Antigens, Surface ; analysis ; Antiretroviral Therapy, Highly Active ; CD28 Antigens ; analysis ; CD56 Antigen ; analysis ; HIV Infections ; drug therapy ; immunology ; Humans ; Killer Cells, Natural ; immunology ; Lectins, C-Type ; analysis ; NK Cell Lectin-Like Receptor Subfamily B ; NK Cell Lectin-Like Receptor Subfamily D ; analysis ; Receptors, Immunologic ; analysis ; Receptors, KIR

NK cell has antigen-non-specific receptors on its surface. Based on the molecular structure, NK cell receptors can be divided into two types, including Ig superfamily and C-type lectin superfamily. Based on function, NK cell receptors can be divided into activation receptors (NKAR) and inhibition receptors (NKIR). NKAR includes CD16 mediating antibody dependent cytotoxicity, NKR-P1 mediating natural cytotoxicity, KAR conjugated with DAP12 and co-stimulatory receptor. They transduce signal through the ITAM motif in their cytoplasmic region. NKIR mainly include KIR and CD94/NKG2. Their ligands are MHC-I molecules. They are closely related to the recognition of auto cells by NK cells. Inhibition of NKAR activation and cytotoxic effect of NK cells by NKIR are carried out through the ITIM motif and require co-aggregation of NKAR and NKIR.
Antigens, CD ; immunology ; Humans ; Immunity, Cellular ; Killer Cells, Natural ; immunology ; Lectins, C-Type ; immunology ; Ligands ; NK Cell Lectin-Like Receptor Subfamily C ; NK Cell Lectin-Like Receptor Subfamily D ; Receptors, IgG ; immunology ; Receptors, Immunologic ; immunology ; Receptors, KIR ; Receptors, Natural Killer Cell

CD94/NKG2A is a kind of inhibitory receptor belonging to C-type lectin superfamily. It specifically expresses on the surface of some lymphocytes such as NK cells and T cells, and mediates inhibitory signal. In this mini-review, the structure of CD94/NKG2A molecule is described and its biological significance is discussed.
Antigens, CD ; immunology ; HLA Antigens ; immunology ; Histocompatibility Antigens Class I ; immunology ; Humans ; Killer Cells, Natural ; immunology ; Lectins, C-Type ; immunology ; NK Cell Lectin-Like Receptor Subfamily C ; NK Cell Lectin-Like Receptor Subfamily D ; Receptors, Immunologic ; immunology ; Receptors, Natural Killer Cell ; T-Lymphocytes ; immunology

<b>OBJECTIVEb>To investigate the regulatory effect of IFN-gamma on recognition of target cells by human natural killer (NK) cells.

<b>METHODSb>The 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.

<b>RESULTSb>Both 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.

<b>CONCLUSIONb>IFN-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

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

<b>METHODSb>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.

<b>RESULTSb>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.

<b>CONCLUSIONb>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.

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

<b>OBJECTIVEb>To observe the effect of Ly49A transfected mouse spleen cells on graft versus host disease (GVHD) and graft versus leukemia (GVL) effect after haploidentical allogeneic bone marrow transplantation in mice.

<b>METHODSb>Ly49A gene was transfected into spleen cells of C57BL/6 mice by retrovirus and the expression rate of Ly49A receptor was evaluated by flow cytometry. The murine model of haploidentical allogeneic acute GVHD was established by using C57BL/6(H - 2b) mouse as donor, and (BALB/c x C57BL/6) F1(H - 2d/b) (CB(6)F(1)) mouse as the recipient which was injected EL9611 cells before transplantation. After irradiation (TBI, (60)Co 10.5 Gy), the recipient received mixed graft of spleen cells and bone marrow cells to establish a GVHD model. The effects of Ly49A transfected spleen cells on GVHD and GVL post haploidentical allogeneic bone marrow transplantation were detected with this model.

<b>RESULTSb>The expression rate of Ly49A receptor was (42.20 +/- 4.87)%, (18.67 +/- 2.48)% and (18.73 +/- 3.82)% for pLXSN-Ly49A, pLXSN transfected and untransfected spleen cells respectively. Among haploidentical allo-BMT (C57BL/6(H - 2b)-->CB6F1(H - 2d/b)) groups, the survival time was (7.80 +/- 3.36) days for irradiation group; (21.70 +/- 2.87) days for cyclophosphomide therapy group; (29.40 +/- 6.43) days for mixed bone marrow cells and spleen cells transplantation group; (29.10 +/- 7.39) days for mixed bone marrow cells and pLXSN transfected spleen cells transplantation group and (45.00 +/- 12.38) days for mixed bone marrow cells and Ly49A transfected spleen cells transplantation group, which was much longer than that of any other groups (P = 0.000).

<b>CONCLUSIONb>The Ly49A transfected spleen cell transplantation could alleviate GVHD and retain GVL effect in the acute GVHD model post haploidentical allo-BMT.

Animals ; Antigens, Ly ; genetics ; immunology ; Bone Marrow Transplantation ; Cell Transplantation ; adverse effects ; Female ; Graft vs Host Disease ; etiology ; immunology ; mortality ; Graft vs Leukemia Effect ; immunology ; Lectins, C-Type ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; NK Cell Lectin-Like Receptor Subfamily A ; Receptors, NK Cell Lectin-Like ; Spleen ; cytology ; metabolism ; Survival Rate ; Time Factors ; Transfection

The study was purposed to explore the effects of NKG2D receptor and its ligands RAE-1 and H60 on graft-versus-tumor (GVT) response induced by MHC haploidentical bone marrow/spleen cell transplantation. Female (BALB/c x C57BL/6) F1 mice (CB6F1, H-2K(b/d)) inoculated with H22 cells to develop a solid tumor model were the recipients, and bone marrow mixed with spleen cells of the healthy male C57BL/6 (H-2K(b)) mice were the donor cells. GVT response was observed after transplantation that from donor cells T and NK cells were purged with anti-CD3 and anti-NK monoclonal antibody, and the NKG2D receptor was blocked with anti-NKG2D monoclonal antibody, the expression levels of RAE-1 and H60 mRNA in tumor tissue were measured by means of semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) at different time points after transplantation. The results showed that the GVT response of transplantation was reduced after in vitro depletion of T and NK cells or blocking NKG2D receptor in donor cells of the graft, the expression levels of RAE-1 and H60 mRNA in tumor tissue increased after transplantation of haploidential bone marrow mixed with spleen cells. It is concluded that NKG2D and its ligands RAE-1 and H60 may play important roles in GVT response.
Animals ; Female ; Graft vs Leukemia Effect ; drug effects ; immunology ; Hematopoietic Stem Cell Transplantation ; Killer Cells, Natural ; drug effects ; immunology ; Leukemia, Experimental ; immunology ; therapy ; Ligands ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Mice, Inbred Strains ; Minor Histocompatibility Antigens ; biosynthesis ; genetics ; NK Cell Lectin-Like Receptor Subfamily K ; Nuclear Matrix-Associated Proteins ; biosynthesis ; genetics ; Nucleocytoplasmic Transport Proteins ; biosynthesis ; genetics ; Receptors, Immunologic ; blood ; genetics ; Receptors, Natural Killer Cell

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

<b>OBJECTIVEb>To analyze the clinicopathologic features of extranodal NK/T cell lymphoma, nasal type (ENKTCL-N), to explore the expression of NK cell-associated receptors in ENKTCL-N and the relationship with prognosis, and to establish a prognostic model.

<b>METHODSb>One hundred and twenty-six cases of ENKTCL-N were selected from the files of the Department of Pathology, West China Hospital of Sichuan University. The relevant clinical and follow-up data were collected, and the histopathology was reviewed. All specimens were stained immunohistochemically for CD16, ICAM-1 and LFA-1. RT-PCR was used to detect the expression of CD94, NKG2 and KIR. The relationship between the prognosis of ENKTCL-N, clinical features, histopathological characteristics and expression of these markers were also analyzed.

<b>RESULTSb>ENKTCL-N mainly occurred in middle-age and young patients (median age, 41 years). The male to female ratio was 3.2:1. Sites more commonly involved were the nose and upper aerodigestive tract whereas those for the non-nasal type were the skin and gut. Only six cases involved two or more extranodal sites. Most (86.5%, 109/126) of the patients were in clinical stages I/II. The tumors showed predominately medium-sized tumor cells and large-sized tumor cells accounted for only 9.5% (12/126). Coagulative necrosis was present in all cases. The expression rates of CD56, CD16, CD94, LFA-1 and ICAM-1 were 82.6% (95/115), 15.1% (19/126), 55.4% (41/74), 40.5% (51/126) and 0, respectively. The expression rate of NKG2 receptor was 90.5% (67/74) overall. NKG2 receptor expression was independent of CD94. The overall expression rate of KIR receptor was 33.8% (25/74) and KIR receptor restriction was not detected in 20.8% (5/24) of the cases. Follow-up data was available in all patients, with median and average survival time being 15 months and 20.2 months, respectively. Survival analysis showed that prognostic factors included the gender, age, disease type, extranodal involvement, stage, the expression of CD16, LFA-1 and CD94. Cox's proportional hazard regression analysis revealed four factors, age, involved site, stage and CD16 expression, were independent prognostic factors.

<b>CONCLUSIONSb>The age, disease type, stage and CD16 expression are independent prognostic factors. Establishment of a prognostic model based on the above four factors can be more accurate in the prognostication of ENKTCL-N. The differences in the clinical features, prognosis, and expression of NK cell-associated receptors are obvious between nasal NK-cell lymphoma and non-nasal NK-cell lymphoma.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; CD56 Antigen ; metabolism ; Child ; Female ; Follow-Up Studies ; Humans ; Intercellular Adhesion Molecule-1 ; metabolism ; Lymphocyte Function-Associated Antigen-1 ; metabolism ; Lymphoma, Extranodal NK-T-Cell ; metabolism ; pathology ; Male ; Middle Aged ; NK Cell Lectin-Like Receptor Subfamily D ; metabolism ; Neoplasm Staging ; Nose Neoplasms ; metabolism ; pathology ; Prognosis ; Proportional Hazards Models ; Receptors, IgG ; metabolism ; Receptors, KIR ; metabolism ; Receptors, NK Cell Lectin-Like ; metabolism ; Survival Rate ; Young Adult