IN VIVO EFFECTS OF BACTERIAL SUPERANTIGENS

细菌超抗原在体内具有深远的作用，并已被 与中毒性休克综合征等人类疾病有关，成人 呼吸窘迫综合征(ARDS)和自身免疫性疾病。此外, 分泌超抗原的金黄色葡萄球菌菌株已经被 与流感病毒导致的意外死亡有关。一只小鼠 已经开发了模型来研究细菌之间的相互作用 超抗原、葡萄球菌肠毒素B(SEB)与流感感染。 将SEB注射到正常小鼠体内有许多效果，包括 携带相关T细胞受体(TCR)Vbeta的T细胞的激活 元素、非特异性免疫抑制、无能、细胞凋亡和大量 T细胞和MHC II+递呈细胞分泌细胞因子。 尽管在体内有这些戏剧性的作用，但细菌超抗原并不是 对老鼠来说是致命的。而小鼠注射SEB后7天无明显变化。 致命的流感病毒感染会导致迅速死亡。 这里提出的实验是为了了解病毒的作用 使小鼠对SEB的致死作用敏感的感染，以及在 更广泛的意义，以确定超抗原对并发 对传染性病毒的免疫反应。这具有临床意义， 因为继发性细菌感染通常与病毒有关 会导致呼吸道的病理改变。

Bacterial superantigens have profound in vivo effects and have been implicated in human diseases such as toxic shock syndrome, adult respiratory distress syndrome (ARDS), and autoimmune disease. In addition, superantigen-secreting strains of Staphylococcus aureus have been associated with unexpected death resulting from influenza virus. A murine model has been developed to study the interplay between the bacterial superantigen, Staphylococcus enterotoxin B (SEB) and influenza infection. Injection of SEB into normal mice has numerous effects, including activation of T cells bearing the relevant T cell receptor (TCR) Vbeta elements, non-specific immune suppression, anergy, apoptosis, and massive cytokine secretion, both by T cells and MHC class II+ presenting cells. Despite these dramatic in vivo effects, bacterial superantigens are not lethal in mice. However, injection of SEB into mice 7 days after non- lethal infection with influenza virus results in the rapid onset of death. The experiments proposed here are designed to understand the role of viral infection in sensitizing mice to the lethal effects of SEB, and, in a broader sense, to determine the effects of superantigen on a concurrent immune response to infectious virus. This is of clinical relevance, because secondary bacterial infections are commonly associated with viruses that cause pathology in the respiratory tract.