NK细胞受体NCR在肿瘤和病毒感染中的作用

自然杀伤细胞(natural killer cell, NK cell)作为固有免疫应答的主要效应细胞,在机体抗肿瘤和抗病毒感染过程中发挥关键作用。自然细胞毒性受体( natural cytotoxicity receptors, NCR)是NK细胞表面的活化性受体,主要包括NKp30、 NKp44和NKp46。这些受体和同源性细胞表面或病毒来源的配体相互结合,可促使NK细胞活化,进而发挥杀伤功能以及分泌细胞因子。相反,肿瘤细胞和病毒也可以通过NCR实现免疫逃逸,促进疾病的发生发展。     

Expression of natural cytotoxicity receptors and a2V-ATPase on peripheral blood NK cell subsets in women with recurrent spontaneous abortions and implantation failures

PROBLEM: Natural cytotoxicity receptors (NCRs) are unique markers, which regulate NK cell cytotoxicity and cytokine production. a2V-ATPase is expressed on subsets of PBMC and regulates the extracellular environment, which facilitates NK cytotoxicity or cytokine secretion. In this study, we aim to investigate the expression of NCRs and a2V-ATPase in peripheral blood NK cells of women with recurrent spontaneous abortions (RSA) or implantation failures. METHOD OF STUDY: Peripheral blood NK cells (CD56(dim) and CD56(bright) were analyzed for the expression of NCRs (NKp46, NKp44 and NKp30) and a2V-ATPase using 3-color flow cytometry in women with RSA (n=24), implantation failures (n=19) or normal healthy women (n=13). RESULTS: CD56+/NKp46+ cells were markedly decreased (P<0.05) and CD56(bright)/a2V-ATPase+ cells were significantly increased (P<0.05) in women with RSA as compared to those of normal controls. In women with RSA or implantation failures, expression of NKp46, NKp44, NKp30, and a2V-ATPase on CD56(bright) NK cells was significantly up-regulated as compared with those of CD56(dim) NK cells. CONCLUSION: The differential expression of NCRs and a2V-ATPase in NK cell subsets may suggest dysregulation of NK cytotoxicity and cytokine production in women with RSA and implantation failures.     

Elevated NK Cell Cytotoxicity,CD158a Expression in NK Cells and Activated T Lymphocytes in Peripheral Blood of Women with IVF Failures

Citation Chernyshov VP, Sudoma IO, Dons’koi BV, Kostyuchyk AA, Masliy YV. Elevated NK cell cytotoxicity, CD158a expression in NK cells and activated T lymphocytes in peripheral blood of women with IVF failures. Am J Reprod Immunol 2010; 64: 58–67 Problem The aim of this study was to evaluate the role of elevated natural killer cytotoxicity (NKc) in women with multiple implantation failures (IF) in vitro fertilization–embryo transfer (IVF–ET) cycles. Methods of study Seventy‐nine antiphospholipid antibodies‐negative women with IF including 33 women with elevated NKc were selected for investigation. K‐562 cell line was used to evaluate NKc. Lymphocyte subsets, intracellular cytokines [interferon (IFN)‐γ, interleukin (IL)‐4, tumour necrosis factor, IL‐10], expression of activating markers [CD69, human leukocyte antigen (HLA)‐DR], CD8, KIR (CD158a), CD95, and chemokine receptors (CXCR3, CCR4) were estimated by flow cytometry. Results In women with IF, levels of NKc were higher than in IVF successful women. IF was associated with higher expression of CD8, CD158a, and HLA‐DR in NK cells, activating markers in T lymphocytes, and lower levels of CCR4+ and IL‐4+ T lymphocyte subsets. Predictive value of single elevated NKc for IVF success was 0.85, but addition of two other abnormal parameters resulted in its decrease to <0.39. Conclusions Elevated NKc is negative factor, though not critical for implantation in IVF cycles. Immune mechanism of IVF failure includes not only elevated NKc but also some other factors, such as elevated expression of CD8 and CD158a on NK cells, T lymphocyte activation, and diminished T helper 2 parameters.     

ORIGINAL ARTICLE: Women with Multiple Implantation Failures and Recurrent Pregnancy Losses have Increased Peripheral Blood T Cell Activation

Citation Yang KM, Ntrivalas E, Cho HJ, Kim NY, Beaman K, Gilman‐Sachs A, Kwak‐Kim J. Women with multiple implantation failures and recurrent pregnancy losses have increased peripheral blood T cell activation. Am J Reprod Immunol 2010 Problem We aim to determine whether peripheral blood T cell activation is associated with repeated implantation failures or recurrent pregnancy losses (RPLs). Method of study Women with a history of repeated implantation failure (n = 18) or RPLs (n = 17) comprise the study group. Normal fertile women (n = 11) are included as controls. Proportion of activated peripheral blood T cells (CD69⁺, CD154⁺) and Th1/Th2 cell ratios are measured by flow cytometric analysis. Results Proportions (%) of CD4⁺/154⁺ of CD4⁺ and CD8⁺/154⁺ of CD8⁺ cells were significantly higher in study group than those of controls. Proportions (%) of CD3⁺/69⁺ of CD3⁺ cells and CD8⁺/69⁺ of CD8⁺ cells were significantly increased in study group compared to controls. Proportion (%) of CD4⁺/69⁺ cells significantly correlated with % CD4⁺/154⁺ cells (P = 0.003). Activated cytotoxic T cells (CD8⁺/154⁺, CD8⁺/69⁺) inversely correlated with INF‐γ/IL‐10 producing CD3⁺/4⁺ T cell ratios. Proportion of activated CD3⁺/8⁺/69 and CD3⁺/8⁺/154⁺ cells was inversely correlated with IFN‐γ/IL‐10 expressing CD3⁺/4⁺ T cell ratios. Conclusion Women with MIFs or RPLs have increased T cell activation in peripheral blood lymphocytes, and T cell suppressor activation seems to be associated with decreased Th1 immunity. Further studies on T cell activation may elucidate molecular mechanisms controlling Th1 effectors.     

Changes of NK Cells in Preeclampsia

The regulation of uterine and circulating peripheral blood natural killer (NK) cells has been associated with reproductive immunology such as recurrent pregnancy losses, implantation failures, or preeclampsia. Preeclampsia is a hypertensive disorder of pregnancy characterized by increased blood pressure accompanied by proteinuria and is a major cause of maternal and fetal mortality. Natural cytotoxicity receptors (NCRs) are unique markers, which regulate NK cell cytotoxicity and cytokine production. The relation of NCRs to reproduction is not fully characterized yet. The different profile of NCRs expression may suggest presence of abnormal regulation of NK cell in women with reproductive failures. Pregnant women with preeclampsia carry immunological abnormalities of NCRs on peripheral blood NK cells during pregnancy. The lower expression of NKp46⁺ NK cells in women with preeclampsia may account for the higher production of NK1 cytokine that is known as NK1 shift in pregnant women with preeclampsia. Evaluation of NKp46 on peripheral blood NK cells may be applicable to find the onset of preeclampsia. In this review, various expressions of NK cell surface markers including NCRs on NK cells, NK cell cytotoxicity, and production of cytokines and angiogenic factors by NK cells were reviewed in relation to preeclampsia.     

ORIGINAL ARTICLE: Peripheral Blood NK Cells Reflect Changes in Decidual NK Cells in Women With Recurrent Miscarriages

Citation Park DW, Lee HJ, Park CW, Hong SR, Kwak‐Kim J, Yang KM. Peripheral blood NK cells reflect changes in decidual NK cells in women with recurrent miscarriages. Am J Reprod Immunol 2010; 63: 173–180 Problem We aimed to investigate if peripheral blood natural killer (pNK) cell levels are correlated with decidual NK (dNK) cell levels, and if chemokine expression has any role in dNK cell regulation. Method of study Decidual tissues of women having two or more miscarriages with normal karyotype were collected after miscarriage and an immuno‐histochemisty study was made. pNK cells were evaluated using flow cytometric analysis. Results The %CD3^?/56⁺ and %CD3^?/56⁺/16⁺ pNK cells showed a significant correlation with mean number of CD56⁺ dNK cells. The number of decidual CD16⁺ cells was significantly higher in women with elevated pNK (≥15%) than that of normal pNK (<15%). The %CD3^?/56⁺ and %CD3^?/56⁺/16⁺ pNK cells showed an inverse correlation with duration of gestation. The CCL3⁺ and CXCL12⁺ cells were present in the decidua; however, staining intensity was not correlated with number of dNK cells. Conclusion The pNK cell levels reflect changes in dNK cell levels. This implicates that pNK cell level is a clinically useful marker to predict pregnancy outcome. Further study is needed to examine if elevated pNK cells enhance recruitment of dNK cells in the decidua.     

Up-Regulated Expression of CD56+, CD56+/ CD16+, and CD19+ Cells in Peripheral Blood Lymphocytes in Pregnant Women With Recurrent Pregnancy Losses

PROBLEM : To analyze immunophenotypic profiles of peripheral blood and humoral autoimmune responses in women with a history of recurrent spontaneous abortions (RSA). METHOD : Peripheral blood lymphocyte subsets by flow cytometry and autoantibodies to phospholipids and nuclear components by ELISA were measured in non pregnant and pregnant women with RSA of unknown etiology. Thirty-five pregnant and eighty-one nonpregnant women with RSA were studied. Seventeen nonpregnant and twenty-two pregnant normal controls were included. RESULTS : Natural killer (NK) cells (CD56+) were significantly elevated in nonpregnant women with RSA as compared with nonpregnant controls. Pregnant women with RSA demonstrated significantly increased NK (CD56+, CD56+/CD16+) and B cells (CD19+) as compared with pregnant controls. Women who miscarried the index pregnancy demonstrated significantly lower CD3+ cells in comparison with normal controls. Women with RSA and antiphospholipid antibodies showed significantly elevated NK cells when compared with women without antiphospholipid antibodies. Women with autoantibodies to nuclear components demonstrated significantly elevated CD19+/CD5+ cells when compared to women without autoantibodies to nuclear components. CONCLUSIONS : Women with RSA demonstrate an abnormal cellular immune response by increasing peripheral natural killer cells and B cells as compared with normal controls.     

A High Dose of Intravenous Immunoglobulin Increases CD94 Expression on Natural Killer Cells in Women with Recurrent Spontaneous Abortion

Problem  A high dose of intravenous immunoglobulin (HIVIg) therapy is effective in various diseases such as autoimmune diseases, and also is expected to have efficacy in recurrent spontaneous abortion (RSA). The aim of this study was to understand immunological mechanisms of this therapy.
Method of study  By flowcytometric analyses, we examined phenotypic changes of a variety of immunological cells including natural killer (NK) cells, cytotoxic T cells, regulatory T cells and macrophages in peripheral blood of RSA women with HIVIg therapy ( n  = 8).
Results  Expression percentages of inhibitory CD94 on NK cells significantly ( P =  0.01) increased after the therapy (58.8 ± 21.4% versus 71.0 ± 17.6%).
Conclusion  Mechanisms of possible efficacy of HIVIg therapy for RSA may include enhancement of CD94 expression and subsequent suppression of NK cell cytotoxicity.     

Decidual Natural Killer Cytotoxicity Decreased in Normal Pregnancy but Not in Anembryonic Pregnancy and Recurrent Spontaneous Abortion

PROBLEM : The natural killer (NK) cell activity is depressed in the decidua of early normal pregnancy. Recently Morii et al. (Am J Reprod Immunol 1993;29:1–4) found that all early intradecidual CD3⁺ T cells expressed either T cell receptor (TCR) α/β or γ/δ but that the expression of the CD3⁺/TCR complex was down-regulated. METHOD : To test whether these changes in decidual cellular immunity are different among normal pregnancy, anembryonic pregnancy and recurrent spontaneous abortion, we examined the immune cell subpopulations in the decidua from these three types of pregnancy using flow cytometry and an NK cytotoxicity assay. RESULTS : Intradecidual CD3⁺ T cells expressed either TCR α/β or γ/δ, and the level of expression of the CD3/TCR complex was down-regulated in normal pregnancy, anembryonic pregnancy, and recurrent spontaneous abortion. Although the relative proportion of decidual NK cells was increased to approximately the same extent in all three types of pregnancy, decidual NK activity was higher in anembryonic pregnancies and in recurrent spontaneous abortions than it was in normal pregnancies. CONCLUSION : Decidual NK cell responses are different in anembryonic pregnancies and in recurrent spontaneous abortions than in normal pregnancies. Whether this difference is pathogenic or is the response to a dead embryo remains to be elucidated.     

Natural killer (NK) cell subsets and NK cell cytotoxicity in women with histories of recurrent spontaneous abortions

PROBLEM: Natural Killer (NK) cell measurement and NK cytotoxicity are two measurements for assessing the cellular immune response. Both of the techniques have been reported to be prognostic for women with recurrent spontaneous abortion (RSA), We evaluated the two methods to determine the relationship of the two assays. Because both methods portend to evaluate the same process, the previous clinical data suggested that the methods evaluate the same phenomena. We undertook these studies to determine whether simple NK cell counts may be sufficient in the evaluation of NK activity in RSA. METHOD OF STUDY: The NK cell cytotoxicity at effector-to-target ratios of 50:1 and 25:1 was determined using a flow cytometric NK cell cytotoxicity assay. These values were then correlated with the percentages and absolute counts of three peripheral blood NK cell subsets. RESULTS: The data indicate that the flow cytometric assay is reproducible and precise and can be successfully used to evaluate patient samples. Linear regression analysis indicated a lack of correlation between peripheral blood NK cell cytotoxicity and percentages or absolute counts of ***CD56+CD16+, CD56+CD16 — or CD3+CD56+ lymphocyte subsets (range of correlation coefficients, 0.1–0.3). CONCLUSIONS: NK cell cytotoxicity and peripheral blood NK cell values measure different aspects of NK cells and do not correlate. These data indicate that simple enumeration of NK cells may not be sufficient in the evaluation of NK cells in RSA.     

Phenotype of NK Cells and Cytotoxic/Apoptotic Mediators Expression in Ectopic Pregnancy

Citation Laskarin G, Redzovic A, Vukelic P, Veljkovic D, Gulic T, Haller H, Rukavina D. Phenotype of NK cells and cytotoxic/apoptotic mediators expression in ectopic pregnancy. Am J Reprod Immunol 2010 Problem The expression of cytotoxic/apoptotic mediators and the phenotype characteristics of uterine NK cells (uNK) in tubal ectopic pregnancy (EP) were investigated. Method of study Samples of uterine decidua and tubal mucosa as well as peripheral blood (PB) of the same women with EP were used for phenotype characterization of NK cells and detection of cytotoxic/apoptotic mediators and IL‐15. Results In tubal mucosa, perforin, FasL, granulysin and IL‐15 were almost completely absent, but they were present in normal and EP uterine deciduas. TRAIL was present on trophoblast and tubal mucosa, contrary to its lack in normal and EP uterine decidua. CD16^?CD56^dim NK cells, mostly CD94^? and NKG2A^?, predominate in tubal mucosa, whereas CD16^?CD56^bright NK cells, predominantly CD94⁺ and NKG2A⁺ prevail in EP uterine decidua. NK cells at the EP implantation site express lower percentages of perforin and granulysin, but they express a higher percentage of TRAIL than do EP uterine decidual and PB NK cells. Lower percentage of TNF‐α‐expressing and IL‐4‐expressing NK cells were found at the implantation site compared to EP uterine decidua. Conclusions Authentic uNK cell population seems to be insufficient to restrict trophoblast invasion because of low expression of cytotoxic/apoptotic mediators.     

Timed Sexual Intercourse Facilitates the Recruitment of Uterine CD56bright Natural Killer Cells in Women with Infertility

Problem  The aim of this study was to investigate the influence of sexual intercourse on uterine NK cell subsets.
Method of study  Mid-secretory endometrial samples obtained from 56 women were submitted for flow cytometric analysis. Basal body temperature was used to determine the day of ovulation. A total of 27 women had sexual intercourse before ovulation (pre-ovulation group) and eight women had only after ovulation (post-ovulation group) without any contraceptive devices. A total of 21 women did not have sexual intercourse during the experimental cycle (abstinence group). Endometrial NK cells were analyzed for the expression of CD16 and CD56 using 3-color flow cytometry.
Results  CD16⁻/CD56^bright cells were markedly increased in the pre-ovulation group as compared with that of the post-ovulation group ( P  < 0.01) and the abstinence group ( P  < 0.01). CD16⁺/CD56^dim cells were significantly decreased in the pre-ovulation group as compared with that of the post-ovulation group ( P  < 0.01) and the abstinence group ( P  < 0.05).
Conclusion  It is suggested that seminal plasma participates in the recruitment of CD56^bright NK cells into endometrium.