[ti:Flu Virus Disarms Immune System's First Responders] [ar:Milagros Ardin] [al:Health Report] [by:www.51voa.com] [00:00.00]From VOA Learning English, [00:02.67]this is the Health Report. [00:06.19]Infection by the influenza virus may be [00:10.36]more complex than scientists first thought. [00:14.57]Researchers in the United States reported recently [00:19.09]that the virus appears to disarm [00:22.11]the body's first line of defense against disease. [00:27.08]When the flu virus attacks, [00:29.15]the body's natural defenses produce white blood cells. [00:34.91]The cells make antibodies design to linkup [00:39.77]to the invading microorganism, neutralize it, [00:44.49]and in that way, prevent or at least lessen infection. [00:51.36]The special cells also keep a memory of the invader [00:56.68]so that the natural defenses can fight it again [01:01.35]if the individual is re-infected. [01:05.41]That is the traditional understanding of [01:08.49]how the body fights the flu virus. [01:12.82]Now, biologists have discovered how the virus [01:17.24]can disarm those white blood cells, known as B cells. [01:22.73]Hidde Ploegh led the team of researchers, [01:25.93]he is with the Whitehead Institute [01:29.13]for Biomedical Research in Cambridge, Massachusetts. [01:33.89]Studies with genetically-bred mice suggest [01:38.01]the flu virus enters the B cells [01:41.53]and interferes with the production of antibodies, [01:46.49]this can kill the cells and the body's first line of defense. [01:53.31]If true, says Mr Ploegh, the process of infection [01:58.34]may be more complex than scientists have thought. [02:03.26]"And so we think that this really provides a new window [02:06.37]on how the virus goes about its business. [02:08.53]It may have implications in terms of explaining [02:11.65]why certain strains of flu cause a nastier version [02:15.42]of the disease than others," said Ploegh. [02:16.88]Normally, the frontline antibodies [02:19.79]occupy lung cells to protect the body [02:23.85]against future viral invasion through breathing. [02:28.47]But the flu virus having disabled the antibodies, [02:33.13]may instead target lung cells. [02:36.56]In that way, the virus blocks the antibody's ability [02:41.39]to remember the deadly invader, and labeling the virus [02:46.91]to launch an attack on the body's defenses. [02:50.77]"So this suggests that the initial encounter [02:53.99]of the very type of white blood cell [02:56.39]that we think defends us against the virus [02:58.85]may be taken out by this initial wave of infection," said Ploegh. [03:01.92]By neutralizing an interfering with the body's 'front line troops', [03:07.85]Mr Ploegh says the flu virus has more time [03:12.46]to reproduce and establish itself in the cells, [03:17.49]that keeps the immune system [03:19.78]from developing a second line of defense. [03:23.66]A report on how influenza overcomes the body's immune system [03:28.69]was published in the journal Nature. [03:32.01]And that's the Health Report from VOA Learning English. [03:36.19]You can read, listen and learn English [03:40.09]with health news and more on our website 51voa.com. [03:48.39]You can also watch our captioned videos [03:51.70]at the VOA Learning English channel on YouTube. [03:56.62]I'm Milagros Ardin. [03:58.72]¸ü¶àÌýÁ¦Çë·ÃÎÊ51voa.com