Scientists Design Assassin Immune Cells to Kill HIV-Infected Cells

By Nina Bai | November 10, 2008 6:36 pm

t-cellScientists say they have bred super immune cells that are able to recognize and destroy many variants of HIV-infected cells. The news comes after a bleak year for AIDS research that saw the failure of the Merck HIV vaccine trial and the cancellation of another. “I think the field as a whole has been taking a step back and thinking we need some different ideas all together,” [New Scientist] said immunologist Philip Goulder.

The researchers’ novel idea was to create a mutant type of immune cells, called T-cells, that would target SL9, a protein that is part of HIV and also appears on the surface of HIV-infected cells. They started with particularly strong T-cells taken from a patient who had resisted HIV infection. “When we tested the T cells from this patient, it looked as if he was responding to a number of those variants that normally escape the immune system,” [The Guardian] said researcher Brent Jakobsen. Through a process of directed evolution, the researchers selected for T-cell mutants that had receptors enhanced to recognize and latch onto SL9. In Nature Medicine [subscription required], the researchers report that in lab cultures of human cells, the souped-up T-cells easily destroyed HIV-infected cells and even recognized tricky variants of the SLP9 protein.

One reason HIV has been able to skirt our immune systems, drugs and vaccines is the virus’s chameleon-like behaviour – thanks to a genome that mutates with ease, HIV can quickly change guise to evade an attack. But some parts of HIV are so vital to its functioning that changes result in dead or severely compromised viruses [New Scientist]; the SL9 protein is one of these essential parts of HIV’s anatomy.

If the new and improved immune cell fighters don’t kill the virus outright, they could still have a beneficial impact. “In the face of our engineered assassin cells, the virus will either die or be forced to change its disguises again, weakening itself along the way,” [BBC News] said researcher Andy Sewell. Billions of these elite assassin T-cell could reportedly be created in just two weeks.

Next, the researchers will test the T-cells in mice engineered to produce human immune cells and infected with HIV. They hope to begin trials in human patients as soon as next year. Treating patients will involve taking a blood sample and adding an engineered virus containing genes for the improved T cell receptor. The patient’s own T cells then take up the genes and so are equipped with the improved receptor. These cells are then injected back into the patient [The Guardian]. There are caveats: One is that the assassin T-cells may be too specific and not recognize variants of SL9 that exist in different human races. Another is that they may not be specific enough and could attack other proteins, including human proteins.

Related Content:
80beats: HIV Vaccine Trial Canceled in a Setback for AIDS Research
DISCOVER: Immune to a Plague

Image: iStockphoto

CATEGORIZED UNDER: Health & Medicine
  • http://imonly10idonthaveone Grace

    that is so cool! assassin cells that could kill off HIV viruses would really help and change the world. could there be a way that scientists could “train” the assassin cells to ignore human proiens? just a thought. here’s another project. could scientists create another asassin cell to kill off AIDs? could the assassin cell used to kill off HIV also be used to kill AIDs?

  • assassin

    “could scientists create another asassin cell to kill off AIDs? could the assassin cell used to kill off HIV also be used to kill AIDs?”

    If HIV is the direct cause of AID’s, then expect that eliminating the direct cause eliminates anything that it causes. The body has repair mechanisms to revert back to optimal condition if there wasn’t that much damage done(I think) . I think the assassin cells could be made to continue (not do anything) if it reaches the human proteins and target HIV.

  • assassin

    Whats needed now is a control mechanism.

  • Carter Kindley

    Very exciting news for HIV research. My only issue (and a huge issue it is; I am rather outraged) is the use of the word ‘races’ near the end of the article. Come on, Discover, you so-called scientific publication. And, Nina Bai, you should be chastised for unscientific and offensive writing. A race is defined as a biological subspecies of a species. And, as we know, there exists not enough genetic difference between any two human beings to define any subspecies of Homo sapiens.

    Come on, Discover. You can (and ought to) do better.

  • F26BP

    Re: Carter Kindley

    In human society, “race” is a political construct. However, using this construct, one can recognize trends in genetic variation in protein expression. It’s pretty obvious to me, at least, that this post is referring to “human races” as the categories that we use in society, not the scientific definition that you’ve advanced.

    As Dr. Ade Fakoya, from the International HIV/AIDS Alliance states in the BBC article cited in the post: “The genetic make up of these receptors do vary with different racial populations.” Sure, there’s an argument as to why race is not the best paradigm for describing genetic variation. However, racial differences in HIV susceptibility have been characterized. Further, because racial construction resulted in differential treatment of races, etc., it’s not an anachronism for the discussion of health care delivery.

  • Malcolm

    To Carter Kindley

    You are right, ‘Discover’ is a science based publication and in being so they are perfectly correct in using the word ‘race’. As scientists we celebrate diversity and genetic differences because without it our species would be doomed to extinction through inbreeding depression. One of the reasons humans have been able to evolve to the point where we are able to engineer these assassin cells that are able to target what we want them to is this great genetic diversity. The term ‘race’ should no longer be seen as a term of segregation, that should be left in the past. It should be used as a way of celebrating our diversity and absolutely amazing good fortune that humans have managed to survive this long. If HIV had mutated from SIV during the Middle Ages for example, our species would not have stood a chance.

  • Chuck

    “One is that the assassin T-cells may be too specific and not recognize variants of SL9 that exist in different human races. Another is that they may not be specific enough and could attack other proteins, including human proteins.”

    Didn’t Livescience just say last week that race didn’t exist. Haha

  • assasin

    One thing is certain, this has all to do with design science and little to do with chance and luck “Darwinian Evolution”. This is engineering 101 and it doesn’t take a genius to realize that.

  • g

    There are millions of people suffering from HIV, it is time to find the cure, people are tired of waiting and meds that stop the virus but damage different organs ! When enough is enough

  • Theo J

    As long as they carry Nun-chucks and wear bandannas over their faces i’ll be happy

  • motoko

    we need to act quickly…
    This is a serious diseases that cannot be ignored because anyone can have it.. whether who you are rich or poor, boy or girl, sexual active or not.
    Someone is dying in this diseases. Everyone can contribute to find the cure.. Am a victim also of this disease.
    Hoping that one day this diseases will be cured.

  • http://www.ign.com/blogs/ariceptandpsychiatr aricept and psychiatric disturbance

    WoafYr thanx big man

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