Kyung Ho Choi

Researchers designing antitumor treatments have long focused on eliciting tumor-specific CD8 cytotoxic T lymphocytes (CTL) because of their potent killing activity and their ability to reject transplanted organs. The resulting treatments, however, have generally been surprisingly poor at inducing complete tumor rejection, both in experimental models and in the clinic. Although a few scattered studies suggested that CD4 T "helper" cells might also serve as antitumor effectors, they have generally

The expression profiling and molecular grouping of stomach cancers has been a challenging task because of their complexity and variation. We have analyzed gene expression profiles of 22 gastric cancer/nontumor mucosa couples using 14K cDNA microarray chips designed for gastric cancer analysis. Upon pairwise analysis of the individual couples at the false significance rate 0.91%, 79 and 398 genes were reported to be up-regulated and down-regulated in tumors, respectively. Tumors were clustered in

Transglutaminase (TGase) 2 is a ubiquitously expressed enzyme that modifies proteins by cross-linking or polyamination. An aberrant activity of TGase 2 has implicated its possible roles in a variety of diseases including age-related cataracts. However, the molecular mechanism by which TGase 2 is activated has not been elucidated. In this report, we showed that oxidative stress or UV irradiation elevates in situ TGase 2 activity. Neither the expression level nor the in vitro activity of TGase 2 a

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS and remyelination in MS ultimately fails. Although strategies to promote myelin repair are eagerly sought, mechanisms underlying remyelination in vivo have been elusive. CXCR2 is expressed on neutrophils and oligodendrocyte lineage cells in the CNS. CXCR2-positive neutrophils facilitate inflammatory demyelination in demyelination models such as experimental autoimmune encephalomyelitis (EAE) and cuprizone intoxication. S

Cytotoxic T lymphocyte-associated antigen 4 (CTLA4) has been known to be a strong tolerance-inducing inhibitory receptor on T-cell surface. Systemic blocking of CTLA4 function with blocking antibodies has been regarded as an attractive strategy to enhance antitumor immunity. However, this strategy accompanies systemic autoimmune side effects that are sometimes problematic. Therefore, we developed a novel CTLA4 mutant that could be expressed in tumor antigen-specific T cells to enhance antitumor

BACKGROUND: Antibodies to aquaporin-4 (AQP4-Ab), known as NMO-IgG, are a sensitive and specific marker for neuromyelitis optica (NMO). METHODS: To develop an enzyme-linked immunosorbent assay (ELISA) for AQP4-Ab, we expressed M23 isoform of human AQP4 in a baculovirus system, and used it as an antigen. We measured AQP4-Ab in the sera of 300 individuals: 64 with definite NMO, 31 with high-risk NMO, 105 with multiple sclerosis (MS), 57 with other neurological diseases (ONDs), and 43 healthy contro

Real-time in vivo cell trafficking is feasible using PET imaging of 89Zr-DFO-labeled CAR T-cells. This can be used to investigate cellular kinetics, initial in vivo biodistribution, and safety profiles in future CAR T-cell development.

Induction of T-cell clonal anergy involves serial activation of transcription factors, including NFAT and Egr2/3. However, downstream effector mechanisms of these transcription factors are not fully understood yet. Here we identify Ndrg1 as an anergy factor induced by Egr2. Ndrg1 is upregulated by anergic signalling and maintained at high levels in resting anergic T cells. Overexpression of Ndrg1 mimics the anergic state and knockout of the gene prevents anergy induction. Interestingly, Ndrg1 is

Chimeric antigen receptor T (CAR-T) cells show remarkable efficacy for some hematological malignancies. However, CAR targets that are expressed at high level and selective to tumors are scarce. Several strategies have been proposed to tackle the on-target off-tumor toxicity of CAR-T cells that arise from suboptimal selectivity, but these are complicated, with many involving dual gene expression for specificity. In this study, we show that switchable CAR-T cells with a tumor targeting adaptor can

TCR stimulation not only initiates positive signals for T cell activation, but also induces negative signals that down-regulate T cells. We previously reported that Sprouty1, a negative regulator of Ras-MAPK pathway of receptor tyrosine kinases, was induced by TCR signal and inhibited TCR signaling in CD4+ T cell clones. In this study, we addressed the mechanism underlying Sprouty1 inhibition of T cells. When overexpressed in Jurkat T cells, Sprouty1 inhibited TCR signal-induced IL-2 transcripti

Donor lymphocyte infusion (DLI) followed by hematopoietic stem cell transplantation has served as an effective prevention/treatment modality against the relapse of some hematologic tumors, such as chronic myeloid leukemia (CML). However, the therapeutic efficacies of DLI for other types of leukemia, including acute lymphocytic leukemia (ALL), have been limited thus far. Therefore, we examined whether increasing the reactivity of donor T cells by gene modification could enhance the therapeutic ef