메뉴 건너뛰기




Volumn 69, Issue 5, 2001, Pages 719-726

Green tea polyphenol (-)-epigallocatechin-3-gallate treatment to mouse skin prevents UVB-induced infiltration of leukocytes, depletion of antigen-presenting cells, and oxidative stress

Author keywords

( ) epigallocatechin 3 gallate (EGCG); Antigen presenting cell; Green tea; Immune suppression; Oxidative stress; Ultraviolet radiation

Indexed keywords

CD11B ANTIGEN; EPIGALLOCATECHIN GALLATE; HYDROGEN PEROXIDE; MAJOR HISTOCOMPATIBILITY ANTIGEN CLASS 1; MAJOR HISTOCOMPATIBILITY ANTIGEN CLASS 2; MYELOPEROXIDASE; NITRIC OXIDE;

EID: 0035011985     PISSN: 07415400     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article
Times cited : (227)

References (48)
  • 1
    • 0003255752 scopus 로고
    • Oxidative stress in skin chemical carcinogenesis
    • (J. Fuchs, L. Packer, ed.). New York, NY, Marcel Dekker
    • Agarwal, R., Mukhtar, H. (1993) Oxidative stress in skin chemical carcinogenesis. In Oxidative Stress in Dermatology: (J. Fuchs, L. Packer, ed.). New York, NY, Marcel Dekker, 207-241.
    • (1993) Oxidative Stress in Dermatology , pp. 207-241
    • Agarwal, R.1    Mukhtar, H.2
  • 2
    • 0024437914 scopus 로고
    • Antioxidants and multistage carcinogenesis in mouse skin
    • Perchellet, J.-P., Perchellet, E. M. (1989) Antioxidants and multistage carcinogenesis in mouse skin. Free Radic. Biol. Med. 7, 377-408.
    • (1989) Free Radic. Biol. Med. , vol.7 , pp. 377-408
    • Perchellet, J.-P.1    Perchellet, E.M.2
  • 3
    • 0031607310 scopus 로고    scopus 로고
    • Natural antioxidants in chemoprevention
    • Dragsted, L. O. (1998) Natural antioxidants in chemoprevention. Arch. Toxicol. Suppl. 20, 209-226.
    • (1998) Arch. Toxicol. Suppl. , vol.20 , pp. 209-226
    • Dragsted, L.O.1
  • 4
    • 0024355849 scopus 로고
    • Prevention of cancer: Vegetables and plants
    • Hoeman, G. (1989) Prevention of cancer: vegetables and plants. Comp. Biochem. Physiol. B 93, 201-212.
    • (1989) Comp. Biochem. Physiol. B , vol.93 , pp. 201-212
    • Hoeman, G.1
  • 6
    • 0025177898 scopus 로고
    • Inhibition of carcinogenesis by naturally occurring and synthetic compounds
    • (Y. Kuroda, D. M. Shankel , M. D. Waters, ed.), New York, NY, Plenum Publishing Corp.
    • Wattenberg, L. W. (1990) Inhibition of carcinogenesis by naturally occurring and synthetic compounds. In Antimutagenesis and Anticarcinogenesis, Mechanism II, (Y. Kuroda, D. M. Shankel , M. D. Waters, ed.), New York, NY, Plenum Publishing Corp. 155-166.
    • (1990) Antimutagenesis and Anticarcinogenesis, Mechanism II , pp. 155-166
    • Wattenberg, L.W.1
  • 7
    • 0031328735 scopus 로고    scopus 로고
    • Tea antioxidants in cancer chemoprevention
    • Katiyar, S. K., Mukhtar, H. (1997) Tea antioxidants in cancer chemoprevention. J. Cellular Biochem. 27, 59-67.
    • (1997) J. Cellular Biochem. , vol.27 , pp. 59-67
    • Katiyar, S.K.1    Mukhtar, H.2
  • 8
    • 0028284693 scopus 로고
    • Nonmelanoma skin cancer in the United States: Incidence
    • Miller, D. L., Weinstock, M. A. (1994) Nonmelanoma skin cancer in the United States: incidence. J. Am. Acad. Dermatol. 30, 774-778.
    • (1994) J. Am. Acad. Dermatol. , vol.30 , pp. 774-778
    • Miller, D.L.1    Weinstock, M.A.2
  • 11
    • 0030903321 scopus 로고    scopus 로고
    • Protective effects of silymarin against photocarcinogenesis in a mouse skin model
    • Katiyar, S. K., Korman, N. J., Mukhtar, H., Agarwal, R. (1997) Protective effects of silymarin against photocarcinogenesis in a mouse skin model. J. Natl. Cancer Inst. 89, 556-566.
    • (1997) J. Natl. Cancer Inst. , vol.89 , pp. 556-566
    • Katiyar, S.K.1    Korman, N.J.2    Mukhtar, H.3    Agarwal, R.4
  • 12
    • 0025205234 scopus 로고
    • Susceptibility to effects of UVB radiation on induction of contact hypersensitivity as a risk factor for skin cancer in humans
    • Yoshikawa, T., Rae, V., Bruins-Slot, W., van den Berg, J. W., Taylor, J. R., Streilein, J. W. (1990) Susceptibility to effects of UVB radiation on induction of contact hypersensitivity as a risk factor for skin cancer in humans. J. Invest. Dermatol. 95, 530-536.
    • (1990) J. Invest. Dermatol. , vol.95 , pp. 530-536
    • Yoshikawa, T.1    Rae, V.2    Bruins-Slot, W.3    Van Den Berg, J.W.4    Taylor, J.R.5    Streilein, J.W.6
  • 13
    • 0029903307 scopus 로고    scopus 로고
    • Enhanced growth of murine melanoma in ultraviolet-irradiated skin is associated with local inhibition of immune effector mechanisms
    • Donawho, C. K., Muller, H. K., Bucana, C. D., Kripke, M. L. (1996) Enhanced growth of murine melanoma in ultraviolet-irradiated skin is associated with local inhibition of immune effector mechanisms. J. Immunol. 157, 781-786.
    • (1996) J. Immunol. , vol.157 , pp. 781-786
    • Donawho, C.K.1    Muller, H.K.2    Bucana, C.D.3    Kripke, M.L.4
  • 14
    • 0018866633 scopus 로고
    • Epidermal Langerhans cell density determines whether contact hypersensitivity or unresponsiveness follows skin painting with DNFB
    • Toews, G. B., Bergstresser, P. R., Streilein, J. W., Sullivan, S. (1980) Epidermal Langerhans cell density determines whether contact hypersensitivity or unresponsiveness follows skin painting with DNFB. J. Immunol. 124, 445-453.
    • (1980) J. Immunol. , vol.124 , pp. 445-453
    • Toews, G.B.1    Bergstresser, P.R.2    Streilein, J.W.3    Sullivan, S.4
  • 16
    • 0021354790 scopus 로고
    • Mechanism of systemic immune suppression by UV irradiation in vivo. II. The UV effects on number and morphology of epidermal Langerhans cells and the UV-induced suppression of contact hypersensitivity have different wavelength dependencies
    • Noonan, F. P., Bucana, C., Sauder, D. N., DeFabo, E. C. (1984) Mechanism of systemic immune suppression by UV irradiation in vivo. II. The UV effects on number and morphology of epidermal Langerhans cells and the UV-induced suppression of contact hypersensitivity have different wavelength dependencies. J. Immunol. 132, 2408-2416.
    • (1984) J. Immunol. , vol.132 , pp. 2408-2416
    • Noonan, F.P.1    Bucana, C.2    Sauder, D.N.3    DeFabo, E.C.4
  • 17
    • 0026465224 scopus 로고
    • The effect of ultraviolet B irradiation and urocanic acid isomers on dendritic cell migration
    • Moodycliffe, A. M., Kimber, I., Norval, M. (1992) The effect of ultraviolet B irradiation and urocanic acid isomers on dendritic cell migration, Immunology 77, 394-399.
    • (1992) Immunology , vol.77 , pp. 394-399
    • Moodycliffe, A.M.1    Kimber, I.2    Norval, M.3
  • 19
    • 0026718744 scopus 로고
    • Effects of ultraviolet radiation on murine epidermal Langerhans cells: Doses of ultraviolet radiation that modulate ICAM-1 (CD54) expression and inhibit Langerhans cell function cause delayed cytotoxicity in vitro
    • Tang, A., Udey, M. C. (1992) Effects of ultraviolet radiation on murine epidermal Langerhans cells: doses of ultraviolet radiation that modulate ICAM-1 (CD54) expression and inhibit Langerhans cell function cause delayed cytotoxicity in vitro. J. Invest. Dermatol. 99, 83-89.
    • (1992) J. Invest. Dermatol. , vol.99 , pp. 83-89
    • Tang, A.1    Udey, M.C.2
  • 20
    • 0027260841 scopus 로고
    • Neutrophils, differentiated macrophages, and monocyte/macrophage antigen presenting cells infiltrate murine epidermis after UV injury
    • Cooper, K. D., Duraiswamy, N., Hammerberg, C., Allen, E., Kimbrough-Green, C., Dillon, W., Thomas, D. (1993) Neutrophils, differentiated macrophages, and monocyte/macrophage antigen presenting cells infiltrate murine epidermis after UV injury. J. Invest. Dermatol. 101, 155-163.
    • (1993) J. Invest. Dermatol. , vol.101 , pp. 155-163
    • Cooper, K.D.1    Duraiswamy, N.2    Hammerberg, C.3    Allen, E.4    Kimbrough-Green, C.5    Dillon, W.6    Thomas, D.7
  • 21
    • 0028149953 scopus 로고
    • Active induction of unresponsiveness (tolerance) to DNFB by in vivo ultraviolet-exposed epidermal cells is dependent upon infiltrating class II MHC+ CD1lb (bright) monocytic/macrophagic cells
    • Hammerberg, C., Duraiswamy, N., Cooper, K. D. (1994) Active induction of unresponsiveness (tolerance) to DNFB by in vivo ultraviolet-exposed epidermal cells is dependent upon infiltrating class II MHC+ CD1lb (bright) monocytic/macrophagic cells. J. Immunol. 153, 4915-4924.
    • (1994) J. Immunol. , vol.153 , pp. 4915-4924
    • Hammerberg, C.1    Duraiswamy, N.2    Cooper, K.D.3
  • 22
    • 0024509534 scopus 로고
    • Disparate effects of in vitro low-dose UVB irradiation on intravenous immunizations with purified epidermal cell subpopulations for the induction of contact hypersensitivity
    • Cruz, P. D., Nixon-Fulton, J., Tigelaar, R. E., Bergstresser, P. R. (1989) Disparate effects of in vitro low-dose UVB irradiation on intravenous immunizations with purified epidermal cell subpopulations for the induction of contact hypersensitivity. J. Invest. Dermatol. 92, 160-165.
    • (1989) J. Invest. Dermatol. , vol.92 , pp. 160-165
    • Cruz, P.D.1    Nixon-Fulton, J.2    Tigelaar, R.E.3    Bergstresser, P.R.4
  • 23
    • 0030589296 scopus 로고    scopus 로고
    • Reversal of immunosuppression inducible through ultraviolet-exposed skin by in vivo anti-CD1lb treatment
    • Hammerberg, C., Duraiswamy, N., Cooper, K. D, (1996) Reversal of immunosuppression inducible through ultraviolet-exposed skin by in vivo anti-CD1lb treatment. J. Immunol. 157, 5254-5261.
    • (1996) J. Immunol. , vol.157 , pp. 5254-5261
    • Hammerberg, C.1    Duraiswamy, N.2    Cooper, K.D.3
  • 24
    • 0032489921 scopus 로고    scopus 로고
    • Activated complement component 3 (C3) is required for ultraviolet induction of immunosuppression and antigenic tolerance
    • Hammerberg, C., Katiyar, S. K., Carroll, M. C., Cooper K. D. (1998) Activated complement component 3 (C3) is required for ultraviolet induction of immunosuppression and antigenic tolerance. J. Exp. Med. 187, 1133-1138.
    • (1998) J. Exp. Med. , vol.187 , pp. 1133-1138
    • Hammerberg, C.1    Katiyar, S.K.2    Carroll, M.C.3    Cooper, K.D.4
  • 25
    • 0028928899 scopus 로고
    • Inhibition of tumor growth by elimination of granulocytes
    • Pekarek, L. A., Starr, B. A., Toledano, A. Y., Schreiber, H. (1995) Inhibition of tumor growth by elimination of granulocytes. J. Exp. Med. 181, 435-440.
    • (1995) J. Exp. Med. , vol.181 , pp. 435-440
    • Pekarek, L.A.1    Starr, B.A.2    Toledano, A.Y.3    Schreiber, H.4
  • 26
    • 0029078313 scopus 로고
    • Synergy between T-cell immunity and inhibition of paracrine stimulation causes tumor rejection
    • Sueng, L. P., Rowley, D. A., Dubey, P., Schreiber, H. (1995) Synergy between T-cell immunity and inhibition of paracrine stimulation causes tumor rejection. Proc. Natl. Acad. Sci. USA 92, 6254-6258.
    • (1995) Proc. Natl. Acad. Sci. USA , vol.92 , pp. 6254-6258
    • Sueng, L.P.1    Rowley, D.A.2    Dubey, P.3    Schreiber, H.4
  • 27
    • 0028799287 scopus 로고
    • Antigenic cancer cells that escape immune destruction are stimulated by host cells
    • Sueng, L. P., Seung, S. K., Schreiber, H. (1995) Antigenic cancer cells that escape immune destruction are stimulated by host cells. Cancer Res. 55, 5094-5100.
    • (1995) Cancer Res. , vol.55 , pp. 5094-5100
    • Sueng, L.P.1    Seung, S.K.2    Schreiber, H.3
  • 29
    • 0029398608 scopus 로고
    • Protection against ultraviolet-B radiation-induced local and systemic suppression of contact hypersensitivity and edema responses in C3H/HeN mice by green tea polyphenols
    • Katiyar, S. K., Elmets, C. A., Agarwal, K., Mukhtar, H. (1995) Protection against ultraviolet-B radiation-induced local and systemic suppression of contact hypersensitivity and edema responses in C3H/HeN mice by green tea polyphenols. Photochem. Photobiol. 62, 855-861.
    • (1995) Photochem. Photobiol. , vol.62 , pp. 855-861
    • Katiyar, S.K.1    Elmets, C.A.2    Agarwal, K.3    Mukhtar, H.4
  • 30
    • 0032740780 scopus 로고    scopus 로고
    • Prevention of UVB-induced immunosuppression in mice by the green tea polyphenol (-)-epigallocatechin-3-gallate may be associated with alterations in IL-10 and IL-12 production
    • Katiyar, S. K., Challa, A., McCormick, T. S., Cooper, K. D., Mukhtar, H. (1999) Prevention of UVB-induced immunosuppression in mice by the green tea polyphenol (-)-epigallocatechin-3-gallate may be associated with alterations in IL-10 and IL-12 production. Carcinogenesis 20, 2117-2124.
    • (1999) Carcinogenesis , vol.20 , pp. 2117-2124
    • Katiyar, S.K.1    Challa, A.2    McCormick, T.S.3    Cooper, K.D.4    Mukhtar, H.5
  • 31
    • 0027210133 scopus 로고
    • The ultraviolet C energy emitted from FS lamps contributes significantly to the induction of human erythema and murine ear edema
    • Learn, D. B., Beard, J., and Moloney, S. J. (1993) The ultraviolet C energy emitted from FS lamps contributes significantly to the induction of human erythema and murine ear edema. Photodermatol. Photoimmunol. Photomed. 9, 147-153.
    • (1993) Photodermatol. Photoimmunol. Photomed. , vol.9 , pp. 147-153
    • Learn, D.B.1    Beard, J.2    Moloney, S.J.3
  • 32
    • 0020051148 scopus 로고
    • Measurement of cutaneous inflammation: Estimation of neutrophil content with an enzyme marker
    • Bradley, P. P., Priebat, D. A., Christensen, R. D., Rothstein, G. (1982) Measurement of cutaneous inflammation: estimation of neutrophil content with an enzyme marker. J. Invest. Dermatol. 78, 206-209.
    • (1982) J. Invest. Dermatol. , vol.78 , pp. 206-209
    • Bradley, P.P.1    Priebat, D.A.2    Christensen, R.D.3    Rothstein, G.4
  • 33
    • 0033070601 scopus 로고    scopus 로고
    • Polyphenolic antioxidant (-)-epigallocatechin-3-gallate from green tea reduces UVB-induced inflammatory responses and infiltration of leukocytes in human skin
    • Katiyar, S. K., Matsui, M. S., Elmets, C. A., Mukhtar, H. (1999) Polyphenolic antioxidant (-)-epigallocatechin-3-gallate from green tea reduces UVB-induced inflammatory responses and infiltration of leukocytes in human skin. Photochem. Photobiol. 69, 148-153.
    • (1999) Photochem. Photobiol. , vol.69 , pp. 148-153
    • Katiyar, S.K.1    Matsui, M.S.2    Elmets, C.A.3    Mukhtar, H.4
  • 35
    • 0032896873 scopus 로고    scopus 로고
    • UVB activates ERK1/2 and p38 signaling pathways via reactive oxygen species in cultured keratinocytes
    • Peus, D., Vasa, R. A., Beyerle, A., Meyes, A., Krautmacher, C. Pittelkow, M. R. (1999) UVB activates ERK1/2 and p38 signaling pathways via reactive oxygen species in cultured keratinocytes. J. Invest. Dermatol. 112, 751-756.
    • (1999) J. Invest. Dermatol. , vol.112 , pp. 751-756
    • Peus, D.1    Vasa, R.A.2    Beyerle, A.3    Meyes, A.4    Krautmacher, C.5    Pittelkow, M.R.6
  • 37
    • 0018866633 scopus 로고
    • Epidermal Langerhans cell density determines whether contact hypersensitivity or unresponsiveness follows skin painting with DNFB
    • Toews, G. B., Bergstresser, P. R., Streilein, J. W., Sullivan, S. (1980) Epidermal Langerhans cell density determines whether contact hypersensitivity or unresponsiveness follows skin painting with DNFB. J. Immunol. 124, 445-453.
    • (1980) J. Immunol. , vol.124 , pp. 445-453
    • Toews, G.B.1    Bergstresser, P.R.2    Streilein, J.W.3    Sullivan, S.4
  • 38
    • 0006534336 scopus 로고
    • Impairment of antigen presenting cell function by ultraviolet radiation
    • Greene, M. I., Sy, M. S., Kripke, M. L., Benacerraf, B. (1979) Impairment of antigen presenting cell function by ultraviolet radiation. Proc. Natl. Acad. Sci. USA 76, 6591-6595.
    • (1979) Proc. Natl. Acad. Sci. USA , vol.76 , pp. 6591-6595
    • Greene, M.I.1    Sy, M.S.2    Kripke, M.L.3    Benacerraf, B.4
  • 39
    • 0019429614 scopus 로고
    • Suppression of contact hypersensitivity in mice by ultraviolet irradiation is associated with defective antigen presentation
    • Noonan, F. P., Kripke, M. L., Pedersen, G. M., Greene, M. I. (1981) Suppression of contact hypersensitivity in mice by ultraviolet irradiation is associated with defective antigen presentation. Immunology 43, 527-533.
    • (1981) Immunology , vol.43 , pp. 527-533
    • Noonan, F.P.1    Kripke, M.L.2    Pedersen, G.M.3    Greene, M.I.4
  • 40
    • 0025855718 scopus 로고
    • Inhibition of epidermal Langerhans cell function by low dose ultraviolet B radiation: Ultraviolet B radiation selectively modulates ICAM-1 (CD54) expression by murine Langerhans cells
    • Tang, A., Udey, M. C. (1991) Inhibition of epidermal Langerhans cell function by low dose ultraviolet B radiation: ultraviolet B radiation selectively modulates ICAM-1 (CD54) expression by murine Langerhans cells. J. Immunol. 146, 3347-3355.
    • (1991) J. Immunol. , vol.146 , pp. 3347-3355
    • Tang, A.1    Udey, M.C.2
  • 41
    • 0025054647 scopus 로고
    • Low dose ultraviolet B-irradialed Langerhans cells preferentially activate CD4+ cells of the T helper 2 subset
    • Simon, J. C., Cruz, P. D., Jr., Bergstresser, P. R., Tigelaar, R. E. (1990) Low dose ultraviolet B-irradialed Langerhans cells preferentially activate CD4+ cells of the T helper 2 subset. J. Immunol. 145, 2087-2091.
    • (1990) J. Immunol. , vol.145 , pp. 2087-2091
    • Simon, J.C.1    Cruz P.D., Jr.2    Bergstresser, P.R.3    Tigelaar, R.E.4
  • 42
    • 0026669423 scopus 로고
    • UV exposure reduces immunization rates and promotes tolerance to epicutaneous antigens in humans: Relationship to dose, CD1a-DR+ epidermal macrophage induction, and Langerhans cell depletion
    • Cooper, K. D., Oberhelman, L., Hamilton, T. A., Baadsgaard, O., Terhune, M., LeVee, G., Anderson, T., Koren, H. (1992) UV exposure reduces immunization rates and promotes tolerance to epicutaneous antigens in humans: relationship to dose, CD1a-DR+ epidermal macrophage induction, and Langerhans cell depletion. Proc. Natl. Acad. Sci. USA 89, 8497-8501.
    • (1992) Proc. Natl. Acad. Sci. USA , vol.89 , pp. 8497-8501
    • Cooper, K.D.1    Oberhelman, L.2    Hamilton, T.A.3    Baadsgaard, O.4    Terhune, M.5    LeVee, G.6    Anderson, T.7    Koren, H.8
  • 43
    • 0023934529 scopus 로고
    • Human epidermal cells from ultraviolet light-exposed skin preferentially activate autoreactive CD4+ 2H4+ suppressor-inducer lymphocytes and CD8+ suppressor/ cytotoxic lymphocytes
    • Baadsgaard, O., Fox, D. A., Cooper, K. D. (1988) Human epidermal cells from ultraviolet light-exposed skin preferentially activate autoreactive CD4+ 2H4+ suppressor-inducer lymphocytes and CD8+ suppressor/ cytotoxic lymphocytes. J. Immunol. 140, 1738-1744.
    • (1988) J. Immunol. , vol.140 , pp. 1738-1744
    • Baadsgaard, O.1    Fox, D.A.2    Cooper, K.D.3
  • 44
    • 0021995312 scopus 로고
    • Effects of ultraviolet radiation on human epidermal cell alloantigen presentation: Initial depression of Langerhans cell-dependent function is followed by the appearance of T6-DR+ cells that enhance epidermal alloantigen presentation
    • Cooper, K. D., Fox, P., Neises, G., Katz, S. I. (1985) Effects of ultraviolet radiation on human epidermal cell alloantigen presentation: initial depression of Langerhans cell-dependent function is followed by the appearance of T6-DR+ cells that enhance epidermal alloantigen presentation. J. Immunol. 134, 129-137.
    • (1985) J. Immunol. , vol.134 , pp. 129-137
    • Cooper, K.D.1    Fox, P.2    Neises, G.3    Katz, S.I.4
  • 46
    • 0028196674 scopus 로고
    • Inflammation, chromosomal instability, and cancer: The schistosomiasis model
    • Rosin, M. P., Anwar, W. A., Ward, A. J. (1994) Inflammation, chromosomal instability, and cancer: the schistosomiasis model. Cancer Res. 54 (Suppl.), 1929s-1933s.
    • (1994) Cancer Res. , vol.54 , Issue.SUPPL.
    • Rosin, M.P.1    Anwar, W.A.2    Ward, A.J.3
  • 47
    • 0343659099 scopus 로고
    • Oxidant-dependent metabolic activation of polycyclic aromatic hydrocarbons by phorbol ester-stimulated human polymorphonuclear leukocytes: Possible link between inflammation and cancer
    • Trush, M. A., Seed, J. L., Kensler, T. W. (1995) Oxidant-dependent metabolic activation of polycyclic aromatic hydrocarbons by phorbol ester-stimulated human polymorphonuclear leukocytes: Possible link between inflammation and cancer. Proc. Natl. Acad. Sci. USA 82, 5194-5198.
    • (1995) Proc. Natl. Acad. Sci. USA , vol.82 , pp. 5194-5198
    • Trush, M.A.1    Seed, J.L.2    Kensler, T.W.3
  • 48
    • 0021914668 scopus 로고
    • Phagocytes as carcinogens: Malignant transformation produced by human neutrophils
    • Weitzman, S. A., Clark, E. P., Stossel, T. P. (1985) Phagocytes as carcinogens: malignant transformation produced by human neutrophils. Science 227, 1231-1233.
    • (1985) Science , vol.227 , pp. 1231-1233
    • Weitzman, S.A.1    Clark, E.P.2    Stossel, T.P.3


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.