Pre-eclampsia: a mistake of trophoblastic cells for tumour cells?

Pre-eclampsia is a severe form of hypertension induced by pregnancy. In pre-eclampsia, there is deficient trophoblast invasion of the spiral arteries terminating in the placental bed. Perhaps some abnormality occurs in the immunosuppressive process as the maternal immune system encounters paternal antigens expressed by immunosuppressive decidual cells. This immunosuppressive abnormality might cause the deficient trophoblast invasion. Abnormal placentation might then lead to maternal endothelial cell damage by an ongoing process. There might be a recurring sequence of 4 steps: (1) The placenta releases trophoblastic cells with potentially cytotoxic characteristics. These circulating trophoblastic cells have an abnormal pattern of expression of integrins and perhaps other glycoproteins or proteins. (2) The circulating trophoblastic cells loosely bind to maternal endothelial cells, targeting them for anti-tumourigenesis. (3) The maternal immune system reacts against targeted maternal endothelial cells through anti-tumourigenic mechanisms. (4) Widespread maternal endothelial damage causes the characteristic kidney lesion called glomerula endotheliosis.     

α-Fetoprotein impairs activation of natural killer cells by inhibiting the function of dendritic cells

α-Fetoprotein (AFP) is a tumour-associated antigen in hepatocellular carcinoma (HCC). The biological properties of AFP have been identified in its regulatory effects on immune responses of T cells and B cells. However, AFP effects on natural killer (NK) cells are still unclear. In this study, we examined the immunoregulation of AFP on NK activity. The cytolytic activity against K562 cells and Huh7 cells of NK cells co-cultured with AFP-treated dendritic cells (DCs) (AFP-DCs) was lower than that with albumin-treated DCs (Alb-DCs). Direct addition of AFP to NK cells did not alter the cytolytic activity of NK cells. Adding AFP inhibited the interleukin (IL)-12 production of DCs after stimulation with lipopolysaccharide (LPS) [Toll-like receptor (TLR)-4 ligand], or Poly(I:C) (TLR-3 ligand), but not IL-18 production. The mRNAs of IL-12p35 and IL-12p40 were significantly inhibited in AFP-DCs compared with Alb-DCs, but those of TLR-4 or TLR-3 were not. Transwell experiments revealed that soluble factors derived from DCs played roles in inhibition of the ability of activating NK cells by AFP-DCs. Adding the neutralizing antibody of IL-12 to NK cells co-cultured with Alb-DCs resulted in a decrease of cytolytic activity to the levels of NK cells co-cultured with AFP-DCs. Adding IL-12 to NK cells co-cultured with AFP-DCs resulted in an increase of cytolytic activity to the levels of NK cells co-cultured with Alb-DCs. These demonstrated that the impairment of IL-12 production from AFP-DCs resulted in inhibition of the ability of the activation of NK cells by DCs, and thus suggests a role of AFP in HCC development.     

Function of intestinal γδ T cells

Mucosal tissues including the intestine, lung, reproductive tract, and skin form the major interfaces between the outside and internal milieus. Facing the outside is an epithelial cell layer, the epithelium, built on a vascular connective surface. In addition to performing specialized functions, mucosal tissues are sites where immune, epithelial, and neuronal cell types act in concert to maintain tissue integrity and fightin vading pathogens. This article presents the latest findings from my laboratory describing a novel protective function for the intestinal intraepithelial γδ T cells (γδ intraepithelial lymphocytes).     

Sarcoma of follicular dendritic cells with features of sinus lining cells—a new subtype of reticulum cell sarcoma?

Dendritic cell neoplasms of the World Health Organization classification comprise Langerhans cell histiocytosis, Langerhans cell sarcoma, interdigitating dendritic cell sarcoma, follicular dendritic cell sarcoma, and dendritic cell sarcoma, not otherwise specified. Several studies based on immunohistochemical and ultrastructural analysis tried to further clarify the origin of these neoplasms which are thought to derive from mesenchymal or bone marrow precursors. Lymphatic vessel endothelium hyaluronan receptor-1 (LYVE-1) was recently described as a marker for lymphatic endothelium which is expressed on normal liver blood sinusoid lining cells, spleen endothelium, activated tissue macrophages, blood vessels in the lung, endothelial cells of lymphatic sinuses, and in fibroblastic reticular cells in lymph nodes. We present a case of LYVE-1-positive reticulum cell neoplasm in an axillary lymph node. To the best of our knowledge, there has been no report about LYVE-1 expression in histiocytic or dendritic cell neoplasms so far. Due to the assumed specificity of this antibody, we propose designation of this reticulum cell sarcoma as lymphatic sinus lining cell sarcoma which might finally represent another subtype of reticulum cell sarcomas.     

Expansions of NK-like αβT cells with chronologic aging: novel lymphocyte effectors that compensate for functional deficits of conventional NK cells and T cells

As the repertoire of αβT cell receptors (TCR) contracts with advancing age, there is an associated age-dependent accumulation of oligoclonal T cells expressing of a variety of receptors (NKR), normally expressed on natural killer (NK) cells. Evidences for differential regulation of expression of particular NKRs between T cells and NK cells suggest that NKR expression on T cells is physiologically programmed rather than a random event of the aging process. Experimental studies show NKRs on aged αβT cells may function either as independent receptors, and/or as costimulatory receptors to the TCR. Considering the reported deficits of conventional αβTCR-driven activation and also functional deficits of classical NK cells, NKR(+) αβT cells likely represent novel immune effectors that are capable of combining innate and adaptive functions. Inasmuch as immunity is a determinant of individual fitness, the type and density of NKRs could be important contributing factors to the wide heterogeneity of health characteristics of older adults, ranging from institutionalized frail elders who are unable to mount immune responses to functionally independent community-dwelling elders who exhibit protective immunity. Understanding the biology of NKR(+) αβT cells could lead to new avenues for age-specific intervention to improve protective immunity.     

Channel-induced apoptosis of infected host cells—the case of malaria

Infection of erythrocytes by the malaria pathogen Plasmodium falciparum leads to activation of several distinct anion channels and a non-selective, Ca²⁺-permeable cation channel. All channel types are presumably activated by the oxidative stress generated by the pathogen. Similar or identical channels are activated by oxidation of non-infected erythrocytes. Activation of the non-selective cation channel allows entry of Ca²⁺ and Na⁺, both of which are required for intracellular growth of the pathogen. The entry of Ca²⁺ stimulates an intraerythrocytic scramblase that facilitates bi-directional phospholipid migration across the bilayer, resulting in breakdown of the phosphatidylserine asymmetry of the cell membrane. The exposure of phosphatidylserine at the outer surface of the cell membrane is presumably followed by binding to phosphatidylserine receptors on macrophages and subsequent phagocytosis of the affected erythrocyte. The lysosomal degradation may eventually eliminate the pathogen. The channel may thus play a dual role in pathogen survival. Absence of the channels is not compatible with pathogen growth, enhanced channel activity accelerates erythrocyte apoptosis that may represent a host defence mechanism serving to eliminate infected erythrocytes.     

Y-27632 promotes differentiation of fiuman embryonic stem cells into neuron-like cells北大核心

BACKGROUND: Y-27632 is a Rho-associated coil-formed protein kinase inhibitor that can regulate the self-renewal of stem cells, promote clonal formation and cell survival, and regulate and protect neuronal cell growth and development. How to improve the differentiation efficiency of embryonic stem cells into neuron-like cells is highly important for nerve injury repair and nerve regeneration. OBJECTIVE: To investigate the effect of Y-27632 on the differentiation efficiency and function of human embryonic stem cells into neuron-like cells. METHOD5: After resuscitation, human embryonic stem cells at passage 16 were subjected to morphological observation and staining identification. The embryoid bodies were prepared by suspension culture, and after 8 days of incubation, the cells were cultured in Sato medium containing different concentrations of Y-27632 (0, 5, 10, 20, 40 µmol/L) for 10 days and identification by staining. After induction for 18 days, the differentiation efficiency and neurite outgrowth were identified by immunofluorescence staining. RE5ULT5 AND CONCLU5ION: The human embryonic stem cells co-expressed Oct4 and SSEA-3 stem cell specific markers. After suspension culture for 8 days and further adherent culture for 10 days, the cells could be differentiated into neuron-like cells with neurogenic morphology and expressing Tuj-1., '-27632, especially at a concentration of 10 µmol/L, not only promoted cell proliferation (a significant increase in adherent cells an Tuj-1 positive cells), but also facilitated cell differentiation into neurons. Immunofluorescence staining findings showed that 10 µmol/L Y-27632 significantly increased the number of Tuj-1 positive cells and neurites and the length of neurites after 18 days of differentiation. These results indicate that Y-27632 not only promotes the differentiation of human embryonic stem cells into neuron-like cells, but also accelerates neurite outgrowth. © 2018, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

Selective inhibition of Hepatocarcinoma cells by apatite nanoparticles

In 1 994,Hideki Aoki and his colleagues happened to find that apatite (HAP)nanoparticlesinhibited growth of cancer cells when they tried to determine the possi-bility for HAP nanoparticles to act as tumor suppressing drugs carrier〔1〕.LaterShipu Li etal.…     

Selective Function of PKC-θ in T cells

T cell activation is a critical process in initiating adaptive immune response since only through this process the naive antigen specific T cells differentiate into armed effector T cells that mediate the actual immune response. During T cell activation, naive T cells undergo clonal expansion and acquire the capability to kill target cells infected with pathogens or produce cytokines essential for regulating immune response. Inappropriate activation or inactivation of T cells leads to autoimmunity or severe immunodeficiencies. PKC-θ is selectively expressed in T cells and required for mediating T cell activation process. Mice deficient in PKC-θ exhibit defects in T cell activation, survival and activation-induced cell death. PKC-θ selectively translocates to immunological synapse and mediates the signals required for activation of NF-κB, AP1 and NFAT that are essential for T cell activation. Furthermore, PKC-θ^-│- mice displayed multiple defects in the development of T cell-mediated immune responses in vivo. PKC-θ is thus a critical molecule that regulates T cell function at multiple stages in T cell-mediated immune responses in vivo.     

NKT cells - conductors of tumor immunity?

NKT cells are key players in the regulation of antitumor immunity, particularly in experimental models of tumor immunotherapy, such as IL-12 or alpha-galactosylceramide administration. They may also operate in natural antitumor immunity. NKT cells are best known for their immunosuppressive functions; however, NKT cells interact with a range of other cell types (particularly dendritic cells and NK cells) and the outcome of NKT-cell stimulation depends on these and on the cytokine/co-stimulatory milieu.     

Transcriptional response of human mast cells stimulated via the FcεRI and identification of mast cells as a source of IL-11

Background  

In asthma and other allergic disorders, the activation of mast cells by IgE and antigen induces the cells to release histamine and other mediators of inflammation, as well as to produce certain cytokines and chemokines. To search for new mast cell products, we used complementary DNA microarrays to analyze gene expression in human umbilical cord blood-derived mast cells stimulated via the high-affinity IgE receptor (FcεRI).     

Generation of anti-tumour effector T cells from naïve T cells by stimulation with dendritic/tumour fusion cells

Tumour-draining lymph node T cells are an excellent source of effector T cells that can be used in adoptive tumour immunotherapy because they have already been sensitized to tumour-associated antigens in vivo. However, such tumour-specific immune cells are not readily obtained from the host due to poor immunogenicity of tumours and reduced host immune responses. One obstacle in implementation of adoptive immunotherapy has been insufficient sensitization and expansion of tumour-specific effector cells. In this study, we aim to improve adoptive immunotherapy by generating anti-tumour effector T cells from naïve T lymphocytes. We attempted to achieve this by harnessing the advantages of dendritic cell (DC)-based anti-cancer vaccine strategies. Electrofusion was routinely employed to produce fusion cells with 30–40% efficiency by using the poorly immunogenic murine B16/F10 cell line, D5 cells, and DC generated from bone marrow cells. CD62L-positive T cells from spleens of naïve mice and the fusion cells were cocultured with a low concentration of IL-2. After 9 days of culture, the antigen-specific T cells were identified with an upregulation of CD25 and CD69 expression and a downregulation of CD62L expression. These cells secreted IFN-γ upon stimulation with irradiated tumour cells. Moreover, when transferred into mice with 3-day established pulmonary metastases, these cells with coadministration of IL-2 exhibited anti-tumour efficacy. In contrast, naïve T cells cocultured with a mixture of unfused DC and irradiated tumour cells did not exhibit anti-tumour efficacy. Our strategy provides the basis for a new approach in adoptive T cell immunotherapy for cancer.