Featured Research

from universities, journals, and other organizations

Methamphetamine Drastically Increases Virus' Ability To Replicate In Brain Tissue

Date:
June 5, 2002
Source:
Ohio State University
Summary:
A controversial research study here has found that exposing cells infected with feline immunodeficiency virus - a surrogate for HIV - to methamphetamine increases those cells' ability to replicate the deadly virus as much as 15-fold.

COLUMBUS, Ohio - A controversial research study here has found that exposing cells infected with feline immunodeficiency virus - a surrogate for HIV - to methamphetamine increases those cells' ability to replicate the deadly virus as much as 15-fold.

The finding, if confirmed by ongoing animal studies, could answer important questions about how lentiviruses such as FIV and HIV can gain a foothold in the brain. That knowledge is vital in slowing or lessening the dementia that often accompanies AIDS and similar diseases.

Ohio State University researchers reported this finding in a paper to be published in the next issue of the Journal of NeuroVirology.

The paper also reports that before a nerve cell can become infected with the virus, it must be associated with a specific type of lymphocyte, or immune cell. Lastly, the researchers discovered that once the virus infects the cells, it mutates into a form that no longer needs this immune-cell association to reproduce.

"We found that after about two weeks of chronic methamphetamine exposure, the ability of these infected cell lines to mass-produce virus increases dramatically," explained Michael Podell, a professor of veterinary clinical sciences and neurosciences.

The concentration of the drug the cells were exposed to was equal to an average level of methamphetamine in an adult abuser's bloodstream, Podell said.

Like HIV, or human immunodeficiency virus, FIV belongs to a family of pathogens called lentiviruses. Lentivirus infections are particularly problematic since these viruses can escape detection by a healthy immune system, mutate quickly and lead to life-long infections in the host, Podell said.

FIV is one of the principal stand-ins for studies of HIV since the viruses are closely related. Studies of this kind using HIV cannot be done safely or ethically in humans.

Viruses spread within the body by first breaching the cell wall and taking up residence within the cellular environment. Once there, the virus begins replicating, or reproducing, until its numbers are so great the cell literally bursts, spreading the virus to nearby cells and throughout the bloodstream.

The Ohio State researchers focused on astrocytes, nerve cells that may make up as much as half of the brain but which for a long time were thought to play a minimal role. Recent research has shown that astrocytes are among the most important cells in the brain and may play a key role in immunity. While scientists had known that FIV and HIV could infect astrocytes, they believed the infection was merely a latent one with the virus remaining almost in dormancy.

Podell, along with colleagues Lawrence Mathes, professor of veterinary biosciences and director of OSU's Center for Retroviral Research, and Mikhail A. Gavrilin, a research scientist in the Department of Veterinary Clinical Sciences, found that FIV is only able to infect astrocytes when they are associated with a peripheral blood mononuclear cell, or PBMC.

A receptor molecule on the astrocyte's cell membrane allows the virus to enter the astrocyte, the researchers found. Both FIV and HIV are able to use the same receptor - CXCR4 - on astrocytes and on immune system cells. They believe CXCR4 may be the principal receptor for all lentiviruses on astrocytes.

The researchers noticed that once it had infected the astrocytes, the virus began to rapidly reproduce - an observation that was contrary to scientists' belief that FIV resulted only in a latent infection. "We found that the reason the virus multiplies so rapidly is that it mutates into a different strain," Podell said, one that isn't dependent on the presence of the other PBMC cells.

This virus strain - MD-A - appears to be completely independent of any immune system interaction. "That means that any drugs intended to interfere with, or influence the immune system may have absolutely no effect on the astrocyte infection in the brain," Podell said.

The experiments with methamphetamine exposure to the cells were surprising to the researchers.

"We found that if you treat these astrocyte cell lines with methamphetamine at the time that they are infected with FIV, and if you continuously expose them to the drug, you can see as much as a 15-fold increase in viral replication," Podell said.

"You can basically take this cell that normally has a limited ability to consistantly replicate virus and just dramatically turn it on, simply by adding methamphetamine."

The research team is now analyzing data obtained from as series of experiments that used cats as an animal model. If the findings are corroborated in the animals, Podell and his colleagues will try to unravel the precise mechanisms that are controlling FIV infection in these cells.

"The most difficult issue lies ahead, and that is understanding what mechanism is occurring and potentially discovering how to stop or block viral infection and replication in this environment," he said.

The project was supported by grants from the National Institute on Drug Abuse and the National Institutes of Health.


Story Source:

The above story is based on materials provided by Ohio State University. Note: Materials may be edited for content and length.


Cite This Page:

Ohio State University. "Methamphetamine Drastically Increases Virus' Ability To Replicate In Brain Tissue." ScienceDaily. ScienceDaily, 5 June 2002. <www.sciencedaily.com/releases/2002/06/020605072448.htm>.
Ohio State University. (2002, June 5). Methamphetamine Drastically Increases Virus' Ability To Replicate In Brain Tissue. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2002/06/020605072448.htm
Ohio State University. "Methamphetamine Drastically Increases Virus' Ability To Replicate In Brain Tissue." ScienceDaily. www.sciencedaily.com/releases/2002/06/020605072448.htm (accessed July 31, 2014).

Share This




More Health & Medicine News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Xtreme Eating: Your Daily Caloric Intake All On One Plate

Xtreme Eating: Your Daily Caloric Intake All On One Plate

Newsy (July 30, 2014) The Center for Science in the Public Interest released its 2014 list of single meals with whopping calorie counts. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins