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, firstname.lastname@example.org.
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!
Team discovers how bacteria exploit a chink in the body's armor
20.01.2017 | University of Illinois at Urbana-Champaign
Rabies viruses reveal wiring in transparent brains
19.01.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences