恒定的自然杀伤T淋巴细胞在肝脏抗肿瘤免疫中的作用与机制

恒定的自然杀伤T淋巴细胞(iNKT细胞)是来源于胸腺的T淋巴细胞亚群,同时表达自然杀伤细胞相关受体和T淋巴细胞受体。iNKT细胞广泛分布于全身,在肝脏内富集,表现出独特的功能特性,可以分泌细胞因子并调节微环境其他免疫细胞活性,以达到免疫监视及预防疾病的作用,尤其是在肿瘤微环境中,iNKT细胞能够激发肝脏抗肿瘤免疫反应、逆转免疫抑制微环境状态。就iNKT细胞的生物学特性及其在肝脏免疫稳态中的特殊作用,尤其就iNKT细胞的抗肿瘤作用与机制作一综述。     

Modulation of hypothalamic beta-endorphin-regulated expression of natural killer cell cytolytic activity regulatory factors by ethanol in male Fischer-344 rats

BACKGROUND: We have previously shown that ethanol administration suppresses natural killer (NK) cell cytolytic activity, partly by decreasing the action of hypothalamic beta-endorphin (beta-EP) on the spleens of male Fischer-344 rats. This study was conducted to examine the effects of ethanol and central administration of beta-EP on perforin, granzyme B, and the cytokine interferon (IFN)-gamma--factors that modulate NK cell cytolytic activity--to understand the mechanism involved in ethanol's suppression of NK cell activity. METHODS: A group of male Fischer-344 rats were fed an ethanol-containing diet (8.7% v/v), and a control group was pair-fed an isocaloric diet. At the end of 2 weeks, both groups were infused with beta-EP 100 ng/hr into the paraventricular nucleus of the hypothalamus for 18 hr, and spleen tissues were immediately removed for analysis of perforin, granzyme B, and IFN-gamma messenger RNA (mRNA) and protein levels. The mRNA levels of perforin, granzyme B, and IFN-gamma were evaluated by quantitative real-time polymerase chain reaction, and the protein levels of perforin and granzyme B were analyzed by Western blot. RESULTS: Paraventricular nucleus administration of beta-EP increased the mRNA and protein expression of granzyme B and mRNA expression of IFN-gamma in pair-fed animals. Ethanol significantly reduced both basal and beta-EP-induced levels of granzyme B and IFN-gamma. CONCLUSIONS: These data suggest that chronic ethanol consumption suppresses beta-EP-induced NK cytolytic activity, granzyme B, and IFN-gamma in male Fischer-344 rats.     

Chronic Alcohol Consumption Is Associated With an Increased Cytotoxic Profile of Circulating Lymphocytes That May Be Related With the Development of Liver Injury

Background: Apoptosis has recently emerged as a key component of acute and chronic liver diseases and it could be related to alcoholic liver disease. In the present study, we attempted to analyze the cytotoxic profile of circulating lymphocytes in chronic alcoholic patients grouped according to ethanol intake status and presence of liver disease. Methods: We investigate the phenotypic and functional behavior of different compartments of peripheral blood (PB) cytotoxic T and natural killer (NK) cells in chronic alcoholic patients without liver disease and active ethanol intake (AWLD group; n = 22), and in subjects with alcohol liver cirrhosis (ALC group; n = 22). Results: AWLD patients showed an expansion of both CD4+/CD8+ cytotoxic T cells and NK/T cells, in association with an enhanced cytolytic activity against K562 cells and a higher ability to induce in vitro expression of the pro‐apoptotic protein APO2.7 in HepG2 cells. Conversely, ethanol intake in ALC patients was associated with decreased NK cell numbers, a reduced cytotoxic activity against K562 cells without significant changes in the expression of APO2.7, and a pro‐fibrotic profile of cytokine secretion. Conclusions: Overall, our results suggest that alcoholic patients display different phenotypical and functional changes in circulating PB cytotoxic lymphocytes according to the presence of alcoholic liver disease, which could be related to the development and progress of liver injury.     

Decreased natural killer cell responses and altered interleukin-6 and interleukin-10 production in alcoholism: an interaction between alcohol dependence and African-American ethnicity

BACKGROUND: Epidemiological data indicate that among alcoholics African-American men have higher rates of infections compared with white alcoholics. Alcohol is thought to reduce natural killer (NK) cell responses and to alter cellular immunity by changing the relative balance of Th1 versus Th2 cytokine response profiles. However, translation of these basic immunological observations into the clinical setting is limited, and what clinical data are available are contradictory, in part, because of heterogeneity within the alcoholic patient population. Whether ethnic characteristics contribute to variation in the immunological effects of alcohol is not known. METHODS: This study compared NK activity, interleukin (IL)-2-stimulated NK activity, and concanavalin A-stimulated peripheral blood mononuclear cell production of Th1 (IL-12 and IL-2), Th2 (IL-10), and proinflammatory (IL-6) cytokines in 31 hospitalized chronic alcoholic patients and 31 age-matched controls who were stratified on the basis of ethnicity. RESULTS: NK-cell responses were significantly different across the four groups, and African-American alcoholics showed the lowest levels of NK activity (F = 9.5;p < 0.001) and IL-2-stimulated NK activity (F = 2.9; p < 0.05). Compared with the other three groups, African-American alcoholics also showed lower levels of IL-6 (F = 7.2;p < 0.01) and higher levels of IL-10 (F = 4.9;p < 0.05). Stimulated production of IL-2 and IL-12 were similar in the four groups. Regression analyses showed that alcohol dependence and ethnicity predicted NK activity, whereas the interaction between alcohol dependence and ethnicity predicted levels of IL-6 and IL-10. CONCLUSIONS: In summary, the immunological effects of alcohol dependence are modified by ethnicity status, consistent with the increased health risks found in African-American alcoholics.     

过敏性紫癜患者红细胞免疫功能与NK细胞活性的变化

目的 探讨红细胞免疫及天然杀伤细胞（ＮＫＣ）在过敏性紫癜（ＨＳＰ）发病中的可能作用。方法 红细胞免疫采用郭峰法测定２２例ＨＳＰ患者,红细胞Ｃ３ｂ受体花环率（ＲＢＣ－Ｃ３ｂＲＲ）,与免疫复合物受体花环率（ＲＢＣ－ＩＣＲ）,流式细胞仪与单克隆抗体（ＣＤ１６）测定ＮＫ细胞的活性。并与２０名正常体检儿童对照。结果 ＨＳＰ患者ＲＢＣ－Ｃ３ｂＲＲ及ＮＫＣ活性低于正常对照组（Ｐ〈０．０１）,ＲＢＣ－ＩＣＲ高于正     

Role of beta-endorphin, corticotropin-releasing hormone, and autonomic nervous system in mediation of the effect of chronic ethanol on natural killer cell cytolytic activity

BACKGROUND: We have recently shown that alcohol feeding suppresses natural killer (NK) cell cytolytic activity partly by decreasing the function of hypothalamic beta-endorphin (beta-EP) neurons. The neuronal mechanism by which hypothalamic beta-EP communicates with the spleen to regulate the action of ethanol on NK cells is not known. In the present study, we evaluated the roles of beta-EP neurons, corticotropin releasing hormone (CRH) neurons, and the autonomic nervous system (ANS) in regulation of the ethanol effect on splenic NK cell cytolytic function. METHODS: Male rats were fed an ethanol-containing liquid diet or control diets. These rats were used to determine the hormone release from the paraventricular nuclei (PVN) of the hypothalamus or used to determine the splenic NK cell cytolytic function after PVN administration of CRH or intraperitoneal (i.p.) administration of a ganglionic blocker chlorisondamine. The release of hormones from the PVN was measured using the push-pull perfusion method. Splenic cytolytic activity was determined using the 4-hour (51)Cr release assay against YAC-1 lymphoma target cells. RESULTS: Alcohol feeding decreased the amount of beta-EP but increased the amount of CRH in the push-pull perfusate (PPP) samples collected from the PVN. When exogenous beta-EP was perfused into the PVN, it suppressed the release of endogenous CRH found in PPP samples of the PVN. Conversely, perfusion of an opiate antagonist naltrexone into the PVN increased the levels of endogenous CRH in PPP samples of the PVN. In addition, administration of exogenous beta-EP in the PVN stimulated the cytolytic function of NK cells, an action that was antagonized by CRH as well as by ethanol. Corticotropin-releasing hormone and ethanol alone also had an inhibitory action on NK cells. Finally, the ganglionic blocker used prevented the effect that ethanol, beta-EP, and CRH had on NK cells. These data suggest that ethanol inhibits the function of NK cells partly by suppressing the influence of the beta-EP-CRH-ANS signal to the spleen.     

Reduced Fatty Acid Ethyl Ester Synthase Activity in the White Blood Cells of Alcoholics

Purpose: Fatty acid ethyl esters (FAEEs), esterification products of ethanol and fatty acids, have been implicated as mediators of ethanol-induced organ damage. It has been shown that FAEE synthase, the enzyme responsible for the formation of FAEE, is present selectively in the organs commonly damaged by ethanol abuse. Recently, we have made the observation that FAEEs are also present in the serum after ethanol ingestion. The current study was performed to determine whether cellular elements of the blood and/or plasma are capable of synthesizing FAEEs from fatty acids and ethanol. Materials and Methods: Heparinized blood samples were collected from 10 healthy volunteers, and the red blood cells, platelets, plasma, and several white blood cell populations were assayed for FAEE synthase activity. Blood samples from control subjects and individuals admitted to an alcoholic detoxification unit at a local hospital were also assayed for FAEE synthase activity. Results: We observed that the FAEE synthase activity is present in whole blood, primarily within white blood cells. Fractionation of the white blood cells revealed that the lymphocyte-monocyte fraction isolated using Ficoll-hypaque contained ?3.5-fold higher activity than the granulocyte fraction. The cell type that contained the highest FAEE synthase activity (1220 pmol/hr/10⁶ cells) was the natural killer (NK) cell population. B cells contained ?40% of the enzyme activity found in NK cells, and the B-cell activity was slightly greater than that found in CD4⁺ and CD8⁺ T cells. Having shown that FAEE synthase exists in a blood cell, we subsequently demonstrated that alcoholic individuals have approximately half the white blood cell FAEE synthase activity of that found in normal controls. We also demonstrated that white blood cell FAEE synthase could be induced nearly 2-fold upon ingestion of 2 oz of scotch whiskey for 6 days. The enzyme activity returned to baseline levels despite ingestion of 2 oz of scotch whiskey/day for 3 additional days. Conclusions: These data indicate that ethanol ingestion results in increased FAEE production, particularly by NK cells. FAEE synthesis after ethanol ingestion may explain the presence of FAEE in the serum. The lower enzyme activity observed in white blood cells of alcoholics from a detoxification center may be the result of years of ethanol abuse or it may be that alcoholics congenitally have low levels of FAEE synthase. If the latter is true, this finding may explain in part the genetic predisposition of many alcoholic individuals to ethanol abuse.     

Peripheral blood lymphocyte subsets in polymyalgia rheumatica

Summary Peripheral blood lymphocytes from 23 patients with polymyalgia rheumatica (PMR) were characterized using monoclonal antibodies and flow cytometry in a two-year prospective study. There were no significant differences in absolute numbers or relative percentages of lymphocytes or CD3+, CD4+, CD8+ T cells or the CD4+T cell functional subsets, virgin (CD4+CD45RA+) and memory (CD4+CD29+) T cells, in patients before or during corticosteroid treatment compared to controls. Previous reports on decreased levels of CD8+T cells as a characteristic of PMR/giant cell arteritis was not confirmed. The absolute number and relative percentage of lymphocytes with natural killer cell activity, CD16+ CD56+ cells, were significantly lower in patients with active untreated PMR as well as during corticosteriod treatment compared to controls, but at the two-year follow-up the difference was less marked.     

The modulation of B16BL6 melanoma metastasis is not directly mediated by cytolytic activity of natural killer cells in alcohol-consuming mice

BACKGROUND: Previous studies in our laboratory indicate that alcohol consumption suppresses the metastasis of B16BL6 melanoma, whereas the cytolytic activity of natural killer (NK) cells is decreased in female C57BL/6 mice given 20% w/v alcohol in their drinking water. In the present study, we further evaluated the involvement of NK cells and alcohol consumption in the cytolytic activity of NK cells, the surface expression of NK phenotypic markers, and metastasis of B16BL6 melanoma in C57BL/6 beige (bgJ/bgJ) mutant mice, which possess inherently low NK-cell cytolytic activity. METHODS: Beige and control (bgJ/+) mice were given either water or 20% w/v of alcohol in drinking water for 6 1/2 to 7 weeks before assay for cytolytic activity, surface marker expression, and inoculation with B16BL6 melanoma intravenously or into the pinna of the ear. RESULTS: NK cytolytic activity was suppressed in beige mice, and alcohol consumption did not modulate further the cytolytic activity. Beige mice had a lower percentage of NK cells in the peripheral blood and spleen than control mice. Peripheral blood lymphocytes from beige mice also exhibited a reduced percentage of CD4+ T lymphocytes. Alcohol consumption similarly reduced the percentages of NK1.1- and LGL-1-expressing lymphocytes in the peripheral blood and spleen and reduced the percentage of CD8+ T lymphocytes in the peripheral blood in both control and beige mice. Tumor lung colonization was increased in beige mice relative to control mice after intravenous inoculation of B16BL6 melanoma. The increase was more pronounced in water-drinking beige mice than in control mice irrespective of alcohol consumption. Tumor lung colonization was significantly decreased (p < 0.05) by alcohol consumption in one experiment and partially decreased (p = 0.07) in the other. Mice that were inoculated into the pinna of the ear also exhibited a blunted antimetastatic response to alcohol consumption. CONCLUSIONS: These data suggest that the presence of the beige mutation diminishes the antimetastatic effect of alcohol consumption and that there is no interaction between alcohol consumption and NK-cell activity in the modulation of lung metastasis of B16BL6 melanoma cells.     

Exogenous IL-15 in Combination With IL-15Rα Rescues Natural Killer Cells From Apoptosis Induced by Chronic Alcohol Consumption

Background:  Chronic alcohol consumption reduces the percentage and number of peripheral natural killer (NK) cells in mice and in humans. The underlying mechanism for these changes is only partly known. We recently found that chronic alcohol consumption inhibits NK cell release from the bone marrow (BM) and that this is associated with a decrease in splenic NK cells. The number of peripheral NK cells is tightly controlled by homeostatic proliferation. It is not known whether this mechanism is initiated in response to the reduction in splenic NK cells, or if so, why the steady state levels of NK cells are not restored.
Methods:  To examine this mechanism, female C57BL/6 mice were given 20% w/v alcohol in the drinking water for 3 months. NK cell proliferation and apoptosis were determined before and after treatment with IL-15 alone or combined with its alpha receptor.
Results:  Chronic alcohol consumption invoked homeostatic proliferation of splenic NK cells in an attempt to return NK cells to normal levels; however, this did not happen due to enhanced apoptosis of NK cells relative to proliferation. Chronic alcohol consumption decreased IL-15 producing cells in the spleen but not in the BM. The numbers of NK cells in the alcohol-consuming mice returned to normal levels in the spleen and were higher than normal in the BM after 2 daily injections of IL-15; however, the enhanced rate of apoptosis due to alcohol consumption was not decreased in the spleen or BM. Combined IL-15 and IL-15Rα treatment decreased apoptosis of NK cells from alcohol-consuming mice to levels similar to untreated water-drinking mice and greatly increased the percentage and number of NK cells in both the spleen and BM.
Conclusion:  Chronic alcohol consumption causes a self-unrecoverable loss of NK cells in the spleen by compromising NK cell release from the BM and enhancing splenic NK cell apoptosis that can be reversed with IL-15/IL-15Rα treatment.     

Impaired natural killer cell function in hemophiliacs with or without continuous substitution

Summary In the present study, 28 hemophiliacs substituted continuously and 5 hemophiliacs who had received almost no blood products were investigated. Cells of OKT 3⁺, OKT 4⁺, and OKT 8⁺ subsets were counted. Percoll separated fractions of peripheral blood mononuclear cells were examined by morphological criteria and were tested for NK cell activity. We found that the NK cell activity of both groups of hemophiliacs was decreased on testing Ficoll separated cells or low density Percoll separated cells. Normal NK cell activity was found in medium density cells of hemophiliacs. Two possible explantations are discussed: first, the NK cell activity may be suppressed in hemophiliacs and secondly, there may be a block in maturation of NK cell activity. It is unlikely that chronic substitution by blood products counts for these alterations. The possible role of chronic infections is discussed.     

Identification of the CD16low CD56low CD38pos Natural Killer Cell as a Key Subset in Patients with Multiple Myeloma

Background: Natural killer (NK) cells are classified as innate immune cells which can directly recognize and kill tumor cells without antigen sensitization. NK cell-based adoptive immunotherapy for blood malignancies has attracted more attention in recent years. Objective: To analyze different NK cell subsets in the peripheral blood and bone marrow (BM) of patients with multiple myeloma (MM). Methods: Using flow cytometry we analyzed: (i) the distribution of distinct NK cell subpopulations (i.e. CD16low CD56low, CD16pos CD56high, CD16neg CD56high, CD16high CD56low, CD16neg CD56low, CD16low CD56low CD38pos) in the BM from MM patients at distinct disease stages. (ii) the expression of NKG2D, DNAM-1 and NKp30, and (iii) the expression of CD107a in CD16low CD56low CD38pos and CD16low CD56low CD38neg NK cells subsets. Results: CD16low CD56low CD38pos was the dominant subset in BM from patients with MM at the CR stage with a decreased expression of NKp30. CD16low CD56low CD38pos subset showed a higher proportion of CD107a expression compared to CD16low CD56low CD38neg cells. In vitro experiments indicated that the CD16low CD56low CD38pos NK cell subset possesses more cytotoxicity than CD16low CD56low CD38neg NK cells. Conclusion: Our data suggest that CD16low CD56low CD38pos NK cells may reflect as an effector population with the potential therapeutic target in patients with MM. This group of cells may be useful for adoptive immunotherapy in MM in the future.     

State of the art in natural killer cell malignancies

The recently updated World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues, published in 2008, has made great advances in revising the disorders previously included in the pool of natural killer (NK) cell tumors. Although NK cell neoplasms represent a relatively rare group of diseases, accounting for <5% of all lymphoid neoplasms, they include very distinctive conditions both clinically and pathologically. This family of diseases includes the most indolent clinical forms, such as the provisional new entry of chronic lymphoproliferative disorder of NK cells (CLPD-NK) in the WHO classification, as well as one of the most fatal diseases recognized in medical oncology, aggressive NK cell leukemia (ANKL), which is characterized by a prognosis of weeks, or even days. In addition, some disorders previously identified as blastic NK cell lymphoma within the NK cell system have been more properly defined and included in the blastic plasmacytoid dentritic cell neoplasms, although rare cases of bona fide immature NK lymphoid tumors (now classified as NK cell lymphoblastic leukemia/lymphoma) have been reported in the literature. This paper focuses on recent concepts and progress in morphology, pathogenesis, clinicopathological features, treatment approaches, and outcomes of NK cell malignancies.     

乙型肝炎病毒对自然杀伤细胞免疫活性的影响

目的 了解HBV对NK细胞免疫功能的影响.方法 健康者外周血来源的NK细胞单独培养,或与浆样树突状细胞(pDC)共同培养(NK∶ pDC=5∶1)48 h,加入HepG2.2.15细胞来源的HBV.流式细胞技术测定细胞活性分子的表达,ELISA和细胞内细胞因子染色法(ICS)测定细胞因子含量,检测NK细胞对K562靶细胞的杀伤能力以及NK细胞内穿孔素和颗粒酶的含量以判定NK细胞的杀伤毒性.Wilcoxon符号秩检验进行配对样本分析.结果 HBV对细胞因子(IL-12/IL-18,IL-18/IFNα)活化的NK细胞分泌IFNγ无直接的抑制作用(均P＞0.05).CpG寡脱氧核酸能促进pDC诱导的NK细胞产生IFNγ (1135.4 pg/mL),而HBV对pDC诱导的NK细胞分泌IFNγ具有显著的抑制作用(146.1 pg/mL,P=0.0005).HBV并不影响pDC介导的NK细胞表面活性分子的表达,也不影响pDC介导的NK细胞对K562靶细胞的杀伤毒性以及NK细胞内穿孔素和颗粒酶的含量.结论 HBV并不激活,而是显著抑制pDC诱导的NK细胞分泌IFNγ,从而增加HBV持续感染的可能性.     

Immune Function in Alcoholism: A Controlled Study

Several studies have shown an increased risk for infection and cancer in alcoholic patients. The mechanisms for such observations remain largely unknown. In an effort to investigate the possibility of immunological dysfunction in alcoholism, we studied three immune parameters in 47 hospitalized chronic alcoholic patients and 47 age-and sex-matched normal controls. The immune measures were: (1) lymphocyte phenotyping, with estimates of percentages of T cells, B cells, T helpers, T suppressors, natural killer (NK) cells, and cells carrying the activation markers IL₂R₁ and l₂; (2) NK cell activity; and (3) lymphokine-activated killer cell activity. Results indicate a significant increase in the IL₂R and l₂ lymphocyte markers in alcoholic patients compared with matched controls. We also found a nonsignificant trend for a decrease in the percentage of suppressor T cells in the alcoholic group, as well as a trend for a negative correlation between the percentage of T suppressor cells and age. There were no significant differences in either NK or lymphokine-activated killer cell activities between the two groups. Furthermore, there were no significant associations between duration and intensity of alcohol consumption and any of the immune measures. These results suggest subtle alterations in immune regulation in alcoholic patients that cannot be explained solely on the basis of duration and/or amount of alcohol consumed.     

原发性肝癌患者射频消融治疗前后外周血T细胞亚群及NK细胞的变化

目的观察原发性肝癌患者射频消融（RFA）治疗前后T细胞亚群及NK细胞的变化。方法23例原发性肝癌患者接受RFA治疗;采用流式细胞仪检测患者和23例健康体检人群外周血CD3＋T细胞、CD4＋T细胞、CD4＋/CD8＋、CTL细胞及NK细胞水平。结果原发性肝癌患者CD3＋T细胞、CD4＋T细胞、CTL细胞、NK细胞的比例及CD4＋/CD8＋比值分别为61.9±13.8%、33.3±5.0%、10.3±4.9%、4.4±1.3%和1.4±0.6,均显著低于健康人群（75.7±12.3%、41.1±10.1%、19.7±5.8%、16.7±8.2%、1.7±0.6,P〈0.05）;CD8＋T细胞的比例为25.5±5.1%,高于健康人（21.7±6.7%,P〈0.05）;RFA治疗后1周和2周,CD3＋T细胞（72.1±9.8%、73.3±7.3%）、CD4＋T细胞（39.6±10.9%、39.0±10.0%）、CTL细胞（14.8±9.6%、12.3±7.4%）、NK细胞（11.1±4.9%、12.8±8.1%）均较治疗前上升,而CD8＋T 细胞（22.6±5.8%、22.0±9.6%）比例下降,CD4＋/CD8＋比值（1.7±0.8、1.9±0.4）上升,差异均有统计学意义（P〈0.05）。结论原发性肝癌患者大多处于免疫抑制状态,RFA治疗可调节其T细胞亚群的平衡,升高NK细胞水平。     

急性和慢性乙型肝炎患者外周血NK细胞和T淋巴细胞亚群的动态变化

目的：观察急性和慢性乙型肝炎患者急性期和恢复期外周血NK细胞和T淋巴细胞亚群的变化。方法在40例急性乙型肝炎和40例慢性乙型肝炎患者,分别在急性期和恢复期检测CD3＋CD4＋T细胞、CD3＋CD8＋T细胞和NK（CD3-CD16＋CD56＋）细胞占淋巴细胞的比率（%）。结果在急性乙型肝炎急性期NK细胞计数为（15.7±7.5）%,而在恢复期则上升至（21.9±8.2）%,（P＜0.05）;急性乙型肝炎患者在急性期CD3＋CD4＋T细胞为（35.5±6.8）%,到恢复期则显著下降（33.6±7.0）%,（P＜0.05）;急性乙型肝炎在急性期CD3＋CD8＋T细胞为（35.6±7.6）%,而在恢复期则显著下降（30.0±7.5）%,（P＜0.05）,后者仍比慢性乙型肝炎患者在病情恢复期高（19.1±7.1）%,（P＜0.05）。结论在急性乙型肝炎病程中,NK细胞呈上升趋势,CD3＋CD8＋T细胞呈下降趋势,而在慢性乙型肝炎患者NK细胞及T淋巴细胞数量下降,致病情迁延不愈。     

慢性乙型肝炎患者外周血NK细胞杀伤细胞凝集素样受体G1表达及其对NK细胞杀伤功能的影响*

目的 探讨CHB患者外周血NK细胞杀伤细胞凝集素样受体亚家族G成员1(KLRG1)表达的变化以及其对NK细胞杀伤功能的影响。方法 在120例CHB患者和120例健康体检者,抽取外周血,提取外周血单个核细胞,使用流式细胞仪检测NK细胞、KLRG1⁺ NK细胞和分泌γ-干扰素的NK细胞百分率,体外检测NK细胞对LX-2细胞的杀伤力。结果 CHB患者外周血NK细胞百分率为(17.2±7.7)%,显著高于对照组 [(11.3±6.9)%,t=9.85,P=0.01】, KLRG1⁺NK细胞百分率为(52.2±20.3)%,显著高于对照组 【(30.3±16.9)%,t=6.57,P=0.01】,分泌IFN-γ的NK细胞百分率为(14.6±3.8)%,显著低于对照组【(42.5±9.5)%,t=11.24,P=0.01】;CHB患者外周血NK细胞CD38、CD69、HLA-DR和TRAIL表达均显著高于对照组(P=0.012,P=0.015,P=0.025,P=0.019);CHB患者NK细胞诱导LX-2细胞发生早期凋亡率为11.5% (6.6%～13.7%),晚期凋亡率为7.2% (5.1%～8.5%),与对照组的15.4% (11.5%～24.3%)和13.5% (8.1%～20.4%) 比,显著降低 (U=6.50, P=0.025;U=2.02,P=0.002) 。结论 CHB患者NK细胞表达KLRG1增强,通过减少分泌INF-γ而导致其杀伤功能减弱,可能系造成慢性感染的重要原因。     

Alloreactive natural killer cells in mismatched hematopoietic stem cell transplantation

Natural killer (NK) cell-mediated, donor-vs.-recipient alloresponses occur following transplantation of human leukocyte antigen (HLA) haplotype-mismatched hematopoietic stem cells (HSCs). NK cell alloreactivity reduced the risk of relapse in acute myeloid leukemia patients while improving engraftment and protecting against graft-vs.-host disease (GvHD). NK cells are primed to kill by several activating receptors. NK killing of autologous cells is prevented because NK cells co-express inhibitory receptors (killer cell Ig-like receptors, KIR) that recognize groups of (self) MHC class I alleles. As KIRs are clonally distributed, the NK population in any individual is constituted of a repertoire with different allospecificities. NK cells in the repertoire mediate alloreactions when the allogeneic targets do not express class I alleles that block them. High resolution molecular HLA typing of recipient and donor, positive identification of donor KIR genes, and in some cases, functional assessment of donor NK clones will identify haploidentical donors who are able to mount donor-vs.-recipient NK alloreactions.     

Ethanol decreases natural killer cell activation but only minimally affects anatomical distribution after administration of polyinosinic:polycytidylic acid: role in resistance to B16F10 melanoma

BACKGROUND: Natural killer (NK) cells are critical in resistance to B16F10 lung metastases in B6C3F1 mice. Activation of NK cells by polyinosinic:polycytidylic acid (poly I:C; 0.1 mg, intraperitoneally) increases resistance to B16F10 cells. This effect is reduced after administration of ethanol (EtOH; 6 g/kg by oral gavage). The present study was conducted to determine whether decreased resistance is due to alteration of the distribution and/or the activation of NK cells. METHODS: These parameters were measured in the spleen, lungs, and peripheral blood 4 and 12 hr after EtOH and poly I:C administration. For assessing the time after poly I:C administration during which NK cells are important in resistance to B16F10 cells, anti-NK1.1 antibody was used to deplete NK cells in vivo 48 hr before and 0, 6, 12, and 24 hr after intravenous injection of B16F10 tumor cells. RESULTS: Depletion of NK cells at any time up to 12 hr after B16F10 administration significantly increased the number of tumor nodules in the lungs, but depletion at 24 hr had a smaller effect. Flow cytometry revealed that there was a small but significant increase in the percentage of NK cells in the lungs at 12 hr, which was not changed by EtOH. Corresponding NK cell lytic function in the lungs was increased significantly at both 4 and 12 hr by poly I:C. However, the increase was not significantly different from the naive control value at 4 hr in mice treated with poly I:C plus EtOH, indicating that EtOH decreased activation of NK cells in the lungs at 4 hr. In the spleen, no treatment significantly altered the percentage of NK cells at 4 or 12 hr. However, poly I:C significantly enhanced lytic function, and this enhancement was suppressed by EtOH (by approximately 50%). In the blood, the only significant change in NK cell percentage or lytic activity was an increase in the percentage of NK cells at 12 hr, which was equivalent in the poly I:C and the poly I:C plus EtOH groups. CONCLUSIONS: These results demonstrate that EtOH partially abrogates the poly I:C-induced enhancement of resistance to B16F10 cells and that decreased activation of NK cells in the lungs at a critical time early in the response to poly I:C may contribute to this effect. Other parameters could also contribute, but there was little support for an important role for changes in NK cell distribution.