OBJECTIVETo 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.

METHODSTwenty 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.

RESULTSThe 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.

CONCLUSIONPBC 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.

Flow Cytometry ; Humans ; Killer Cells, Natural ; Liver Cirrhosis, Biliary ; NK Cell Lectin-Like Receptor Subfamily K

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.
Child ; Humans ; Arthritis, Juvenile/pathology* ; Ligands ; NK Cell Lectin-Like Receptor Subfamily K ; Prospective Studies ; T-Lymphocytes/pathology*

OBJECTIVETo investigate NK cell cytotoxicity to leukemic cell by NKG2D receptors and NKG2D ligands interaction upregulated by hydroxyurea (HU).

METHODSLeukemic 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.

RESULTSLeukemic 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 \[(76.0 ± 5.3)% vs (46.0 ± 4.5)%, P = 0.00\].

CONCLUSIONHU selectively upregulated NKG2D ligand expression on leukemic cell lines, and enhanced NK cell cytotoxicity against leukemic cells through NKG2D receptors and NKG2D ligands interaction.

Cell Line, Tumor ; Humans ; Hydroxyurea ; pharmacology ; Killer Cells, Natural ; drug effects ; immunology ; Leukemia ; immunology ; Ligands ; NK Cell Lectin-Like Receptor Subfamily K ; immunology

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.
Cell Line, Tumor ; Flow Cytometry ; Hematologic Neoplasms ; immunology ; metabolism ; Humans ; Killer Cells, Natural ; immunology ; NK Cell Lectin-Like Receptor Subfamily K ; immunology ; metabolism

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.
Cell Line, Tumor ; Cytotoxicity, Immunologic ; HL-60 Cells ; Histocompatibility Antigens Class I ; Humans ; Ligands ; NK Cell Lectin-Like Receptor Subfamily K ; Phthalazines ; Piperazines ; Poly(ADP-ribose) Polymerase Inhibitors

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.
Humans ; Mice ; Animals ; Receptors, Chimeric Antigen/genetics* ; Interleukin-15 ; NK Cell Lectin-Like Receptor Subfamily K/metabolism* ; Granzymes ; Cell Line, Tumor ; Multiple Myeloma/therapy* ; Perforin

Carcinoma, Hepatocellular ; immunology ; Female ; Histocompatibility Antigens Class I ; blood ; Humans ; Killer Cells, Natural ; immunology ; Liver Neoplasms ; immunology ; Male ; NK Cell Lectin-Like Receptor Subfamily K ; metabolism

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.
Aminopyridines ; Benzamides ; GPI-Linked Proteins ; Histocompatibility Antigens Class I ; Humans ; Intercellular Signaling Peptides and Proteins ; K562 Cells ; Killer Cells, Natural ; immunology ; NK Cell Lectin-Like Receptor Subfamily K

OBJECTIVETo investigate the characteristics of inhibitory and activating receptor expressions on natural killer (NK) cells in HIV/HCV co-infected patients.

METHODSNumbers, 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.

RESULTSThe 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.

CONCLUSIONNK 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.

Adult ; Female ; Flow Cytometry ; HIV Infections ; genetics ; metabolism ; Hepatitis C ; genetics ; metabolism ; Humans ; Killer Cells, Natural ; metabolism ; Male ; Middle Aged ; NK Cell Lectin-Like Receptor Subfamily C ; genetics ; metabolism ; NK Cell Lectin-Like Receptor Subfamily K ; genetics ; metabolism ; Natural Cytotoxicity Triggering Receptor 1 ; genetics ; metabolism ; Natural Cytotoxicity Triggering Receptor 3 ; genetics ; metabolism ; Receptors, KIR2DL1 ; genetics ; metabolism ; Receptors, KIR2DL3 ; genetics ; metabolism ; Young Adult

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.
Adolescent ; Child ; Female ; Flow Cytometry ; Gene Expression Regulation ; Humans ; Immunosuppression ; Killer Cells, Natural ; immunology ; metabolism ; Male ; NK Cell Lectin-Like Receptor Subfamily C ; blood ; immunology ; NK Cell Lectin-Like Receptor Subfamily K ; blood ; immunology ; Natural Cytotoxicity Triggering Receptor 1 ; blood ; immunology ; Natural Cytotoxicity Triggering Receptor 3 ; blood ; immunology ; Receptors, KIR2DL1 ; blood ; immunology ; Transfusion Reaction ; beta-Thalassemia ; blood ; immunology ; pathology