Scientist Develops Virus That Targets HIV: Using a Virus to Kill a Virus

In what represents an important step toward curing HIV, a USC scientist has created a virus that hunts down HIV-infected cells.

Dr. Pin Wang's lentiviral vector latches onto HIV-infected cells, flagging them with what is called "suicide gene therapy" -- allowing drugs to later target and destroy them.

"If you deplete all of the HIV-infected cells, you can at least partially solve the problem," said Wang, chemical engineering professor with the USC Viterbi School of Engineering.

The process is analogous to the military practice of "buddy lasing" -- that is, having a soldier on the ground illuminate a target with a laser to guide a precision bombing strike from an aircraft.

Like a precision bombing raid, the lentiviral vector approach to targeting HIV has the advantage of avoiding collateral damage, keeping cells that are not infected by HIV out of harm's way. Such accuracy has not been achieved by using drugs alone, Wang said.

So far, the lentiviral vector has only been tested in culture dishes and has resulted in the destruction of about 35 percent of existing HIV cells. While that may not sound like a large percentage, if this treatment were to be used in humans, it would likely be repeated several times to maximize effectiveness.

Among the next steps will be to test the procedure in mice. While this is an important breakthrough, it is not yet a cure, Wang said.

"This is an early stage of research, but certainly it is one of the options in that direction," he said.

Wang's research, which was funded by the National Institutes of Health, appears in the July 23 issue of Virus Research.

New HIV came from gorillas

A new form of HIV from gorillas has been identified in a woman from Cameroon. The 62-year old woman, who is now living in Paris, appears to have a new human lineage of HIV virus type 1 and is the first definite human infection of HIV-1 from a non-chimpanzee ape source.

Jean-Christophe Plantier, of the University of Rouen in France, and his colleagues found the new virus to be highly similar to gorilla simian immunodeficiency virus but not to have undergone recombination with chimpanzee SIV. They propose the new lineage be labelled P as it is distinct from the currently known types M, O, and N.

“Our findings indicate that gorillas, in addition to chimpanzees, are likely sources of HIV-1,” write the authors in Nature Medicine. “The discovery of this novel HIV-1 lineage highlights the continuing need to watch closely for the emergence of new HIV variants, particularly in western central Africa, the origin of all existing HIV-1 groups.”

The current prevalence of the new HIV in humans is unknown. The researchers say that the woman detailed in the new paper currently shows no signs of AIDS and probably caught the virus from another person as she has not had contact with apes or bushmeat.

Paul Sharp, of the University of Edinburgh, believes the new strain probably transferred from chimpanzees to gorillas before arriving in humans. He also says it will probably not spread widely, which is fortunate as he adds, “the medical implication is that, because this virus is not very closely related to the other three HIV-1 groups, it is not detected by conventional test” (BBC).

An ‘aerial view’ of HIV

The complex shapes that the HIV genome twists itself into have been totally mapped by the first time by a team of US researchers. RNA viruses such as HIV like to fold themselves up and a proper picture of the shapes they form has been lacking, with researchers generally confining themselves to looking at small sections. In this week’s, Joseph Watts, of the University of North Carolina, and his colleagues set out to look at the bigger picture.

In the research paper, Hashim Al-Hashimi of the University of Michigan, Ann Arbor, notes that structural biologists usually “cut out” the motifs formed by RNA and then “zoom in to determine their three-dimensional structures in an attempt to further understand their function. … However, Watts et al. zoom out and provide an ‘aerial view’ of the secondary structure of the entire HIV-1 genome.”

What they produced is, in Wired’s words, “the cellular equivalent of a rough wiring diagram”. “What this may reveal is some of the proteins operating at a level below the structures, which may have all sorts of functions within the virus,” says David Robertson, of the University of Manchester (BBC). “More generally, if we can unpick the structures then we can compare the systems of different viruses and gain new understanding of how they work.” Study author Kevin Weeks says the technique used here with HIV could also be applied to other virus such as influenza and might open up new opportunities for drug treatmen.