메뉴 건너뛰기




Volumn 32, Issue 5, 2010, Pages 370-383

Strongyloides ratti infection induces transient nematode-specific Th2 response and reciprocal suppression of IFN-γ production in mice

Author keywords

Immune modulation; Nematode infection; Strongyloides ratti; Th2 response

Indexed keywords

GAMMA INTERFERON; IMMUNOGLOBULIN G1; IMMUNOGLOBULIN M; INTERLEUKIN 10; INTERLEUKIN 13; INTERLEUKIN 3; INTERLEUKIN 4; INTERLEUKIN 5;

EID: 77950649421     PISSN: 01419838     EISSN: 13653024     Source Type: Journal    
DOI: 10.1111/j.1365-3024.2010.01199.x     Document Type: Article
Times cited : (35)

References (54)
  • 1
    • 38449093513 scopus 로고    scopus 로고
    • Strongyloides spp (May 23, 2007)
    • doi/10.1895/wormbook.1.141.1. Available at
    • Viney ME Lok JB. Strongyloides spp (May 23, 2007), WormBook, ed. The C. elegans Research Community, WormBook, doi/10.1895/wormbook.1.141.1. Available at http://www.wormbook.org.
    • The C. Elegans Research Community, WormBook
    • Viney, M.E.1    Lok, J.B.2
  • 2
    • 33646692232 scopus 로고    scopus 로고
    • The biology and genomics of Strongyloides
    • Viney ME. The biology and genomics of Strongyloides. Med Microbiol Immunol 2006 195 : 49 54.
    • (2006) Med Microbiol Immunol , vol.195 , pp. 49-54
    • Viney, M.E.1
  • 4
    • 39749193847 scopus 로고    scopus 로고
    • Reproduction in Strongyloides (Nematoda): A life between sex and parthenogenesis
    • DOI 10.1017/S003118200700399X, PII S003118200700399X
    • Streit A. Reproduction in Strongyloides (Nematoda): a life between sex and parthenogenesis. Parasitology 2008 135 : 285 294. (Pubitemid 351311235)
    • (2008) Parasitology , vol.135 , Issue.3 , pp. 285-294
    • Streit, A.1
  • 5
    • 40249086494 scopus 로고    scopus 로고
    • Strongyloides hyperinfection syndrome: An emerging global infectious disease
    • Marcos LA, Terashima A, Dupont HL Gotuzzo E. Strongyloides hyperinfection syndrome: an emerging global infectious disease. Trans R Soc Trop Med Hyg 2008 102 : 314 318.
    • (2008) Trans R Soc Trop Med Hyg , vol.102 , pp. 314-318
    • Marcos, L.A.1    Terashima, A.2    Dupont, H.L.3    Gotuzzo, E.4
  • 7
    • 56349118052 scopus 로고    scopus 로고
    • Strongyloides stercoralis Infection in the Immunocompromised Host
    • Ramanathan R Nutman T. Strongyloides stercoralis Infection in the Immunocompromised Host. Curr Infect Dis Rep 2008 10 : 105 110.
    • (2008) Curr Infect Dis Rep , vol.10 , pp. 105-110
    • Ramanathan, R.1    Nutman, T.2
  • 8
    • 0013646847 scopus 로고
    • Studies on active acquiered resistance, natural and artificial, in the rat to infection with Strongyloides ratti
    • Sheldon A. Studies on active acquiered resistance, natural and artificial, in the rat to infection with Strongyloides ratti. Am J Hyg 1937 25 : 53 65.
    • (1937) Am J Hyg , vol.25 , pp. 53-65
    • Sheldon, A.1
  • 10
    • 34250617156 scopus 로고    scopus 로고
    • The immune response during a Strongyloides ratti infection of rats
    • DOI 10.1111/j.1365-3024.2007.00945.x
    • Wilkes CP, Bleay C, Paterson S Viney ME. The immune response during a Strongyloides ratti infection of rats. Parasite Immunol 2007 29 : 339 346. (Pubitemid 46944444)
    • (2007) Parasite Immunology , vol.29 , Issue.7 , pp. 339-346
    • Wilkes, C.P.1    Bleay, C.2    Paterson, S.3    Viney, M.E.4
  • 11
    • 0018946446 scopus 로고
    • Strongyloides ratti: Susceptibility to infection and resistance to reinfection in inbred strains of mice as assessed by excretion of larvae
    • Dawkins HJ, Grove DI, Dunsmore JD Mitchell GF. Strongyloides ratti: susceptibility to infection and resistance to reinfection in inbred strains of mice as assessed by excretion of larvae. Int J Parasitol 1980 10 : 125 129.
    • (1980) Int J Parasitol , vol.10 , pp. 125-129
    • Dawkins, H.J.1    Grove, D.I.2    Dunsmore, J.D.3    Mitchell, G.F.4
  • 12
    • 0019425897 scopus 로고
    • Kinetics of primary and secondary infections with Strongyloides ratti in mice
    • Dawkins HJ Grove DI. Kinetics of primary and secondary infections with Strongyloides ratti in mice. Int J Parasitol 1981 11 : 89 96.
    • (1981) Int J Parasitol , vol.11 , pp. 89-96
    • Dawkins, H.J.1    Grove, D.I.2
  • 13
    • 0020323668 scopus 로고
    • Strongyloides ratti infections in congenitally hypothymic (nude) mice
    • Dawkins HJ, Mitchell GF Grove DI. Strongyloides ratti infections in congenitally hypothymic (nude) mice. Aust J Exp Biol Med Sci 1982 60 : 181 186.
    • (1982) Aust J Exp Biol Med Sci , vol.60 , pp. 181-186
    • Dawkins, H.J.1    Mitchell, G.F.2    Grove, D.I.3
  • 14
    • 0020111286 scopus 로고
    • Attempts to establish infections with Strongyloides stercoralis in mice and other laboratory animals
    • Dawkins HJ Grove DI. Attempts to establish infections with Strongyloides stercoralis in mice and other laboratory animals. J Helminthol 1982 56 : 23 26.
    • (1982) J Helminthol , vol.56 , pp. 23-26
    • Dawkins, H.J.1    Grove, D.I.2
  • 15
    • 0028957574 scopus 로고
    • Strongyloides stercoralis: Protective immunity to third-stage larvae in BALB/cByJ mice
    • Abraham D, Rotman HL, Haberstroh HF, et al. Strongyloides stercoralis: protective immunity to third-stage larvae in BALB/cByJ mice. Exp Parasitol 1995 80 : 297 307.
    • (1995) Exp Parasitol , vol.80 , pp. 297-307
    • Abraham, D.1    Rotman, H.L.2    Haberstroh, H.F.3
  • 17
    • 33749247631 scopus 로고    scopus 로고
    • Role of eosinophils and neutrophils in innate and adaptive protective immunity to larval Strongyloides stercoralis in mice
    • DOI 10.1128/IAI.01958-05
    • Galioto AM, Hess JA, Nolan TJ, Schad GA, Lee JJ Abraham D. Role of eosinophils and neutrophils in innate and adaptive protective immunity to larval Strongyloides stercoralis in mice. Infect Immun 2006 74 : 5730 5738. (Pubitemid 44484558)
    • (2006) Infection and Immunity , vol.74 , Issue.10 , pp. 5730-5738
    • Galioto, A.M.1    Hess, J.A.2    Nolan, T.J.3    Schad, G.A.4    Lee, J.J.5    Abraham, D.6
  • 18
    • 33646054896 scopus 로고    scopus 로고
    • Complement component C3 is required for protective innate and adaptive immunity to larval strongyloides stercoralis in mice
    • Kerepesi LA, Hess JA, Nolan TJ, Schad GA Abraham D. Complement component C3 is required for protective innate and adaptive immunity to larval Strongyloides stercoralis in mice. J Immunol 2006 176 : 4315 4322. (Pubitemid 44264410)
    • (2006) Journal of Immunology , vol.176 , Issue.7 , pp. 4315-4322
    • Kerepesi, L.A.1    Hess, J.A.2    Nolan, T.J.3    Schad, G.A.4    Abraham, D.5
  • 19
    • 0034667902 scopus 로고    scopus 로고
    • Role of IL-5 in innate and adaptive immunity to larval Strongyloides stercoralis in mice
    • Herbert DR, Lee JJ, Lee NA, Nolan TJ, Schad GA Abraham D. Role of IL-5 in innate and adaptive immunity to larval Strongyloides stercoralis in mice. J Immunol 2000 165 : 4544 4551.
    • (2000) J Immunol , vol.165 , pp. 4544-4551
    • Herbert, D.R.1    Lee, J.J.2    Lee, N.A.3    Nolan, T.J.4    Schad, G.A.5    Abraham, D.6
  • 20
    • 0036120465 scopus 로고    scopus 로고
    • The role of B cells in immunity against larval Strongyloides stercoralis in mice
    • DOI 10.1046/j.0141-9838.2001.00441.x
    • Herbert DR, Nolan TJ, Schad GA Abraham D. The role of B cells in immunity against larval Strongyloides stercoralis in mice. Parasite Immunol 2002 24 : 95 101. (Pubitemid 34225278)
    • (2002) Parasite Immunology , vol.24 , Issue.2 , pp. 95-101
    • Herbert, D.R.1    Nolan, T.J.2    Schad, G.A.3    Abraham, D.4
  • 21
    • 39149137531 scopus 로고    scopus 로고
    • Eosinophils act as antigen-presenting cells to induce immunity to Strongyloides stercoralis in mice
    • Padigel UM, Hess JA, Lee JJ, et al. Eosinophils act as antigen-presenting cells to induce immunity to Strongyloides stercoralis in mice. J Infect Dis 2007 196 : 1844 1851.
    • (2007) J Infect Dis , vol.196 , pp. 1844-1851
    • Padigel, U.M.1    Hess, J.A.2    Lee, J.J.3
  • 22
    • 33646914079 scopus 로고    scopus 로고
    • Eosinophils can function as antigen-presenting cells to induce primary and secondary immune responses to Strongyloides stercoralis
    • DOI 10.1128/IAI.02067-05
    • Padigel UM, Lee JJ, Nolan TJ, Schad GA Abraham D. Eosinophils can function as antigen-presenting cells to induce primary and secondary immune responses to Strongyloides stercoralis. Infect Immun 2006 74 : 3232 3238. (Pubitemid 43794511)
    • (2006) Infection and Immunity , vol.74 , Issue.6 , pp. 3232-3238
    • Padigel, U.M.1    Lee, J.J.2    Nolan, T.J.3    Schad, G.A.4    Abraham, D.5
  • 23
    • 0033813166 scopus 로고    scopus 로고
    • The crucial role of granulocytes in the early host defense against Strongyloides ratti infection in mice
    • Watanabe K, Noda K, Hamano S, et al. The crucial role of granulocytes in the early host defense against Strongyloides ratti infection in mice. Parasitol Res 2000 86 : 188 193.
    • (2000) Parasitol Res , vol.86 , pp. 188-193
    • Watanabe, K.1    Noda, K.2    Hamano, S.3
  • 24
    • 0344442866 scopus 로고    scopus 로고
    • Strongyloides ratti: The role of interleukin-5 in protection against tissue migrating larvae and intestinal adult worms
    • DOI 10.1079/JOH2003187
    • Watanabe K, Sasaki O, Hamano S, et al. Strongyloides ratti: the role of interleukin-5 in protection against tissue migrating larvae and intestinal adult worms. J Helminthol 2003 77 : 355 361. (Pubitemid 37463214)
    • (2003) Journal of Helminthology , vol.77 , Issue.4 , pp. 355-361
    • Watanabe, K.1    Sasaki, O.2    Hamano, S.3    Kishihara, K.4    Nomoto, K.5    Tada, I.6    Aoki, Y.7
  • 25
    • 0031732065 scopus 로고    scopus 로고
    • Regulation of primary Strongyloides ratti infections in mice: A role for interleukin-5
    • Ovington KS, McKie K, Matthaei KI, Young IG Behm CA. Regulation of primary Strongyloides ratti infections in mice: a role for interleukin-5. Immunology 1998 95 : 488 493.
    • (1998) Immunology , vol.95 , pp. 488-493
    • Ovington, K.S.1    McKie, K.2    Matthaei, K.I.3    Young, I.G.4    Behm, C.A.5
  • 26
    • 0025765158 scopus 로고
    • The role of interleukin-5 in protective immunity to Strongyloides venezuelensis infection in mice
    • Korenaga M, Hitoshi Y, Yamaguchi N, Sato Y, Takatsu K Tada I. The role of interleukin-5 in protective immunity to Strongyloides venezuelensis infection in mice. Immunology 1991 72 : 502 507.
    • (1991) Immunology , vol.72 , pp. 502-507
    • Korenaga, M.1    Hitoshi, Y.2    Yamaguchi, N.3    Sato, Y.4    Takatsu, K.5    Tada, I.6
  • 27
    • 38149045608 scopus 로고    scopus 로고
    • IL-27 suppresses Th2 cell development and Th2 cytokines production from polarized Th2 cells: A novel therapeutic way for Th2-mediated allergic inflammation
    • Yoshimoto T, Yoshimoto T, Yasuda K, Mizuguchi J Nakanishi K. IL-27 suppresses Th2 cell development and Th2 cytokines production from polarized Th2 cells: a novel therapeutic way for Th2-mediated allergic inflammation. J Immunol 2007 179 : 4415 4423.
    • (2007) J Immunol , vol.179 , pp. 4415-4423
    • Yoshimoto, T.1    Yoshimoto, T.2    Yasuda, K.3    Mizuguchi, J.4    Nakanishi, K.5
  • 28
    • 0022382588 scopus 로고
    • Defective protective capacity of W/W(υ) mice against Strongyloides ratti infection and its reconstitution with bone marrow cells
    • Nawa Y, Kiyota M, Korenaga M Kotani M. Defective protective capacity of W/Wv mice against Strongyloides ratti infection and its reconstitution with bone marrow cells. Parasite Immunol 1985 7 : 429 438. (Pubitemid 16242728)
    • (1985) Parasite Immunology , vol.7 , Issue.4 , pp. 429-438
    • Nawa, Y.1    Kiyota, M.2    Korenaga, M.3    Kotani, M.4
  • 30
    • 0027363412 scopus 로고
    • Intestinal protection against Strongyloides ratti and mastocytosis induced by administration of interleukin-3 in mice
    • Abe T, Sugaya H, Ishida K, Khan WI, Tasdemir I Yoshimura K. Intestinal protection against Strongyloides ratti and mastocytosis induced by administration of interleukin-3 in mice. Immunology 1993 80 : 116 121. (Pubitemid 23284198)
    • (1993) Immunology , vol.80 , Issue.1 , pp. 116-121
    • Abe, T.1    Sugaya, H.2    Ishida, K.3    Khan, W.I.4    Tasdemir, I.5    Yoshimura, K.6
  • 31
    • 24344491927 scopus 로고    scopus 로고
    • IL-18 with IL-2 protects against Strongyloides venezuelensis infection by activating mucosal mast cell-dependent type 2 innate immunity
    • DOI 10.1084/jem.20042202
    • Sasaki Y, Yoshimoto T, Maruyama H, et al. IL-18 with IL-2 protects against Strongyloides venezuelensis infection by activating mucosal mast cell-dependent type 2 innate immunity. J Exp Med 2005 202 : 607 616. (Pubitemid 41248412)
    • (2005) Journal of Experimental Medicine , vol.202 , Issue.5 , pp. 607-616
    • Sasaki, Y.1    Yoshimoto, T.2    Maruyama, H.3    Tegoshi, T.4    Ohta, N.5    Arizono, N.6    Nakanishi, K.7
  • 32
    • 0032485483 scopus 로고    scopus 로고
    • Role for interleukin-3 in mast-cell and basophil development and in immunity to parasites
    • Lantz CS, Boesiger J, Song CH, et al. Role for interleukin-3 in mast-cell and basophil development and in immunity to parasites. Nature 1998 392 : 90 93.
    • (1998) Nature , vol.392 , pp. 90-93
    • Lantz, C.S.1    Boesiger, J.2    Song, C.H.3
  • 33
    • 0034176101 scopus 로고    scopus 로고
    • A role of mast cell glycosaminoglycans for the immunological expulsion of intestinal nematode, Strongyloides venezuelensis
    • Maruyama H, Yabu Y, Yoshida A, Nawa Y Ohta N. A role of mast cell glycosaminoglycans for the immunological expulsion of intestinal nematode, Strongyloides venezuelensis. J Immunol 2000 164 : 3749 3754. (Pubitemid 30169831)
    • (2000) Journal of Immunology , vol.164 , Issue.7 , pp. 3749-3754
    • Maruyama, H.1    Yabu, Y.2    Yoshida, A.3    Nawa, Y.4    Ohta, N.5
  • 34
    • 38449109808 scopus 로고    scopus 로고
    • Strongyloides stercoralis: A model for translational research on parasitic nematode biology (February 17, 2007)
    • doi/10.1895/wormbook.1.134.1. Available at
    • Lok JB. Strongyloides stercoralis: a model for translational research on parasitic nematode biology (February 17, 2007). WormBook, ed. The C. elegans Research Community, WormBook, doi/10.1895/wormbook.1.134.1. Available at http://www.wormbook.org.
    • The C. Elegans Research Community, WormBook
    • Lok, J.B.1
  • 35
    • 0025217835 scopus 로고
    • Strongyloides venezuelensis infections in mice
    • Sato Y Toma H. Strongyloides venezuelensis infections in mice. Int J Parasitol 1990 20 : 57 62.
    • (1990) Int J Parasitol , vol.20 , pp. 57-62
    • Sato, Y.1    Toma, H.2
  • 36
    • 0027249172 scopus 로고
    • Mucosal mast cells and the expulsive mechanisms of mice against Strongyloides venezuelensis
    • Khan AI, Horii Y, Tiuria R, Sato Y Nawa Y. Mucosal mast cells and the expulsive mechanisms of mice against Strongyloides venezuelensis. Int J Parasitol 1993 23 : 551 555.
    • (1993) Int J Parasitol , vol.23 , pp. 551-555
    • Khan, A.I.1    Horii, Y.2    Tiuria, R.3    Sato, Y.4    Nawa, Y.5
  • 37
    • 33747158847 scopus 로고    scopus 로고
    • Expression of IL-4 receptor on non-bone marrow-derived cells is necessary for the timely elimination of Strongyloides venezuelensis in mice, but not for intestinal IL-4 production
    • Negrao-Correa D, Pinho V, Souza DG, et al. Expression of IL-4 receptor on non-bone marrow-derived cells is necessary for the timely elimination of Strongyloides venezuelensis in mice, but not for intestinal IL-4 production. Int J Parasitol 2006 36 : 1185 1195.
    • (2006) Int J Parasitol , vol.36 , pp. 1185-1195
    • Negrao-Correa, D.1    Pinho, V.2    Souza, D.G.3
  • 38
    • 67349198552 scopus 로고    scopus 로고
    • Counterregulation of Th2 immunity by interleukin 12 reduces host defenses against Strongyloides venezuelensis infection
    • Machado ER, Carlos D, Lourenco EV, et al. Counterregulation of Th2 immunity by interleukin 12 reduces host defenses against Strongyloides venezuelensis infection. Microbes Infect 2009 11 : 571 578.
    • (2009) Microbes Infect , vol.11 , pp. 571-578
    • MacHado, E.R.1    Carlos, D.2    Lourenco, E.V.3
  • 39
    • 0035091761 scopus 로고    scopus 로고
    • The effect of interleukin-4 on the induction of intestinal mast cells and chronological cytokine profiles during intestinal nematode Strongyloides ratti infection
    • Watanabe K, Hamano S, Yada S, et al. The effect of interleukin-4 on the induction of intestinal mast cells and chronological cytokine profiles during intestinal nematode Strongyloides ratti infection. Parasitol Res 2001 87 : 149 154.
    • (2001) Parasitol Res , vol.87 , pp. 149-154
    • Watanabe, K.1    Hamano, S.2    Yada, S.3
  • 42
    • 34548703138 scopus 로고    scopus 로고
    • Density-dependent immune responses against the gastrointestinal nematode Strongyloides ratti
    • Bleay C, Wilkes CP, Paterson S Viney ME. Density-dependent immune responses against the gastrointestinal nematode Strongyloides ratti. Int J Parasitol 2007 13 : 1501 1509.
    • (2007) Int J Parasitol , vol.13 , pp. 1501-1509
    • Bleay, C.1    Wilkes, C.P.2    Paterson, S.3    Viney, M.E.4
  • 43
    • 49249138735 scopus 로고    scopus 로고
    • Immunological responses elicited by different infection regimes with Strongyloides ratti
    • Paterson S, Wilkes C, Bleay C Viney ME. Immunological responses elicited by different infection regimes with Strongyloides ratti. PLoS ONE 2008 3 : e2509.
    • (2008) PLoS ONE , vol.3 , pp. 2509
    • Paterson, S.1    Wilkes, C.2    Bleay, C.3    Viney, M.E.4
  • 44
    • 0028579449 scopus 로고
    • Low-level infection with Trichuris muris significantly affects the polarization of the CD4 response
    • Bancroft AJ, Else KJ Grencis RK. Low-level infection with Trichuris muris significantly affects the polarization of the CD4 response. Eur J Immunol 1994 24 : 3113 3118.
    • (1994) Eur J Immunol , vol.24 , pp. 3113-3118
    • Bancroft, A.J.1    Else, K.J.2    Grencis, R.K.3
  • 45
    • 0019782632 scopus 로고
    • Effects of prednisolone on murine strongyloidiasis
    • Grove DI Dawkins HJ. Effects of prednisolone on murine strongyloidiasis. Parasitology 1981 83 : 401 409.
    • (1981) Parasitology , vol.83 , pp. 401-409
    • Grove, D.I.1    Dawkins, H.J.2
  • 46
    • 0025931870 scopus 로고
    • Antibody responses and protective immunity in rats receiving repeated inoculations of Strongyloides ratti
    • Uchikawa R, Ichiki H Komaki E. Antibody responses and protective immunity in rats receiving repeated inoculations of Strongyloides ratti. J Parasitol 1991 77 : 737 741.
    • (1991) J Parasitol , vol.77 , pp. 737-741
    • Uchikawa, R.1    Ichiki, H.2    Komaki, E.3
  • 48
    • 85047692430 scopus 로고    scopus 로고
    • IL-10-producing and naturally occurring CD4+ Tregs: Limiting collateral damage
    • O'Garra A, Vieira PL, Vieira P Goldfeld AE. IL-10-producing and naturally occurring CD4+ Tregs: limiting collateral damage. J Clin Invest 2004 114 : 1372 1378.
    • (2004) J Clin Invest , vol.114 , pp. 1372-1378
    • O'Garra, A.1    Vieira, P.L.2    Vieira, P.3    Goldfeld, A.E.4
  • 51
    • 42949155819 scopus 로고    scopus 로고
    • Functional analysis of effector and regulatory T cells in a parasitic nematode infection
    • Rausch S, Huehn J, Kirchhoff D, et al. Functional analysis of effector and regulatory T cells in a parasitic nematode infection. Infect Immun 2008 76 : 1908 1919.
    • (2008) Infect Immun , vol.76 , pp. 1908-1919
    • Rausch, S.1    Huehn, J.2    Kirchhoff, D.3
  • 52
    • 34447575642 scopus 로고    scopus 로고
    • Expansion and activation of CD4(+)CD25(+) regulatory T cells in Heligmosomoides polygyrus infection
    • Finney CA, Taylor MD, Wilson MS Maizels RM. Expansion and activation of CD4(+)CD25(+) regulatory T cells in Heligmosomoides polygyrus infection. Eur J Immunol 2007 37 : 1874 1886.
    • (2007) Eur J Immunol , vol.37 , pp. 1874-1886
    • Finney, C.A.1    Taylor, M.D.2    Wilson, M.S.3    Maizels, R.M.4
  • 53
    • 34548488741 scopus 로고    scopus 로고
    • Heligmosomoides polygyrus promotes regulatory T-cell cytokine production in the murine normal distal intestine
    • Setiawan T, Metwali A, Blum AM, et al. Heligmosomoides polygyrus promotes regulatory T-cell cytokine production in the murine normal distal intestine. Infect Immun 2007 75 : 4655 4663.
    • (2007) Infect Immun , vol.75 , pp. 4655-4663
    • Setiawan, T.1    Metwali, A.2    Blum, A.M.3
  • 54
    • 53149119570 scopus 로고    scopus 로고
    • Colonization with Heligmosomoides polygyrus suppresses mucosal IL-17 production
    • Elliott DE, Metwali A, Leung J, et al. Colonization with Heligmosomoides polygyrus suppresses mucosal IL-17 production. J Immunol 2008 181 : 2414 2419.
    • (2008) J Immunol , vol.181 , pp. 2414-2419
    • Elliott, D.E.1    Metwali, A.2    Leung, J.3


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.