Stress Causes Reduced Natural Killer Activity in Mice

The natural killer (NK) activity of spleen cells from C57B1/10 mice subjected to standardized stress conditions was reduced when compared with that of untreated controls. Both the total number of nucleated spleen cells and their cytotoxic activity against an NK-sensitive target were reduced. The reduction appeared after induction of stress, and the NK activity was reduced throughout an 8-day stress period.     

Altered Natural Killer Cell Activity in Childhood Acute Non-lymphoid Leukaemia

Peripheral blood and bone marrow mononuclear cells from 25 children with acute non-lymphoid leukaemia were analysed for natural killer cell activity and for cells with the Leu-7 and Leu-11b (CD 16) markers. Significantly reduced spontaneous cytotoxicity was detected in peripheral blood from children with untreated and active acute non-lymphoid leukaemia compared with that of the controls (P = 0.01 and P less than 0.05). Patients in remission, however, had normal natural cytotoxicity and normal numbers of Leu-7 and Leu-11b (CD 16)-positive cells. The natural killer cell activity in bone marrow from patients with untreated acute non-lymphoid leukaemia was also significantly reduced (P = 0.025). On the other hand, patients in remission had both an increased percentage of Leu-7 and Leu-11b (CD 16)-positive cells (P less than 0.05) and an increased natural killer cell activity (P less than 0.0005) in their bone marrow cells in comparison with the control group. This augmented natural killer cell activity is most probably a result of anti-leukaemic treatment. Stimulation with recombinant alpha interferon and recombinant interleukin 2 caused an increase in natural killer cell activity that was both significant and normal in both peripheral blood and bone marrow from children with acute non-lymphoid leukaemia.     

Altered Peripheral Invariant Natural Killer T Cells in Atopic Dermatitis

Background  

Conflicting data exist on the number of invariant NKT (iNKT) cells in atopic dermatitis (AD); furthermore, no data have been published on their functional capacity.     

Changes in Natural Killer Activities in Experimental Secondary Amyloidosis

Natural killer (NK) cell activity in experimental murine amyloidosis was studied. In CBA/J mice, which show a high incidence of amyloidosis, NK activity was significantly decreased after 1 week of casein treatment. In C3H mice, which show a low incidence of amyloidosis, NK activity was not changed by casein treatment. Pretreatment with lipopolysaccharide in vivo enhanced the NK activities in CBA/J and C3H mice. These increases were not observed after casein treatment. The lowered NK activity of cells from CBA/J mice after casein treatment was restored to the normal range by indomethacine in vitro. Depletion of adherent cells from the spleen cells treated with casein had no effect on NK activity. Single-cell assay showed that casein treatment impaired the killing but not the binding of NK cells to target cells. After casein treatment, the splenic serum amyloid A (SAA) level gradually increased in CBA/J mice but remained low in C3H mice. NK activity was suppressed by the addition of serum obtained from CBA/J mice treated with casein but not by normal control serum. And partially purified AA protein obtained from the spleen of CBA/J mice treated with casein also suppressed NK activity in vitro.     

Effect of Methionine Enkephalin on Natural Killer Cell and Cytotoxic T Lymphocyte Activity in Mice Infected with Influenza a Virus

Methionine enkephalin (Met-Enk) was evaluated for efficacy as an immune activator and potential therapeutic agent in influenza A/NWS/33 (H1N1) viral infections in female BALB/C mice. Influenza infection was induced intranasally with an approximate 90% lethal dose of virus and mice were treated intraperitoneally with doses of 10, 3 and 1 mg/kg/day, with treatments given 24 h pre-, 24 h post-and 72 h post-virus exposure. Splenocytes were assayed for natural killer cell (NK) and cytotoxic T lymphocyte (CTL) activity at time periods 76, 96 and 120 h post virus exposure. the 10 mg/kg dosage level significantly increased both CTL and NK activity at all time periods assayed. Other treatment schedules included single doses of 20, 10 and 3 mg/kg/day Met-Enk at either 24 h post-or 72 h post-virus exposure, with highly significant increases in NK and CTL activity noted after the latter treatment. the results of this study demonstrate the immunomodulatory effects of Met-Enk on NK and CTL in influenza infected mice and suggest a potential for therapeutic applications.     

Lymphokine-Activated Killer Cells in Mouse Bone Marrow Chimaeras The Relationship to Natural Killer Cells and to Alloreactive Cytotoxic T Cells

Spleen cells from mouse bone marrow chimaeras were cultured in vitro in mixed lymphocyte cultures (MLC) or in the presence of interleukin 2 (IL-2) without the added alloantigen. Precursors for the nonspecific cytotoxic cells (in this study: lymphokine-activated killer (LAK) cells) lysing natural killer (NK) cell-sensitive YAC-1 lymphoma could be found 10-12 days after the bone marrow reconstitution, simultaneously with the appearance of the NK activity. The ability of LAK cells to lyse NK-resistant tumour targets as well was demonstrated using the P 815 mastocytoma cell line; reactivity against this target was demonstrable 1 week later than the appearance on YAC-1 lysing cells. Phenotypically LAK cells derived from spleen cell cultures of bone marrow chimaeras did not differ from LAK cells derived from normal spleen cell cultures: precursors resided within the Thy 1-, asialo-GM1+ cell population, and effectors expressed both of these antigens. Splenic NK cells of early bone marrow chimaeras (up to 14-18 days after the bone marrow reconstitution) were Thy 1+ cells, and thus LAK cells of bone marrow chimaeras were not derived from these Thy 1+ NK cells. The treatment of effector cells with anti-Thy 1 antibody plus complement (C) abolished the lytic activity totally. However, these cells were not cytotoxic T cells, since alloreactivity, as an indication of the T-cell cytotoxicity, could not be demonstrated until 4-5 weeks after the bone marrow reconstitution.     

Natural Killer Cell Response to Lymphocytic Choriomeningitis Virus in Beige Mice

Lymphocytic choriomeningitis virus (LCMV) induced low levels of natural killer (NK) tell activity in C57BL6 mutant beige (bg/bg) mice, which had previously been reported to have no cytotoxic NK cells. NK cell-mediated lysis by bg/bg splenocytes was observed against a cell line (YAC-I) very sensitive to NK cell cytotoxicity, but not appreciably against a less scum live cell line (L-929), The bg/bg mutant mice with this very low NK cell activity and control stains of mice (bg/+, C57BL6) with high NK cell activity synthesized comparable amounts of virus and interferon in the spleen, suggesting that NK cells may not play a significant role in curtailing viral synthesis before the advent of the specific immune response mechanisms     

Activated Natural Killer Cells Suppress Myelopoiesis in Mice with Severe Combined Immunodeficiency

The in vivo effect of natural killer (NK) cell activation on aulologous myelopoiesis was studied in an environment deficient of functional Tand B cells. Administration of 3.6-bis[2-(Dimethylamino)-ethoxy]-9H-xanthen-9-one dihydrochloride) Tilorone) or recombinant interleukin-2 (rIL-2) to mice with severe combined immunodeficiency (C. B. -I7 scid/scid) resulted in an increase in YAC-1 lysis by their splenocytes as well as bone marrow cells. Recombinant IL-2 furthermore led to a fivefold increase in the cellularity of the spleen. When assayed against human NK/lymphokine-activated killer (LAK) target, K562 cell line. the IL-2-activated mouse cells exhibited no cytotoxicity across the species barrier. Both agents induced a profound suppression of myelopoietic progenitor cells as measured in a 7-day granulocyte-macrophage colony forming cell (GM-CFC) assay. We conclude that the presence of neither functional T nor B cells is necessary for NK cells to mediate inhibition cf myelopoiesis in the autologous host.     

Histaminergic Regulation of Natural Killer Cell-Mediated Clearance of Tumour Cells in Mice

Treatment of Swiss albino mice with histamine enhanced the clearance of natural killer (NK)-cell sensitive YAC-1 lymphoma and B16/F10 melanoma cells from lung tissue in vivo , but did not affect the elimination of NK-cell-insensitive P815mastocytoma cells. The effect of histamine was apparently mediated by H₂-type histamine receptors (H₂R) since it was blocked by ranitidine, an H₂R antagonist. Histamine did not affect clearance of tumour cells in animalsdepleted of NK cells in vivo by treatment with antibodies to asialo-GM1 or NK1.1. The effect of histamine was time-dependent: pretreatment with histamine for 3 h significantly augmented the clearance of YAC-1 cells, whereas, pretreatmentwith histamine for 5 min was ineffective. Histamine potentiated the anti-tumour properties of NK-cell activators such as interleukin-2 (IL-2) or interferon-α (IFN-α) in vivo . None of these lymphokines significantly affected theclearance of YAC-1 cells unless animals were concomitantly treated with histamine. Treatment with ranitidine alone reduced the in vivo clearance of YAC-1 cells from lungs but did not affect the clearance of NK-cell-insensitive P815 cells. Effects of ranitidine on NK-cell function in vivo were not shared by a chemical control to ranitidine, AH20239AA, thus indicating that the inhibition of NK-cells results from H₂R antagonism rather than non-specific toxicity. It is concludedthat histaminergic mechanisms may be involved in the regulation of NK cell function in vivo     

应激对小鼠T、B细胞分裂原反应性及天然杀伤细胞活性的影响

自Jerne提出免疫网络学说,对免疫调节的研究日益深入。但这些工作多限于研究免疫系统内部的相互作用,而忽略了免疫系统外的因素对免疫应答的影响。近年来有些作者注意到神经-内分泌系统对免疫反应的调控作用,应激的研究应为其中之一。应激往往引起神经-内分泌系统的一系列变化,并导致免疫功能的改变。手术、创伤、疼痛引起的应激反应,往往造成患者的抗感染、抗肿瘤的能力下降,认为与应激介导的免疫抑制效应有关。但未见有关手术应激的动物实验报告。本文重点研究了手术应激动物模型的建立,证明此种应激可明显抑制小鼠的分裂原反应性及NK活性。比较不同分裂原反应性受抑的动力变化,发现不同分裂原反应性对手术应激的抑制效应的敏感性不     

Effects of X-RAY Irradiation on Natural Killer (NK) Cell System. II. Increased Sensitivity to Natural Killer Cytotoxic Factor (NKCF)

Irradiation with low-doses of X-rays of tumor cells elevated their susceptibility to lysis by natural killer (NK) cells in an accompanying paper. Cytotoxicity assays conducted at the single cell level revealed that X-ray irradiation of K562 cells did not affect the number of effector-target conjugates but increased the frequency of dead conjugated target cells. During interaction with K562 cells large granular lymphocytes released a soluble cytotoxic factor (NKCF) that killed the target cells. X-ray irradiation did not affect the NKCF stimulatory ability of K562 cells, while it elevated their sensitivity to the lytic effect of NKCF. In contrast to X-rays, exposure to ultraviolet (UV) radiation of K562 cells did not elevate their NK sensitivity but rather reduced it. Treatment with mitomycin C produced no effect on NK sensitivity. These results indicate that X-ray irradiation elevates the target sensitivity to NKCF, which may be involved in the increased NK sensitivity, and that the X-ray effect may be different from that of UV radiation or DNA synthesis inhibition.     

Effects of X-RAY Irradiation on Natural Killer (NK) Cell System. II. Increased Sensitivity to Natural Killer Cytotoxic Factor (NKCF)

Abstract

Irradiation with low-doses of X-rays of tumor cells elevated their susceptibility to lysis by natural killer (NK) cells in an accompanying paper. Cytotoxicity assays conducted at the single cell level revealed that X-ray irradiation of K562 cells did not affect the number of effector-target conjugates but increased the frequency of dead conjugated target cells. During interaction with K562 cells large granular lymphocytes released a soluble cytotoxic factor (NKCF) that killed the target cells. X-ray irradiation did not affect the NKCF stimulatory ability of K562 cells, while it elevated their sensitivity to the lytic effect of NKCF. In contrast to X-rays, exposure to ultraviolet (UV) radiation of K562 cells did not elevate their NK sensitivity but rather reduced it. Treatment with mitomycin C produced no effect on NK sensitivity. These results indicate that X-ray irradiation elevates the target sensitivity to NKCF, which may be involved in the increased NK sensitivity, and that the X-ray effect may be different from that of UV radiation or DNA synthesis inhibition.     

Splenectomy Delays Uterine Natural Killer Cell Recruitment to Implantation Sites and Prolongs Pregnancy in Mice

Uterine natural killer (uNK) cells are the dominant lymphocytes found in pregnant mammals that develop uterine decidualization. Four stages of mouse uNK cell differentiation are recognized using Dolichos biflorus agglutinin (DBA) lectin histochemistry. Each uNK cell subtype has a preferential domain. In human and mouse normal pregnancies, uNK cells are activated interferon gamma‐producing cells that promote angiogenesis and development of the decidua and placenta. Murine transplant models suggest that uNK cells differentiate from self‐renewing progenitors found in peripheral secondary lymphoid tissues, particularly spleen and lymph nodes. In this work, the spleen was removed 7 days before mice were mated to address whether absence of the spleen reduced uNK cell numbers or altered the distributions of maturing uNK cell subsets using quantitative lectin histochemistry. Splenectomy delayed uNK cell maturation within implantation sites. This coincided with delayed decidual and placental development and a significant (48 hr) lengthening of gestation without loss of viability. These studies characterize spleen as a biologically important progenitor tissue for uNK precursor cells. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.     

Natural Killer Cell Cytotoxicity and Antibody-Dependent Cellular Cytotoxicity to Herpes Simplex Virus-Infected Cells in Human Pregnancy

ABSTRACT: Natural killer cell (NKC) cytotoxicity and antibody-dependent cellular cytotoxicity (ADCC) represent the ability of human leukocyte effector cells to destroy target cells in the absence and presence of antibody, respectively. Since these immune systems play a pivotal role in the body's primary lines of defense against a variety of pathogens including herpes simplex virus (HSV), a study was undertaken to evaluate the influence of pregnancy on these systems. Eleven uncomplicated gravidas were followed serially through each trimester and compared to 11 nonpregnant female controls. Mononuclear cells were acquired by Ficoll-Hypaque centrifugation of heparinized blood. Chang liver cells infected with HSV-I were utilized as target cells in a ⁵¹Cr release assay. Mean NKC values in the pregnant patients were uniformly lower than in the controls. No similar decreases in ADCC activity were observed in a comparison between the two study populations. These data support previous observations suggesting that pregnancy represents a relatively immunocompromised state. Differences apparently exist between NKC and ADCC effector cell populations with regard to the influence of pregnancy. Although these physiologic alterations in immunoregulation may help support the fetoplacental allograph, detrimental conditions may exist regarding susceptibility to various pathogens such as HSV.     

Natural Killer Cells and Cytotoxic T Cells Induce DNA Fragmentation in Both Human and Murine Target Cells in Vitro

DNA fragmentation induced by cytolytic lymphocytes in human erythromyeloid cell line K562 and murine T lymphoma cell line YAC-1 was investigated by means of agarose gel electrophoresis. Murine natural killer (NK) and cytotoxic T (Tc) cells induced DNA fragmentation in YAC-1 cells, with the fragments being approximately multiples of 180 bp. More significantly, murine NK cells can induce a similar pattern of DNA fragmentation in human K562 cells. Therefore, cytolytic lymphocytes can induce apoptosis or programmed cell death in human target cells.     

Altered Invariant Natural Killer T cell Subsets and its Functions in Patients with Oral Squamous Cell Carcinoma

Invariant natural killer T (iNKT) cells are glycolipid‐reactive T lymphocytes that share receptors and function with natural killer (NK) cells and reportedly play a pivotal role in various immune responses. However, iNKT cells are not well characterized in patients with oral squamous cell carcinoma (OSCC). We investigated the populations and functions of circulating iNKT (CD3⁺6B11⁺) cells from thirty‐eight patients with OSCC and twenty‐eight healthy donors by flow cytometry. Circulating iNKT cells were significantly lower (P < 0.01) in patients as compared to those in healthy controls. Further, iNKT subsets revealed a marked decrease in CD4^?CD8^? (double negative, DN) subset with concomitant increase in CD8⁺ subset in patients as compared to healthy controls (P = 0.03 and P < 0.01, respectively), whereas CD4⁺ subset was similarly distributed in both groups. The functional analysis demonstrated that residual iNKT cells from patients had impaired proliferative response to α‐galactosylceramide (α‐GalCer)‐pulsed dendritic cells (DCs) and Th2‐like cytokine profile. However, in vitro activation with α‐GalCer‐pulsed DCs restores IFN‐γ expression and enhances antitumour activity to human cancer cells lines (SCC‐4, KB and MCF7). It appears that the selectively enriched iNKT subsets and modulation of their function by specific ligand/agonist may be useful for cellular therapy in patients with OSCC. Further, reduced levels of iNKT cells and its DN subset may be used as potential prognostic factors for patients with OSCC.     

KRN7000 Reduces Airway Inflammation via Natural Killer T Cells in Obese Asthmatic Mice

Although natural killer T cells (NKT cells) are altered in obese asthmatic mice, their function remains completely unclear. To further explore the potential mechanism of NKT cells in airway inflammation of obesity-associated asthma, we examined the effects of α-galactosylceramide (KRN7000) on airway inflammation in obese asthmatic mice. Male C57BL/6J mice were divided into five groups: (1) control; (2) asthma; (3) A + KRN, asthma with KRN7000; (4) obese asthma; and (5) OA + KRN, obese asthma with KRN7000. Cytometric bead array (CBA) was used to detect interleukin-4 (IL-4), IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) in the serum. Flow cytometry was used to detect NKT cells and CD69⁺ NKT cells. Airway inflammation was observed in pathological sections, and calmodulin (CaM) expression was observed by immunohistochemistry in lung tissues. Airway inflammation in the obese asthma group was more severe than that of the asthma group. Airway inflammation of the OA + KRN group was reduced more than that of the A + KRN group. CD69+ NKT cells were only significantly reduced in the OA + KRN group. The levels of serum IFN-γ and TNF-α increased more in the OA + KRN group than in the A + KRN group. CaM is widely expressed in the cytoplasm of the lung tissues and was sharply decreased in the OA + KRN group. KRN7000 can significantly reduce airway inflammation in obesity-associated asthma by regulating NKT cell cytokine secretion and intracellular calcium. These results may contribute to the development of novel therapeutic approaches.

     

Diverse Roles of Natural Killer T Lymphocytes in Liver and Spleen in Mice with Experimental Autoimmune Uveitis

Natural killer T lymphocytes (NKT cells) have diverse roles in different organs. However, it is still unclear whether NKT cells play different roles in the liver and spleen in mice with experimental autoimmune uveitis. In the present study, we explored their diverse roles of NKT cells in the liver and spleen and found that liver-derived NKT cells could efficiently inhibit Th1 and Th17 differentiation, whereas the function of spleen-derived NKT cells was less potent. Meanwhile, the occurrence of the peak ratios of NKT cells/T cells in the spleen and liver was markedly asynchronous after immunization. Moreover, different methods of immunization could result in different immune responses in mice. Furthermore, the memory response was also found in the generation of NKT cells in mice when they received the same antigen. These results indicate that the functional roles of NKT cells possess diversity in the spleen and liver in mice with experimental autoimmune uveitis.     

细胞因子诱导杀伤（CIK）细胞的大容量扩增与杀伤活性观察

建立大容量细胞因子诱导杀伤(Cytokine-inducedkiller,CIK)细胞培养方法,观察CIK细胞回输后对患者细胞免疫功能的影响。采用1000ml培养袋大量扩增患者自体CIK细胞,用MTT法检测CIK细胞杀伤活性,比较回输前后患者外周血单个核细胞(PBMNC)对靶细胞的杀伤活性及其毒副作用。结果表明大容量培养法使自体CIK细胞扩增总量达1.6×1010以上,回输CIK细胞使患者PBMNC的杀伤活性明显增加,未出现毒副作用。因此CIK细胞大容量扩增方法在治疗肿瘤微小残留病变上有着良好的临床应用前景。