肝癌、肝硬化中自然杀伤细胞的免疫组织化学研究

目的: 研究原发性肝细胞癌、肝硬化、正常肝组织中自然杀伤(nature killer,NK)细胞数量、分布及其与患者预后的关系.方法: 原发性肝细胞癌60例,单纯性肝硬化62例,正常肝组织23例,以SP免疫组化法检测NK细胞.结果: ①癌中与癌旁组织的NK细胞计数明显高于肝硬化(P<0.01),癌中NK细胞计数高于正常肝组织(P<0.05).②肝癌组织学分级与NK细胞数量无明显关系.③癌中NK细胞随着临床分期的发展有下降的趋势(P<0.05).④15月内转移复发组癌中和癌旁的NK细胞计数均明显低于无转移复发组(P<0.01).结论: NK细胞计数可能是反映机体抗肿瘤免疫状态和判断患者预后的重要指标.     

Human Fas-ligand expression on porcine endothelial cells does not protect against xenogeneic natural killer cytotoxicity

Several human leukocyte subsets including natural killer (NK) cells, cytotoxic T lymphocytes (CTL), and polymorphonuclear neutrophils (PMN) participate in cellular immune responses directed against vascularized pig-to-human xenografts. As these leukocytes express the death receptor Fas either constitutively (PMN) or upon activation (NK, CTL), we explored in vitro whether the transgenic expression of Fas ligand (FasL) on porcine endothelial cells (EC) is a valuable strategy to protect porcine xenografts. The porcine EC line 2A2 was stably transfected with human FasL (2A2-FasL) and interactions of 2A2-FasL with human leukocytes were analyzed using functional assays for apoptosis, cytotoxicity, chemotaxis, adhesion under shear stress, and transmigration. FasL expressed on porcine EC induced apoptosis in human NK and T cells, but did not protect porcine EC against killing mediated by human NK cells. 2A2-FasL released soluble FasL, which induced strong chemotaxis in human PMN. Adhesion under shear stress of PMN on 2A2-FasL cells was increased whereas transendothelial migration was decreased. In contrast, FasL had no effect on the adhesion of NK cells but increased their transmigration through porcine EC. Although FasL expression on porcine EC is able to induce apoptosis in human effector cells, it did not provide protection against xenogeneic cytotoxicity. The observed impact of FasL on adhesion and transendothelial migration provides evidence for novel biological functions of FasL.     

The association between stressful life events and respiratory infections during the first 4 years of life: The Environmental Determinants of Diabetes in the Young study

The aim of this study was to conduct a prospective analysis of the association between negative life events (NLEs) and respiratory infections in children genetically at risk for islet autoimmunity (IA) and type 1 diabetes (T1D). Long‐ and short‐term temporal associations between NLEs and rate of respiratory infection episodes (RIEs) in 5,618 children in The Environmental Determinants of Diabetes in the Young study for at least 1 up to 4 years were analysed. All models were adjusted for demographic, day care, season of infection, and psychosocial factors associated with the rate of child RIEs between study visits. The rate of child RIEs was 26% higher in Europe (Sweden, Finland, Germany) than in the United States (rate ratio [RR] = 1.26, p < 0.001). However, the percentage of child NLEs (odds ratio [OR] = 1.18, p < 0.001) and mother NLEs (OR = 1.83, p < 0.001) was higher in the United States compared with Europe. In both continents (Europe, RR = 1.12, p < 0.001; United States, RR = 1.07, p = 0.006), high child cumulative NLEs (>1 NLE per year since study inception) was significantly associated with an increased rate of child RIEs. This large‐scale prospective study confirms observations that stress may increase the susceptibility for infections in paediatric populations and suggests at least one mechanism by which stress could increase risk for IA and T1D in genetically at risk children.     

The augmentation of lymphokine-activated killer cells induced by partial hepatectomy in mice

Spleen cells that are cultured with interleukin 2 for as short a time as 4 days develop the ability to lyse syngeneic natural killer-resistant tumor cells but not to lyse syngeneic lymphoblasts. When mice were subjected to partial hepatectomy (HEP), the spleen cells exhibited not only an augmentation of natural killer activity, but also an augmentation ofin vitro induction of lymphokine activated killer (LAK) cells. Furthermore, the LAK cells exhibited lytic activities against syngeneic lectin-induced lymphoblasts and regenerating liver cells. The sensitivity of regenerating liver cells to lysis by LAK cells was detected as early as one day after HEP, and continued until day 14. Analysis by cell depletion techniques using monoclonal antibodies and complement, as well as discontinuous gradient sedimentation, indicated that the LAK cells activated by HEP were Thy-1⁺, Lyt-2⁺, asialo GM1⁺ and Lyt-1⁻, lymphocytes with a low density. After the intravenous (i.v.) administration of anti-asialo GM1 before HEP, thein vitro induction of LAK cells was remarkably inhibited.     

The trauma constellation identification scale: A measure of the psychological impact of a stressful life event

This investigation reports the development of a self-report instrument designed to assess maladaptive cognitive schemata and negative affects associated with a stressful or traumatic life event. Participants included undergraduate university students (N=228) who completed a questionnaire packet including the Approach-Avoidance Scale (AAS), the Trauma Constellation Identification Scale (TCIS), the Impact of Event Scale (IES), and the SCL-90-R. The data were analyzed to determine the psychometric properties of the TCIS. The TCIS has high internal consistency reliability (Cronbach's alpha = 0.94), and its 15 subscales load on two higher-order factors. TCIS scores were significantly related to intrusions, denial, avoidance coping, and all SCL-90-R psychological outcome variables. There was also evidence for the subscales to have differential relationships with coping and outcome variables as well as type of stressor. The TCIS may be utilized for research or in a clinical setting to document an individual's affective and cognitive response profile.     

The impact of donor natural killer cell alloreactivity on allogeneic hematopoietic transplantation

Although natural killer (NK) cells are triggered to kill by many activating receptors, lysis of autologous cells is blocked by inhibitory receptors (called Killer cell Ig-like receptors or KIRs) which recognize epitopes shared by certain major histocompatibility complex (MHC) class I allele groups (called KIR ligands). As these inhibitory receptors are clonally distributed, they constituted a repertoire containing different allospecificities. Thus, the NK cells in the repertoire are lytic against allogeneic targets that do not express their inhibitory KIR ligands. In hematopoietic human-leukocyte-antigen (HLA)-haplotype mismatched transplantation, donor-vs-recipient alloreactive NK cells improve engraftment, decrease the incidence of leukemia relapse and do not cause Graft-vs-Host disease (GvHD). Pre-transplant molecular high-resolution HLA of recipient and donor, KIR genotyping of the donor and direct assessment of the donor NK repertoire identify donors with the potential for donor-vs-recipient NK cell alloreactivity.     

Effects of diethylstilbestrol and estramustine phosphate (estracyt) on natural killer cell activity and tumor susceptibility in male mice

The effects of estramustine phosphate (EMP) and diethylstilbestrol (DES) on natural killer (NK) cell activity, tumor growth, and artificial metastases were investigated in male C57BL/6 mice. Kinetic analysis and studies at the single-cell level indicated that EMP did not influence the number of NK cells but interfered with their lytic activity thereby reducing the actual killer capacity. NK cells from EMP-exposed animals responded normally to the interferon inducer Poly I:C which restored NK activity to control levels. Spleen cells from DES-treated animals had lytic activity comparable to that of control animals. However, more detailed analysis showed that DES reduced the number of lymphocytes able to recognize target cells, while the individual NK cell had an increased lytic activity and recycling capacity. Moreover, NK cells from DES-treated animals were refractory to poly-I:C stimulation, suggesting that they were prestimulated in vivo. The pertubations of the NK cell system induced by both EMP and DES were reversible and normalization of NK activity was reached within a week. The incidence of tumor takes after subcutaneous inoculation of the syngeneic Lewis lung carcinoma was increased in EMP as well as DES-treated animals. Artificial lung metastasis produced by intravenous injection of the same tumor was increased in EMP but not in DES-exposed animals.     

A prospective study of the relationship between breast cancer and life events,type A behaviour,social support and coping skills

Two thousand one hundred and sixty-three women completed an extensive set of psychosocial measures prior to a breast examination. These women were subsequently diagnosed as having cancer, a cyst, benign breast disease or normal breasts. It was found that the cancer group had experienced significantly more loss- or illness-related events, perceived life events generally as more stressful, used fewer and poorer coping skills and were significantly lower on type A behaviour.     

Differential role of natural killer group 2D in recognition and cytotoxicity of hepatocyte‐like cells derived from embryonic stem cells and induced pluripotent stem cells

Stem cell–based approaches have the potential to address the organ shortage in transplantation. Whereas both embryonic stem cells and induced pluripotent stem cells have been utilized as cellular sources for differentiation and lineage specification, their relative ability to be recognized by immune effector cells is unclear. We determined the expression of immune recognition molecules on hepatocyte‐like cells (HLC) generated from murine embryonic stem cells and induced pluripotent stem cells, compared to adult hepatocytes, and we evaluated the impact on recognition by natural killer (NK) cells. We report that HLC lack MHC class I expression, and that embryonic stem cell–derived HLC have higher expression of the NK cell activating ligands Rae1, H60, and Mult1 than induced pluripotent stem cell–derived HLC and adult hepatocytes. Moreover, the lack of MHC class I renders embryonic stem cell–derived HLC, and induced pluripotent stem cell–derived HLC, susceptible to killing by syngeneic and allogeneic NK cells. Both embryonic stem cell–derived HLC, and induced pluripotent stem cell–derived HLC, are killed by NK cells at higher levels than adult hepatocytes. Finally, we demonstrate that the NK cell activation receptor, NKG2D, plays a key role in NK cell cytotoxicity of embryonic stem cell–derived HLC, but not induced pluripotent stem cell–derived HLC.     

Expansion of natural killer cells in patients with head and neck cancer: detection of "noninhibitory" (activating) killer Ig-like receptors on circulating natural killer cells

BACKGROUND: In a group of patients with head and neck cancers (H&NC), the expansion of the population of CD3-,CD16+ natural killer (NK) cells in the peripheral blood was studied. METHODS: Cytofluorimetric analysis of the expression of killer Ig-like receptors (KIR, namely p58.1, p58.2, p58.3, p70, and p140) and CD94-NKG2a was performed. Cytolytic activities were studied using 51Cr release assay. T and NK cell cloning was performed using limiting dilution culture conditions. Cytokine production was analyzed using commercial enzyme immunoassays. RESULTS: Phenotypic analysis showed that the expanded populations were heterogeneous. Even in the presence of a large number of circulating NK cells, "nonspecific" cytolytic capacities were heavily reduced, whereas cytolytic capacity related to T cells was virtually normal. Unlike NK cell clones derived from healthy donors, most NK cells derived from H&NC patients expressed surface "activating" NK cell receptors (KAR) for HLA, detected by use of a redirected cytolytic assay. Analysis of the CD4+ subpopulation at the clonal level demonstrated that they had a severe proliferative defect. CONCLUSION: These experimental data indicated that H&NC patients have a polyclonal expansion of functionally deficient NK cells expressing KAR. In addition, the proliferative capacity of patients' "helper" cells was strongly inhibited, thus accounting for a severe impairment of cytolytic activity of the expanded NK cells.     

The relationship of natural killer cells to metastasis of a transplantable prostate adenocarcinoma

Natural killer (NK) cells have been proposed to play a significant role in the inhibition of metastasis. The prostate adenocarcinoma (PA-11) in the Lobund-Wistar (L-W) rat provides a unique model of spontaneous metastasis in which to study NK response. Cultured PA-11 tumor cells were shown to be resistant to NK lysis in vitro, and enhancement or inhibition of NK reactivity in vivo using drugs or antiserum did not change the rate or extent of metastasis evident at autopsy. Exposure to PA-11 tumor cells, supernatants from cultured tumor cells, or sera from rats with advanced PA-11 in vitro did not result in inhibition of NK activity. Exposure to PA-11 tumor cells in vivo also did not cause suppression of NK activity. These data indicate that, in the PA-11/L-W system, metastasis is independent of NK activity.     

The regulation of natural killer cell activity by splenic nonspecific suppressor cells and its modification in cancer patients

Spleen cells (SC), splenic venous blood lymphocytes (SVL) and peripheral blood lymphocytes (PBL) from gastric and esophageal cancer patients were simultaneously tested for natural killer (NK) and nonspecific suppressor (Ts) cell activities. Furthermore, the influence of Ts activity on the augmentation of NK activity by a biological response modifier (BRM) was also investigated. Positive Ts activities were frequently detected in the SC, SVL and PBL of advanced cancer patients. The NK activities of SC and SVL were maintained even in advanced cancer patients, though significantly depressed NK activities were observed in the PBL of advanced cases. Cancer patient SC, SVL and PBL with positive Ts activity showed low NK activities. Moreover, the NK activities of SVL and PBL were low in the patients with positive Ts activity in SC. The NK activity of normal control PBL was strongly augmented by interleukin 2, interferon and OK-432. These BRMs exhibited comparable capacities to augment the NK activities of SC, SVL and PBL with negative Ts activity in cancer patients, however, the effects of these agents seemed to be low in cells with a positive Ts activity. These results suggested that NK activity might be regulated by nonspecific suppressor cells and the presence of suppressor cells might affect the augmentation of NK activity through BRM in circulating blood lymphocytes and also in spleen cells.     

Reduction of natural killer and natural killer T cells is not protective in cisplatin-induced acute renal failure in mice

Aims: A recent report showed that fractalkine (CX3CL1), which functions as both a potent chemoattractant and adhesion molecule for monocytes and natural killer (NK) cells was significantly increased in cisplatin‐induced acute renal failure (CisARF) in mice. Therefore, we developed the hypothesis that increased CX3CL1 expression in CisARF initiates NK cell infiltration in the kidney. The aim of the present study was to determine the role of NK cells in CisARF in mice. Methods: Time course of pan‐NK positive cells in CisARF was investigated by using immunohistochemistry (IHC) for CD49b. Pan‐NK positive cells were reduced by using anti‐NK1.1 mAb. The model of pan‐NK positive cells reduction was confirmed by flow cytometry of the spleen and IHC of the kidney. The expression of granzyme A and caspase‐1 was examined, and the activity of caspase‐1 was also determined. We performed a study on whether there was significant protection of renal function after reduction of pan‐NK positive cells. Results: (i) Infiltration of pan‐NK positive cells was prominent on day 3 after cisplatin administration. (ii) granzyme A expression was significantly increased in CisARF and CisARF+NK1.1 Ab compared to vehicle. (iii) Caspase‐1 expression and activity was significantly increased in CisARF mice compared to vehicle and CisARF+NK1.1 Ab. (iv) Reduction of pan‐NK positive cells was not protective in cisplatin‐induced acute renal failure in mice. Conclusions: Although infiltration of pan‐NK cells was significantly increased in CisARF, reduction of infiltration of pan‐NK cells into the kidney was not protective against CisARF in mice.     

Impaired natural killer cell lysis in breast cancer patients with high levels of psychological stress is associated with altered expression of killer immunoglobin-like receptors

BACKGROUND: We previously reported that cancer-related psychological stress is associated with reduced natural killer (NK) cell lysis. We hypothesized that reduced NK cell cytotoxicity in patients with increased levels of stress would correlate with alterations in the expression of inhibitory NK cell receptors (killer immunoglobulin-like receptors, or KIRs). The specific aim of this study was to examine KIR expression in patients with high or low levels of psychologic stress and correlate alterations in KIR expression with NK cell function. MATERIALS AND METHODS: Two hundred twenty-seven patients underwent baseline evaluation of cancer-related psychological stress and were randomized to psychosocial intervention versus observation. From this population, two groups were defined based on pretreatment measurements of NK lytic activity, stress levels, and the availability of cryopreserved peripheral blood mononuclear cells (PBMC). Group I (n=9) had low stress by the Impact of Events Scale (IES), and high NK cell lysis at the 50:1 effector: target ratio (NK(50)=52-89%). Group II (n=8) had high stress and low NK(50) (27-52%). Lymphokine activated killer (LAK) activity, antibody dependent cellular cytotoxicity (ADCC), and expression of cytokine receptors, adhesion molecules, and killer immunoglobulin-like receptors (KIRs) were assessed in PBMC. RESULTS: Incubation of PBMC with NK-stimulatory cytokines (IL-2, IL-12, or IL-15) led to significant increases in cytotoxic activity regardless of IES/NK(50) scores. There were no significant group differences in NK cell surface expression of the IL-2 receptor components CD25 and CD122, antibody-dependent lysis of HER2/neu-positive SKBr3 cells treated with an anti-HER2/neu monoclonal antibody, expression of adhesion molecules (CD2, CD11a, CD18) and markers of activation (CD69), or expression of the KIRs CD158a, NKG2a, NKB1, and CD161. However, levels of CD158b were significantly higher in Group I after incubation in media alone or with IL-2, and CD94 expression was significantly lower in Group I after incubation with IL-2. CONCLUSIONS: In this study of a small subset of breast cancer patients chosen from a previous clinical trial of psychosocial intervention for breast cancer, impaired NK lysis in breast cancer patients with high levels of psychological stress was associated with alterations in surface expression of killer immunoglobulin-like receptors. However, immune effectors retained the ability to lyse antibody-coated targets and to initiate lymphokine-activated killer activity, irrespective of stress levels or baseline NK(50).     

The role of natural killer T cells in costimulation blockade‐based mixed chimerism

Distinct lymphocyte populations have been identified that either promote or impede the establishment of chimerism and tolerance through allogeneic bone marrow transplantation (BMT). Natural killer T (NKT) cells have pleiotropic regulatory properties capable of either augmenting or downmodulating various immune responses. We investigated in this study whether NKT cells affect outcome in mixed chimerism models employing fully mismatched nonmyeloablative BMT with costimulation blockade (CB). The absence of NKT cells had no detectable effect on chimerism or skin graft tolerance after conditioning with 3Gy total body irradiation (TBI), and a limited positive effect with 1Gy TBI. Stimulation of NKT cells with alpha‐galactosylceramide (alpha‐gal) at the time of BMT prevented chimerism and tolerance. Activation of recipient (as opposed to donor) NKT cells was necessary and sufficient for the alpha‐gal effect. The detrimental effect of NKT activation was also observed in the absence of T cells after conditioning with in vivo T‐cell depletion (TCD). NKT cells triggered rejection of BM via NK cells as chimerism and tolerance were not abrogated when NKT cells were stimulated in the absence of both NK cells and T cells. Thus, activation of NKT cells at the time of BMT overcomes the effects of CB, inhibiting the establishment of chimerism and tolerance.     

Stressful life events and adolescent well‐being: The role of parent and peer relationships

It is well established that stressful life events (e.g., family bereavements or moving to a new country) are damaging to psychological health and well‐being. Indeed, social relationships are often noted as an important factor that can influence well‐being and buffer the negative effects of stress. However, the quality and source of these relationships, particularly for adolescents, are often overlooked. Using the Growing Up in Ireland Survey, a population‐based study of 13‐year‐old Irish adolescents (N = 7,525; 51.1% female), the current study examines the quality of both parent and peer relationships as potential mechanisms explaining the association between stressful life events and psychological well‐being indices in adolescents. As expected, results showed that stressful life events negatively impacted the psychological well‐being of adolescents. Parallel mediation analyses indicated that both parent and peer relationship quality mediated this association. Further exploratory analyses found that for girls, greater numbers of stressful life events were associated with poorer quality relationships with both their parents and peers, and in turn, these were linked to lower levels of psychological well‐being. For boys, this effect was only evident for parental relationship quality, but not peers. The implication of these findings for adolescent's psychological well‐being, particularly for girls, is discussed.     

Stress,savouring, and coping: The role of savouring in psychological adjustment following a stressful life event

There is increasing research on the role of savouring positive emotional experience in the context of stress. As such, we need a better understanding of how savouring and coping relate to each other and to psychological adjustment outcomes following a stressful life event. In particular, this study seeks to understand whether savouring is better conceptualized as a coping resource or a coping response. Three hundred people who experienced a highly stressful event in the past year completed measures of impact of event, savouring, coping, positive emotions, depression, anxiety, and life satisfaction. Results of bivariate correlations showed that savouring is positively correlated with positive coping (i.e., mastery and meaning‐based coping) and socially‐supported coping (i.e., using emotional and instrumental support) and negatively correlated with negative coping (i.e., self‐judgement and avoidance coping). The results of path analyses support a model that positions savouring as a coping response that relates to other coping responses and indirectly relates to better psychological adjustment through positive emotions (when psychological adjustment is conceptualized as depression or life satisfaction but not anxiety). Findings provide preliminary support for conceptualizing savouring as a coping response; future research should consider measuring savouring as a coping response to further our understanding of savouring following a stressful life event.     

Effect in vitro and in vivo of a rat anti-CD2 monoclonal antibody (LO-CD2b) on pig-to-baboon xenogeneic cellular (T and natural killer cells) immune response

Abstract: Although hyperacute rejection of discordant xenogeneic grafts can be prevented, baboon or human anti-pig cellular response may lead to acute xenograft rejection. Among the immune cellular actors participating in such a xenograft rejection are both T and natural killer (NK) cells. In the pre-clinical model of pig-to-baboon discordant xenograft, there is however, a lack of specific immunological therapeutic agent, in particular antibaboon T-cell monoclonal antibodies do not exist. We therefore developed a rat anti-CD2 monoclonal antibody (LO-CD2b) that recognizes both baboon and human CD2 + cells. In this study, we show that in vitro LO-CD2b inhibits a pig-to-baboon mixed lymphocyte reaction, the direct cytotoxicity of baboon peripheral blood lymphocytes to pig aortic endothelial cells, as well as the baboon NK activity against K562 cell line. In vivo, LO-CD2b produces a strong depletion of all peripheral CD2+ cells including NK CD2+ cells. In summary, LO-CD2b represents an important immunological tool that can be used in the preclinical model of discordant pig-to-baboon vascularized xenograft.