title: Resistance to Toxoplasma gondii infection in mice treated with silk protein by enhanced immune responses.
abstract: This study investigated whether elevated host immune capacity can inhibit T. gondii infection. For this purpose, we used silk protein extracted from Bombyx mori cocoons as a natural supplement to augment immune capacity. After silk protein administration to BALB/c mice for 6 weeks, ratios of T lymphocytes (CD4(+) and CD8(+) T-cells) and splenocyte proliferative capacities in response to Con A or T. gondii lysate antigen (TLA) were increased. Of various cytokines, which regulate immune systems, Th1 cytokines, such as IFN-γ, IL-2, and IL-12, were obviously increased in splenocyte primary cell cultures. Furthermore, the survival of T. gondii (RH strain)-infected mice increased from 2 days to 5 or more days. In a state of immunosuppression induced by methylprednisolone acetate, silk protein-administered mice were resistant to reduction in T-lymphocyte (CD4(+) and CD8(+) T-cells) numbers and the splenocyte proliferative capacity induced by Con A or TLA with a statistical significance. Taken together, our results suggest that silk protein augments immune capacity in mice and the increased cellular immunity by silk protein administration increases host protection against acute T. gondii infection.
authors.affiliation: Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University Medical Research Center, Seoul 110-799, Korea.
authors.forename: Joung-Ho
authors.initials: JH
authors.lastname: Moon
authors.forename: Kyoung-Ho
authors.initials: KH
authors.lastname: Pyo
authors.forename: Bong-Kwang
authors.initials: BK
authors.lastname: Jung
authors.forename: Hyang Sook
authors.initials: HS
authors.lastname: Chun
authors.forename: Jong-Yil
authors.initials: JY
authors.lastname: Chai
authors.forename: Eun-Hee
authors.initials: EH
authors.lastname: Shin
mesh_terms: D000818:Animals; D012831:Bombyx / Q000737:chemistry*; D016516:CD4-CD8 Ratio; D049109:Cell Proliferation; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D019476:Insect Proteins / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D047011:Silk / Q000276:immunology; D013154:Spleen / Q000276:immunology; D016019:Survival Analysis; D014122:Toxoplasma / Q000276:immunology* / Q000472:pathogenicity; D014124:Toxoplasmosis, Animal / Q000276:immunology / Q000517:prevention & control*
chemical_list: D016207:Cytokines; D019476:Insect Proteins; D047011:Silk
references.citation: Biomaterials. 2003 Feb;24(3):401-16
references.pmid: 12423595
references.citation: Am J Vet Res. 2008 Sep;69(9):1123-8
references.pmid: 18764681
references.citation: J Interferon Cytokine Res. 2006 Jul;26(7):489-99
references.pmid: 16800788
references.citation: Cell Microbiol. 2003 Nov;5(11):755-60
references.pmid: 14531891
references.citation: Blood. 2003 Jan 15;101(2):585-93
references.pmid: 12393559
references.citation: Nutr Res. 2010 Nov;30(11):783-90
references.pmid: 21130298
references.citation: Infect Immun. 2002 Feb;70(2):434-43
references.pmid: 11796568
references.citation: J Immunol. 2009 Dec 1;183(11):6883-92
references.pmid: 19923474
references.citation: Korean J Parasitol. 2008 Mar;46(1):45-8
references.pmid: 18344678
references.citation: Immunol Lett. 1992 Jun;33(1):41-6
references.pmid: 1427989
references.citation: Alcohol Alcohol. 2008 May-Jun;43(3):246-53
references.pmid: 18263900
references.citation: J Immunol. 2001 Oct 15;167(8):4574-84
references.pmid: 11591786
references.citation: Vet Parasitol. 2006 Oct 10;141(1-2):66-83
references.pmid: 16757117
references.citation: Korean J Parasitol. 2003 Sep;41(3):147-54
references.pmid: 12972728
references.citation: Biosci Biotechnol Biochem. 2008 Dec;72(12):3189-96
references.pmid: 19060395
references.citation: Korean J Parasitol. 2011 Jun;49(2):115-23
references.pmid: 21738266
references.citation: Int Immunopharmacol. 2009 Jul;9(7-8):931-6
references.pmid: 19348966
references.citation: Immunol Lett. 2003 Oct 9;89(1):9-15
references.pmid: 12946859
references.citation: J Cosmet Dermatol. 2005 Dec;4(4):250-7
references.pmid: 17168872
references.citation: Am J Clin Nutr. 2010 Apr;91(4):940-9
references.pmid: 20200256
references.citation: Korean J Parasitol. 2010 Jun;48(2):171-4
references.pmid: 20585536
references.citation: Int J Parasitol. 2003 May;33(5-6):469-78
references.pmid: 12782048
references.citation: Biosci Biotechnol Biochem. 2003 Apr;67(4):729-35
references.pmid: 12784611
references.citation: J Parasitol. 2007 Oct;93(5):1036-45
references.pmid: 18163337
references.citation: Vet Parasitol. 2007 Oct 21;149(1-2):77-84
references.pmid: 17719178
references.citation: J Immunol. 2007 Jun 1;178(11):7211-21
references.pmid: 17513770
references.citation: Mem Inst Oswaldo Cruz. 2009 Mar;104(2):201-10
references.pmid: 19430645