect, and slope gradient by using structural equation model to quantify influencing coefficients. Our results showed that: 1) The Patrick, Shannon, Pielou, and Simpson indcies of bryophytes under plant canopy were 63.4%, 66.6%, 91.0%, and 68.3% lower than that without plant canopy, respectively, while the thickness, biomass, and chlorophyll content of bryophyte crusts were 0.5, 0.2, and 1.3 times higher than that without plant canopy, respectively. 2) The Patrick, Shannon, Pielou, and Simpson indexes of bryophytes on the north slope were 0.6, 0.9, 5.6, and 0.9 times higher than those on the south slope, while the thickness, biomass, and chlorophyll content of bryophyte crusts were 0.3, 0.3, and 0.6 times higher than those on the south slope, respectively. 3) As the slope increasing from 14° to 34°, the Patrick, Shannon, Pielou, and Simpson indexes of bryophyte were decreased by 59.8%, 84.1%, 57.3% and 68.0%, and the thickness, biomass, and chlorophyll content of bryophyte crusts were decreased by 15.2%, 25.0%, and 16.5%, respectively. 4) The importance of the three microhabitat factors on bryophyte diversity and the development of bryophyte crusts followed an order of plant canopy cover > slope aspect > slope gradient. The primary influencing pathway varied among the microhabitat factors. In conclusion, plant cover, slope aspect, and slope gradient significantly affected the distribution of bryophytes species and developmental level of bryophyte crusts through direct and indirect pathways. Therefore, full consideration should be given to microhabitat conditions when using bryophyte crusts to control desertification.

[Responses of moss biocrusts respiration to simulated grazing and trampling disturbance with different intensities on the fenced forestland of Loess Plateau, China]. / 黄土高原封禁林地藓结皮呼吸速率对放牧踩踏干扰强度的响应.

The changes in soil properties caused by grazing and trampling are important reasons for the changes in soil respiration rates, carbon fixation, and emission. However, the effects of different intensities of grazing and trampling on biocrusts respiration rate are unclear. In this study, we simulated grazing and trampling disturbances of 10%, 30%, 50%, and 70% intensity on moss biocrusts developed in aeolian sandy soil on Loess Plateau, with undisturbed moss biocrusts serving as a control. The changes in respiration rate of moss biocrusts were monitored continuously, and its responses to different disturbance intensities were analyzed. The results showed that: 1) moderate disturbance stimulated moss biocrusts respiration, while heavy disturbance inhibited that. The respiration rate of moss biocrusts was increased by 41.1% and 22.2% at disturbance intensities of 10% and 30%, but was decreased by 8.9% and 15.3% at disturbance intensities of 50% and 70%, respectively. 2) The trampling disturbance significantly changed soil temperature but did not affect soil water content. In comparison to the control, soil temperature of biocrusts was decreased by 0.4 and 1.2 ℃ at disturbance intensities of 10% and 30%, but it was increased by 1.1 and 1.0 ℃ at disturbance intensities of 50% and 70%, respectively. 3) The respiration rate of moss biocrusts showed a significant exponential relationship with soil temperature and a linear positive relationship with soil water content under different disturbance intensities. However, the correlation between respiration rate of moss biocrust and the characteristics of moss biocrust was not significant. Soil temperature and water content could explain 70.6%-96.3% and 49.1%-70.0% of the total variation of respiration rate of moss biocrusts, respectively. In conclusion, grazing and trampling affected the respiration rate of moss biocrusts, with short-term moderate grazing and trampling would have positive effects. On the other hand, excessive grazing and trampling would reduce the rate of moss biocrust respiration. As a result, future studies on soil carbon balance of the Loess Plateau should consider the effects of grazing and trampling on biocrust respiration.

The Interaction of HLA-C1/KIR2DL2/L3 Promoted KIR2DL2/L3 Single-Positive/NKG2C-Positive Natural Killer Cell Reconstitution, Raising the Incidence of aGVHD after Hematopoietic Stem Cell Transplantation.

NKG2C+ natural killer (NK) cell plays a vital role in CMV infection control after hematopoietic stem cell transplantation (HSCT). However, the modulation on NKG2C+ NK cell reconstitution is still unclear. NK cell education is affected by the interactions of HLA-I/killer immunoglobulin receptor (KIR). Our aim is to figure out which HLA-I/KIR interaction plays a dominant role in NKG2C+ NK education. Based on allogeneic haploidentical HSCT, we investigated the expansion and function of single KIR positive NKG2C+ NK cells via the interaction of KIR with both donor HLA and recipient HLA at days 30, 90, and 180 after HSCT. KIR2DL2/L3 single-positive/NKG2C+ cells were significantly expanded compared with KIR2DL1 or KIR3DL1 single-positive/NKG2C+ cells when donors and recipients were both HLA-C1/C1 or HLA-C1C1BW4 (p < 0.05), with higher NKp30 expression (p < 0.05). Moreover, the proportion of single KIR positive NK cells increased in both NKG2C+/NKG2A- NK cells and conventional NKG2C-/NKG2A- NK cells over time. We also observed that increased proportion of KIR2DL2/L3 single-positive/NKG2C+ NK cells correlated with higher incidence of acute graft-versus-host disease (aGVHD). Our study allows a better understanding of HLA-I/KIR interaction in the NKG2C+ NK cell education after HSCT.

Donor NKG2C homozygosity contributes to CMV clearance after haploidentical transplantation.

CMV infection remains an important cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Several investigators have reported that adaptive NKG2C+ NK cells persistently expand during CMV reactivation. In our study, 2 cohorts were enrolled to explore the relationships among the NKG2C genotype, NKG2C+ NK cell reconstitution, and CMV infection. Multivariate analysis showed that donor NKG2C gene deletion was an independent prognostic factor for CMV reactivation and refractory CMV reactivation. Furthermore, adaptive NKG2C+ NK cells' quantitative and qualitative reconstitution, along with their anti-CMV function after transplantation, was significantly lower in patients grafted with NKG2Cwt/del donor cells than in those grafted with NKG2Cwt/wt donor cells. At day 30 after transplantation, quantitative reconstitution of NKG2C+ NK cells was significantly lower in patients with treatment-refractory CMV reactivation than in patients without CMV reactivation and those with nonrefractory CMV reactivation. In humanized CMV-infected mice, we found that, compared with those from NKG2Cwt/del donors, adaptive NKG2C+ NK cells from NKG2Cwt/wt donors induced earlier and stronger expansion of NKG2C+ NK cells as well as earlier and stronger CMV clearance in vivo. In conclusion, donor NKG2C homozygosity contributes to CMV clearance by promoting the quantitative and qualitative reconstruction of adaptive NKG2C+ NK cells after haploidentical allo-HSCT.

[Dihydroartemisinin Induces Apoptosis of Human Acute T Lymphocytic Leukemia Cells by Activating Oxidative Stress].

OBJECTIVE: To investigate the effects of dihydroartemisinin (DHA) on the proliferation and apoptosis of human T-cell acute lymphoblastic leukemia (T-ALL) Jurkat cell. METHODS: The effects of DHA on the proliferation of Jurkat cells and the recovery of DHA-inhibited cell viability by N-acetyl-L-cysteine (NAC) were examined by CCK-8 assay. Flow cytometry was performed to analyze the cell apoptosis and generation of reactive oxygen species (ROS). Western-blot was used to detected protein expression of DNA damage-related genes, as well as apoptosis-associated genes, respectively. RESULTS: DHA inhibited the proliferation of Jurkat cells, and shows a concentration-dependent manner(r =0.936), and NAC could partially restore the activity of DHA on cell proliferation inhibition. With the increase of drug concentration, the apoptosis rate (r =0.946) and ROS accumulation was increased (r =0.965). Western blot showed that the protein expressions of DNA damage-related gene γ-H2AX and apoptosis-related genes p53, c-Caspase3, BAX and cPARP were significantly increased, and BCL-2 protein expression was decreased. CONCLUSION: DHA can induce ROS production in Jurkat cells, which can cause DNA damage, activate the P53 apoptotic pathway, and promote apoptosis of cells.

[Dihydroartemisinin Induces AML cell Apoptosis by Inhibition of PTEN/AKT pathway].

OBJECTIVE: To study the effects of dihydroartemisinin (DHA) on the proliferation and apoptosis of acute myeloid leukemia (AML) cells. METHODS: The effects of DHA on the proliferation of acute myeloid leukemia cells and the inhibitory effect of Z-VAD-FMK on the DHA-induced cell apoptosis were detected by CCK-8 assay. The expression level of cleaved-caspased 3 was detected by indirect immunofluorescence. Western blot was used to quantify the protein expression of PTEN, p-Akt, AKT, ß-actin, and the apoptosis-associated proteins, such as C-PARP, Cleaved-caspase3 and Caspase3 respectively. RESULTS: DHA induced the AML cell apoptosis with concentration-dependent manner (rKasumi-1=-0.959, rKG-1=-0.956). The DHA could induce the accumulation of cleaved-caspase 3 and C-PARP in AML cells, activate PTEN gene and inhibited Akt phosphorylation. Apoptosis inhibitor Z-VAD-FMK could partially restored the activity of DHA-inhibited cell proliferation. CONCLUSION: Dihydroartemisinin induces AML cell apoptosis by inhibition of PTEN/AKT pathway. Dihydroartemisinin is expected to be a safe and effective drug for treatment of acute myeloid leukemia.

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

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.

The impact of donor characteristics on the invariant natural killer T cells of granulocyte-colony-stimulating factor-mobilized marrow grafts and peripheral blood grafts.

INTRODUCTION: Invariant natural killer T cells (iNKTs) are a rare but vital subset of immunomodulatory T cells and play an important role in allogeneic hematopoietic stem cell trans-plantation (HSCT). The association of donor characteristics with the number and frequency of the iNKTs subsets in allografts remains poorly understood. In this paper, we prospectively investigate the association of donor characteristics with iNKTs dose and frequency in granulocyte-colony-stimulating factor (G-CSF) mobilized marrow and peripheral blood harvests. MATERIALS AND METHODS: 100 bone marrow (BM) units and 100 peripheral blood (PB) units from 100 healthy donors were examined. Parameters including donor age, sex, weight, height, BMI and blood count [including white blood cells (WBCs), lymphocytes and monocytes] at three time points [donor's steady state before G-CSF administration, the day of G-BM harvesting and the day of G-PB apheresis] were analyzed to explore the impact of donor characteristics on iNKTs composition in BM and PB grafts. RESULTS: Multivariate analysis showed monocyte counts before G-BM harvest could predict higher frequency of iNKTs in WBC (OR = 2.593, 95%CI: 1.128-5.961, p = 0.025), higher total CD4+ iNKTs dose (OR = 2.250, 95%CI: 1.011-5.008, p = 0.047) and higher total iNKTs dose (OR = 2.662, 95%CI: 1.187-5.970, p = 0.017) in mixture allografts. DISCUSSION: The results suggested that monocyte counts pre G-BM harvest could predict the yield of total CD4+ iNKTs and total iNKTs in mixture allografts. The male and older donors were associated with a higher dose of total CD4- iNKTs in mixture allografts.