小鼠在被蜜蜂叮咬后，对毒液产生过敏反应，而在这之后对其注射致命剂量的毒液，小鼠更有可能会活下来。这些发现说明过敏对小鼠是有益的，并揭示了反应中的一些分子机制，不过专家表示，过敏对人类的影响尚不清楚。

在人类和其他哺乳动物中，免疫系统会对抗那些不熟悉的以及有潜在危害性的物质，比如病毒或者毒素。消灭病毒、细菌和其他微生物时发生的反应被称为类型1。类型2反应则是通过一系列的症状——包括打喷嚏、咳嗽和腹泻——将过敏物质排出体外。

为了探索类型2反应的影响及其存在的潜在好处，美国斯坦福大学医学院病理学家Stephen Galli和同事将小鼠暴露在一种常见的过敏原中，即蜜蜂毒液。

实验表明，类型2反应可能已经进化到可以保护小鼠免于毒液和寄生虫的伤害。近日，该团队将报告发表在《免疫学》期刊上。Galli称，这种防御机制也许帮助人类在富有挑战的环境中生存下来。

“这是非常引人注目的杰出研究。”马里兰州约翰·霍普金斯大学的免疫遗传学家Kathleen Barnes称，“不过，我们需要小心地将这些发现应用在人类身上。”

生物谷推荐的英文摘要



Immunity   10.1016/j.immuni.2013.10.005

A Beneficial Role for Immunoglobulin E in Host Defense against Honeybee Venom

Thomas Marichal, Philipp Starkl, Laurent L. Reber, Janet Kalesnikoff, Hans C. Oettgen, Mindy Tsai, Martin Metz, Stephen J. Galli

Allergies are widely considered to be misdirected type 2 immune responses, in which immunoglobulin E (IgE) antibodies are produced against any of a broad range of seemingly harmless antigens. However, components of insect venoms also can sensitize individuals to develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. We found that mice injected with amounts of honeybee venom similar to that which could be delivered in one or two stings developed a specific type 2 immune response that increased their resistance to subsequent challenge with potentially lethal amounts of the venom. Our data indicate that IgE antibodies and the high affinity IgE receptor, FcεRI, were essential for such acquired resistance to honeybee venom. The evidence that IgE-dependent immune responses against venom can enhance survival in mice supports the hypothesis that IgE, which also contributes to allergic disorders, has an important function in protection of the host against noxious substances.