母乳灭活丙型肝炎病毒的感染性

StephenW

Inactivation of Hepatitis C Virus Infectivity by Human Breast Milk

    Stephanie Pfaender1,
    Julia Heyden1,
    Martina Friesland1,
    Sandra Ciesek2,
    Asim Ejaz3,
    Joerg Steinmann4,
    Jochen Steinmann5,
    Angelika Malarski6,
    Heribert Stoiber3,
    Georgios Tsiavaliaris7,
    Werner Bader8,
    Gerhard Jahreis6,
    Thomas Pietschmann1 and
    Eike Steinmann1

+ Author Affiliations

    1Institute for Experimental Virology, TWINCORE Centre for Experimental and Clinical Infection Research; a joint venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Feodor-Lynen-Str. 7, Hannover 30625, Germany
    2Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Germany
    3Institute of Virology, Medical University, Innsbruck
    4Institute of Medical Microbiology, University Hospital Essen, Essen, Germany
    5MikroLab GmbH, Bremen, Germany
    6Department of Nutritional Physiology, Institute of Nutrition, Friedrich Schiller University, Jena, Germany
    7Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
    8KRH Klinikum Nordstadt Frauenklinik, Hannover, Germany

    Correspondence: PD Dr Eike Steinmann, Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research; a joint venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Feodor-Lynen-Str 7, 30625 Hannover, Germany ([email protected]).

Abstract

Background. Hepatitis C virus (HCV) is spread through direct contact with blood, although alternative routes of transmission may contribute to the global burden. Perinatal infection occurs in up to 5% of HCV-infected mothers, and presence of HCV RNA in breast milk has been reported. We investigated the influence of breast milk on HCV infectiousness.

Methods/Results. Human breast milk reduced HCV infectivity in a dose-dependent manner. This effect was species-specific because milk from various animals did not inhibit HCV infection. Treatment of HCV with human breast milk did not compromise integrity of viral RNA or capsids but destroyed the lipid envelope. Fractionation of breast milk revealed that the antiviral activity is present in the cream fraction containing the fat. Proteolytic digestion of milk proteins had no influence on its antiviral activity, whereas prolonged storage at 4°C increased antiviral activity. Notably, pretreatment with a lipase inhibitor ablated the antiviral activity and specific free fatty acids of breast milk were antiviral.

Conclusions. The antiviral activity of breast milk is linked to endogenous lipase-dependent generation of free fatty acids, which destroy the viral lipid envelope. Therefore, nursing by HCV-positive mothers is unlikely to play a major role in vertical transmission.

StephenW

背景。丙型肝炎病毒（HCV）的传播是通过直接接触血液，虽然其他的传播途径可能造成的全球负担。围产期感染发生在高达5 ％的丙型肝炎病毒感染的母亲，母乳中存在HCV RNA的报道。我们调查的影响母乳对丙型肝炎病毒的传染性。

方法/结果。人类母乳减少丙型肝炎病毒的传染性在剂量依赖性。这种作用是牛奶由各种动物种属特异性的，因为没有抑制丙型肝炎病毒感染。治疗丙型肝炎病毒与人类母乳没有损害病毒RNA的衣壳，但破坏脂质包膜的完整性。分馏的母乳中发现的抗病毒活性是存在于含有脂肪的奶油分数。乳蛋白的蛋白水解消化不影响其抗病毒活性，在4℃下长时间存储而增加的抗病毒活性。值得注意的是，前处理用的脂肪酶抑制剂烧蚀的抗病毒活性，抗病毒和特定的游离脂肪酸母乳。

结论。母乳中的抗病毒活性与脂肪酶依赖内源性产生的游离脂肪酸，破坏病毒的脂质包膜。因此， HCV阳性母亲哺乳是不可能垂直传播中发挥了重要作用。