Protective effect of adiponectin on glucose and lipid metabolism by suppressing MHCⅡ expression

AIM: To investigate whether the protective effect of adiponectin on glucose and lipid metabolism is achieved through down-regulating major histocompatibility complex class Ⅱ (MHCⅡ) in the adipose tissue. METHODS: Adiponectin knockout (KO) mice and C57BL/6(WT) mice were fed with high-fat diet and standard diet for 24 weeks, respectively. The body weight, fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), hepatic histology, and class Ⅱ trans-activator (CⅡTA), histocompatibility 2 class Ⅱ antigen E beta (H2-Eb1) and cluster of differentiation 74(CD74) mRNA and MHC Ⅱ protein levels in adipose tissue were measured at sacrifice. siRNA targeting MHC Ⅱ and overexpression vector was used in 3T3-L1 cells to explore the effect of adiponectin on the protein level of MHCⅡ. RESULTS: The levels of body weight, FBG, FINS, HOMA-IR, TC, TG, LDL-C, hepatic steatosis, CⅡTA, H2-Eb1 and CD74 mRNA expression, and MHCⅡ protein expression in the KO mice were higher than those in the WT mice that fed with high-fat diet or standard diet. In 3T3-L1 cells, inhibition of adiponectin reversed MHC Ⅱ protein level induced by specific siRNA. The expression of MHC Ⅱ in adipocytes decreased after adiponectin was overexpressed. CONCLUSION: Adiponectin improves glucose and lipid metabolism through suppressing the expression of MHCⅡ in the adipose tissue.     

Relationship between helper T lymphocytes immune deviation and class Ⅱ MHC antigen expression in acute rejection of transplanted heart

AIM: To observe the relationship between the immune deviation of Th1 and Th2 cell clones and class Ⅱ major histocompatibility complex (MHC) antigen expression in different stages of acute rejection in transplanted hearts. METHODS: Heart transplantation were performed in rats.Isografts and non-transplanted animals were used as control group. Donor class II MHC antigen expression were detected with monoclonal antibodies and immunostaining technique and the amount of type Ⅰ and Ⅱ cytokines mRNA expression were detected by semiquantitative RT-PCR in cardiac allografts. RESULTS: Myocardial IL-2 mRNA and donor class Ⅱ MHC antigen expression were significantly in-creased, accompanied with development of acute rejection (P<0.01). However, IL-4 mRNA decreased significantly (P<0.01). The immune deviation between type Ⅰ and Ⅱ cytokines mRNA expression occurred in the rejecting stage at which the cardiac allograft tissue infiltrated by multiple foci of lymphocytes and class Ⅱ MHC antigen became highly expressed. CONCLUSION: There was correlationship between Th cells immune deviation and donor class Ⅱ MHC antigen expression in the process of acute rejection in cardiac allografts. Immune deviation of T cells may facilitated the expression of donor MHC class Ⅱ antigen on transplanted heart.     

The characteristics of TCRVα24+ NKT cells in response to in vitro stimulation

AIM: To investigate the amount and patterns of expressing CD69, IL-4 and IFN-γ on TCRVα24⁺ NKT cells, and compare with that of CD3⁺ T cells from human peripheral blood in response to in vitro stimulation. METHODS: The whole blood was stained with three-color immunofluorescence directly or after cultured with PDB+ionomycin (Ion) for 6 h, then the mononuclear cells were separated by lysing red blood cells. The expression rates of CD69, IL-4 and IFN-γ on TCRVα24⁺ NKT cells and CD3⁺ T cells were estimated by flow cytometer. RESULTS: As a proportion of mature T cells, the ratio of TCRVα24⁺ NKT cells to CD3⁺ T cells was about (1.34±0.42)%. The expression rates of CD69 on TCRVα24⁺ NKT cells and CD3⁺T cells in response to PDB+Ion for 6 h were (96.71±1.33)% and (98.60±0.47)%, respectively, while the ratio were (11.47±2.86)% and (1.07±0.45)% in the unstimulated group, and there were significant difference between them. The expression rates of IL-4 and IFN-γ on TCRVα24⁺ NKT cells stimulated with PDB+Ion for 6 h were (48.62±2.44)% and (46.65±8.91)%, respectively, which were significantly higher than that of unstimulated group [(31.57±3.31)%, (13.45±6.29)%] and that of stimulated CD3⁺ T cells, though the expression rates on stimulated CD3⁺ T cells were significantly higher than that of unstimulated CD3⁺ T cells. CONCLUSION: There is small amount of NKT cells in adult human peripheral blood. The expression rates of IFN-γ and IL-4 on these lymphocytes are higher than CD3⁺ T cells, suggesting that NKT cells are important immunomodulatory cells in special microvironments.     

Early apoptotic T lymphocytes induce DCs from bone marrow to tolerogenic DCs

AIM: To study the immunosuppressive effects of early apoptotic T lymphocytes.METHODS: Early apoptotic spleen T cells were induced by ultraviolet irradiation for 5 min.After irradiation,spleen T cells were incubated at 37 ℃ with 5% CO₂ for 2 h and thus early apoptotic T lymphocytes were obtained.Three to four freeze thaw cycles resulted in disruption of the spleen T cells into fragments.imdendribic cells(DCs) were prepared from red cells and T cells depleted bone marrow cells.The imDCs were divided into five groups: group A: necrotic spleen T cells were added to imDCs;group B: early apoptotic spleen T cells were added to imDCs;group C: supernatants from early apoptotic spleen T cells alone with necrotic spleen T cells were added to imDCs;group D: TGFβ₁ neutralizing antibody along with early apoptotic T lymphocytes were added to imDCs;group E: immature dendridic cells culture in RPMI-1640 for 5 days were used as negative control.Flow cytometry was employed to analyze the expression of MHCⅡ,CD40,CD80 and CD86 on DCs in each group.ELISA was employed to assay the IL-12 p70 produced by DCs in different groups.The amounts of TGFβ₁ released by early apoptotic T lymphocytes were also determined by ELISA.T cells proliferation assay was employed to study DCs T cells stimulatory capacity.RESULTS: The DCs expressed high level of MHCⅡ,CD40,CD80 and CD86 when exposed to necrotic cells while early apoptotic cells did not.The supernatants from early apoptotic spleen T cells suppressed the expression of MHCⅡ,CD40,CD80 and CD86 on DCs exposed to necrotic spleen T cells.When TGFβ₁ neutralizing antibody along with early apoptotic spleen T were added to imDCs,the expression of MHCⅡ,CD40,CD80 and CD86 was increased significantly.The necrotic spleen T cells increased IL-12 p70 production by DCs,while apoptotic spleen T cells at early stage did not (P<0.01,group B vs group A or B;P>0.05,group B vs group E).Only the DCs that exposed to necrotic spleen T cells gained significant T lymphocytes stimulatory capacity,while DCs exposed to apoptotic cells at early stage did not.The amounts of TGFβ₁ released by early apoptotic spleen T cells were much higher than those released by viable spleen T cells.CONCLUSION: Apoptotic spleen T cells at early stage have the capacity to induce the generation of tolerogenic DCs.     

Study on the immunological function of sodium butyrate-induced immature human monocyte-derived dendritic cells

AIM: To investigate the immunological function of sodium butyrate-induced immature dendritic cells in vitro.METHODS: The human monocyte-derived dendritic cells were induced in the presence of human granulocyte macrophage-colony stimulating factor(GM-CSF) and interleukin-4 (IL-4), combined with sodium butyrate. The immunological function of sodium butyrate-induced dendritic cells was detected by the FCM, endocytic activity, T cells stimulatory proliferation capacity, and interleukin-12 (IL-12) production.RESULTS: Sodium butyrate could down-regulate the major histocompatibility complex(MHC) class II and costimulatory molecules of dendritic cells, increase the endocytic activity, induce a stage of T-cell anergey, and inhibit the T helper cell type 1-skewing factor IL-12 production. CONCLUSION: Sodium butyrate inhibits the maturation of dendritic cells and induces production of immature dendritic cells, which may help to explore the machenism of its epigenitic modification.     

Autoimmune reaction mediates myocardial injury after acute myocardial infarction in rats

AIM: The study was designed to explore the autoimmune mechanism of myocardial injury and ventricular remodeling after acute myocardial infarction (AMI). METHODS: An experimental animal model of AMI was adopted in Wistar rats. After 6 weeks, splenocytes were freshly transferred to syngeneic inbred rats. Four weeks later, these recipient rats were anesthetized for hemodynamics analysis by catheter technique. Serum antibody against cardiac myosin heavy chanin (MHC) was screened by ELISA. Histopathological studies were performed on all hearts. The phenotypes of T lymphocytes in myocardium were analyzed by histocytochemistry stain. RESULTS: Histopathological studies showed the lymphocytes infiltration in non-infarction myocardium in AMI rats and the organ specific inflammation of myocardium in all succedent recipient (AMI-T) rats. Histocytochemistry stain revealed the predominant CD4+T cells infiltration in myocardium. The antibody against MHC was examined in 8/22 cases of AMI rats and AMI-T rats, but none in sham-T rats. The left ventricular dysfunction was found in AMI-T rats, which was characterized by slight decline of +dp/dtmax. CONCLUSIONS: The study showed inflammatory response of non-infarction myocardium in AMI rats and demonstrated the lymphocytes-mediated myocardial injury and cardiac dysfunction by adoptive transfer of splenocytes of AMI rats. The autoimmune-mediated myocardial injury might be a novel mechanism of ventricular remodeling after AMI.     

Expansion capacity and cytokine releasing characteristics of TCRVα24+Vβ11+NKT cells in peripheral blood of patients with lymphoma

AIM: To analyze the quantity of TCRVα24+Vβ11+ natural killer T (NKT) cells and cytokines production induced by α-galactosylceramide (α-Galcer) in vitro in lymphoma patients. METHODS: Flow cytometry was utilized to enumerate TCRVα24+Vβ11+NKT cells in peripheral blood mononuclear cells (PBMNCs) in 30 cases of lymphoma patients and 30 cases of age- and gender-matched healthy controls. NKT cells were activated with α-Galcer and interleukin-2 (IL-2) after expansion in vitro. The percentages of positive NKT cells which expressed intracellular interleukin-4 (IL-4), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) were then determined by flow cytometry. RESULTS: The rates of NKT cells in PBMNCs were 0.17%±0.10% and 0.28%±0.18%(P<0.05) in lymphoma patients and controls, respectively. Seven days after expansion and activation with α-Galcer and IL-2, the fold of expansion of NKT cells in two groups was 101.37±44.61 and 129.66±56.31(P<0.05), respectively. The ratio of TCRVα24+NKT cells that secreted IFN-γ or TNF-α in lymphoma patients was significantly lower than that in controls (41.96%±15.06% vs 52.48%±18.85%, P<0.05; 46.30%±16.03% vs 71.37%±17.28%, P<0.05). While the ratio of TCRVα24+NKT cells that secreted IL-4 was not significantly different between the two groups (36.19%±11.74% vs 33.12%±12.95%, P>0.05). There was no significant difference in above parameters among different groups of lymphoma patients subdivided by pathology and clinical stage. CONCLUSION: The quantity of NKT cells in PBMNCs in lymphoma patients is lower than that in controls. The expansion capacity and the function of producing cytokines IFN-γ and TNF-α of NKT cells stimulated with α-Galcer are decreased. This decrease is independent of lymphoma pathology type or clinical stage.     

国际葡萄基因组学学术研讨会在美国圣路易斯市召开

国际葡萄基因组学学术研讨会(INternational Grape Genomics Symposium)于2005年7月12~14日在美国密苏里州圣路易斯市召开。本次会议由西南密苏里州立大学(SMSU)主办,国际葡萄基因组计划(International Grape Ge-nome Program)和美国葡萄栽培与酿酒学会东部分会(ASEV-ES)协办。     

Differentiation of embryonic-like stem cells derived from human bone marrow into multinucleated fibers in vitro

AIM: To compare the capacity of in vitro differentiation into multinucleated fibers between embryonic-like stem cells (ELSCs) and mesenchymal stem cells (MSCs) derived from human bone marrow. METHODS: To isolate ELSCs, human bone marrow mononuclear cells were cultured in gelatin-coated flask with serum-free Knockout-DMEM medium designed for the expansion of human embryonic stem cells. MSCs were isolated from the same bone marrow by the traditional method. The morphological characters of both ELSCs and MSCs were observed under inverted phase-contrast microscope, and the expression of their multipotent antigen markers was identified by immunofluorescent staining. ELSCs and MSCs were cultured in myogenic differentiation medium. The protein levels of muscle-specific antigen markers myosin heavy chain (MHC), myogenin and MyoD were detected by the method of immunostaining. The mRNA expression of MHC, myogenin and MyoD was detected by RT-PCR. The capacity of in vitro differentiation into multinucleated fibers was compared between ELSCs and MSCs by calculating the proportion of MHC-positive multinucleated fibers. RESULTS: ELSCs, which weakly expressed the multipotential markers Oct-4, Nanog-3 and Sox-2, were isolated from bone marrow by the method of serum-free medium. ELSCs appeared smaller, slenderer and more homogeneous, and were morphologically different from MSCs derived from the same marrow. No multipotential marker in MSCs was expressed. ELSCs and MSCs were induced into long multinucleated fibers expressing MHC and myogenin at mRNA and protein levels by culturing in the myogenic differentiation medium. However, on the 10th day after induction, the proportion of the MHC-positive fibers in ELSCs was (25.7?4.1)%, and the proportion in MSCs was (15.8?7.6)%.The capacity for differentiation into muscle in ELSCs was significantly higher than that in MSCs (P<0.05). CONCLUSION: Bone marrow ELSCs are induced into multinucleated fibers and have the stronger myogenic differentiation capacity than MSCs derived from the same marrow. ELSCs are a more ideal candidate for muscular disease therapy.     

Effect of pregnancy uterine microenvironment on the expression of NKG2A,NKG2D and their ligands in decidual NK cells

AIM：To investigate the expression of NKG2A,NKG2D and their ligands in pregnancy uterine micro-environment and to probe the function of NKG2A and NKG2D imbalance expression during the immunotolerance at the fetal-maternal boundary.METHODS：Decidual lymphocytes and peripheral lymphocytes were obtained from 30 women during 6-9 weeks of pregnancy who were undergoing selective termination.FACS technology was used to detect NK cells number and NKG2A,NKG2D expression.RT-PCR was used to investigate HLA-E and MICA mRNA in trophoblast tissue.RESULTS：Natural killer cells predominate,accounting for 70% of pregnancy endometrial lymphocytes.FACS results indicated that NKG2A was significantly increased in decidual NK cells as compared with that in peripheral NK cells,accounting for 97.86%±1.75% and 33.35%±10.92%.The difference between them in NKG2A expression was significant (P<0.05).Although the levels of NKG2D in decidual NK cells were similar to that in peripheral NK cells,accounting for 93.21%±4.52% and 97.80%±1.72%,respectively,the difference between them in NKG2A expression was also significant (P<0.05).At the same time,we found HLA-E mRNA in the trophoblast tissue.There was no proof yet on the expression of NKG2D ligand-MICA on trophoblast.CONCLUSIONS：Natural killer cells are the predominant lymphocytes during the first trimester of decidual tissue.These cells have a great different antigenic phenotype with peripheral natural killer cells.Decidual natural killer cells have high expression of NKG2A and trophoblast tissue expressed HLA-E.This may be an important factor contributing to the immunotolerance at the fetal - maternal boundary during pregnancy.     

Expression of MHC Ⅱ on rat corneal keratocytes is inhibited by special siRNA targeting CⅡTA

AIM: To investigate the feasibility to inhibit the expression of MHCⅡ by special siRNA targeting class Ⅱ major histocompatibility complex (MHC Ⅱ) transactivator (CⅡTA), which might regulate MHC Ⅱexpression for suppressing immune rejection. METHODS: Five different siRNA were designed, synthesized and transfected into freshly isolated rat corneal keratocytes. At 24 hours posttransfection, the changes of MHC Ⅱexpression were detected by flowcytometry, and the mRNA abundance of CⅡTA and MHC Ⅱ was measured by FQ-PCR after inducing with recombinant rat interferon-gamma (IFN-γ). RESULTS: Different siRNA showed different reduction in MHC Ⅱ and CⅡTA expression compared with the control (P<0.01). Among the five groups, the siRNA-4 was the most efficient. The mRNA content of CⅡTA and MHC Ⅱ were reduced by 95.10%±1.25% and 82.70%±1.95% respectively and the expression of MHC Ⅱ was inhibited by over 80% in siRNA-4 group at 24 hours posttransfection. CONCLUSIONS: The special siRNA targeting to CⅡTA inhibits CⅡTA mRNA and further inhibits its regulation of MHC Ⅱ molecular expression. The blockade of MHC Ⅱ by siRNA may be useful for further studying allogeneic corneal limbal transplantation.     

Establishment of T-lymphocytes that express CD20scFv-IgGFc-CD28-ζ and CD20scFv-IgGFc and their killing activity of B-lymphoma cells

AIM: To investigate the target killing effect of T lymphocytes with chimeric CD20scFv gene on Daudi cells and the activation of T lymphocytes. METHODS: Two kinds of plasmids were transfected into retrovirus-packed PA317 cell lines. The supernatant was collected from successfully transfected PA317 culture and was used to infect peripheral blood T lymphocytes. After one-week screening with G418, the cells were used to kill Daudi and K562 cells. The positive rates of AnnexinⅤ in Daudi cells were measured at different times points respectively by flow cytometry. Meanwhile, the level of IL-2 and IFN-γ were determined by ELISA. RESULTS: The Annexin V positive rate was significant higher in Daudi cells compared to control K562 cell lines at 24 h. No difference of AnnexinV in Daudi cells was observed in CD20 modification T lymphocyte groups. The secretions of IL-2 and IFN-γ in CD20scFv-CD80-IgGFc-CD28-ζ gene modified T cells co-cultured with Daudi cells were dramatically higher than that in CD20scFv-IgGFc group at 72 h. CONCLUSION: ① The two kinds of genetic modified specific T cells have no significant difference in inducing early apoptosis of Daudi cells. CD28-ζ cant affect Daudi cell early apoptosis at the CD20scFv target killing. ② The increase in the secretions of IL-2 and IFN-γ is more obvious in CD20scFv-IgGFc-CD28-ζ group, indicating that the self-activation takes place in CD3ζ and CD28 modified T cells without MHC restriction and then increases the activation and killing function of T cells.     

The biological characteristics of cytokine-induced killer cells

AIM:To investigate the biological characteristics of cytokine-induced killer (CIK) cellsin vitro.METHODS:The non-adhere peripheral blood monoclear cells from healthy donors were induced into CIK cells in the presence of IFN-γ, IL-1β, IL-2 and anti-CD3 antibody. LAK (lymphokine activated killer) cells were prepared as a control. The cellular phenotype were detected by FCM and immunocytochemistry and the cytotoxicity was measured by LDH release assay.RESULTS:After 2 weeks of induction, the proliferation rate of CIK cells reached a peak and the proportion of CD3⁺ population was above 95%, and then the cells growth entered to plateau phase at week 3. The proportion of CD3⁺CD56⁺ NKT subset cells was 16.5% on day 15 and it had no obvious variety between 2 and 4 weeks. Correspondingly, LAK cells grew slowly and had lower proliferation rate compared with the CIK cells (P<0.01). CIK cells showed higher specific lysis rates to BeL-7402 hepatoma cells than those of LAK cells at different effector to target ratio (P<0.01). Immunocytochemical staining showed the CIK cells highly co-expressed HLA-DR and CD54 antigens. The NKT cells were slightly bigger than CD3⁺CD56^- cells and a large quantity of pseudopodia were observed on their surface.CONCLUSION:The CIK cells have higher proliferation potency and stronger cytotoxicity to lyse tumor cells than LAK cellsin vitro.Within the span of time from 14 to 21 days, the proliferation rate and the proportion of CD3⁺CD56⁺ subset of CIK cells all reach peaks. Therefore, CIK cells in this period are suitable for clinical application.     

Chemokine receptors in regulating immune response and therapy

Although adhesion molecules have long been recognized to be differentially expressed on naive and effector/memory T cells, it has recently been found that a number of chemokine receptors are also differentially expressed on T cells, depending on their Ag experience and type of polarizat ion. Recent data suggests that chemokines and their receptors are essential elements that regulate the positioning of T cells and their partners for priming and T helper 1 (Th1)- or Th2-mediated responses, therefore, are probably the most promising targets for treating immune diseases.     

Effect of siRNA for survivin gene on growth and apoptosis in A549 cells

AIM:To observe the influence of lentiviral vectors expressing siRNA for survivin gene knockdown in A549 cells, sequentially as tools to explore the molecule pathogenesis and new gene therapy of lung adenocarcinoma. METHODS:The lentiviral vectors, which express survivin siRNA, were constructed and transfected into A549 cell strain. The titers of the lentiviruses were determined by 293T cells. The expressions of survivin and caspase-3 were detected by Western blotting and RT-PCR. The cell cycle and cell growth of A549 cells were examined by MTT and FCM．RESULTS:The expression of survivin was suppressed effectively by siRNA targeting survivin. The expression of survivin mRNA decreased by 97%. The expression of survivin protein decreased by 94%. The rate of cell growth was decreased. The G1 phase cells were increased, whereas S phase cells were decreased. CONCLUSION:The lentivirus vectors expressing siRNA for survivin can significantly inhibit gene expression and the cell growth, and markedly induce the apoptosis. It is hopeful to be a new gene therapy of lung adenocarcinoma.     

Identification of tumor antigen epitopes by MHC-I/peptide binding prediction and immunological experiments

AIM:To establish the methods to identify immune epitopes of tumor antigens restricted by human leukocyte antigen (HLA) alleles frequent in the Chinese population for the isolation and identification of tumor-specific T cells and the cloning of tumor antigen-specific T-cell receptor gene. METHODS:Three cancer/testis antigens NY-ESO,MAGE-A1 and KK-LC-1 were selected as the model antigens to predict the MHC-I binding peptides by major histocompatibility complex (MHC)-peptide binding prediction software. The HLA alleles of healthy volunteers were determined by PCR. The predicted epitopes restricted by HLA-A*11:01 and HLA-B*46:01 of the volunteers were selected for the long peptide design. ELISPOT and flow cytometry were used to analyze the interferon-γ (IFN-γ) spots of the activated T-cells and the up-regulation of CD137 to verify the effectiveness of peptides for T-cell-specific stimulation. We selected long peptides with the best response to verify short peptides. RESULTS:Three cancer/testis antigens containing many strong binding epitopes restricted by 35 HLA alleles common in Chinese population were found. It was found that the predicted epitopes were not equally distributed in the protein sequences. KK-LC-1 antigen was selected for further study. The 2 long peptides stimulated T-cell activation:the release of IFN-γ and up-regulation of CD137 molecules by T cells of the volunteers with the matched HLA alleles. The short peptides worked better than the long peptides.CONCLUSION:Tumor antigen epitopes are quickly identified by MHC/peptide binding prediction and T-cell stimulation analysis. According to the reaction of the long peptide, the short peptide is synthesized to verify the precise epitope. This study provides a new way to determine tumor antigen epitopes quickly.     

Role of NK cells in mouse allogeneic bone marrow transplantation

AIM: To study the effect of natural killer(NK)-cells on graft-versus-host disease(GVHD), graft rejection, engraftment and reconstituting of hematopoiesis in mouse allogeneic bone marrow transplantation. METHODS: Lethally irradiated BALB/c(H-2^d) mice were transplanted with C57/6j(H-2^b) bone marrow containing donor peripheral T cells and/or NK cells. Recipients CD₃₄⁺ cell counts and the expression of H-2K^b＋ cell were detected by flow cytometry, peripheral white blood cell(WBC) was detected by auto-cytometry, and the recipients survival rates, GVHD, engraftment and hematopoiesis recovery were then observed. RESULTS: In the group of transplanted with NK cells infusion, the incidence of GVHD was evidently lessened, the survival rates, WBC and CD₃₄⁺ cell counts and the expression of H-2K^b＋ cell were significantly high than that without NK cells infusion. CONCLUSION: In mouse allogeneic bone marrow transplantation, alloreactivity NK cells prevents GVHD, reduces graft rejection, and promotes engraftment and reconstituting of hematopoiesis.     

Effects of allicin on anti-tumor activity of rat NK cells in vitro

AIM: To investigate the role of allicin on the anti-tumor activity of rat NK cells in vitro. METHODS: CD3^-NKR-P1⁺ NK cells were isolated from rat spleen using Dynabeads FlowComp^TM Flexi system. The proliferation and apoptosis of the NK cells induced by allicin were analyzed by the method of flow cytometry. The levels of IFN-γ in the supernatants were measured by ELISA. Lactate dehydrogenase release assay was used to detect the cytotoxicity of the NK cells.RESULTS: In vitro, allicin significantly promoted the proliferation of NK cells, inhibited NK cell apoptosis, increased the level of IFN-Fγ in supernatants and enhanced the cytotoxicity of the NK cells to Yac-1 tumor cells in a dose-dependent manner. Allicin at concentration of 30 mg/L exerted the maximal effect on activating NK cells. CONCLUSION: Allicin enhances the activity of NK cells in vitro by upregulating IFN-γ expression.     

Biological characteristics of uNK and pNK cells in pregnancy

AIM: To study the biological characteristics of uterine natural killer cells (uNK cells) and peripheral natural killer cells (pNK cells) in early gestation and their difference on physiological functions. METHODS: MTT assay was used to detect cytotoxicity and proliferation of the uNK and pNK cells. RT-PCR technique was applied to examine the altered gene expression of the chemotaxis, angiopoiesis and other biological activity in uNK and pNK cells. RESULTS: Compared with pNK group, uNK cells showed a higher cytotoxicity against K562 and a lower proliferation activity. The expression of some chemokine receptor genes and angiogenic growth factor genes in uNK cells and pNK cells were detected, such as CCR1, CCR5, CCR7, CXCR2, CXCR4 and CX3CR1 expressed by uNK cell and high contents of CXCR4 and CX3CR1 mRNA were found. The ligand genes of the chemokine receptor were expressed by decidual tissue or trophoblast tissue in early pregnancy. PIGF and AngⅡ mRNA were only found in uNK cells. CONCLUSION: Compared with pNK cells, uNK cells have peculiarities of the behaviour that might contribute to uterine unique microenvironment during pregnancy.