医学部を目指し、Natureなど科学・医学記事を英語で読む

Nature WEB FOCUS---2

1月24日の投稿で紹介した「概要」とかさなるところが多いが、以下も文でも1918年のスペイン風邪のウイルスの特徴が推測されている。ここに書かれている「特徴」を簡単にまとめてみましょう。

The work of Kobasa et al. substantiates the findings of Kash et al., who showed in mice that the 1918 virus triggered a vigorous innate immune response that was linked to fatalities. Although the mechanisms of tissue destruction were not addressed in either study, the work clearly demonstrates the vital function of early innate immune defences in controlling the virus. It seems that the pandemic 1918 virus had a genetic composition and rapid replication kinetics that may have resulted in an excessively vigorous innate immune and inflammatory response that contributed to severe tissue damage, disease and death.
These conclusions correspond to the striking epidemiological data showing that, unlike contemporary influenza strains, which typically affect the very young and the elderly most severely, the 1918 influenza pandemic was mostly fatal in young adults, who generally possess more robust immune systems. Unveiling the contribution of an aberrant host response to the pathogenesis of the 1918 virus is just the beginning of efforts to understand the disease mechanisms underlying the 1918 pandemic and new virulent strains of influenza virus. The emergence of the H5N1 avian influenza or 'bird flu' virus, and its transfer to the human population, are real and continuing threats1 that underscore the importance of the current study and of characterizing highly pathogenic forms of flu virus. A better understanding of the origin, transmission and virulence of pandemic influenza viruses, and their interactions with host immune processes, will assist our preparation against future and possibly deadly influenza pandemics.
[from"Influenza: Fatal immunity and the 1918 virus"(Nature,18 January 2007)]

Nature WEB FOCUS 1918 influenza pandemic

Nature WEB FOCUS 1918 influenza pandemic

以下のサイトに目次があります。ただし、記事自体は購読が必要です。（学士編入指導ではいくつかピックアップして指導しています。）
http://www.natureasia.com/japan/focus/1918flu/index.php
最新記事では、
NEWS
Concern as revived 1918 flu virus kills monkeys
が読みやすいです。

以下は、Letterの概要です。
The 1918 influenza pandemic was unusually severe, resulting in about 50 million deaths worldwide1. The 1918 virus is also highly pathogenic in mice, and studies have identified a multigenic origin of this virulent phenotype in mice2, 3, 4. However, these initial characterizations of the 1918 virus did not address the question of its pathogenic potential in primates. Here we demonstrate that the 1918 virus caused a highly pathogenic respiratory infection in a cynomolgus macaque model that culminated in acute respiratory distress and a fatal outcome. Furthermore, infected animals mounted an immune response, characterized by dysregulation of the antiviral response, that was insufficient for protection, indicating that atypical host innate immune responses may contribute to lethality. The ability of influenza viruses to modulate host immune responses, such as that demonstrated for the avian H5N1 influenza viruses5, may be a feature shared by the virulent influenza viruses.

1918年に大流行したスペイン風邪は非常に大きな被害を及ぼし、世界中でおよそ5000万人が死亡した。1918年のウイルスはマウスにおいても非常に病原性が強く、マウスでの病原性発現にはいくつかのウイルス遺伝子が関与していることが明らかになっている。しかし、これまで1918年のウイルスの霊長類における病原性については不明であった。本論文では、1918年のウイルスが、カニクイザルで非常に重篤な呼吸器感染を引き起こし、致死的な急性呼吸窮迫症の誘因となったことを明らかにする。感染した動物では、抗ウイルス応答の調節異常が認められ、感染防御には至らない免疫応答の高進が観察された。このことは、宿主の自然免疫応答の異常が感染個体の致死に影響を及ぼした可能性を示している。H5N1鳥インフルエンザウイルスで示されているように、インフルエンザウイルスが宿主の免疫応答に影響を与える能力は、高病原性インフルエンザウイルスに共通の特徴である可能性がある。

Aberrant innate immune response in lethal infection of macaques with the 1918 influenza virus