Neuraminidase Treatment Enhances Allogeneic Stimulation of Unprimed CD8+ T Cells

Kim,Kilhyoun The Korea Science and Technology Center 1997 BMB Reports Vol.30 No.6

Many cell types are known to stimulate CD8+ T cells in allogeneic recognition such as mixed lymphocyte reaction (MLR). Whereas dendritic cells are most potent among them. T cells are usually considered very poor in stimulating CD8+ T cells although there are some tumor cells that are weakly stimulatory. T cells, as a stimulator, cultured in the presence of concanavalin A that were otherwise nonstimulatory to CD8+ T cells appeared to stimulate CD8+ T cells strongly when they were pretreated with neuraminidase. The enhancement of MLR by neuraminidase could be achieved by treating either the stimulators or responders with neuraminidase. Removal of negatively-charged sialic acid moieties from the cell surface, which reduced electrostatic repulsion between responders and stimulators to give better cell-cell contact might be responsible for the enhanced MLR. In addition, neuraminidase treatment also appeared to deliver activation signal to responding T cells since it could activate CD8+ T cells in synergy with phorbol myristate acetate. The maximal responses were observed when both responders and stimulators were treated with neuraminidase.

Antitumor Responses of Adoptively-Transferred Tumor-Specific T-Cell Cultures in a Murine Lymphoma Model

Kim, Hee-Sue,Lee, Hee Gu,Lim, Jong-Seok,Lee, Ki-Young,Kim, Jaewha,Chung, Kyeong-Soo,Choe, Yong-Kyung,Choe, In-Seong,Chung, Tai-wha,Kim, Kilhyoun 梨花女子大學校 藥學硏究所 1995 藥學硏究論文集 Vol.- No.5

The purpose of this study was to establish an in vitro culture method of tumor-specific T cells, and determine the efficacy of the cultured tumor-specific cytotoxic T-1ymphocytes (CTL) as an agent of anti-tumor immunotherapy against a murine lymphoma, TIMI.4. Tumor-specific T-lymphocytes derived from C57BL/6 mice (thy-1.2) immune to TIMI.4 were activated by in vitro stimulation with the irradiated TIMI.4 cells, and expanded by restimulation with TIMI.4 in the presence of the concanavalin A-stimulated rat spleen culture supematant, and splenic antigen-presenting cells. In vitro restimulation enhanced markedly the proportion of CD8^+, a predominant surface marker of CTL, and the cytotoxic activity in the cultured immune T cell population. The resulting TIMl.4-specific T cells were adoptively transferred into nude mice. The tumor cells residing in the host after 7 days of adoptive transfer to B6.PL (thy-1.1) mice were quantified by use of an antibody directed to the thy-1.2 allele. The TIMI.4 cells in the recipient nude mice were decreased in a dose-dependent manner. Anti-tumor activity of the TIMI.4-specific T cells was also demonstrated by a survival test, where the tumor-bearing nu/nu mice which received the activated T-cells survived about 30% longer than the control mice which received the tumor cells alone. These suggest that adoptive transfer of TIMI.4-specific T cells could be a candidate for effective therapy of the murine lymphoma.

Differential Activation of T Cells by T-Cell Receptor Ligand Analogs

Kim,Kilhyoun,Choi,Yunhi,Suh,Yujin The Korea Science and Technology Center 1997 BMB Reports Vol.30 No.6

Although CD4+ T cell responses to protein-derived antigen have well been understood, the epitopes recognized by hapten-specific CD4+ T cells have not been fully defined. In this study, we characterized the response of a T cell hybridoma (5D10.1B8) which is specific for a hapten, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB) restricted by MHC class Ⅱ I-A. Using three different antigen presenting cells (APCs) expressing I-A, the role of class Ⅱ MHC proteins in haptenic antigen presentation and subsequent activation of 5D10.1B8 has been examined. Activation of 5D10.1B8 T cells by HSAB analogs was also performed. Our results show that each APC activated T cells differentially and that interleukin-2 (IL-2) augmented antigen-presenting ability of all the APCs, suggesting that increased expression of class Ⅱ MHC protein by IL-2 played on important role in HSAB presentating and T cell activation. Finally, early T cell receptor-dependent signals induced by HSAB or its analogs were examined by phosphotyrosine immunoblot analysis, and showed that tyrosine phosphorylation level of a 18-20 kD protein increased upon stimulation.

Antitumor Responses of Adoptively-Transferred Tumor-Specific T-Cell Cultures in a Murine Lymphoma Model

Kim, Hee-Sue,Lee, Hee Gu,Lim, Jong-Seok,Lee, Ki-Young,Kim, Jaewha,Chung, Kyeong-Soo,Choe, Yong-Kyung,Choe, In-Seong,Chung, Tai-Wha,Kim, kilhyoun 이화여자대학교 생명과학연구소 1995 생명과학연구논문집 Vol.6 No.-

The purpose of this study was to establish an in vitro culture method of tumor-specific T cells, and determine the dfficacy of the cultured tumor-specific cytotoxic T-lymphocytes(CTL) as an agent of anti-tumor immunotherapy against a murine lymphoma, TIMM1.4. Tumor-specific T-lymphocytes deruved from C57BL/6 mice(thy-1.2) immune to TIM1.4. were activated by in vitro stimulation with the irradiated TIM1.4 cells, and expanded by restimulation with TIM1.4 in the presence of the concanavalin A-stimulated rat spleen culture sueprnatant, and splenic antigen-presenting cells. In vitro restimulation enhanced markedly the proportion of CD8^_, a predominant surface marker of CTL, and the cytotoxic activity in the culturesd immune T cell population. The resulting TIM1.4-specific T cells were adoptively transferred into nude mice. The tumor cells residing in the host after 7 days of adoptive transfer to B6.PL(thy-1.1) mice were quantified by use of an antibody directed to the thy-1.2 allele. The TIM1.4 cells in the recipient nude mice were decreased in a dose-dependent manner. Anti-tumor activity of the TIM1.4-specific T cells was also demonnstrated by survuval test, where the tumor-bearing nu/nu midce which received the activated T-cells survived about 30% longer than the control mice which received the tumor cells alone. thses suggest that adoptive transfer of TIm1.4-specific T cells could ve a candidate for effective therapy of the murine lymphoma.

Neuraminidase Treatment Enhances Allogeneic Stimulation of Unprimed CD8^+ T Cells

Kim, Kilhyoun 梨花女子大學校 藥學硏究所 1998 藥學硏究論文集 Vol.- No.7

Many cell types are know to stimulate CD8^+ T cells in allogeneic recognition such as mixed lymphocyte reaction (MLR). Whereas dendritic cells are most potent among them, T cells are usually considered very poor in stimulating CD8^+ T cells although there are some tumor cells that are weakly stimulatory. T cells, as a stimulator, cultured in the presence of concanavalin A that were otherwise nonstimulatory to CD8^+ T cells appeared to stimulate CD8^+ T cells strongly when they were pretreated with neuraminidase. The enhancement of MLR by neuraminidase could be achieved by treating either the stimulators or responders with neuraminidase. Removal of negatively-charged sialic acid moieties from the cell surface, which reduced electrostatic repulsion between responders and stimulators to give better cell-cell contact might be responsible for the enhanced MLR In addition, neuraminidase treatment also appeared to deliver activation signal to responding T cells since it could activate CD8^+ T cells in synergy with phorbol myristate acetate. The maximal responses were observed when both responders and stimulators were treated with neuraminidase.

Diversity and Complexity of CD8^+ T Cell Responses against a Single Epitope of Adenovirus E1B

Kim, Mihyung,Kim, Kilhyoun 梨花女子大學校 藥學硏究所 2002 藥學硏究論文集 Vol.- No.11

This study describes the characteristics of the immune responses against adenovirus in 057BL/6 mice. CTL responsescould be induced against E1Bp of adenovirus type 5, when whole viruses were immunized. A panel of ElBp-specific CTLclones showed a wide range of T cell avidity, Recognition of the E1BP Peptide and a panel of variant peptides containing asingle alanine substitution by CTL clones revealed that the fine specificity of the CTL response was quite diverse, rather thanbeing limited to a certain clonal preference. Moreover, the variant peptides with a substitution at the TCR contact residue hadantagonistic properties to some of the CTL clones, while being agonistic to others, reflecting the exxtensive diversity of the T cellsThese results imply fat the functional diversity of T cells to even a single epitope should be considered in manipulating immunityto viruses and in developing adoptive immunotherapy for imnunocompromised individuals.

Telomerase Activity is Constitutively Expressed in the Murine $CD8^+$ T Cells and Controlled Transcriptionally and Post-Translationally

Kim, SoJung,Kim, MiHyung,Kim, KilHyoun The Korean Association of Immunobiologists 2004 Immune Network Vol.4 No.3

Background: Telomerase, a ribonucleoprotein enzyme capable of synthesizing telomeric repeats, attracts attention for its possible role in determining the replicative capacity of normal somatic cells, transformed cells, and cells of the germline lineage. Differently from normal somatic cells with no telomerase activity, normal lymphocytes has been reported to have telomerase activity comparable to that found in transformed cells during development and activation, which substantiate a role in supporting the capacity of lymphocytes for extensive clonal expansion. Methods: Here, in order to define the telomerase regulation in murine T lymphocytes, telomerase activity in cloned murine $CD8^+$ T cells and naive $CD8^+$ T cells isolated from C57BL/6 mice was examined. Next, the regulatory mechanism of telomerase activity at transcriptional and post- translational levels was investigated by determining the expression level of the TERT protein, a key component for telomerase activity. Results: It was demonstrated that telomerase activity was expressed in an inactivated state as well as in an activated state in the murine $CD8^+$ T lymphocytes by using TRAP assay. The increase of telomerase activity was partially dependent on the net increase of TERT expression. Also, telomerase activity was decreased after treatment with protein kinase inhibitors, indicating that telomerase activation was prevented by inhibition of phosphorylation. Conclusion: Therefore, these results suggest that telomerase activity is constitutively expressed in the murine resting T lymphocytes and controlled by both transcriptional regulation and post- ranslational modifications.

Telomerase Activity is Constitutively Expressed in the Murine CD8<SUP>+</SUP> T Cells and Controlled Transcriptionally and Post-Translationally

Sojung Kim,Mihyung Kim,Kilhyoun Kim 대한면역학회 2004 Immune Network Vol.4 No.3

Tetramethoxy hydroxyflavone p7F downregulates inflammatory mediators via the inhibition of nuclear factor kappaB.

Lee, Hee-Gu,Kim, Hyoson,Oh, Won-Keun,Yu, Kyung-Ae,Choe, Yong-Kyung,Ahn, Jong-Seog,Kim, Dong-Soo,Kim, Soo-Hyun,Dinarello, Charles A,Kim, Kilhyoun,Yoon, Do-Young New York Academy of Sciences 2004 Annals of the New York Academy of Sciences Vol.1030 No.1

<P>Artemisia has been traditionally used in Korean herbal medicine to clear damp heat and to treat uteritis and jaundice. Flavonoids isolated from Artemisia are also known to possess anti-inflammatory activities. In this study, 5,6,3',5'-tetramethoxy 7,4'-hydroxyflavone (p7F) was isolated from Artemisia absinthium. We examined in vitro and in vivo regulatory functions of p7F on the production of nitric oxide (NO), prostaglandin E(2) (PGE(2)), and tumor necrosis factor-alpha (TNF-alpha) as well as the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and collagen-induced arthritis. p7F inhibited the expression or production of proinflammatory mediators such as COX-2/PGE(2) and iNOS/NO in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. p7F also suppressed the serum level of TNF-alpha in mice treated with collagen and inhibited nuclear factor-kappaB (NF-kappaB) activation as well as NF-kappaB promoter activity in RAW 264.7 cells stimulated with LPS. This compound directly inhibited the intracellular accumulation of reactive oxygen species in hydrogen peroxide-stimulated RAW 264.7 cells. p7F has antioxidant activity and inhibits NF-kappaB activation. Taken together, these results suggest that p7F can be clinically applied to the treatment of inflammatory diseases.</P>

B형 간염 바이러스 단백질에 있어서 HLA-A2에 의해 표현되는 Epitope 펩타이드 들의 분석

이희구,임종석,김승목,이기영,김희수,김승호,권태종,최인성,정태화,김길현 이화여자대학교 생명과학연구소 1995 생명과학연구논문집 Vol.6 No.-

The cytotoxic T lymphocyte(CTL) are an important component in host defense mechanism against viral infection. They can recongnize virus-derived peptides presented by the ClassⅠ MHC molecule at the cell surface of the infected cells. On searching for effective CTL epitopes of hepatitis B virus(HBV), we synthesized a distinct set of 9-10 mer peptide containing amino acid sequence of hepatitis B virus surface proteion that are selected on the basis of a computer modeling and the previously described HLA-A2 specific motifs. Binding assay of the synthetic peptides to HLA-A2 molecules using human antigen processing defectantn T2 cells showed what 3 out of 4 synthetic peptides enhaced the expression of HLA-A2 molemule on T2 cell surface. Two anchor positions, namely P2 and P9(or P10) appeared to play a decisive role for binding. Structural chacteristics of the peptides addressed by molecular dynamics simulation was analysed and compared. These peptides also parially triggerd CTL isolatied frmo human peripheral blood mononuclear cells of HBV positive patients, and the response was peptide-specific. These results showed that negatively-charged amino acid residue at P2 hampered binding affinity of the peptides to HLA-A2 molecules, and that binding affinity of the peptides are not always reflected by thier immunogenicity among natural T cell repertoire.