Researchers report new findings on cells’ natural defense against HIV

Posted on 08 Mar 2007 at 7:41pm
By Staff Reports

Researchers have reported a new discovery that could inhibit the transmission of HIV, according to a report published Monday, March 5 by HealthDay News.

The article, written by E.J. Mundell, said that Dutch researchers have discovered that cells in the mucosal lining of human genitalia produce a protein that “eats up” invading HIV, and that enhancing the activity of this protein could be a way to curtail the transmission of the virus.

The cells, called Langerin, are produced by Langerhans cells, which form a web-like network in skin and mucosa that is one of the first structures HIV confronts as it attempts to infect its host, the HealthDay article said.

Lead researcher Teunis Geijtenbeek, an immunologist researcher at Vrije University Medical Center in Amsterdam, added, however, that Langerin appears to be able to “scavenge viruses from the surrounding environment, thereby preventing infection.”

The Dutch researchers’ findings, reported in the March 4 online issue of Nature Medicine, could explain the relative inefficiency of HIV transmission, Dr. Jeffrey Laurence, director of the Laboratory for AIDS Virus Research at the Weill Cornell Medical College in New York City, told the HealthDay reporter.

Laurence said that in one episode of penile-vaginal intercourse with an HIV-infected partner, the chance that the virus will be passed to the other partner is between 1 in 100 and 1 in 200, compared to the chance of contracting HPV the virus which causes cervical cancer during one such encounter, which is nearly 100 percent.

The Dutch study was conducted in a laboratory using Langerhans cells from 13 human donors. The study showed that when HIV comes in contact with genital mucosa, its ultimate targets are immune system T-cells. The virus uses Langerhans cells as “vehicles” by which it migrates to the lymph tissue where the T-cells are located.

The research by Geijtenbeek’s team has cast doubt on long-held belief that the Langerhans cells are easily infected by the HIV, showing instead that the cells “do not become infected by HIV-1, because the cells have the protein Langerin on their cell surface,” Geijtenbeek said. “Langerin captures HIV-1 very efficiently, and this Langerin-bound HIV-1 is taken up by the Langerhans cells and destroyed.”

He said the Langerhans cell act, basically, “more like a virus vacuum cleaner,” and only in situations where HIV levels are very high or Langerin activity is particularly week are the Langerhans cells actually infected.

The research also suggests a possible reason why some people are more susceptible than others to HIV infection, he said.

Geijtenbeek said his team is investigating the possibilities for enhancing Langerin function as a way of preventing HIV transmission.

Laurence, who called the findings “very intriguing,” according to the HealthDay News report, did warn that while the research is very important “in the test tube there are many things in the test tube that don’t occur when you get into an animal or a human.”

This article appeared in the Dallas Voice print edition March 09, 2007

Comments

comments

Powered by Facebook Comments