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 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

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

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.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Female ; Histocompatibility Antigens Class I ; genetics ; metabolism ; Humans ; Infant ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; Male ; Middle Aged ; NK Cell Lectin-Like Receptor Subfamily C ; genetics ; metabolism ; NK Cell Lectin-Like Receptor Subfamily K ; genetics ; metabolism ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; 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

OBJECTIVETo investigate the regulatory effect of IFN-gamma on recognition of target cells by human natural killer (NK) cells.

METHODSThe cytotoxic activity of human NK cell lines (NK92, NKL) was detected by MTT method. Expression of NK cell receptors (NKG2D, NKG2A/B, KIR2DL1 and KIR2DS1) and MICA on target cells (the ligand of NKG2D) was measured by RT-PCR.

RESULTSBoth NK92 and NKL cells exerted higher cytotoxicity to tumor cells with MICA expression, while tumors without MICA expression could resist NK cell lysis. IFN-gamma (> 1000 U/ml) inhibited NK lysis of tumor cells with MICA expression through down-regulating the expression of NKG2D, but up-regulating the expression of NKG2A/B and KIR2DL1.

CONCLUSIONIFN-gamma has a negative effect on activation and cytotoxicity of human NK cells by altering the balance between the expression of activating and inhibitory receptors on NK cells in favor of inhibition. This may serve to limit NK cell over-activation in vivo.

Cell Division ; drug effects ; Cytotoxicity, Immunologic ; drug effects ; Histocompatibility Antigens Class I ; analysis ; physiology ; Humans ; Interferon-gamma ; pharmacology ; Killer Cells, Natural ; immunology ; NK Cell Lectin-Like Receptor Subfamily C ; NK Cell Lectin-Like Receptor Subfamily K ; Receptors, Immunologic ; metabolism ; Receptors, KIR2DL1 ; Receptors, Natural Killer Cell ; Recombinant Proteins ; Tumor Cells, Cultured

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.
Alkaloids ; pharmacology ; Cell Line, Tumor ; GPI-Linked Proteins ; metabolism ; Gene Expression Regulation, Leukemic ; Histocompatibility Antigens Class I ; metabolism ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; K562 Cells ; NK Cell Lectin-Like Receptor Subfamily K ; metabolism ; Quinolizines ; pharmacology ; Tumor Cells, Cultured

OBJECTIVETo study the expression of membrane MICA (mMICA), soluble MICA (sMICA) and NKG2D receptor in cases of osteosarcoma and to analyze its clinical significance.

METHODSExpression of mMICA in osteosarcoma tissue of 43 cases was detected with immunohistochemistry. Expression of NKG2D in peripheral blood lymphocytes of 16 cases was analyzed by flow cytometry. Serum level of soluble MICA (sMICA) was measured by ELISA.

RESULTSmMICA was widely expressed in osteosarcoma tissue (37/43). Expression of NKG2D in peripheral blood lymphocytes was significantly decreased. High levels of mMICA and NKG2D expression were associated with better differentiation and earlier tumor stage of osteosarcoma (P < 0.05). A significant increase in serum level of sMICA was demonstrated in patients with metastasis and advanced tumor.

CONCLUSIONSThe mMICA expression in tumor tissue, NKG2D expression in peripheral lymphocytes and serum sMICA level correlate with the differentiation and stage of osteosarcoma. These parameters may thus represent potential diagnostic and prognostic markers in patients with osteosarcoma. Manipulation of the MICA-NKG2D pathway may become a target of immunotherapy for osteosarcoma.

Bone Neoplasms ; blood ; metabolism ; pathology ; Cell Differentiation ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Histocompatibility Antigens Class I ; blood ; metabolism ; Humans ; Immunohistochemistry ; Lymphocytes ; immunology ; NK Cell Lectin-Like Receptor Subfamily K ; metabolism ; Neoplasm Staging ; Osteosarcoma ; blood ; metabolism ; pathology

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.
Antibodies, Monoclonal ; pharmacology ; Cell Line, Tumor ; Culture Media ; chemistry ; Cytokine-Induced Killer Cells ; metabolism ; Humans ; Interferon-gamma ; pharmacology ; Interleukin-2 ; pharmacology ; Ligands ; Monocytes ; cytology ; metabolism ; NK Cell Lectin-Like Receptor Subfamily K ; metabolism