This study evaluated the determinants of mortality and the T cell immune response in patients with persistent Staphylococcus aureus bacteremia (SAB). This was a prospective cohort study and patients with confirmed SAB were enrolled from 2008 to 2020. We compared clinical, microbiological, and genotypic features between surviving and deceased patients with persistent SAB.
View Article and Find Full Text PDFBackground: αGal-deficient xenografts are protected from hyperacute rejection during xenotransplantation but are still rejected more rapidly than allografts. Despite studies showing the roles of non-Gal antibodies and αβ T cells in xenograft rejection, the involvement of γδ T cells in xenograft rejection has been limitedly investigated.
Methods: Six male cynomolgus monkeys were transplanted with porcine vessel xenografts from wild-type (n = 3) or GGTA1 knockout (n = 3) pigs.
Due to the highly immunogenic nature of renal cell carcinoma (RCC), the tumor microenvironment (TME) is enriched with various innate and adaptive immune subsets. In particular, gamma-delta (γδ) T cells can act as potent attractive mediators of adoptive cell transfer immunotherapy because of their unique properties such as non-reliance on major histocompatibility complex expression, their ability to infiltrate human tumors and recognize tumor antigens, relative insensitivity to immune checkpoint molecules, and broad tumor cytotoxicity. Therefore, it is now critical to better characterize human γδ T-cell subsets and their mechanisms in RCCs, especially the stage of differentiation.
View Article and Find Full Text PDFThe γδ T cells are unconventional lymphocytes that function in both innate and adaptive immune responses against various intracellular and infectious stresses. The γδ T cells can be exploited as cancer-killing effector cells since γδ TCRs recognize MHC-like molecules and growth factor receptors that are upregulated in cancer cells, and γδ T cells can differentiate into cytotoxic effector cells. However, γδ T cells may also promote tumor progression by secreting IL-17 or other cytokines.
View Article and Find Full Text PDFCorrect temporal and spatial control of actin dynamics is essential for the cytotoxic T cell effector function against tumor cells. However, little is known whether actin engineering in tumor-targeted T cells can enhance their antitumor responses, thereby potentiating the adoptive T cell therapy. Here, we report that TAGLN2, a 22-KDa actin-stabilizing protein which is physically associated with lymphocyte function-associated antigen-1 (LFA-1), potentiates the CD8 T cells to kill the intercellular adhesion molecule-1 (ICAM-1)-positive/OVA-presenting E0771 cells, but not ICAM-1-negative OVA-B16F10 cells, suggesting an 'inside-out' activation of LFA-1, which causes more efficient immunological synapse formation between T cells and tumor cells.
View Article and Find Full Text PDFBackground: Despite the development of α1,3-galactosyl transferase-knockout (GTKO) pigs, acute humoral xenograft rejection caused by antibodies against non-Gal antigens, along with complement activation, are hurdles that need to be overcome. Among non-Gal antigens, N-glycolylneuraminic acid (Neu5Gc) is considered to play an important role in xenograft rejection in human.
Methods: We generated human embryonic kidney 293 (HEK293) cells that expressed xenogeneic Neu5Gc (HEK293-pCMAH) or α1,3Gal (HEK293-pGT) antigen and investigated the degree of human antibody binding and complement-dependent cytotoxicity (CDC) against these antigens using 100 individual human sera.
We previously generated humanized TB34N mice that received human fetal thymus (T), bone tissue (B) and fetal liver-derived (FL)-CD34(+) cells (34) in immunodeficient, NOD/SCID IL2Rγ(null) (N) mice. Although humanized TB34N mice had excellent hematopoiesis, here, we sought to further improve this model by additional transplantation of human spleen tissue (S) as a secondary hematopoietic tissue (TBS34N). The human spleen grafts were enlarged and differentiated into a similar morphology of adult humans, including follicular lymphoid structures with T- and B-cells.
View Article and Find Full Text PDFBoth the thymus (T) and bone (B) are necessary hematopoietic niches in adult humans. We previously showed that co-transplantation of human fetal T and B tissues into neonatal immunodeficient NOD/SCID IL2Rγ(null) (NSG, N) mice facilitated hematopoiesis. However, transplantation into neonatal mice resulted in high frequency of early death, making it unrealistic for repetitive experiments.
View Article and Find Full Text PDFBackground: In many humanized mouse models, there are few T cells in the engrafted human cell, whereas the number of B cells is high. We attempted to overcome this limitation and investigate whether the entire process of human T cell development arose similarly to the process in humans, as previously reported.
Methods: To produce an advanced humanized mice model, we transplanted human fetal liver/thymus tissue subrenally and injected human CD34(+) stem cells intravenously into NOD/SCID/IL2Rgamma null (NSG) mice.
BACKGROUND/AIM To determine if overexpression of the glaucoma gene MYOC is involved in the development of open-angle glaucoma (OAG) and if its promoter variants are associated with glaucoma in the Korean population. METHODS Human trabecular meshwork cells were cultured in the presence of ophthalmic steroids such as fluorometholone, fluorometholone acetate, dexamethasone, prednisolone acetate and rimexolone. The cells were cultured at a hydrostatic pressure of 32 mm Hg above atmospheric pressure and induction of MYOC was evaluated by northern blot analysis.
View Article and Find Full Text PDFEvidence for the epigenetic regulation of hematopoietic stem cells (HSCs) is growing, but the genome-wide epigenetic signature of HSCs and its functional significance remain unclear. In this study, from a genome-wide comparison of CpG methylation in human CD34(+) and CD34(-) cells, we identified a characteristic undermethylation dip around the transcription start site of promoters and an overmethylation of flanking regions in undifferentiated CD34(+) cells. This "bivalent-like" CpG methylation pattern around the transcription start site was more prominent in genes not associated with CpG islands (CGI(-)) than CGI(+) genes.
View Article and Find Full Text PDFThe aim of the present study was to determine the expression profile of the hedgehog (Hh) signaling molecules in normal, hyperplastic, and carcinomatous uterine endometrium. For this purpose, 271 endometrial tissue samples, (62 of normal endometrium, 127 of endometrial hyperplasias, and 82 endometrial adenocarcinomas) were studied using antibodies recognizing Hh-related signaling proteins, such as, sonic hedgehog (Shh), Patched (PTCH), Smoothened (Smo), Suppressor of fused [Su(Fu)], Gli-1, Gli-2, and Gli-3 by immunohistochemistry. The mRNA expression of these molecules was also assessed on reverse transcription-polymerase chain reaction.
View Article and Find Full Text PDFLow in vivo transduction efficiency and safety concerns have been hurdles for effective hematopoietic stem cell (HSC) gene therapy. Here, we investigate whether the safety and efficiency of retroviral gene transfer into HSCs can be improved by using human allogeneic umbilical cord blood (UCB)-derived supplements instead of fetal bovine serum (FBS). When CD34(+) cells were cultured ex vivo in UCB-derived serum (CBS) or plasma (CBP), comparable or higher maintenance of HSCs was observed than in FBS and serum-free substitution medium (SFM) as assessed by the frequency of positive engraftment and the level of engraftment in NOD/SCID mice after transplantation of cultured cells.
View Article and Find Full Text PDFFLK1-expressing (FLK1(+)) mesoderm generates blood and vessels. Here, we show that combined BMP, Notch, and Wnt signaling is necessary for efficient FLK1(+) mesoderm formation from embryonic stem cells (ESCs). Inhibition of BMP, Notch, and Wnt signaling pathways greatly decreased the generation of FLK1(+) mesoderm and expression of the Ets transcription factor Er71.
View Article and Find Full Text PDFMolecular mechanisms that regulate the generation of hematopoietic and endothelial cells from mesoderm are poorly understood. To define the underlying mechanisms, we compared gene expression profiles between embryonic stem (ES) cell-derived hemangioblasts (Blast-Colony-Forming Cells, BL-CFCs) and their differentiated progeny, Blast cells. Bioinformatic analysis indicated that BL-CFCs resembled other stem cell populations.
View Article and Find Full Text PDFEmbryonic stem (ES) cells differentiate efficiently in vitro and give rise to many different somatic cell types. Hematopoietic progenitors present within differentiated ES cells (embryoid bodies, EBs) can be identified by replating EB cells into semisolid media with hematopoietic growth factors. The developmental kinetics of various hematopoietic lineage precursors within EBs and molecular and cellular studies of these cells have suggested that the sequence of events leading to the onset of hematopoiesis within EBs is similar to that found within the mouse embryo.
View Article and Find Full Text PDFThe receptor tyrosine kinase FLK1 and the transcription factor SCL play crucial roles in the establishment of hematopoietic and endothelial cell lineages in mice. We have previously used an in vitro differentiation model of embryonic stem (ES) cells and demonstrated that hematopoietic and endothelial cells develop via sequentially generated FLK1(+) and SCL(+) cells. To gain a better understanding of cellular and molecular events leading to hematopoietic specification, we examined factors necessary for FLK1(+) and SCL(+) cell induction in serum-free conditions.
View Article and Find Full Text PDFAccumulating studies support the idea that a common progenitor, termed the hemangioblast, generates both hematopoietic and endothelial cell lineages. To better define the relationship between these cell lineages, we have generated knock-in embryonic stem (ES) cells carrying a non-functional human CD4 at the Scl locus. By using in vitro differentiated Scl(+/CD4) ES cells, we demonstrate that FLK1 and SCL are molecular determinants of the hemangioblast.
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