IRIS affects certain HIV-infected individuals whose immune systems are heavily damaged by the virus and who have a treated or undiagnosed AIDS-associated infection. When these individuals start antiretroviral therapy and their immune cells begin to regenerate, the immune system unexpectedly produces an exaggerated response that unmasks or worsens the symptoms of the co-infection.
IRIS has become a notable challenge in treating HIV disease, particularly in resource-limited settings. The scientists hope that better understanding how and why the syndrome occurs will lead to targeted prevention or therapy.
To find immunologic patterns that distinguish individuals who develop IRIS from those who do not, the researchers analyzed blood samples from HIV-infected individuals, focusing their analysis on a group of immune cells called T lymphocytes. Most of the studied patients had an AIDS-associated fungal, viral or bacterial infection before they started antiretroviral therapy.
The analysis showed that the individuals who developed IRIS had a higher proportion of activated T cells before starting antiretroviral therapy compared with those who did not develop IRIS. These activated T cells had the propensity to make a key infection-fighting molecule called interferon gamma both before therapy began and during IRIS episodes, suggesting that the cells may participate in the exaggerated immune response seen during IRIS. In addition, the surface markers expressed by the T cells—some with a stimulatory effect and some restraining in nature—suggested they were highly activated as a result of an encounter with the microbes co-infecting the HIV-infected individuals.
A companion study describes a new animal model that can be used to directly analyze the immunologic mechanisms that cause IRIS. This model employs mice infected with Mycobacterium avium, a pathogen frequently seen in HIV-infected individuals who develop IRIS. To mimic the immunologic condition of IRIS-susceptible HIV-infected individuals, the researchers began with mycobacterium-infected mice that had extremely low numbers of T cells. The scientists found that rebuilding the population of T cells in these mice, as usually occurs during antiretroviral therapy in humans, triggered an IRIS-like disease. In addition, the researchers observed that interferon-gamma production by the repopulating T cells in the mice clearly facilitated the development of experimentally induced IRIS. The study also implicated a type of immune cell known as a macrophage in sparking IRIS in the mice.
ARTICLES: LRV Antonelli et al. Elevated frequencies of highly activated CD4+ T cells in HIV+ patients developing immune reconstitution inflammatory syndrome. Blood DOI: 10.1182/blood-2010-05-285080 (2010).
DL Barber et al. Th1-driven immune reconstitution disease in Mycobacterium avium-infected mice. Blood DOI: 10.1182/blood-2010-05-286336 (2010).
WHO: Irini Sereti, M.D., M.H.S., a clinical investigator in the NIAID Laboratory of Immunoregulation, and Daniel Barber, Ph.D., a postdoctoral fellow in the NIAID Laboratory of Parasitic Diseases, are available to discuss the research.
CONTACT: To schedule interviews, please contact Laura Sivitz Leifman, 301-402-1663, email@example.com.
NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.
The National Institutes of Health (NIH)—The Nation's Medical Research Agency—includes 27 Institutes and Centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.
Laura Sivitz Leifman | EurekAlert!
Hot cars can hit deadly temperatures in as little as one hour
24.05.2018 | Arizona State University
3D images of cancer cells in the body: Medical physicists from Halle present new method
16.05.2018 | Martin-Luther-Universität Halle-Wittenberg
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
24.05.2018 | Ecology, The Environment and Conservation
24.05.2018 | Medical Engineering
24.05.2018 | Physics and Astronomy