艾滋病病毒 z-bo 2020-09-19 374

　　HIV is the most studied virus in the world, but this discovery still surprises us. It turns out that this virus can pump directly from one cell to another through the main junction between two cells, infecting and killing immune cells.

　　Until recently, we still believed that HIV mainly circulates in the blood, infecting and destroying important immune cells called CD4 T cells. According to this classic model, a virus infects T cells, it changes the cell mechanism, replicates thousands of individuals into the bloodstream, and ultimately consumes and kills the host cell.

　　This kind of thinking is based on the way of studying viruses with blood, which is a relatively easy method. New research methods show that this is only part of the story. The Nagrini team at the University of California, San Francisco, using tissue culture methods, studies have shown that in fact a large number of viruses are often pumped directly from one CD4 T cell to another. And it seems that this process kills the vast majority of CD4 cells-not a single virus infection.

　　blocking transmission

　　HIV invades neighboring cells by changing the cell system. Immune synapses are short-term connections between immune cells that allow them to transmit chemical messages. HIV usually flows from one infected CD4 cell to another uninfected cell.

　　There is evidence that this process is hundreds, or even thousands, times more effective than the traditional model of external infection. Greene said that 95% of the CD4 cells that died during the process they studied were infected this way, not by a single virus.

　　This new cognition opens up new ways to fight the virus, and it will also affect the way we choose drugs to treat diseases. Walter of Yale University has been studying the cell-to-cell transmission of HIV. He said that although most antiretroviral drugs are effective for both types of infection, they are more efficient for the virus to enter cells directly. These drugs can be overwhelming and make them less effective.

　　But this discovery may open the way for new treatment options. HIV in monkeys can also spread directly from cell to cell, but monkeys can tolerate this process.

　　Unlike humans, monkeys' CD4 cells can survive a large number of viruses. Greene believes that they have mutated to avoid self-destruction. He hopes that anti-inflammatory drugs can be used to mimic human CD4 cells. At the laboratory stage, a potential drug candidate, VX-765, looks promising.

　　looking for a vaccine

　　Kenneth Meyer of the Fenway Institute in Boston said that a better understanding of how the virus spreads directly between cells may be an important part of the AIDS puzzle. He said that ignoring this mode of transmission may at least partially explain the failure of recent vaccine research.

　　The HIV vaccine allows the body to fight the virus by producing antibodies. However, studies have shown that different types of antibodies are needed to kill viruses, and they can only kill viruses in cells, which float freely in the body. The virus hidden in the cell may be easier to evade destruction, or it may be found to be easier to evolve antibodies against vaccines.

　　Carl Dieffenbacher of the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, said that to better understand how to prevent cell infections, we need better vaccine candidates. He said: "Will the vaccine be ineffective against cell-to-cell transmission? We don't know the answer, because we don't have a safe, effective and durable HIV vaccine to understand the exact mechanism."