Hepatitis C ; immunology ; Humans ; Killer Cells, Natural ; immunology

Mesenchymal stem cells (MSCs) can inhibit T cell proliferation, the effects of MSCs on various T cell subsets have showed different immune regulatory reactions, and their mechanisms mainly include cell-cell contact and mediation by cytokines secreted from MSCs. Encouragingly, recent studies have showed that the effects of MSCs on T-cell response to pathogens is not significant, but can obviously suppress T cell response to allogeneic antigens. In addition, MSCs can regulate the proliferation, survival, antibody secretion and differentiation of B cells, inhibit the production, proliferation, migration and antigen-presentation of DCs, and modulate the differentiation and maturation of DCs, and regulate the proliferation, cell toxicity and cytokine secretion of NK cells. In this review, the research advances on immunomodulatory effects of MSCs on various immune cells including T-lymphocytes, B-lymphocytes, NK cells and DCs are summarized with emphasis on the immunoregulatory effects of MSCs on T-lymphocytes.
B-Lymphocytes ; immunology ; Dendritic Cells ; immunology ; Humans ; Killer Cells, Natural ; immunology ; Mesenchymal Stromal Cells ; cytology ; immunology ; T-Lymphocytes ; immunology

The invariant (i) natural killer (NK)T cells represent a unique subset of T lymphocytes which express the V alpha14 chain of the T cell receptor (TCR), that recognizes glycolipid antigens presented by the nonpolymorphic major histocompatibility complex (MHC) class I-like antigen presentation molecule CD1d, and they participate in protection against some microbial pathogens. Although iNKT cells have originally been regarded as T cells co-expressing NKR-P1B/C (NK1.1: CD 161), they do not seem to consistently express this marker, since NK1.1 surface expression on iNKT cells undergoes dramatic changes following facultative intracellular bacterial infection, which is correlated with functional changes of this cell population. Accumulating evidence suggests that NK1.1 allows recognition of "missing-self", thus controling activation/inhibition of NK1.1-expressing cells. Therefore, it is tempting to suggest that iNKT cells participate in the regulation of host immune responses during facultative intracellular bacterial infection by controlling NK1.1 surface expression. These findings shed light not only on the unique role of iNKT cells in microbial infection, but also provide evidence for new aspects of the NK1.1 as a regulatory molecule on these cells.
Animals ; Humans ; Listeria Infections/*immunology ; Listeria monocytogenes/*immunology ; Natural Killer T-Cells/*immunology/*microbiology

Natural killer T cells are innate-like and tissue-resident lymphocytes, which recognize lipid antigens and are enriched in the liver. Natural killer T cells play important roles in infections, tumors, autoimmune diseases, and metabolic diseases. In this study, we summarize recent findings on biology of natural killer T cells and their roles in hepatitis B virus and hepatitis C virus infection, autoimmune liver diseases, alcoholic liver disease, nonalcoholic fatty liver disease, and hepatocellular carcinoma. Controversial results from previous studies are discussed, and indicate the dynamic alteration in the role of natural killer T cells during the progression of liver diseases, which might be caused by changes in natural killer T subsets, factors skewing cytokine responses, and intercellular crosstalk between natural killer T cells and CD1d-expressing cells or bystander cells.
Animals ; Autoimmune Diseases ; immunology ; Humans ; Liver ; pathology ; Liver Diseases ; immunology ; Natural Killer T-Cells ; immunology

OBJECTIVEThis review aimed at understanding pregnancy-induced changes in the maternal immune response and mechanisms for the establishment of feto-maternal tolerance.

DATA SOURCESArticles cited in this review were obtained from PubMed in English from 2000 to 2014, and the search string included keywords such as feto-maternal tolerance, dendritic cells, macrophage, T regulatory cells, natural killer cells, cytokines and hormone.

STUDY SELECTIONArticles regarding altered maternal immune response, including the proliferation and differentiation of the altered cells, and the production of cytokines and regulation of hormones in the feto-maternal interface were retrieved, reviewed and analyzed.

RESULTSThe changes in immune cells and cytokines in the local uterine microenvironment and peripheral blood are correlated with the establishment of feto-maternal tolerance. The endocrine system regulates the maternal immune system, promoting modifications during pregnancy. In these regulatory networks, every factor is indispensible for others.

CONCLUSIONSThe integration and balance of these immune factors during pregnancy give rise to an environment that enables the fetus to escape rejection by the maternal immune system. This progress is complicated, and needs more comprehensive exploration and explanation.

Dendritic Cells ; immunology ; Female ; Humans ; Immune System ; immunology ; Immune Tolerance ; immunology ; Killer Cells, Natural ; immunology ; Pregnancy ; T-Lymphocytes, Regulatory ; immunology

OBJECTIVESTo evaluate the effects of K562-dendritic cell (DC) and Raji-DC fusion vaccines on the cytotoxicity of cord blood (CB) derived cytokine-induced killer/natural killer (CIK/NK) cells.

METHODSDC and CIK/NK cells were derived from CB mononuclear cells. CB-DC were fused with inactivated K562 or Raji cells by PEG to form K562 or Raji-DC fusion vaccine. The CIK/NK cells stimulated by different co-culture antigens were three groups: K562-DC or Raji-DC fusion vaccine group, inactivated K562 or Raji plus DC group, and CB-DC alone group. The cytotoxicity of CIK/NK cells stimulated by different co-culture antigens was measured by MTT test.

RESULTSAll the antigens used for stimulation could enhance the cytotoxicity of CB-CIK/NK cells, with no specificity difference. At 20:1 effector-target ratio, the cytolytic activities of K562-DC and Raji-DC fusion vaccine groups against Raji cells were (75.44 +/- 4.19)% and (81.33 +/- 4.18)% respectively (P < 0.05); and that of inactivated K562 + DC and Raji + DC group against Raji cells were (73.12 +/- 4.22)% and (80.49 +/- 4.27)%, respectively (P < 0.01). There was no significant difference in the cytotoxicity to K562 cells between the two fusion vaccine groups (P > 0.05). The cytotoxicity of CB-CIK/NK cells immunized by Raji cells was higher than that by K562 cells. In CIK/NK cells co-stimulated by the same tumor antigen, there was no significant difference in the cytotoxicity between DC fusion vaccine group and inactivated cells plus DC group to different tumor cells.

CONCLUSIONSThe cytotoxicity of CB-CIK/NK cells to tumor cells was not specific. There was no significant difference in the cytotoxic activity of CB-CIK/NK cells between the DC fusion vaccine group and inactivated cells plus DC group.

Cancer Vaccines ; immunology ; pharmacology ; Cells, Cultured ; Cytotoxicity, Immunologic ; Dendritic Cells ; immunology ; Fetal Blood ; cytology ; Humans ; K562 Cells ; Killer Cells, Lymphokine-Activated ; immunology ; Killer Cells, Natural ; immunology

Cytokine-Induced Killer Cells ; immunology ; Cytotoxicity, Immunologic ; Dendritic Cells ; immunology ; Fetal Blood ; immunology ; HL-60 Cells ; Humans ; K562 Cells ; Killer Cells, Natural ; immunology

The activity of the NK cells in patients with preeclampsia was studied to investigate the pathogenesis of preeclampsia. By using MTT and 51Cr releasing technique, the proliferation and killing ability of the NK cells in maternal and umbilical blood from preeclampsia patients (n = 18) and normal third trimester pregnant women (n = 18) were detected. The NK-92 cell line was as the positive control. The results showed that the NK cell counts of umbilical blood in preeclampsia patients and normal third trimester pregnant women were significantly greater than those of maternal blood (both P<0.05). Compared with that in normal third trimester pregnant women, the proliferative ability of the NK cells in preeclampsia patients was apparently increased (P<0.05). Compared with that in maternal blood, the proliferative ability of the NK cells in umbilical blood from both preeclampsia patients and normal third trimester pregnant women was dramatically increased. The killing ability of the NK cells in preeclampsia patients was significantly higher than that in normal third trimester pregnant women (P <0.05). It was suggested that both number and function of the NK cells in preeclampsia women were increased, and that in umbilical blood was greater than that in maternal blood, speculating that the function of the NK cells may affect the maintenance of the maternal and fetal immune tolerance during pregnancy.
Cytotoxicity, Immunologic/*immunology ; Fetal Blood/cytology ; Immune Tolerance ; Killer Cells, Natural/*immunology ; Killer Cells, Natural/pathology ; Pre-Eclampsia/blood ; Pre-Eclampsia/*immunology ; Pregnancy Trimester, Third

This study was purposed to investigate the changes of peripheral blood T cells in children with acute leukemia at different stages and understand the immune status of children with leukemia. The CD4⁺, CD8⁺, CD4⁺/ CD8⁺ ratio, CD3⁺ and NK cells in 42 children with acute leukemia and 50 cases of normal children (as control group) were determined by flow cytometry at different periods after complete remission. The results showed that the CD3⁺ CD4⁺, CD8⁺ rate and CD4⁺/CD8⁺ ratio in newly diagnosed ALL and AML children were significantly lower than those in control group (P < 0.05). The NK cell count in newly diagnosed children with acute leukemia was significantly lower than that in control group (P < 0.05). Although the NK cell count in ALL and AML children gradually rose at 3, 6, 12 months after complete remission, but it still was statistically different from normal control group (P < 0.05). It is concluded that children with acute leukima have cellular immune disfunction at onset and during treatment, but the cell immune function gradually recovered after complete remission achieved. However, its recovery rate is slow. The results of this study can provided a basis for subsequently use of immunomodulations in leukemia children.
CD4-CD8 Ratio ; Child ; Flow Cytometry ; Humans ; Killer Cells, Natural ; Leukemia ; immunology ; T-Lymphocyte Subsets ; immunology

Natural killer (NK) cells are important innate immune effector cells with broad applications in killing the tumor cells and pathogens due to its cytotoxicity without prior immune sensitization. Unfortunately, in humans, the activity of NK cells against fungi is poorly characterized. Insight progress in the fields of NK cells activating, pattern recognition receptors, signal modulating and correlated cell factors (IFN-γ, GM-CSF, IL-10 and so on) has revolutionized understanding of the selective killing fungi by NK cells. Different morphotypes also can affect the immune status of NK cells. This article reviews the mechanism of fungi immune reaction, and the interaction between NK cells and fungi, and provides some new ideas for further study on pathogenesis of fungus and other infectious diseases and NK cell adoptively transferred immunotherapy.
Cytotoxicity, Immunologic ; Fungi ; immunology ; Host-Pathogen Interactions ; Humans ; Killer Cells, Natural ; immunology