Relevance of nuclear receptor expression in a Tchreg cell line, HOZOT: RXRα and PPARγ negatively regulate IFN-γ production.

Nuclear receptors (NRs) have recently received much attention for their newly discovered roles in T cell development, as exemplified by RARα (Treg cells) and RORγt (Th17 cells). In previous studies, we characterized a new type of T cell subset, designated as Tchreg (cytotoxic, helper, and regulatory T) cells, in terms of its cytokine signature. In this study, we investigated the expression and functional relevance of NRs in Tchreg cells by performing mRNA profiling of HOZOT, a cord blood-derived Tchreg cell line.

Marked induction of CD4+CD8+ T cells with multifunctional properties by coculturing CD2+ cells with xenogeneic stromal cells.

A number of T cell subsets have been identified, and the in vitro characterization of these subsets largely depends on an appropriate induction system for each one. In previous studies, we characterized a unique T cell line, HOZOT, which possessed a CD4+CD8+ double positive (DP) phenotype and multifunctional properties including cytotoxic, helper, and regulatory functions. Therefore, this T cell subset has been termed Tchreg cells.

Potent anti-tumor killing activity of the multifunctional Treg cell line HOZOT against human tumors with diverse origins.

The T cell line HOZOT has a unique FOXP3+CD4+ CD8+CD25+ phenotype, exhibits suppressive activity in allogeneic mixed lymphocyte reactions (MLR), and produces IL-10, defining HOZOT as regulatory T cells (Tregs). Interestingly, in addition to possessing a suppressive Treg ability, HOZOT was also found to show cytotoxicity against certain representative human cancer cell types. In order to disclose the range of anti-tumor activity by HOZOT, we screened it by using a panel of twenty human tumor cell lines with different origins.

miR-155, a Modulator of FOXO3a Protein Expression, Is Underexpressed and Cannot Be Upregulated by Stimulation of HOZOT, a Line of Multifunctional Treg.

MicroRNAs (miRNAs) play important roles in regulating post-transcriptional gene repression in a variety of immunological processes. In particular, much attention has been focused on their roles in regulatory T (Treg) cells which are crucial for maintaining peripheral tolerance and controlling T cell responses. Recently, we established a novel type of human Treg cell line, termed HOZOT, multifunctional cells exhibiting a CD4(+)CD8(+) phenotype.

A thymus-specific noncoding RNA, Thy-ncR1, is a cytoplasmic riboregulator of MFAP4 mRNA in immature T-cell lines.

Background: Postgenomic transcriptome analyses have identified large numbers of noncoding (nc)RNAs in mammalian cells. However, the biological function of long ncRNAs in mammalian cells remains largely unknown. Our recent expression profiling of selected human long ncRNAs revealed that a majority were expressed in an organ-specific manner, suggesting their function was linked to specific physiological phenomena in each organ.

Stromal cells' B7-1 is a key stimulatory molecule for interleukin-10 production by HOZOT, a multifunctional regulatory T-cell line.

We have previously shown that xenogeneic stromal cell stimulation of naïve T cells resulted in the generation of a new type of regulatory T (Treg) cell termed HOZOT, which has multifunctional properties and a CD4/CD8 double-positive phenotype. Even after the establishment of HOZOT, stromal cells can function as an antigen-presenting cell (APC) by inducing these cells to produce interleukin (IL)-10. When compared with other stimuli, stromal cells showed an IL-10-producing ability comparable to anti-CD3 antibody (Ab) stimulation, and much greater than dendritic cell (DC) stimulation.

Cell-in-cell structures formed between human cancer cell lines and the cytotoxic regulatory T-cell line HOZOT.

We previously established a novel cell line, termed HOZOT, derived from umbilical cord blood mononuclear cells that is characterized as a human cytotoxic regulatory T (Treg) cell line with a FOXP3(+)CD4(+)CD8(+)CD25(+) phenotype. Here, we describe a new property of HOZOT cells: they actively penetrate into a variety of human cancer cell lines, but not into normal cell lines, and form apparent cell-in-cell structures. In the process of cell penetration, we observed that HOZOT cells adhered to target cells seemed to first insert their nuclei into the cytoplasm of target cells, distinct from the process of phagocytosis.

HOZOTs, novel human regulatory T-cell lines, exhibit helper or suppressor activities depending on dendritic cell or anti-CD3 stimulation.

Objective: HOZOT cell lines (HOZOTs) are a new type of regulatory T cells established from human umbilical cord blood without using cytokines. In addition to their unique FOXP3(+)CD4(+)CD8(+)CD25(+) phenotype, HOZOTs are bifunctional and can exert either suppressor or cytotoxic activities. To further characterize HOZOTs, we cocultured HOZOTs with responder T cells under different stimulation conditions and found another function of HOZOTs.

Interleukin-8 and RANTES are signature cytokines made by HOZOT, a new type of regulatory T cells.

Distinct cytokine production profiles define the effector functions of both helper and regulatory T cells. Recently, we established novel cytotoxic regulatory T (Treg) cell lines, HOZOT, which have been characterized as IL-10-producing T cells. In this study, we further characterized HOZOT by performing comprehensive analyses of cytokines produced by HOZOTs in order to identify a signature cytokine profile.

Novel mechanisms of suppressor activity exhibited by cytotoxic regulatory T cell lines, HOZOT.

Objective: Regulatory T (Treg) cells, which play a central role in maintaining immune tolerance, can be grouped into different subtypes, such as naturally occurring Treg, type-1 T regulatory, and Th3. The suppressor activities of Treg cells are mediated through several molecular mechanisms, including immunosuppressive cytokines, cell surface molecules, and cytolytic molecules. In a previous report, we described a novel regulatory human T-cell line (termed HOZOT).

The production of IL-10 by human regulatory T cells is enhanced by IL-2 through a STAT5-responsive intronic enhancer in the IL-10 locus.

STAT5 molecules are key components of the IL-2 signaling pathway, the deficiency of which often results in autoimmune pathology due to a reduced number of CD4(+)CD25(+) naturally occurring regulatory T (Treg) cells. One of the consequences of the IL-2-STAT5 signaling axis is up-regulation of FOXP3, a master control gene for naturally occurring Treg cells. However, the roles of STAT5 in other Treg subsets have not yet been elucidated.

IL-2 activation of STAT5 enhances production of IL-10 from human cytotoxic regulatory T cells, HOZOT.

Objective: Interleukin (IL)-10 is an immunosuppressive cytokine produced by many cell types, including T cells. We previously reported that a novel type of regulatory T (Treg) cells, termed HOZOT, which possesses a FOXP3+CD4+CD8+CD25+ phenotype and dual suppressor/cytotoxic activities, produced high levels of IL-10. In this study, we examined the mechanisms of high IL-10 production by HOZOT, focusing on Janus activating kinase (JAK)/signal transducers and activators of transcription (STAT) signaling pathway.

Comprehensive analysis of FOXP3 mRNA expression in leukemia and transformed cell lines.

Studies of FOXP3 expression have thus far focused on T cells, including both normal and malignant T cells. In particular, adult T cell leukemia/lymphoma (ATLL) cells have been studied intensively because their phenotype resembles that of normal CD4(+)CD25(+) regulatory T (Treg) cells. However, a comprehensive study of FOXP3 expression covering all hematopoietic cell lineages has not yet been performed.

IL-2-independent generation of FOXP3(+)CD4(+)CD8(+)CD25(+) cytotoxic regulatory T cell lines from human umbilical cord blood.

Objective: Since the existence of mouse naturally occurring CD4(+)CD25(+) T regulatory (Treg) cells was demonstrated, a variety of human Treg subsets have been identified as distinct T cell populations. Here we show the establishment of novel Treg cell lines possessing unique characteristics.

Methods: Novel Treg cell lines, designated HOZOT, were generated by coculturing human umbilical cord blood cells with mouse stromal cell lines in the absence of exogenous IL-2 or other cytokines.

Erythropoietin induces sustained phosphorylation of STAT5 in primitive but not definitive erythrocytes generated from mouse embryonic stem cells.

Objective: During embryonic development murine erythropoiesis occurs in two waves by producing first primitive erythroid cells (EryPs) and then definitive erythroid cells (EryDs). Erythropoietin (EPO) signaling is compared between EryPs and EryDs.

Methods: We studied the EPO signaling in EryPs and EryDs using an embryonic stem-derived culture system, which can recapitulate this in vivo development process and has thus been used as a convenient in vitro model system of erythropoiesis.

Glucosyl hesperidin lowers serum triglyceride level in hypertriglyceridemic subjects through the improvement of very low-density lipoprotein metabolic abnormality.

To examine the serum triglyceride (TG)-lowering effect of a soluble hesperidin derivative, glucosyl hesperidin (G-hesperidin), and its mechanisms, we carried out a G-hesperidin administration test in hypertriglyceridemic subjects. G-Hesperidin was administered to the subjects at 500 mg/d for 24 wk. In this study, the subjects were classified into high-TG type (TG > 150 mg/dL), borderline-TG type (TG 110-150 mg/dL) and normal-TG type (TG < 110 mg/dL) on the basis of their initial serum TG values.

Effects of glucosyl hesperidin on serum lipids in hyperlipidemic subjects: preferential reduction in elevated serum triglyceride level.

Although hesperidin lowers serum total cholesterol (TC) or triglyceride (TG) in animal models, its effect in humans remains unclear. Using a soluble hesperidin derivative, glucosyl hesperidin (G-hesperidin), as a hesperidin source, we examined the efficacy on hyperlipidemic subjects. G-Hesperidin was administered to the subjects at 100 or 500 mg/d for 6 wk.

[An elderly case of acute myelocytic leukemia complicated with bleeding gastric angiodysplasia, successfully treated with topical endoscopic polidocanol injection].

A 72-year-old man with acute myelocytic leukemia (AML) suffered relapsing massive bleeding from gastric angiodysplasia. He was referred to our hospital in February 2000 because of anemia and thrombocytopenia. He had hypercellular (nucleated cell count 42 x 10(4)/microl) bone marrow with 90% myeloblasts, and AML (FAB: M1) was diagnosed.

[Acute myelocytic leukemia (M0) in an elderly patient with relapsed granulocytic sarcoma (M7) of bone during the second period of complete remission 5 years after onset].

A 75-year-old man was admitted because of right knee joint pain in December 1999. He had suffered from acute myelocytic leukemia (AML: M0) in November 1994 and achieved the first complete remission (CR) then. His AML relapsed in August 1996, but fortunately he achieved a second CR.

Preliminary evaluation of soluble IL-2 receptor and type III procollagen N-terminal aminopeptide in pleural fluid for differentiating tuberculous, carcinomatous and parapneumonic pleural effusions.

Objective: The aim of the study was to clarify the possibility of using pleural fluid levels of soluble IL-2 receptor (sIL-2R) and type III procollagen N-terminal aminopeptide (PIIIP) for differentiating tuberculous, carcinomatous and parapneumonic pleural effusions.

Methodology: Fifty patients with pleural effusions were investigated retrospectively. The pleural effusions were due to tuberculosis (n = 11), carcinoma (n = 22), pneumonia (n = 9) and heart failure (n = 8).