期刊
INFECTION AND IMMUNITY
卷 75, 期 11, 页码 5200-5209出版社
AMER SOC MICROBIOLOGY
DOI: 10.1128/IAI.00954-07
关键词
-
资金
- NIAID NIH HHS [AI028724, AI42334, AI062789, R37 AI028724, R01 AI042334, R01 AI062789] Funding Source: Medline
Challenge with the intracellular protozoan parasite Toxoplasma gondii induces a potent CD8(+) T-cell response that is required for resistance to infection, but many questions remain about the factors that regulate the presentation of major histocompatibility complex class I (MHC-I) -restricted parasite antigens and about the role of professional and nonprofessional accessory cells. In order to address these issues, transgenic parasites expressing ovalbumin (OVA), reagents that track OVA/MHC-I presentation, and OVA-specific CD8(+) T cells were exploited to compare the abilities of different infected cell types to stimulate CD8(+) T cells and to define the factors that contribute to antigen processing. These studies reveal that a variety of infected cell types, including hematopoietic and nonhematopoietic cells, are capable of activating an OVA-specific CD8(+) T-cell hybridoma, and that this phenomenon is dependent on the transporter associated with antigen processing and requires live T. gondii. Several experimental approaches indicate that T-cell activation is a consequence of direct presentation by infected host cells rather than cross-presentation. Surprisingly, nonprofessional antigen-presenting cells (APCs) were at least as efficient as dendritic cells at activating this MHC-I-restricted response. Studies to assess whether these cells are involved in initiation of the CD8(+) T-cell response to T. gondii in vivo show that chimeric mice expressing MHC-I only in nonhematopoietic compartments are able to activate OVA-specific CD8(+) T cells upon challenge. These findings associate nonprofessional APCs with the initial activation of CD8(+) T cells during toxoplasmosis.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据