• Molecules and Cells
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• 제42권4호
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• pp.313-320
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• 2019

Intraepithelial lymphocytes (IELs) develop through the continuous interaction with intestinal antigens such as commensal microbiome and diet. However, their respective roles and mutual interactions in the development of IELs are largely unknown. Here, we showed that dietary antigens regulate the development of the majority of $CD8{\alpha}{\beta}$ IELs in the small intestine and the absence of commensal microbiota particularly during the weaning period, delay the development of IELs. When we tested specific dietary components, such as wheat or combined corn, soybean and yeast, they were dependent on commensal bacteria for the timely development of diet-induced $CD8{\alpha}{\beta}$ IELs. In addition, supplementation of intestinal antigens later in life was inefficient for the full induction of $CD8{\alpha}{\beta}$ IELs. Overall, our findings suggest that early exposure to commensal bacteria is important for the proper development of dietary antigen-dependent immune repertoire in the gut.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.203.1-203.1
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• 2003

Calcineurin inhibitors, cyclosporine A (CsA)and tacrolimus (FK506), have been studied extensively regarding their effects on T lymphocytes, but their effects on dendritic cells (DC) are relatively unknown. DC can really capture Ag from dead and dying cells for presentation to MHC class I-restricted CTL. The main targets for the immunosuppressive calcinerin inhibitors, FK506 and CsA, have been considered to be activated T cells, but not antigen presenting cells (APCs). (omitted)

• IMMUNE NETWORK
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• 제5권3호
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• pp.150-156
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• 2005

Background: Dendritic cells (DCs) playa critical role not only in the initiation of immune responses, but also in the induction of immune tolerance. In an effort to regulate immune responses through the modulation of antigen presenting cell (APC) function of DCs, we searched for and characterized APC function modulators from natural products. Methods: DCs were cultured in the presence of propolis components, WP and CP, and then examined for their ability to present exogenous antigen in association with major histocompatibility complexes (MHC). Results: WP and CP inhibited class I MHC-restricted presentation of exogenous antigen (cross-presentation) in a DC cell line, DC2.4 cells, and DCs generated from bone marrow cells with GM-CSF and IL-4. The inhibitory activity of WP and CP appeared to be due not only to inhibition of phagocytic activity of DCs, but also to suppression of expression of MHC molecules on DCs. We also examined the effects of WP and CP on T cells. Interestingly, WP and CP increased IL-2 production from T cells. Conclusion: These results demonstrate that WP and CP inhibit MHC-restricted presentation of exogenous antigen through down-regulation of phagocytic activity and suppression of expression of MHC molecules on DCs.

• Clinical and Experimental Pediatrics
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• 제53권2호
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• pp.136-145
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• 2010

Natural killer T (NKT) cell is a special type of T lymphocytes that has both receptor of natural killer (NK) cell (NK1.1, CD161c) and T cell (TCR) and express a conserved or invariant T cell receptor called $V{\alpha}14J{\alpha}18$ in mice or Va24 in humans. Invariant NKT (iNKT) cell recognizes lipid antigen presented by CD1d molecules. Marine-sponge-derived glycolipid, ${\alpha}-galactosylceremide$ (${\alpha}-GalCer$), binds CD1d at the cell surface of antigen-presenting cells and is presented to iNKT cells. Within hours, iNKT cells become activated and start to secrete Interleukin-4 and $interferon-{\gamma}$. NKT cell prevents autoimmune diseases, such as type 1 diabetes, experimental allergic encephalomyelitis, systemic lupus erythematous, inflammatory colitis, and Graves' thyroiditis, by activation with ${\alpha}-GalCer$. In addition, NKT cell is associated with infectious diseases by mycobacteria, leshmania, and virus. Moreover NKT cell is associated with asthma, especially CD4+ iNKT cells. In this review, I will discuss the characteristics of NKT cell and the association with inflammatory diseases, especially asthma.

• 대한이식학회지
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• 제31권4호
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• pp.157-169
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• 2017

Regulatory T cells (Treg) naturally rein in immune attacks, and they can inhibit rejection of transplanted organs and even reverse the progression of autoimmune diseases in mice. The initial safety trials of Treg against graft-versus-host disease (GVHD) provided evidence that the adoptive transfer of Treg is safe and capable of limiting disease progression. Supported by such evidence, numerous clinical trials have been actively investigating the efficacy of Treg targeting autoimmune diseases, type I diabetes, and organ transplant rejection, including kidney and liver. The limited quantity of Treg cells harvested from peripheral blood and subsequent in vitro culture have posed a great challenge to large-scale clinical application of Treg; nevertheless, the concept of CAR (chimeric antigen receptor)-Treg has emerged as a potential resolution to the problem. Recently, two CAR-T therapies, tisagenlecleucel and axicabtagene ciloleucel, were approved by the US FDA for the treatment of refractory or recurrent acute lymhoblastic leukemia. This approval could serve as a guideline for the production protocols for other genetically engineered T cells for clinical use as well. The phase I and II clinical trials of these agents has demonstrated that genetically engineered and antigen-targeting T cells are safe and efficacious in humans. In conclusion, both the promising results of Treg cell therapy from the clinical studies and the recent FDA approval of CAR-T therapies are paving the way for CAR-Treg therapy in clinical use.

• Archives of Pharmacal Research
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• 제22권4호
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• pp.340-347
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• 1999

Dendritic cells (DCs) are potent professional antigen-presenting cells (APC) capable of inducing the primary T cell response to antigen. Although tumor cells express target antigens, they are incapable of stimulating a tumor-specific immune response due to a defect in the costimulatory signal that is required for optimal activation of T cells. In this work, we describe a new approach using tumor-DC coculture to improve the antigen presenting capacity of tumor cells which does not require a source of tumor-associated antigen. Immunization of a weakly immunogenic and progressive tumor cocultured with none marrow-derived DCs generated an effective tumor vaccine. Immunization with the cocutured DCs was able to induce complete protectiv immunity against tumor challenges and was effective for the induction of tumor-specific CTL (cytotoxic T lymphocyte) activity. Furthermore, high NK cell activity was observed in mice in which tumors were rejected. In addition, immunization with tumor-pulsed DC s induced delayed tumor growth, but not tumor eradication in tumor-bearing mice. Our results demonstrate that coculture of DCs with tumors generated antitumor immunity due to the NK cell activation as well as tumor-specific T cell. This approach would be used for designing tumor vaccines using DCs when the information about tumor antigens is limited.

• Clinical and Experimental Reproductive Medicine
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• 제25권2호
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• pp.115-122
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• 1998

The maintenance of a viable pregnancy has long been viewed as an immunological paradox. The deveolping embryo and trophoblast are immunologically foreign to the maternal immune system due to their maternally inherited genes products and tissue-specific differentiation antigens (Hill & Anderson, 1988). Therefore, speculation has arisen that spontaneous abortion may be caused by impaired maternal immune tolerance to the semiallogenic conceptus (Hill, 1990). Loss of recall antigen has been reported in immunosuppressed transplant recipients and is associated with graft survival (Muluk et al., 1991; Schulik et al., 1994). Progesterone $(10^{-5}M)$ has immunosuppressive capabilities (Szekeres-Bartho et al., 1985). Previous study showed that fertile women, but not women with unexplained recurrent abortion (URA), lose their immune response to recall antigens when pregnant (Bermas & Hill, 1997). Therefore, we hypothesized that immunosuppressive doses of progesterone may affect proliferative response of lymphocytes to trophoblast antigen and alloantigen. Proliferative responses using $^3H$-thymidine ($^3H$-TdR) incorporation of peripheral blood mononuclear cells (PBMCs) to the irradiated allogeneic periperal blood mononuclear cells as alloantigen, trophoblast extract and Flu as recall antigen, and PHA as mitogen were serially checked in 9 women who had experienced unexplained recurrent miscarriage. Progesterone vaginal suppositories (100mg b.i.d; Utrogestan, Organon) beginning 3 days after ovulation were given to 9 women with unexplained RSA who had prior evidence of Th1 immunity to trophoblast. We checked proliferation responses to conception cycle before and after progesterone supplementation once a week through the first 7 weeks of pregnancy. All patients of alloantigen and PHA had a positive proliferation response that occmed in the baseline phase. But 4 out of 9 patients (44.4%) of trophoblast antigen and Flu antigen had a positive proliferative response. The suppression of proliferation response to each antigen were started after proliferative phase and during pregnancy cycles. Our data demonstrated that since in vivo progesterone treated PBMCs suppressed more T-lymphocyte activation and $^3H$-TdR incorporation compare to PBMCs, which are not influenced by progesterone. This data suggested that it might be influenced by immunosuppressive effect of progesterone. In conclusion, progesterone may play an important immunological role in regulating local immune response in the fetal-placental unit. Furthermore, in the 9 women given progesterone during a conception cycle, Only two (22%) repeat pregnancy losses occured in these 9 women despite loss of antigen responsiveness (one chemical pregnancy loss and one loss at 8 weeks of growth which was karyotyped as a Trisomy 4). These finding suggested that pregnancy loss due to fetal aneuploidy is not associated with immunological phenomena.

• IMMUNE NETWORK
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• 제13권5호
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• pp.184-193
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• 2013

Co-signaling molecules are surface glycoproteins that positively or negatively regulate the T cell response to antigen. Co-signaling ligands and receptors crosstalk between the surfaces of antigen-presenting cells (APCs) and T cells, and modulate the ultimate magnitude and quality of T cell receptor (TCR) signaling. In the past 10 years, the field of co-signaling research has been advanced by the understanding of underlying mechanisms of the immune modulation led by newly identified co-signaling molecules and the successful preclinical and clinical trials targeting co-inhibitory molecules called immune checkpoints in the treatment of autoimmune diseases and cancers. In this review, we briefly describe the characteristics of well-known B7 co-signaling family members regarding the expression, functions and therapeutic implications and to introduce newly identified B7 members such as B7-H5, B7-H6, and B7-H7.

• Childhood Kidney Diseases
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• 제12권1호
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• pp.23-29
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• 2008

Kidney allograft transplantation is the most effective method of renal replacement for end stage renal disease patients. Still, it is another kind of 'disease', requiring immunosuppression to keep the allograft from rejection(allograft immune reaction). Immune system of the allograft recipient recognizes the graft as a 'pathogen (foreign or danger)', and the allograft-recognizing commanderin-chief of adaptive immune system, T cell, recruits all the components of immune system for attacking the graft. Proper activation and proliferation of T cell require signals from recognizing proper epitope(processed antigen by antigen presenting cell) via T cell receptor, costimulatory stimuli, and cytokines(IL-2). Thus, most of the immunosuppressive agents suppress the process of T cell activation and proliferation.

• 한국미생물·생명공학회지
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• 제23권1호
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• pp.110-117
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• 1995

This study was carried out to immunologically characterize Bacillus thuringiensis (B.t) antigens. Protein patterns of ultrasonicated- antigens of B. thuringiensis subspecies using SDS- PAGE revealed marked similarities among all the strains analyzed except for the difference between quantative variations of bands and some protein antigens. The comparison of the protein patterns showed that the protein antigen of 45 kilodalton (kd) was common in 11 strains and that the difference between B. thuringiensis subsp. canadensis and galleriae was noticed in quantative variations of bands despite of ambiguous serogrouping, suggesting a useful method for identification. All strains examined showed similar antigenic patterns in SDS-PAGE, while immunodominant bands differed in antigenic reactivity in western blot using polyclonal antibodies. Polyclonal antibody to B. thuringiensis subsp. thuringiensis and israelensis in indirect immunofluorescence assay reacted with flagella and cell surface antigens. The present study indicates that SDS-PAGE and western blot analysis may be used as tools for differentiation and identification of B. thuringiensis subspecies.