Korean J Parasitol.  2011 Sep;49(3):303-308. 10.3347/kjp.2011.49.3.303.

Resistance to Toxoplasma gondii Infection in Mice Treated with Silk Protein by Enhanced Immune Responses

• Moon JH
• Pyo KH
• Jung BK
• Chun HS
• Chai JY
• Shin EH

• KMID: 1715657
• DOI: http://doi.org/10.3347/kjp.2011.49.3.303

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-gamma, 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.

Keyword

Toxoplasma gondii; cellular immunity; silk protein; resistance; immunosuppression

MeSH Terms

Animals
Bombyx/*chemistry
CD4-CD8 Ratio
Cell Proliferation
Cells, Cultured
Cytokines/secretion
Insect Proteins/*immunology
Leukocytes, Mononuclear/immunology
Male
Mice
Mice, Inbred BALB C
Silk/immunology
Spleen/immunology
Survival Analysis
Toxoplasma/*immunology/pathogenicity
Toxoplasmosis, Animal/immunology/*prevention & control