Construction of NKG2D CAR-NK92 cells and its killing effect on multiple myeloma cells / 细胞与分子免疫学杂志

Objective This study aims to construct and identify the chimeric antigen receptor NK92 (CAR-NK92) cells targeting NKG2D ligand (NKG2DL) (secreting IL-15Ra-IL-15) and verify the killing activity of NKG2D CAR-NK92 cells against multiple myeloma cells. Methods The extracellular segment of NKG2D was employed to connect 4-1BB and CD3Z, as well as IL-15Ra-IL-15 sequence to obtain a CAR expression framework. The lentivirus was packaged and transduced into NK92 cells to obtain NKG2D CAR-NK92 cells. The proliferation of NKG2D CAR-NK92 cells was detected by CCK-8 assay, IL-15Ra secretion was detected by ELISA and killing efficiency was detected by lactate dehydrogenase (LDH) assay. The molecular markers of NKp30, NKp44, NKp46, the ratio of apoptotic cell population, CD107a, and the secretion level of granzyme B and perforin were detected using flow cytometry. In addition, the cytotoxic mechanism of NKG2D CAR-NK92 cells on the tumor was verified by measuring the degranulation ability. Moreover, after NKG2D antibody inhibited effector cells and histamine inhibited tumor cells, LDH assay was utilized to detect the effect on cell-killing efficiency. Finally, the multiple myeloma tumor xenograft model was constructed to verify its anti-tumor activity in vivo. Results Lentiviral transduction significantly increased NKG2D expression in NK92 cells. Compared with NK92 cells, the proliferation ability of NKG2D CAR-NK92 cells was weaker. The early apoptotic cell population of NKG2D CAR-NK92 cells was less, and NKG2D CAR-NK92 cells had stronger cytotoxicity to multiple myeloma cells. Additionally, IL-15Ra secretion could be detected in its culture supernatant. NKp44 protein expression in NKG2D CAR-NK92 cells was clearly increased, demonstrating an enhanced activation level. Inhibition test revealed that the cytotoxicity of CAR-NK92 cells to MHC-I chain-related protein A (MICA) and MICB-positive tumor cells was more dependent on the interaction between NKG2D CAR and NKG2DL. After stimulating NKG2D CAR-NK92 cells with tumor cells, granzyme B and perforin expression increased, and NK cells obviously upregulated CD107α. Furthermore, multiple myeloma tumor xenograft model revealed that the tumors of mice treated with NKG2D CAR-NK92 cells were significantly reduced, and the cell therapy did not sensibly affect the weight of the mice. Conclusion A type of CAR-NK92 cell targeting NKG2DL (secreting IL-15Ra-IL-15) is successfully constructed, indicating the effective killing of multiple myeloid cells.

Role of CD4+NKG2D+ T cells in the disease activity of juvenile idiopathic arthritis / 中国当代儿科杂志

OBJECTIVES@#To study the expression levels of CD4+NKG2D+ T cells and NKG2D soluble ligands, the soluble MHC class I chain-related molecules A and B (sMICA/sMICB) in the active stage and stable stage of juvenile idiopathic arthritis (JIA) and their role in the disease activity of JIA.@*METHODS@#Nineteen children with systemic JIA and 20 children with articular JIA who were diagnosed in Children's Hospital of Chongqing Medical University from November 2019 to December 2021 were enrolled in this prospective study. Six healthy children were enrolled as the control group. After peripheral blood samples were collected, ELISA was used to measure the levels of sMICA and sMICB, and flow cytometry was used to measure the percentage of CD4+NKG2D+ T cells. Systemic Juvenile Arthritis Disease Activity Score-27 (sJADAS-27)/Juvenile Arthritis Disease Activity Score-27 (JADAS-27) was used to evaluate the disease activity in children with JIA. The Pearson correlation analysis and the receiver operating characteristic (ROC) curve were used to assess the role of CD4+NKG2D+ T cells, sMICA and sMICB in the disease activity of JIA.@*RESULTS@#The active systemic JIA and active articular JIA groups had a significant increase in the percentage of CD4+NKG2D+ T cells compared with the control group and their corresponding inactive JIA group (P<0.05). The JIA groups had significantly higher levels of sMICA and sMICB than the control group (P<0.05), and the active articular JIA group had a significantly higher level of sMICB than the stable articular JIA group (P<0.05). In the children with JIA, the percentage of CD4+NKG2D+ T cells and the levels of sMICA and sMICB were positively correlated with sJADAS-27/JADAS-27 disease activity scores (P<0.05). The ROC curve analysis showed that sMICB had an area under the curve of 0.755 in evaluating the disease activity of JIA, with a specificity of 0.90 and a sensitivity of 0.64.@*CONCLUSIONS@#The percentage of CD4+NKG2D+ T cells and the levels of sMICA and sMICB increase in children with JIA compared with healthy children and are positively correlated with the disease activity of JIA, suggesting that CD4+NKG2D+ T cells and NKG2D ligands can be used as potential biomarkers for evaluating the disease activity of JIA.

Expression Level of SOCS3 in Acute Lymphoblastic Leukemia Cells Affects the Cytotoxicity of NK Cells / 中国实验血液学杂志

OBJECTIVE@#To detect the expression level of suppressors of cytokine signaling 3 （SOCS3） in acute lymphoblastic leukemia (ALL), and to observe the effect of over-expresson of SOCS3 in Jurkat cells on the cytotoxicity of NK cells.@*METHODS@#The expression levels of SOCS3 mRNA in peripheral blood mononuclear cells of 20 children with ALL and 20 healthy children (normal control group) were detected by RT-PCR. The peripheral blood NK cells from healthy subjects were selected by immunomagnetic technique, and the purity was detected by flow cytometry. SOCS3 was overexpressed in Jurkat cells infected with lentivirus vector, and SOCS3 mRNA expression was detected by RT-PCR after lentivirus infection. The NK cells were co-cultured with the infected Jurkat, and LDH release method was used to detect the cytotoxicity of NK cells on the infected Jurkat cells. The concentrations of TNF-α and IFN-γ were determined by ELISA. The expression of NKG2D ligands MICA and MICB on the surface of Jurkat cells were detected by flow cytometry. Western blot was used to detect the effect of SOCS3 overexpression on STAT3 phosphorylation in Jurkat cells.@*RESULTS@#Compared with the control group, the mRNA expression of SOCS3 in the peripheral blood mononucleated cells of ALL children was significantly decreased. The purity of NK cells isolated by flow cytometry could reach more than 70%. The expression of SOCS3 mRNA in Jurkat cells increased significantly after lentivirus infection. Overexpression of SOCS3 in Jurkat cells significantly promoted the killing ability of NK cells and up-regulated the secretion of TNF-α and IFN-γ from NK cells. The results of flow cytometry showed that the expression of NKG2D ligands MICA and MICB on Jurkat cells increased significantly after SOCS3 overexpression. Western blot results showed that overexpression of SOCS3 significantly reduced the phosphorylation level of STAT3 protein in Jurkat cells.@*CONCLUSION@#SOCS3 mRNA expression was significantly decreased in ALL patients, and overexpression of SOCS3 may up-regulate the expression of MICA and MICB of NKG2D ligands on Jurkat cell surface through negative regulation of JAK/STAT signaling pathway, thereby promoting the cytotoxic function of NK cells.

Effect of Chidamide on the Killing Acitivity of NK Cells Targeting K562 Cells and Its Related Mechanism In Vitro / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of chidamide on the killing activity of NK (Natural killer cell, NK) cells targeting K562 cells and its related mechanism.@*METHODS@#K562 cells were pretreated with chidamide at different concentrations and cocultured with NK cells at different effect-target ratios. The killing effect of chidamide on K562 cells by NK cells, the expression of natural killer group 2 member D (NKG2D) ligands and apoptosis rate of K562 cells were detected by flow cytometry.@*RESULTS@#The killing sensitivity of NK cells to K562 cells could be enhanced by chidamide. The expression of ULBP2 on K562 cell surface could be up-regulate, however, the expression of ULBP1 and MICA/MICB showed no statistically difference as compared with control group. Chidamide showed no obvious cytotoxicity to K562 cells.@*CONCLUSION@#Chidamide can significantly improve killing efficiency of NK cells on K562 cells, which may be related to the up-regulation of ULBP2 expression.

Effects and Mechanism of PARP Inhibitor Olaparib on the Expression of NKG2D Ligands in HL-60 Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the regulatory effects of Olaparib on natural killer cell activating receptor (NKG2D) ligands expression on human acute myeloid leukemia (AML) cell line HL-60, and to explore the molecular mechanism of Olaparib on HL-60 cells.@*METHODS@#After HL-60 cells in logarithmic growth phase were treated with Olaparib at different concentrations for different times (24, 48 h), the expression of NKG2D ligand on the surface of HL-60 cells was detected by flow cytometry. Western blot was used to dectect the expression of ERK expression in HL-60 cells. The killing effect of NK cells to HL-60 cells was detected by CFSE/PI method.@*RESULTS@#10 μmol/L Olaparib could upregulate the expression of NKG2D ligand on the surface of HL-60 cell at 24 and 48 hours, while 5 μmol/L Olaparib could induce up-regulation of the expression of ULBP-2 and ULBP-3 at 48 hours. Western blot analysis showed that ERK phosphorylation of HL-60 cells was enhanced after treating with Olaparib. The killing effect of NK cells to HL-60 cells could be enhanced by Olaparib, however, ERK inhibitor could suppress the killing effect of NK cells to HL-60 cells.@*CONCLUSION@#Olaparib can upregulate NKG2D ligands expression on the surface of HL-60 cells and enhance the cytotoxicity of NK cell to HL-60 cells. The mechanism may be related to Olaparib promoting ERK phosphorylation expression.

Microwave-induced Apoptosis and Cytotoxicity of NK Cells through ERK1/2 Signaling / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate microwave-induced morphological and functional injury of natural killer (NK) cells and uncover their mechanisms.</p><p><b>METHODS</b>NK-92 cells were exposed to 10, 30, and 50 mW/cm2 microwaves for 5 min. Ultrastructural changes, cellular apoptosis and cell cycle regulation were detected at 1 h and 24 h after exposure. Cytotoxic activity was assayed at 1 h after exposure, while perforin and NKG2D expression were detected at 1 h, 6 h, and 12 h after exposure. To clarify the mechanisms, phosphorylated ERK (p-ERK) was detected at 1 h after exposure. Moreover, microwave-induced cellular apoptosis and cell cycle regulation were analyzed after blockade of ERK signaling by using U0126.</p><p><b>RESULTS</b>Microwave-induced morphological and ultrastructural injury, dose-dependent apoptosis (P < 0.001) and cell cycle arrest (P < 0.001) were detected at 1 h after microwave exposure. Moreover, significant apoptosis was still detected at 24 h after 50 mW/cm2 microwave exposure (P < 0.01). In the 30 mW/cm2 microwave exposure model, microwaves impaired the cytotoxic activity of NK-92 cells at 1 h and down regulated perforin protein both at 1 h and 6 h after exposure (P < 0.05). Furthermore, p-ERK was down regulated at 1 h after exposure (P < 0.05), while ERK blockade significantly promoted microwave-induced apoptosis (P < 0.05) and downregulation of perforin (P < 0.01).</p><p><b>CONCLUSION</b>Microwave dose-dependently induced morphological and functional injury in NK-92 cells, possibly through ERK-mediated regulation of apoptosis and perforin expression.</p>

Up-regulation of NKG2A inhibitory receptor on circulating NK cells contributes to transfusion-induced immunodepression in patients with β-thalassemia major / 华中科技大学学报（医学）（英德文版）

Accumulating evidence has shown that allogeneic blood transfusions can induce significant immunosuppression in recipients, and thereby increase the risk of postoperative infection and/or tumor relapse. Although it is well known that natural killer (NK) cells are responsible for the immunodepression effects of transfusion, the underlying mechanisms remain obscure. In this study, we investigated the role of NK cells in transfusion-induced immunodepression in β-thalassemia major. The proportion of circulating NK cells and the expression of NK receptors (NKG2A, CD158a, NKP30, NKP46 and NKG2D) as well as CD107a were detected by multicolor flow cytometry. IFN-γ production by circulating NK cells was detected by intracellular cytokine staining. Our results showed that the proportion and cytotoxicity (CD107a expression) of circulating NK cells in transfusion-dependent β-thalassemia major patients were remarkably lower than those of β-thalassemia minor patients or healthy volunteers. Expression of NKG2A inhibitory receptor on circulating NK cells in patients with β-thalassemia major was remarkably up-regulated, but there were no significant differences in the expression levels of NKP30, NKP46, NKG2D, CD158a and IFN-γ. These results indicate NKG2A inhibitory receptor may play a key role in transfusion-induced immunodepression of NK cells in patients with β-thalassemia major.

Expression of NKG2D/MIC in natural killer cell subsets of patients with primary biliary cirrhosis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To compare frequencies of natural killer (NK) cell subsets and their surface expression of the NKG2D receptor in patients with primary biliary cirrhosis (PBC), and to determine the correlation between expression of MICA on monocytes and function-associated receptors on the NK cells of PBC patients.</p><p><b>METHODS</b>Twenty patients with PBC and 18 healthy donors were included in the study. Peripheral blood samples anticoagulated with heparin were labeled with the following antibody combinations: anti-CD45/anti-CD14/anti-MICA, antiCD3/anti-CD56/anti-CD16/anti-NKG2D. Frequencies of MICA-positive monocytes, NK cell subsets, and NK cells with surface expression of NKG2D were measured with flow cytometry. Correlation of MICA expression on monocytes with NKG2D expreesion on NK cells was assessed through linear correlation and regression analysis.</p><p><b>RESULTS</b>The PBC patients had significantly lower percentages of NK cells than the healthy donors (6.8%+/-2.9% vs.16.4%+/-3.4%, P =0.000<0.05). In the PBC patients, the percentage of CD56-positive NK ceils was significantly higher than that of CD16-positive NK cells (4.2%+/-2.8% vs.1.4%+/-0.7%, P=0.003<0.05). The PBC patients also had significantly higher percentage of NKG2D surface expressing CD56-positive NK cells than the healthy donors (79.4%+/-10.2% vs.64.8%+/-10.7%, P=0.000<0.05). The PBC patients and healthy donors showed no statistically significant differences in percentages of NKG2D surface expressing CDl6-positive NK (70.1%+/-12.9% vs.61.1%+/-5.9%, P=0.078>0.05). MICA was seldom detected on normal monocytes (2.6%+/-1.9%), but present for 51.6%+/-16.2% of monoeytes from the PBC patients (P =0.000<0.05). There was a significant difference in frequency of CD14/MICA double-positive monocytes between the healthy donors and PBC patients. No correlation of MICA expression on monocytes with NKG2D expression on NK cells was found.</p><p><b>CONCLUSION</b>PBC patients have lower levels of NK cells in peripheral blood than their healthy counterparts. PBC patients also have higher levels of the CD56+ NK cell subset and cells with surface expression of the activated NKG2D receptor. It appears that PBC patients have a greater level of CD14+MICA+ peripheral blood mononuclear cells. NK cells may be affected by the PBC-related monocytes and participate in disease pathogenesis through immune regulation.</p>

Study of NK cells dysfunction in multiple myeloma patients / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the mechanism of NK cell dysfunction in patients with multiple myeloma (MM).</p><p><b>METHODS</b>The expression of inhibitory receptors (CD158a and CD158b) and activating receptors NKG2D and NCRs (NKp30, NKp44 and NKp46) on CD3-CD56+NK cell of 13 MM patients and 30 healthy controls were analyzed by flow cytometry. The concentration of soluble NKG2D ligands (MICA, MICB, ULBP1, ULBP2 and ULBP3) in serum was detected by enzyme- linked immunosorbent assay (ELISA), and the cytotoxicity of NK cell against MM cell line by flow cytometry.</p><p><b>RESULTS</b>There are no significant differences of percentage and absolute number of NK cells, and the expression level of CD158a and CD158b between MM patients and healthy individuals (P>0.05). No NKp44 expression was detected on fresh isolated NK cells from both groups. There is no difference in inhibitor receptors expression between MM patients and healthy individuals but the expression of NKG2D, NKp30 and NKp46 on NK cells were higher in MM patients as compared with that in healthy individuals. The concentration of soluble NKG2D ligands in serum was higher in MM patients as compared with that in healthy individuals (P<0.05). Cultured healthy individual's NK cells with MM patient's serum could significantly decrease its cytotoxicity against MM cell line U266 cells [(38.5 ± 6.5) % vs (25.4 ± 5.9)%, P=0.044］.</p><p><b>CONCLUSION</b>The higher level of soluble NKG2D ligands in serum may be the mechanism of NK cell dysfunction in MM patient.</p>

The Correlation between NK Cell and Liver Function in Patients with Primary Hepatocellular Carcinoma

BACKGROUND/AIMS: This study aimed to detect the expression of natural killer (NK) cell receptor natural killer group 2D (NKG2D) in the peripheral blood of patients with primary hepatocellular carcinoma and to discuss the correlation between NK cell cytotoxicity and liver function. METHODS: The number of NK cells and the expression of NK cell receptor NKG2D in peripheral blood were determined by flow cytometry in patients with primary hepatocellular carcinoma, hepatitis B cirrhosis, chronic hepatitis B, and healthy controls. RESULTS: When compared with patients in the healthy and the chronic hepatitis B groups, the primary hepatocellular carcinoma group showed significant decreases in all parameters, including the cytotoxicity of NK cells on K562 cells, expression rate of NKG2D in NK cells, number of NKG2D+ NK cells, expression level of NKG2D, and number of NK cells (p<0.05). The activity of NK cells showed a positive correlation, whereas the Child-Pugh scores in the primary hepatocellular carcinoma and the hepatitis B cirrhosis groups showed a negative correlation with all parameters detected above. CONCLUSIONS: The decrease of NK cell activity in patients with primary hepatocellular carcinoma is closely related to their lower expression of NKG2D. Liver function affects the expression of NKG2D and the activity of NK cells.

Effect of thermal stress on MICA/B induction in a human liposarcoma cell line

A possible mechanism by which hyperthermia enhances tumor immunogenicity is the induction of NKG2D ligands on tumor cells. Although the expression of MHC class I chain-related protein A and B [MICA/B] has previously been reported in different carcinomas, there is no information about MICA/B expression in liposarcomas. To investigate MICA/B induction in a human liposarcoma cell line [SW-872] after thermotherapy. SW-872 and HeLa cell lines were subjected to thermal stress for 1 h at 42, 44 and 46[degree sign]C, and after 2, 4 and 6 h of incubation at 37[degree sign]C, MICA/B expression was assessed at the mRNA and protein levels. Despite high levels of MICA/B transcripts in SW-872 cells at baseline, the expression of these genes decreased significantly at both the mRNA and protein levels after almost all thermal treatments. Our data conclude that thermotherapy under 42-46[degree sign]C had no effect on MICA/B induction on SW-872 liposarcoma cell line but the effects of fever-range temperatures remain to be tested on this cell line

Roles of NKG2D in cytokine-induced killer (CIK) against hematological malignant cells lines / 中国实验血液学杂志

This study was purposed to investigate the CIK cell cytotoxicity to hematological malignant cell lines by interaction NKG2D receptors and corresponding ligands. The CIK cells was expanded from healthy individual with interferon (IFN)γ, CD3 monoclonal antibodies (mAb) and interleukin-2 (IL-2). The subset of lymphocyte and the expression of NK cell receptors on CIK cells was detected by flow cytometry; NKG2D ligand expression on hematological malignant cell lines was also analyzed by flow cytometry, the calcein acetoxymethyl ester (CAM) was used for labeling target cells, then the cytotoxicity of CIK cells to hematological malignant cell lines was detected by flow cytometry. The results showed that most of CIK cells expressed CD3 (97.85 ± 1.95%) , CD3(+)CD8(+) cells and CD3(+)CD56(+) cells increased significantly as compared with un-cultured cells (P < 0.001;P = 0.033). About 86% CIK cells expressed NKG2D receptor but no other NK receptors such as CD158a, CD158b and NCR. Different levels of NKG2D ligands were detected in hematological malignant cell lines U266, K562 and Daudi. CIK cells showed high cytotoxicity to these three different cell lines, and this cytotoxicity was partially blocked by treating CIK cells with anti-NKG2D antibody (U266 52.67 ± 4.63% vs 32.67 ± 4.81%, P = 0.008;K562 71.67 ± 4.91% vs 50.33 ± 4.91%, P = 0.007;Daudi 68.67 ± 5.04 vs 52.67 ± 2.60%, P = 0.024) . It is concluded that most of CIK cells express NKG2D receptor, interaction of NKG2D-NKG2D ligands may be one of the mechanisms, by which CIK cells kill hematological malignant cells.

Effects of matrine on the expression of NKG2D ligands in leukemia cells / 中国实验血液学杂志

This study was aimed to analyze the expression of NKG2D ligands in human leukemic cells and to investigate the effects of matrine on NKG2D ligand expression. The expressions of NKG2D ligand MICA/B, ULBP1-3 in several human leukemia cell lines (K562, OUN-1, U937 and K562/AO2), as well as primary leukemic cells isolated from malignant leukemia patients were analyzed by flow cytometry. After treatment with different doses of matrine, the expression level of NKG2D ligands in these leukemic cells was detected by FCM. The results indicated that NKG2D ligand expression was detected in both the leukemia cell lines and primary malignant leukemic cells. Generally, the expression of ULBP was high or obviously higher than that of MICA/B in leukemia cell lines and primary leukemic cells. The expression pattern of NKG2D ligands was different among these cells, possibly due to the different types of leukemia. Not all the expression of NKG2D ligands was upregulated after matrine treatment. Much higher expressions of ULBP2 and ULBP3 were found in K562 cells, compared to the other cell lines, which partly contributes to the higher sensitivity of K562 cells to NK cytotoxicity as target cells. It is concluded that there is universal expression of NKG2D ligand in leukemia cells. The high ULBP expression is prevalent in human leukemia cells. Matrine has the potential to induce the expression of NKG2D ligands in leukemia cells.

Prognostic value of soluble MICA levels in the serum of patients with advanced hepatocellular carcinoma / 癌症

Serum levels of soluble MHC class I-related chain A (sMICA) are related with the prognosis of various types of cancer; however, few studies on the prognostic value of sMICA in hepatocellular carcinoma (HCC) have been reported. In this study, we retrospectively investigated the relationship between sMICA levels and clinical features of advanced HCC, and we assessed the prognostic value of sMICA in advanced HCC. Furthermore, the relationship of serum sMICA levels and natural killer group 2, member D (NKG2D) expression on natural killer (NK) cells was also evaluated. We detected sMICA levels in the serum of 60 advanced HCC patients using enzyme-linked immunosorbent assay (ELISA) and measured expression levels of NKG2D on NK cells using flow cytometry. We found that serum sMICA levels in HCC patients were in the range of 0.10-6.21 ng/mL. Chi-square analyses showed that sMICA level was significantly related with only tumor size. Survival analysis showed that a high sMICA level was significantly related with poor prognosis among HCC patients. Multivariate analyses indicated that sMICA was an independent prognostic factor. In addition, the levels of CD56+NKG2D+ NK cells were within the range of 11.2%-55.4%, and correlation analyses indicated that sMICA level was negatively correlated with the level of NKG2D+ NK cells. Our results suggest that serum sMICA levels may be an independent prognostic factor for advanced HCC.

NKG2D-mediated natural killer cell cytotoxicity against myeloid leukemia cells OUN-1 / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate NK cell cytotoxicity to leukemic cell by NKG2D receptors and NKG2D ligands interaction upregulated by hydroxyurea (HU).</p><p><b>METHODS</b>Leukemic cell lines OUN-1 and primary leukemic cells were cultured for 24 hours in the presence of HU, then the NKG2D ligands expressions were analyzed by flow cytometry (FCM). Isolated NK cells from healthy individual cultured for 72 hours in presence of IL-2 were used as effect cell, and leukemic cell line OUN-1 treated with HU was used as target cell, NK cell cytotoxicity against leukemic cell line was assessed using chromium-51 release assay.</p><p><b>RESULTS</b>Leukemic cell lines showed upregulation of MIC A/B (MFI: 8.9 ± 0.9 vs 23.5 ± 3.4, P = 0.01) and ULBP2 (MFI: 14.5 ± 0.6 vs 33.5 ± 4.8, P = 0.03) following incubation with HU. HU also upregulated the NKG2DLs on primary leukemia cells from patients with acute myeloid leukemia. Treatment of OUN-1 with HU significantly increased the cytotoxicity of NK cells isolated from healthy individual \[(62.0 ± 5.6)% vs (76.0 ± 5.3)%, P = 0.02\], and the enhancing effect of HU was partly blocked by anti-NKG2D Abs \[(76.0 ± 5.3)% vs (46.0 ± 4.5)%, P = 0.00\].</p><p><b>CONCLUSION</b>HU selectively upregulated NKG2D ligand expression on leukemic cell lines, and enhanced NK cell cytotoxicity against leukemic cells through NKG2D receptors and NKG2D ligands interaction.</p>

Natural killer and cytotoxic T lymphocyte-mediated cytotoxicity enhanced by genetic overexpression of MHC class I chain-related protein A in oral squamous cell carcinoma: an experimental study in vivo / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect on natural killer (NK) and cytotoxic T lymphocyte (CTL)-mediated cytotoxicity by genetic overexpression of MHC class I chain-related protein A (MICA) in oral squamous cell carcinoma (OSCC).</p><p><b>METHODS</b>The OSCC cells by genetic overexpression of MICA were detected to identify the biological features including cell growth curve, cell cycle distribution, plate clone forming rate and tumorigenicity in nude mice. The expression of natural killer group 2, member D (NKG2D) receptor and the cytotoxicity to target tumor cells of NK92 and CTL cells, which co-cultured with the transfected OSCC cells or the non-transfected or blank vector-transfected controls, were measured by flow cytometry and lactate dehydrogenase (LDH) release assay.</p><p><b>RESULTS</b>There was no difference in biological features before and after MICA gene transfection to OSCC cells. Flow cytometry and LDH release assay showed that MICA-overexpressed OSCC cells enhanced the cytotoxicity to target tumor cells and up-regulated the expression of NKG2D on NK92 and CTL (P<0.05).</p><p><b>CONCLUSION</b>MICA may be considered as a promising immunotherapy target of OSCC.</p>

Relationship between the changes in immune cells and HBeAg loss following antiviral treatment in chronic hepatitis B patients / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To observe the changes in hepatitis B virus (HBV)-specific and non-specific cellular immunity that accompany viral load decline during adefovir dipivoxil (ADV) treatment in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, and to explore the antiviral immunity mechanism underlying the treatment response.</p><p><b>METHODS</b>Serial analysis of cellular immunological parameters was performed in HBeAg-positive patients (n = 20) throughout the 48-week course of ADV therapy (10 mg/d). HBV-specific T cell reactivity to HBV core antigen (HBcAg) was assessed by enzyme-linked immunosorbent spot assay and cell proliferation assay at pre-treatment (baseline) and post-treatment weeks 4, 12, 24, 36, and 48. Percentage of regulatory T cells (Tregs), as well as activated peripheral natural killer (NK) cells (expressing the NKG2D receptor), was measured by flow cytometry. Comparisons of means were performed by the two-tailed t-test or the Mann-Whitney rank sum test.</p><p><b>RESULTS</b>After 48 weeks of ADV therapy, HBeAg loss was observed in six of the 20 (30%) patients and 14 patients remained HBeAg-positive. In the patients with HBeAg loss, the viral load reduction was accompanied by a significantly enhanced response rate of HBV-specific interferon (IFN)-gamma-producing CD4+ T cells [measured as (spot forming cells/peripheral blood mononuclear cells); baseline: (661.25+/-281.97) *10(-6) vs. week 48: (280.75+/-104.33) *10(-6), P = 0.045]. In contrast, patients without HBeAg loss showed no significant differences in T cell response rates. The patient groups with and without HBeAg loss showed similar proportions of peripheral blood Tregs during the treatment course, which included a trend of gradual decrease from baseline to week 4 with steady levels thereafter. In addition, both groups showed a similar increase in NKG2D expression that began at week 12 and peaked at week 48.</p><p><b>CONCLUSION</b>HBV-specific T cell reactivity temporally increases in some ADV-treated chronic hepatitis B patients, and this trend is strongly associated with HBeAg loss. Furthermore, recovery of HBV-specific T cell reactivity promotes viral clearance and HBeAg seroconversion.</p>

Effect of NKG2D in eliminating hematological malignant cell lines by natural killer cells / 中国实验血液学杂志

The aim of this study was to clarify whether NKG2D plays an activating role in eliminating hematological malignant cells lines by natural killer (NK) cells. Several hematological malignant cell lines (K562, NB4, Kasumi-1 THP-1, MV-4-11, MOLT-4, Jurkat, RS4; 11, Raji) were used as target cells. The expression levels of major histocompatibility complex class I (MHC I)-related molecules A/B (MICA, MICB), whose corresponding ligand was NKG2D, were detected in target cells by flow cytometry. Firstly, the target cell lines were co-incubated with carboxyfluorescein succinimidyl ester (CFSE) for 30 min. In the meanwhile, NK92MI, a kind of NK cell line, was co-incubated respectively with isotype control antibody or blocking antibody, the latter could block NKG2D specifically. Then, NK92MI cells were co-cultured with different target cell lines. After incubation for 2 h, the apoptotic ratio of each target cell line was detected by flow cytometry. The results demonstrated that there was a significant reduction of the apoptotic ratio in Kasumi-1, an acute myeloid leukemia cell line, when NK92MI cells were incubated with NKG2D blocking antibody previously. In contrast, the apoptotic ratio of other cell lines varied minimally. It is concluded that NKG2D can activate NK cells through inducing cytotoxicity to certain target cells.

The studies for activating and inhibitory receptors on natural killer cells in HIV/HCV co-infected patients / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the characteristics of inhibitory and activating receptor expressions on natural killer (NK) cells in HIV/HCV co-infected patients.</p><p><b>METHODS</b>Numbers, frequencies and expressions of activating and inhibitory receptors of NK cells were measured with flow cytometry (FCS) from HIV/HCV co-infected group (n = 24), HCV mono-infected group (n = 34), HIV mono-infected group (n = 21) and healthy control group (HC, n = 20), then analysis and compare were performed among those groups.</p><p><b>RESULTS</b>The NK cell absolute counts in HIV/HCV group were significantly lower than those in other three groups. The NKP30 and NKP46 frequencies on NK cells in HIV/HCV, HIV and HCV groups were all significantly lower than those in HC group, but there were no significant differences of NKP30 among former three groups; and NKP46 frequencies in HIV/HCV and HIV groups were lower than those in HCV group, but there were no significant differences between former two groups. The NKG2A frequencies in HIV/HCV and HCV groups were all higher than those in HIV and HC groups significantly, but the NKG2A frequencies in HIV group were lower than those in HC group; There were no significant differences of NKG2D, CD158a and CD158b among those four groups.</p><p><b>CONCLUSION</b>NK cell numbers and expressions of activiting receptors on NK cells obviously decreased in HIV/HCV co-infected patients, but some inhibitory receptors expressions increased, even higher than those of HIV mono-infected patients. NK cells impairments in HIV/HCV co-infection is more severe than HIV or HCV mono-infection.</p>

Expression of NKG2D and NKG2A with their ligands MHC-I A/B and HLA-E in acute leukemia patients and its significance / 中国实验血液学杂志

This study was aimed to explore the difference of NK cell receptor NKG2D and NKG2A expression on NK cells and CD3(+) T cells and their ligand MHC-I A/B (major histocompatibility complex class I-related chains A/B) and HLA-E expression in leukemia cells, as well as its immunological significance. Flow cytometry was used to detect the killing rate of NK92 cells to 8 leukemia cell lines, and the expression of NKG2D and NKG2A on NK cells and CD3(+) T cells as well as their ligand MHC-I A/B and HLA-E expression on leukemia cells. The results indicated that the NK92 showed different killing activity to different leukemia cell lines. The positive expression rate of NKG2D and NKG2A on NK cells and CD3(+) T cells in ALL patients was no significantly different from that in AML patients (p > 0.05), but positive expression rate of MHC-I A/B and HLA-E in ALL patients was obviously higher than that in AML patients (p < 0.05). It is concluded that there is difference of immune cell function between ALL and AML patients, this difference may be associated with the expression difference of NKG2D and NKG2A ligands on leukemia cells while does not associated with the killing and inhibiting receptors expressed on NK cells and CD3(+) T cells.