2020年のノーベル医学生理学賞は、慢性Ｃ型肝炎の研究者に贈られ、ハービー・アルター氏（米ロチェスター大学）、チャールズ・ライス氏（米ロックフェラー大学）、マイケル・ホートン氏（カナダ アルバーター大学）の３人に授与されることになりました。
目次
ノーベル医学生理学賞受賞者の発表
The Nobel Assembly at Karolinska Institutet has today decided to award the 2020 Nobel Prize in Physiology or Medicine jointly to Harvey J. Alter, Michael Houghton and Charles M. Rice for the discovery of Hepatitis C virus (nobelprizemedicine.org)
ノーベル賞受賞理由: C型肝炎ウイルスの発見
Harvey J. Alter, Michael Houghton and Charles M. Rice made seminal discoveries that led to the identification of a novel virus, Hepatitis C virus. Prior to their work, the discovery of the Hepatitis A and B viruses had been critical steps forward, but the majority of blood-borne hepatitis cases remained unexplained. The discovery of Hepatitis C virus revealed the cause of the remaining cases of chronic hepatitis and made possible blood tests and new medicines that have saved millions of lives. (pm_eng_FINAL_2020.pdf)
肝炎を引き起こすウイルスの種類
There are two main forms of hepatitis. One form is an acute disease caused by Hepatitis A virus that is transmitted by contaminated water or food. The other form is caused by Hepatitis B virus or Hepatitis C virus (this year’s Nobel Prize). This form of blood-borne hepatitis is often a chronic disease that may progress to cirrhosis and hepatocellular carcinoma. (pm_eng_FINAL_2020.pdf)
非A型、非B型肝炎ウイルスの存在を示したハービー・アルターの研究
At that time, Harvey J. Alter at the US National Institutes of Health was studying the occurrence of hepatitis in patients who had received blood transfusions. Although blood tests for the newly-discovered Hepatitis B virus reduced the number of cases of transfusion-related hepatitis, Alter and colleagues worryingly demonstrated that a large number of cases remained. Tests for Hepatitis A virus infection were also developed around this time, and it became clear that Hepatitis A was not the cause of these unexplained cases. It was a great source of concern that a significant number of those receiving blood transfusions developed chronic hepatitis due to an unknown infectious agent. Alter and his colleagues showed that blood from these hepatitis patients could transmit the disease to chimpanzees, the only susceptible host besides humans. Subsequent studies also demonstrated that the unknown infectious agent had the characteristics of a virus. Alter’s methodical investigations had in this way defined a new, distinct form of chronic viral hepatitis. The mysterious illness became known as “non-A, non-B” hepatitis. (pm_eng_FINAL_2020.pdf)
C型肝炎ウイルスを発見したマイケル・ホートンの実験:未知のウイルスのゲノム断片の同定
Michael Houghton, working for the pharmaceutical firm Chiron, undertook the arduous work needed to isolate the genetic sequence of the virus. Houghton and his co-workers created a collection of DNA fragments from nucleic acids found in the blood of an infected chimpanzee. The majority of these fragments came from the genome of the chimpanzee itself, but the researchers predicted that some would be derived from the unknown virus. On the assumption that antibodies against the virus would be present in blood taken from hepatitis patients, the investigators used patient sera to identify cloned viral DNA fragments encoding viral proteins. Following a comprehensive search, one positive clone was found. (pm_eng_FINAL_2020.pdf)
C型肝炎ウイルスが実際に肝炎の原因となることを証明したチャールズ・ライスの実験
Charles M. Rice, a researcher at Washington University in St. Louis, along with other groups working with RNA viruses, noted a previously uncharacterized region in the end of the Hepatitis C virus genome that they suspected could be important for virus replication. Rice also observed genetic variations in isolated virus samples and hypothesized that some of them might hinder virus replication. Through genetic engineering, Rice generated an RNA variant of Hepatitis C virus that included the newly defined region of the viral genome and was devoid of the inactivating genetic variations. When this RNA was injected into the liver of chimpanzees, virus was detected in the blood and pathological changes resembling those seen in humans with the chronic disease were observed. (pm_eng_FINAL_2020.pdf)
2020年ノーベル賞受賞者予想サイト
- 3年連続受賞なるか 日本の注目候補は？（日本経済新聞）