Featured Research

from universities, journals, and other organizations

Innate immune mechanisms can control disease progression in HIV-positive patients

Date:
February 26, 2010
Source:
IDIBAPS - Institut d'Investigacions Biomèdiques August Pi i Sunyer
Summary:
A new study by researchers in Spain shows that dendritic cells in HIV positive patients who spontaneously control the infection produce high levels of alpha-defensins. Results show that cells from these patients produce higher levels of alpha-defensins than the non-infected ones. This reveals a better control of HIV and slower disease progression. The study of patients, especially elite controllers, is relevant since these individuals demonstrate that natural control of HIV without therapy is possible.

HIV/AIDS remains one of the world's most significant public health challenges, particularly in developing countries. The Human Immunodeficiency Virus (HIV-1), the variant responsible for the pandemic, has the ability to infect different cell types such as T cells, macrophages and dendritic cells (DC). These latter cells are crucial in the defense against infectious agents and play a major role in viral pathogenesis.

A new study, led by researchers from Hospital Clinic de Barcelona-IDIBAPS, within the framework of HIVACAT, shows for the first time that dendritic cells in HIV-infected patients who spontaneously control the infection produce high levels of α-defensins 1-3. This is associated with slower disease progression, suggesting potential diagnostic, therapeutic and preventive implications.

The first author of this study is Dr. Marta Rodriguez-Garcia, Emili Letang Fellowship award from Hospital Clinic of Barcelona for her work in this line of research, and currently a postdoc at The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard. The senior researchers of the study are Dr. Teresa Gallart, from the Immunology Service of Hospital Clinic and collaborator of the IDIBAPS team on Infectious Diseases and AIDS, and Dr. Josep M ª Gatell, Head of the Infectious Diseases Department at the Hospital Clinic and leader of the same IDIBAPS team.

The study was done in collaboration with the Catalan Center for HIV Vaccine Research and Development (HIVACAT), a public-private partnership involving IrsiCaixa Foundation and the Infectious Diseases Department at the Hospital Clinic of Barcelona. The research conducted within this initiative is made in coordination with Esteve and with the support of "La Caixa" Foundation and the Health and the Innovation, Universities and Enterprise Departments of the Generalitat de Catalunya.

Defensins are endogenous antimicrobial peptides with broad-spectrum antimicrobial properties and immunomodulatory effects. They have a potent anti-HIV activity, acting directly on the virus and also in target cells. According to its structure, human defensins are classified into two subfamilies: α-defensins and β-defensins, both with anti-HIV activity. The α-defensins, also known as human neutrophil peptides, are stored in neutrophils and, to a lesser extent, in other types of leukocytes. Although the anti-HIV activity of α-defensins1-3 has been clearly demonstrated in vitro, their possible protective role during HIV infection in vivo remains uncertain.

The authors recently demonstrated that α-defensins1-3 are produced by monocyte-derived immature dendritic cells (MDDC) in healthy individuals and they are able to modulate the maduration and differentiation process of MDDC. Dendritic cells (DC) are the main antigen-presenting cells and play a key role in the innate immune response against different viral infections, especially during the response generated against HIV. Due to their mucosal localization, DC are thought to be one of the first cells that encounter the HIV and, after migration to the lymph nodes, they would mediate the transmission of HIV-1 virions to CD4 T cells, the main source of HIV-1 replication and dissemination. For this study, a valid model of in vivo myeloid DC, the MDDC, was analysed. These might be one of the key cells involved in early HIV infection, and therefore their capacity to produce and release α-defensins1-3 by DC may have physiological relevance.

The study enrolled healthy, non-infected controls and HIV-1-infected subjects. These HIV-1-infected individuals were classified as: elite controllers (patients able to spontaneously control VIH infection in the absence of therapy, with plasma viral loads below 50 RNA copies/ml and that constitute the 5% of the infected population), viremic controllers (with PVLs higher than 50 and lower than 5000 RNA copies/ml without therapy), viremic non-controllers (with PVLs higher than 5000 RNA copies/ml without therapy) and patients with antiretroviral therapy (HAART). All patients had CD4 T cell counts higher than 450 cell/mm3. Results revealed that immature dendritic cells from HIV-infected patients who control the infection produced higher levels of α-defensins1-3 than the non-infected control group and these levels were associated with a better control of HIV infection and slower disease progression. The study of controller patients, especially elite controllers, is of particular relevance since these individuals demonstrate that natural control of HIV replication in the absence of antiretroviral therapy is possible.

The findings of this study show that of α-defensins1-3 may be potential prophylactic agents and open a new line of investigation to treat HIV / AIDS, although further studies will be needed to determine the possible value of these molecules as an important diagnostic and therapeutic tool to arrest or slow the replication of HIV in infected patients.


Story Source:

The above story is based on materials provided by IDIBAPS - Institut d'Investigacions Biomèdiques August Pi i Sunyer. Note: Materials may be edited for content and length.


Cite This Page:

IDIBAPS - Institut d'Investigacions Biomèdiques August Pi i Sunyer. "Innate immune mechanisms can control disease progression in HIV-positive patients." ScienceDaily. ScienceDaily, 26 February 2010. <www.sciencedaily.com/releases/2010/02/100224205834.htm>.
IDIBAPS - Institut d'Investigacions Biomèdiques August Pi i Sunyer. (2010, February 26). Innate immune mechanisms can control disease progression in HIV-positive patients. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2010/02/100224205834.htm
IDIBAPS - Institut d'Investigacions Biomèdiques August Pi i Sunyer. "Innate immune mechanisms can control disease progression in HIV-positive patients." ScienceDaily. www.sciencedaily.com/releases/2010/02/100224205834.htm (accessed October 20, 2014).

Share This



More Health & Medicine News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Microneedle Patch Promises Painless Pricks

Microneedle Patch Promises Painless Pricks

Reuters - Innovations Video Online (Oct. 18, 2014) — Researchers at The National University of Singapore have invented a new microneedle patch that could offer a faster and less painful delivery of drugs such as insulin and painkillers. Video provided by Reuters
Powered by NewsLook.com
Raw: Nurse Nina Pham Arrives in Maryland

Raw: Nurse Nina Pham Arrives in Maryland

AP (Oct. 17, 2014) — The first nurse to be diagnosed with Ebola at a Dallas hospital walked down the stairs of an executive jet into an ambulance at an airport in Frederick, Maryland, on Thursday. Pham will be treated at the National Institutes of Health. (Oct. 16) Video provided by AP
Powered by NewsLook.com
Raw: Cruise Ship Returns to US Over Ebola Fears

Raw: Cruise Ship Returns to US Over Ebola Fears

AP (Oct. 17, 2014) — A Caribbean cruise ship carrying a Dallas health care worker who is being monitored for signs of the Ebola virus is heading back to Texas, US, after being refused permission to dock in Cozumel, Mexico. (Oct. 17) Video provided by AP
Powered by NewsLook.com
Spanish Govt: Four Suspected Ebola Cases in Spain Test Negative

Spanish Govt: Four Suspected Ebola Cases in Spain Test Negative

AFP (Oct. 17, 2014) — All four suspected Ebola cases admitted to hospitals in Spain on Thursday have tested negative for the deadly virus in a first round of tests, the government said Friday. Duration: 00:55 Video provided by AFP
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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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