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

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

OBJECTIVETo investigate microwave-induced morphological and functional injury of natural killer (NK) cells and uncover their mechanisms.

METHODSNK-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.

RESULTSMicrowave-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).

CONCLUSIONMicrowave dose-dependently induced morphological and functional injury in NK-92 cells, possibly through ERK-mediated regulation of apoptosis and perforin expression.

Apoptosis ; radiation effects ; Cell Cycle ; radiation effects ; Cell Line ; Dose-Response Relationship, Radiation ; Down-Regulation ; Humans ; Killer Cells, Natural ; radiation effects ; MAP Kinase Signaling System ; Microwaves ; adverse effects ; NK Cell Lectin-Like Receptor Subfamily K ; genetics ; metabolism ; Signal Transduction

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.
Child ; Histocompatibility Antigens Class I/metabolism* ; Humans ; Killer Cells, Natural/cytology* ; Leukocytes, Mononuclear/cytology* ; Ligands ; NK Cell Lectin-Like Receptor Subfamily K/metabolism* ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; RNA, Messenger/genetics* ; Suppressor of Cytokine Signaling 3 Protein/metabolism* ; Tumor Necrosis Factor-alpha/metabolism*

OBJECTIVETo analyze the expression of NKG2D ligands on human nasopharyngeal carcinoma cell line CNE2 and the multidrug-resistant lin CNE2/DDP and investigate its impact on cytotoxicity of natural killer (NK) cells.

METHODSExpression of NKG2D ligands on the surface of CNE2 and CNE2/DDP cells was analyzed by flow cytometry, and their HLA genotypes, along with inhibitory killer cell immunoglobulin-like receptors (KIRs) expressed on NK cells from 5 healthy donors, were determined by PCR with sequence specific primers. Cytotoxicity of NK cells against CNE2 and CNE2/DDP cells was evaluated by LDH-releasing assay at different effector-to-target ratios (E:T). In blocking experiments, different monoclonal antibodies (mAb) were added to the target cells at the E:T of 20:1 ratio.

RESULTSThe HLA genotypes of CNE2 and CNE2/DDP cells were A2, 24, B18, 35, Cw4, 7, and the inhibitory KIR genotypes of the 5 healthy donors were KIR2DL1, KIR2DL3, KIR3DL1, and KIR3DL2, mismatched with the HLA -class I molecules expressed by the CNE2 and CNE2/DDP cells. The expression of MHC class I chain-related proteins A and B (MICA and MICB) on CNE2 cells was higher than that on CNE2/DDP cells (P<0.01), and ULBP1 and ULBP3 were not detectable. NK cells displayed highly in vitro cytotoxicity against CNE2 and CNE2/DDP cells with a mean cell lysis rate of (10.50-/+2.17)%, (4.98-/+0.95)%; (27.68-/+1.47) %, (15.48-/+2.10) %; (36.99-/+3.13) %, (28.46-/+4.30) %; (55.00-/+2.20) %, (40.95-/+2.21) %, respectively, corresponding to the E:T ratios of 5:1, 10:1, 20:1, and 30:1 (P<0.01). Blocking experiments confirmed that killing of CNE2 and CNE2/DDP cells by NK cells was efficiently inhibited by anti-MICA, anti-MICB, and anti-ULBP2 mAbs, whereas anti-ULBP1 and anti-ULBP3 mAbs had no effects on the cytotoxicity of the NK cells.

CONCLUSIONExpression of NKG2D ligands on CNE2 and CNE2/DDP cells is correlated with NK cell-mediated lysis, and NK cells display higher cytotoxicity against parental CNE2 cells than the multidrug-resistant CNE2/DDP cells.

Antibodies ; pharmacology ; Cell Line, Tumor ; Cytotoxicity, Immunologic ; drug effects ; immunology ; Drug Resistance, Multiple ; Flow Cytometry ; Genotype ; HLA Antigens ; genetics ; Histocompatibility Antigens Class I ; immunology ; metabolism ; Humans ; Killer Cells, Natural ; immunology ; NK Cell Lectin-Like Receptor Subfamily K ; immunology ; metabolism ; Nasopharyngeal Neoplasms ; immunology ; metabolism ; pathology ; Polymerase Chain Reaction ; Receptors, KIR ; genetics

Although nickel hypersensitivity is known as a delayed-type hypersensitivity mediated by nickel-specific T cells, it is greatly influenced by other immune cells. Here we show that splenic natural killer cells (NK cells) directly or indirectly respond to nickel by secretion of IFN-gamma. Using enzyme-linked immunosorbent spot (ELISPOT) assays, we found that nickel-reactive cells readily secreted IFN-gamma when splenocytes were cultured in the presence of varying concentrations of nickel sulfate (NiSO4) for 24 h. However, nickel-reactive IL-2- or IL- 4-secreting cells were infrequent during the 24-h culture with NiSO4. Immune responses to nickel were innate, not adaptive, in nature since the frequency of nickel-reactive IFN-gamma-secreting cells did not increase upon previous exposure to NiSO4 and recombination activating gene (RAG)-1-deficient mice contained nickel-reactive IFN-gamma-secreting cells. The involvement of NK cells in the innate response to NiSO4 was confirmed since we could observe a significant reduction of the frequency of nickel-reactive cells in NK cell-depleted mice. Furthermore, the number of IFN-gamma secreting cells was significantly reduced in the ELISPOT assays when NKG2D was blocked by anti-NKG2D antibody. These results suggest that there is an early and rapid innate immune response to nickel, which is mediated by NK cells and the NKG2D receptor. The significance of the innate response to nickel is that it may contribute to development of the late T cell-mediated delayed type hypersensitivity against nickel.
Animals ; Homeodomain Proteins/genetics/metabolism ; Humans ; Immunity, Innate/immunology ; Interferon-gamma/*secretion ; *Irritants/immunology/pharmacology ; *Killer Cells, Natural/drug effects/immunology/secretion ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; NK Cell Lectin-Like Receptor Subfamily K/genetics/metabolism ; *Nickel/immunology/pharmacology ; Spleen/*cytology/immunology