Advancement of chimeric antigen receptor-natural killer cells targeting hepatocellular carcinoma

With the advance of genome engineering technology,chimeric antigen receptors(CARs)-based immunotherapy has become an emerging therapeutic strategy for tumors.Although initially designed for T cells in tumor immunotherapy,CARs have been exploited to modify the function of natural killer(NK)cells against a variety of tumors,including hepatocellular carcinoma(HCC).CAR-NK cells have the potential to sufficiently kill tumor antigen-expressing HCC cells,independent of major histocompatibility complex matching or prior priming.In this review,we summarize the recent advances in genetic engineering of CAR-NK cells against HCC and discuss the current challenges and prospects of CAR-NK cells as a revolutionary cellular immunotherapy against HCC.

HBsAg stimulates NKG2D receptor expression on natural killer cellsand inhibits hepatitis C virus replication

Background： Higher hepatitis B surface antigen （HBsAg） facilitates hepatitis C virus （HCV） clearance inpatients with hepatitis B virus （HBV）/HCV co-infection. We investigated the effect of exogenous HBsAgon the inhibition of HCV replication mediated by natural killer （NK） cells.

Transient Receptor Potential Melastatin 3 and Intracellular Calcium in Natural Killer Cells in Multiple Sclerosis

Background: Natural killer (NK) cell phenotypes have reported to be implicated in the pathomechanism of Multiple Sclerosis (MS). Several investigators have observed reduced peripheral numbers, reduced cytotoxic activity, and altered CD56Dim and CD56Bright NK cell phenotypes. This current project, for the first time, investigates the NK cell cytotoxicity, calcium mobilisation and transient receptor potential melastatin 3 (TRPM3) surface expression. Methods: NK cell cytotoxic activity and calcium signaling were examined in CD56Dim and CD56Bright NK cells before and after stimulation using Ionomycin, Pregnenolone sulphate, 2-Aminoethoxydiphenyl borate and Thapsigargin. Purified NK cells were labelled with antibodies to determine TRPM3, CD69 and CD107a surface expression using flow cytometry. Results: Twenty-two MS patients and 22 healthy controls were recruited for this project. Twelve of the 22 previously received Alemtuzumab (Lemtrada®) and the remaining ten reported nil medication. We report TRPM3 was significantly increased in untreated MS patients compared with healthy controls and treated MS patients (p-value 0.034). There was a significant decrease in CD69 surface expression on CD56Dim NK cell phenotype for untreated MS patients (p-value 0.031) and treated MS patients (p-value 0.036). We report altered calcium mobilisation in CD56Bright NK cells and to a lesser extent CD56Dim NK cells between healthy controls, treated and untreated MS patients. Conclusion: This investigation suggests variations in TRPM3 expression and calcium mobilisation of NK cells may be implicated in the pathogenesis of MS. Further investigation is required to determine the mechanism by which alemtuzumab alters calcium signaling in NK cells.

Natural Killer Cell-Based Immunotherapy for Cancer: Advances and Prospects

Natural killer (NK) cells are key innate immune cells that provide the first line of defense against viral infection and cancer. Although NK cells can discriminate between "self" and "non-self," recognize abnormal cells, and eliminate transformed cells and malignancies in real time, tumors develop several strategies to escape from NK cell attack. These strategies include upregulating ligands for the inhibitory receptors of NK cells and producing soluble molecules or immunosuppressive factors. Various types of NK cells are currently being applied in clinical trials, including autologous or allogeneic NK cells, umbilical cord blood (UCB) or induced pluripotent stem cell (iPSC)-derived NK cells, memory-like NK cells, and NK cell line NK-92 cells, for the treatment of different types of tumors. Chimeric antigen receptors (CARs)-NK cells have recently shown great potential due to their redirect specificity and effective antitumor activity. In this review, we summarize the mechanisms of tumor escape from NK cell recognition, the current status and advanced progress of NK cell-based immunotherapy, ways of enhancing the antitumor capacity of NK cells in vivo, and major challenges for clinical practice in this field.

Immune evasion and therapeutic opportunities based on natural killer cells

Natural killer(NK)cells can elicit an immune response against malignantly transformed cells without recognizing antigens,and they also exhibit cytotoxic effects and immune surveillance functions in tumor immunotherapy.Although several studies have shown the promising antitumor effects of NK cells in immunotherapy,their function is often limited in the tumor microenvironment because tumor cells can easily escape NK cell-induced death.Thus,for efficient tumor immunotherapy,the mechanism by which tumor cells escape NK cell-induced cytotoxicity must be fully understood.Various novel molecules and checkpoint receptors that mediate the disruption of NK cells in the tumor microenvironment have been discovered.In this review,we analyze and detail the major activating and inhibitory receptors on the surface of NK cells to delineate the mechanism by which tumor cells suppress NKG2D ligand expression and increase tumor receptor and inhibitory receptor expression[NKG2A,programmed cell death1(PD-1),and T-cell immunoglobulin and immunoreceptor tyrosine inhibitory motif(TIGIT)]on the NK cell surface,and thus inhibit NK cell activity.We also reviewed the current status of treatments based on these surface molecules.By comparing the therapeutic effects related to the treatment status and bypass mechanisms,we attempt to identify optimal single or combined treatments to suggest new treatment strategies for tumor immunotherapy.

Potential role of killer immunoglobulin receptor genes among individuals vaccinated against hepatitis B virus in Lebanon

AIMTo explore the role of killer immunoglobulin receptor (KIR) genes in responsiveness or non-responsiveness to vaccination against hepatitis B virus. METHODSWe recruited 101 voluntary participants between March 2010 and December 2011. Sera samples from vaccinated and non-vaccinated participants were tested for the presence of anti-HBs antibodies as a measure of protection against hepatitis B, hepatitis B surface antigen and hepatitis B core antibody as indicators of infection by enzyme-linked immunosorbent assay. KIR gene frequencies were determined by polymerase chain reaction. RESULTSSera samples from 99 participants were tested for the levels of anti-HBs as an indicator of protection (≥ 10 mIU/mL) following vaccination as defined by the World Health Organization international reference standard. Among the vaccinated participants, 47% (35/74) had anti-HBs titers above 100 mIU/mL, 22% (16/74) had anti-HBs ranging between 10-100 mIU/mL, and 20% (15/74) had values of less than 10 mIU/mL. We report the lack of significant association between the number of vaccine dosages and the titer of antibodies among our vaccinated participants. The inhibitory KIR2DL1, KIR2DL4, KIR3DL1, KIR3DL2, and KIR3DL were detected in more than 95%, whereas KIR2DL2, KIR2DL3, KIR2DL5 (KR2DL5A and KIR2DL5B) were expressed in 56%, 84% and 42% (25% and 29%) of participants, respectively. The observed frequency of the activating KIR genes ranged between 35% and 55% except for KIR2DS4, detected in 95% of the study participants (40.6% 2DS4*001/002; 82.2% 2DS4*003/007). KIR2DP1 pseudogene was detected in 99% of our participants, whereas KIR3DP*001/02/04 and KIR3DP1*003 had frequencies of 17% and 100%, respectively. No association between the frequency of KIR genes and anti-HBs antibodies was detected. When we compared the frequency of KIR genes between vaccinated individuals with protective antibodies titers and those who lost their protective antibody levels, we did not detect a significant difference. KIR2DL5B was significantly different among different groups of vaccinated participants (group I > 100 mIU/mL, group II 10-100 mIU/mL, group III CONCLUSIONTo our knowledge, this is the first study screening for the possible role of KIR genes among individuals vaccinated against hepatitis B virus (HBV). Our results can be used to design larger studies to better understand the role of KIR genes in protection against or susceptibility to HBV post vaccination.

Why natural killer cells in triple negative breast cancer?

The triple-negative subtype of breast cancer(TNBC)has the bleakest prognosis,owing to its lack of either hormone receptor as well as human epidermal growth factor receptor 2.Henceforth,immunotherapy has emerged as the front-runner for TNBC treatment,which avoids potentially damaging chemotherapeutics.However,despite its documented association with aggressive side effects and developed resistance,immune checkpoint blockade continues to dominate the TNBC immunotherapy scene.These immune checkpoint blockade drawbacks necessitate the exploration of other immunotherapeutic methods that would expand options for TNBC patients.One such method is the exploitation and recruitment of natural killer cells,which by harnessing the innate rather than adaptive immune system could potentially circumvent the downsides of immune checkpoint blockade.In this review,the authors will elucidate the advantageousness of natural killer cell-based immuno-oncology in TNBC as well as demonstrate the need to more extensively research such therapies in the future.

Targeted Therapy of CEA-CAR-NK Cells Against Colorectal Cancer Cells

Objective:Investigate the cytotoxic effect of CAR-NK cells targeting CEA on colorectal cancer cells with positive CEA expression.Methods:The mRNA and protein levels of CEA in different CRC cell lines were detected by qRT-PCR and Western blot analysis.Lentiviral transduction was used to construct CAR-NK cells and empty vector CON-NK cells targeting CEA.Fluorescence microscopy and WB were used to determine whether the cells successfully constructed and expressed CAR structures.The effector NK cells were co-cultured with target cells,and the levels of LDH,IFN-γ,and GM-CSF were detected.The killing rate of effector cells was calculated,and the release of cytokines during the killing of target cells by different effector cells was compared.Results:The expression level of CEA in colorectal cancer patients was significantly higher than that in normal samples and other tumor samples,and the prognosis survival time of patients with high CEA expression was lower than that of CRC patients with low or no CEA expression(P<0.05).The CEA expression of the HT29 cell line was significantly higher than that of the SW1116 cell line at both the mRNA and protein levels.CEA-CAR-NK92 cells and CON-NK92 cells expressed green fluorescence under a microscope,and WB results showed that CEA-CAR-NK92 cells successfully expressed the CAR structure.Compared with CON-NK92 cells and NK92 cells,CEA-CAR-NK92 cells effectively killed HT29 cells(P<0.05).CEA-CAR-NK92 cells secreted a large amount of IFN-γand GM-CSF during the killing of HT29 cells,while the cytokine secretion of CON-NK92 cells and NK92 cells was not significant(P<0.05).Conclusion:CAR-NK92 cells targeting CEA can effectively kill CEA-positive colorectal cancer cells.

Hepatitis B virus-persistent infection and innate immunity defect: Cell-related or virus-related?

The outcomes of hepatitis B virus(HBV) infection are closely related to the age at which infection was acquired. Infection acquired in adult life tends to be selflimited, in contrast to perinatal acquirement, for which chronic persistence of the HBV is a general outcome. Innate immunity plays an indispensable role in early virus infection, facilitating virus clearance. However, it has been reported that HBV is under-recognized and poorly eliminated by the innate immune system in the early stages of infection, possibly explaining the long-lasting persistence of viremia afterwards. Furthermore, due to the existence of covalently closed circular DNA, chronic HBV clearance is very difficult, even when patients are given interferon-α and nucleotide/nucleoside analogs for antiviral therapy. The mechanism by which HBV evades innate immune recognition and establishes persistent infection remains a subject of debate. Besides, some researchers are becoming more interested in how to eradicate chronic HBV infection by restoring or boosting innate immunity. This review aimed to summarize the current knowledge on how intrahepatocyte signaling pathways and innate immune cells act after the onset of HBV infection and how these actions are related to the persistence of HBV. We anticipate the insights presented herein to be helpful for future development of novel immune therapeutic strategies to fight HBV infection.

Role of relevant immune-modulators and cytokines in hepatocellular carcinoma and premalignant hepatic lesions

AIM To assess the levels of different immune modulators in patients with hepatocellular carcinoma(HCC),in relation to other hepatic diseases.METHODS Eighty-eight patients were included in the current study and represented patients with HCC(20),liver cirrhosis(28) and chronic hepatitis(CH;25),and normal controls(NC;15).Peripheral blood was isolated for immunophenotyping of active myeloid dendritic cells(m DCs;CD1 c and CD40),mature inactive myeloid cells(CD1 c and HLA),active plasmacytoid cells(p DCs;CD303 and CD40),mature inactive p DCs(CD30 and HLA),active natural killer(NK) cells(CD56 and CD161),active NK cells(CD56 and CD314) and inactive NK cells(CD56 and CD158) was done by flow cytometry.Serum levels of interleukin(IL)-2,IL-10,IL-12,IL-1β,interferon(IFN)-α,IFN-γ and tumor necrosis factor(TNF)-αR2 were assessed by ELISA.RESULTS Active m DCs(CD1 C+/CD40+) and inactive m DCs(CD1 c+/HLA+) were significantly decreased in HCC patients in relation to NC(P < 0.001).CD40+ expression on active p DCs was decreased in HCC patients(P < 0.001),and its level was not significantly changed among other groups.Inactive p DCs(CD303+/HLA+),inactive NKs(CD56+/CD158+) and active NKs(CD56+/CD161+) were not statistically changed among the four groups studied;however,the latter was increased in CH(P < 0.05).NKG2 D was statistically decreased in HCC,CH and cirrhosis(P < 0.001),and it was not expressed in 63%(12/20) of HCC patients.There was significant decrease of IL-2,IFN-α and IFN-γ(P < 0.001),and a significant increase in IL-10,IL-1β,and TNF-αR2(P <0.01,P < 0.001 and P < 0.001;respectively) in HCC patients.There was inverted correlation between IL-12 and IL-1β in HCC(r =-0.565,P < 0.01),with a strong correlation between p DCs(CD303+/CD40+) and NKs(CD56+/CD161+;r = 0.512,P < 0.05) as well as inactive m DCs(CD1 c+/HLA+) and inactive NK cells(CD56+/CD158+;r = 0.945,P < 0.001).CONCLUSION NKG2 D,CD40,IL-2 and IL-10 are important modulators in the development and progression of HCC.

Multiple sclerosis and the role of immune cells

Multiple sclerosis(MS) is a complex disease with many different immune cells involved in its pathogenesis, and in particular T cells as the most recognized cell type. Recently, the innate immune system has also been researched for its effect on the disease. Hence, cells of the immune system play vital roles in either ameliorating or exacerbating the disease. The genetic and environmental factors, as well as the etiology and pathogenesis are of utmost importance for the development of MS. An insight into the roles play by T cells, B cells, natural killer cells, and dendritic cells in MS and the animal model experimental autoimmune encephalomyelitis, will be presented. Understanding the mechanisms of action for current therapeutic modalities should help developing new therapeutic tools to treat this disease and other autoimmune diseases.

黄芪含药血清对NK细胞活性、NKG2A、NKG2D及细胞因子IFN-γ表达的影响

目的探讨黄芪含药血清对自然杀伤(NK)细胞的杀伤活性和NKG2D、NKG2A、细胞因子干扰素-γ(IFN-γ)表达水平的影响。方法20只SPF级SD大鼠,随机分成黄芪低、中、高剂量组(3.1、6.2、12.4 g/kg体重)和正常对照组,灌胃后制备含药血清。用NK细胞专用培养基培养NK-92MI细胞,用1640培养基培养YAC-1细胞。将NK-92MI细胞与20%不同剂量黄芪含药血清及正常对照血清孵育48 h,即分别为正常对照组、黄芪低剂量组、黄芪中剂量组以及黄芪高剂量组。通过乳酸脱氢酶(LDH)释放测定方法检测NK细胞对靶细胞YAC-1的杀伤活性,ELISA法检测IFN-γ的水平,Western blot检测NKG2D以及NKG2A蛋白表达水平。结果与正常对照组和黄芪低剂量组相比,黄芪中、高剂量组的NK细胞活性显著升高(P<0.01)。IFN-γ的表达在黄芪低、中、高剂量组中均升高,但不随浓度升高而增强。与正常对照组相比,黄芪低、中剂量组NKG2D蛋白表达水平明显升高(P<0.01),而NKG2A蛋白表达水平在各组间无明显差异(P>0.05)。结论黄芪含药血清可增强NK细胞杀伤活性、上调IFN-γ表达水平、上调NK细胞活化型受体的表达,通过调控NK细胞实现对机体的保护作用。

Evaluation of antibody-dependent cell-mediatedcy totoxicity activity and cetuximab response in KRAS wildtype metastatic colorectal cancer patients

AIM:To investigate the prognostic role of invariant natural killer T(iNKT) cells and antibody-dependent cell-mediated cytotoxicity(ADCC) in wild type KRAS metastatic colorectal cancer(mC RC) patients treated with cetuximab.METHODS: Forty-one KRAS wt mC RC patients,treated with cetuximab and irinotecan-based chemotherapy in Ⅱ and Ⅲ lines were analyzed. Genotyping of single nucleotide polymorphism(SNP)s in the FCGR2A,FCGR3A and in the 3' untranslated regions of KRAS and mutational analysis for KRAS,BRAF and NRAS genes was determined either by sequencing or allelic discrimination assays. Enriched NK cells were obtained from lymphoprepperipheral blood mononuclear cell and iN KT cells were defined by co-expression of CD3,TCRVα24,TCRVβ11. ADCC was evaluated as ex vivo NK-dependent activity,measuring lactate dehydrogenase release.RESULTS: At basal,mCRC patients performing ADCC activity above the median level(71%) showed an improved overall survival(OS) compared to patients with ADCC below(median 16 vs 8 mo;P=0.026). We did not find any significant correlation of iN KT cells with OS(P=0.19),albeit we observed a trend to a longer survival after 10 mo in patients with iN KT above median basal level(0.382 cells/microliter). Correlation of OS and progression-free survival(PFS) with interesting SNPs involved in ADCC ability revealed not to be significant. Patients carrying alleles both with A in FCGR2 A and TT in FCGR3A presented a trend of longer PFS(median 9 vs 5 mo;P=0.064). Chemotherapy impacted both iN KT cells and ADCC activity. Their prognostic values get lost when we analysed them after 2 and 4 mo of treatment.CONCLUSION: Our results suggest a link between iN KT cells,basal ADCC activity,genotypes in FCGR2A and FCGR3A,and efficacy of cetuximab in KRAS wt mC RC patients.

Peripheral blood NKT cell number and function in patients with Graves disease and their correlation with hyperthyroidism

Objective:To assess the peripheral blood NKT cell number and function in patients with Graves disease and study their correlation with hyperthyroidism.Methods: The patients who were diagnosed with Graves disease in our hospital between May 2014 and September 2016 were selected as GD group, and 55 healthy volunteers who received physical examination in our hospital during the same period were selected as control group. Peripheral blood was collected to determine the number of CD3+CD56+NKT cells, and serum was collected to detect the contents of cytokines and thyroid function indexes.Results: Peripheral blood CD3+CD56+NKT cell number in Graves disease group was significantly lower than that in control group;serum IL-2, IFN-γ, TNF-α, IL-10 and TGF-β contents in GD group were significantly lower than those in control group and positively correlated with peripheral blood CD3+CD56+NKT cell number while IL-4, IL-5, IL-17, FT3, FT4, TPOAb, TgAb and TRAb contents were significantly higher than those in control group and negatively correlated with peripheral blood CD3+CD56+NKT cell number.Conclusion:The abnormal reduction of peripheral blood NKT cell number in patients with Graves disease can affect the balance of Th1/Th2 and Th17/Treg and increase the TRAb secretion to cause hyperthyroidism.

自然杀伤细胞家族2成员D受体-配体轴在血液瘤中的作用研究进展

自然杀伤细胞家族2成员D(NKG2D)受体通过表达在自然杀伤(NK)细胞和细胞毒性T淋巴(CTLs)细胞上激活这些免疫细胞对抗肿瘤。肿瘤细胞通过降低自然杀伤细胞家族2成员D配体(NKG2DLs)的表达来逃避免疫系统的监视,从而促进肿瘤的免疫逃逸。最新的研究揭示了NKG2D受体-配体轴在血液瘤的发展、免疫监视和治疗中的关键作用,尤其是在阐明免疫逃逸机制和开发新的治疗策略方面显示出巨大潜力。现从NKG2D受体-配体轴在血液瘤发病机制、免疫监测及治疗中的作用进行阐述,在加深对血液瘤病理机制理解的同时,为提升治疗效果开辟了新的策略。

Chimeric antigen receptor- and natural killer cell receptor-engineered innate killer cells in cancer immunotherapy

Chimeric antigen receptor(CAR)-engineered T-cell(CAR-T)therapy has demonstrated impressive therapeutic efficacy against hematological malignancies,but multiple challenges have hindered its application,particularly for the eradication of solid tumors.Innate killer cells(IKCs),particularly NK cells,NKT cells,andγδT cells,employ specific antigen-independent innate tumor recognition and cytotoxic mechanisms that simultaneously display high antitumor efficacy and prevent tumor escape caused by antigen loss or modulation.IKCs are associated with a low risk of developing GVHD,thus offering new opportunities for allogeneic“off-the-shelf”cellular therapeutic products.The unique innate features,wide tumor recognition range,and potent antitumor functions of IKCs make them potentially excellent candidates for cancer immunotherapy,particularly serving as platforms for CAR development.In this review,we first provide a brief summary of the challenges hampering CAR-T-cell therapy applications and then discuss the latest CAR-NK-cell research,covering the advantages,applications,and clinical translation of CAR-and NK-cell receptor(NKR)-engineered IKCs.Advances in synthetic biology and the development of novel genetic engineering techniques,such as gene-editing and cellular reprogramming,will enable the further optimization of IKC-based anticancer therapies.

Ly49 receptors activate angiogenic mouse DBA＋ uterine natural killer cells

In humans, specific patterns of killer immunoglobulin-like receptors （KIRs） expressed by uterine natural killer （uNK） cells are linked through HLA-C with pregnancy complications （infertility, recurrent spontaneous abortion, intrauterine growth restriction and preeclampsia）. To identify mechanisms underpinning the associations between NK cell activation and pregnancy success, pregnancies were studied in mice with genetic knockdown （KD） of the MHC-activated Ly49 receptor gene family. B6.Ly49KD pregnancies were compared to normal control B6.Ly49z29 and C57BL/6 （B6） pregnancies. At mid-pregnancy （gestation day （gd9.5））, overall uNK cell （TCRI^-CD122＋DBA＋DX5- （DBA＋DX5-）） and TCRIβ-CD122＋DBA-DX5＋ （DBA-DX5＋）） frequencies in pregnant uterus were similar between genotypes. Ly49KD lowered the normal frequencies of Ly49＋ uNK cells from 90.3% to 47.8% in DBA-DX5＋ and 78.8% to 6.3% in DBA＋DX5- uNK cell subtypes. B6.Ly49KD matings frequently resulted in expanded blastocysts that did not implant （subfertility）. B6.Ly49KD mice that established pregnancy had gestational lengths and litter sizes similar to controls. B6.Ly49KD neonates, however, were heavier than controls. B6.Ly49KD implantation sites lagged in early （gd6.5） decidual angiogenesis and were deficient in mid-pregnancy （gd 10.5） spiral arterial remodelling. Ultrastructural analyses revealed that B6.Ly49KD uNK cells had impaired granulogenesis, while immunocytochemistry revealed deficient vascular endothelial cell growth factor （VEGFA） production. Perforin and IFNG expression were normal in B6.Ly49KD uNK cells. Thus, in normal mouse pregnancies, Ly49 receptor signaling must promote implantation, early decidual angiogenesis and mid-pregnancy vascular remodelling. Disturbances in these functions may underlie the reported genetic associations between human pregnancy complications and the inability of specific conceptus MHCs to engage activating KIR on uNK cells.

NKG2D介导NK细胞对鼻咽癌细胞杀伤作用的体外研究

目的探讨鼻咽癌CNE2细胞表面HLA-I类分子表型和NKG2D配体的表达情况,进一步了解其对同种异体NK细胞杀伤活性的影响。方法流式细胞仪检测NKG2D的配体MICA、MICB、ULBP1、ULBP2、ULBP3在K562、CNE2细胞的表达情况。PCR-SSP法分析CNE2细胞HLA-A、B、Cw分型和NK细胞KIR分型。LDH释放法测定5例健康者NK细胞在不同效靶比时对K562、CNE2细胞的杀伤活性,效靶比20∶1时观察抗NKG2D配体的单抗对NK细胞杀伤K562、CNE2细胞活性的影响。结果CNE2细胞表达MICA、MICB、ULBP2,不表达ULBP1、ULBP3。K562细胞表面表达MICA、MICB、ULBP1、ULBP2、ULBP3。5例健康者NK细胞抑制性KIR与CNE2细胞表面的HLA-I类分子之间存在错配。效靶比5∶1、10∶1、20∶1、30∶1时NK细胞对K562、CNE2细胞的杀伤活性分别为(29.02±0.45)%、(10.50±2.17)%;(44.43±1.36)%、(27.68±1.47)%;(57.82±1.35)%、(36.99±3.13)%;(71.24±2.36)%、(55.00±2.20)%,在各效靶比时NK细胞对K562细胞的杀伤活性较CNE2细胞明显增强(P=0.000);在效靶比20∶1时anti-MICA、anti-MICB、anti-ULBP1、anti-ULBP2、anti-ULBP3可明显抑制NK细胞对K562细胞的杀伤活性,与阻断前相比有显著性差异(P=0.000);anti-MICA、anti-MICB、anti-ULBP2可明显抑制NK细胞对CNE2细胞的杀伤活性,与阻断前相比有显著性差异(P<0.01),但anti-ULBP1、anti-ULBP3不能阻断NK细胞对CNE2细胞的杀伤活性。结论NKG2D配体影响NK细胞对靶细胞的杀伤活性,提高NKG2D配体的表达有可能提高NK细胞的抗肿瘤活性。

对羟基苯乙基-α-D-葡萄糖甙对小鼠天然杀伤细胞的体外影响

本文用［３Ｈ］ＴｄＲ靶细胞释放法，观察了对羟基苯乙基－α－Ｄ－葡萄糖甙在体外对小鼠脾天然杀伤细胞（ＮＫ）活性的影响．结果表明，对羟基苯乙基－α－Ｄ－葡萄糖甙能提高正常鼠的脾ＮＫ杀伤活性，显著提高环磷酰胺给药后的ＮＫ杀伤活性，减轻由地塞米松引起的ＮＫ活性低下，协同白细胞介素－２明显增强鼠脾细胞的ＮＫ活性，而且剂量与作用呈正比．

NKG2D配体在耐药鼻咽癌细胞的表达及其对NK细胞杀伤活性的影响

目的探讨NKG2D的主要活化性配体在鼻咽癌亲本细胞CNE2和多药耐药细胞CNE2DDP的表达及其对自然杀伤(NK)细胞杀伤活性的影响。方法流式细胞仪检测NKG2D的主要活化性配体MHC-I类链相关蛋白A和B(MICA、MICB)、UL16结合蛋白1-3(ULBP1、ULBP2、ULBP3)在CNE2、CNE2DDP细胞的表达情况;PCR-SSP法检测CNE2、CNE2DDP细胞HLA-A、B、Cw分型和NK细胞KIR分型;LDH释放法测定5例健康者的NK细胞在不同效靶比时对CNE2、CNE2DDP细胞的杀伤活性;效靶比20∶1时观察不同单抗对NK细胞杀伤CNE2、CNE2DDP细胞活性的阻断作用。结果CNE2、CNE2DDP细胞HLA分型为A2,24,B18,35,Cw4,7;5例健康者的NK细胞表达KIR2DL1,KIR2DL3,KIR3DL1,KIR3DL2与CNE2、CNE2DDP细胞表面的HLA-I类分子之间存在错配。CNE2、CNE2DDP细胞均表达NKG2D的配体MICA、MICB、ULBP2,均不表达ULBP1、ULBP3;CNE2细胞MICA、MICB的表达率与CNE2DDP细胞相比差异有统计学意义(P<0.01)。效靶比5∶1、10∶1、20∶1、30∶1时NK细胞对CNE2、CNE2DDP细胞的杀伤活性分别是(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)%。在各效靶比时NK细胞对CNE2细胞的杀伤活性与CNE2DDP细胞相比差异有统计学意义(P<0.01);效靶比20∶1时anti-MICA、anti-MICB、anti-ULBP2单抗可明显抑制NK细胞对CNE2、CNE2DDP细胞的杀伤活性,与阻断前相比差异有统计学意义(P<0.05);anti-ULBP1、anti-ULBP3单抗不能阻断NK细胞对CNE2、CNE2DDP细胞的杀伤活性。结论NKG2D的主要活化性配体MICA、MICB在CNE2、CNE2DDP细胞的表达差异与NK细胞的杀伤活性有关,肿瘤细胞在发生多药耐药的同时获得了免疫逃避能力。