Immune cells in the gut may improve control of HIV growth
The study was led by researchers at the University of California, San Francisco and included Kristina Abel, Ph.D., an assistant professor in the department of microbiology and immunology at UNC, at the time of the study a faculty member at the University of California, Davis. Credit: UNC School of Medicine
The findings of a new study in monkeys may help clarify why some people infected with HIV are better able to control the virus. They also may pinpoint a target for treatment during early HIV infection aimed at increasing the supply of certain immune cells in the gut, which the study shows could be an important factor in limiting HIV growth in cells throughout the body.
The study was led by researchers at the University of California, San Francisco (UCSF) and included Kristina Abel, PhD, an assistant professor in the department of microbiology & immunology at UNC, at the time of the study a faculty member at the University of California, Davis (UCD). "The research involved a rhesus macaque model of HIV, monkeys who were infected with simian immunodeficiency virus, SIV" Abel said. "The course of SIV infection in these monkeys is quite similar to that of HIV in humans."
Both HIV and SIV infections cause severe CD4 T cell loss in the gut during early infection. As a result, the intestinal mucosal barrier, which is like the body's second skin or front line of defense against pathogens, is compromised. The "leaky gut" causes bacteria that are normally located in the gut (the normal flora) to migrate out and activate the immune system throughout the body with disastrous health consequences. "The immune activation contributes to higher replication of the virus. And so the question is, why do some patients progress from infection to AIDS faster than others?" Abel asks.
This new study looked at the balance between certain immune cell populations that might influence disease outcome. The study shows the presence of a subtype of CD4-positive immune cells called Th17 (T helper 17) cells in the gut "could influence disease outcome."
A report of the research appeared in the May 30, 2012 on-line issue of Science Translational Medicine.
Th17 cells are commonly found at mucosal surfaces and activate epithelial or outer layer barrier cells to secrete antimicrobial molecules, thus blocking disease-causing bacteria from entering. Abel points out that they also stimulate the production of "tight junction" proteins that keep all the cells that make up the intestinal barrier in close contact, "so that bacteria of the normal flora or their products cannot leak out."
The researchers wondered if there are more Th17 cells in the gut, would infection with the AIDS virus still have that early massive effect on gut permeability? And if you could keep the intestinal barrier intact during early infection with HIV, would it have an impact on the severity of disease progression, on having less severe disease in the long run?
Results of the study suggest that the answers may be yes. Rhesus macaques with higher numbers of Th17 cells in blood and intestinal tissue before they are infected with SIV subsequently have lower SIV viral loads. "It appears they're more able to control the infection," Abel said.
The study also found that among animals given a drug that increases regulatory T cells and thereby suppresses Th17 cell development, disease progression occurred more rapidly, and they had higher levels of SIV virus six months after infection.
"The main message of the study is that the frequencies of certain immune cell populations in the normal, still uninfected individual are important in subsequent disease progression and outcome," Abel said. "The paper also suggests that treatment aimed at increasing Th17 cells may improve the control of HIV growth by promoting an environment in which T cells having more anti-viral capabilities are produced."
Journal reference: Science Translational Medicine
Provided by University of North Carolina Health Care
- Researchers identify potential new HIV vaccine/therapy target May 30, 2012 | not rated yet | 0
- AIDS resistance secret may be in blood Feb 12, 2007 | not rated yet | 0
- Study pinpoints how a normally defensive immune response can help HIV May 19, 2010 | not rated yet | 0
- Antibodies help protect monkeys from HIV-like virus, scientists show May 05, 2011 | not rated yet | 0
- SIV's natural hosts reveal how humans might better manage HIV infection Mar 08, 2012 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
HIV & AIDS 23 hours ago | 5 / 5 (3) | 0 |
Detection of HIV antibodies is used to diagnose HIV infection and monitor trials of experimental HIV/AIDS vaccines. New, more sensitive detection systems being developed use microspheres to capture HIV antibodies ...
HIV & AIDS May 23, 2013 | 5 / 5 (1) | 0
(HealthDay)—For HIV-infected individuals with recurrent Clostridium difficile infection, fecal microbiota therapy is feasible, according to a letter published in the May 21 issue of the Annals of Intern ...
HIV & AIDS May 22, 2013 | not rated yet | 0
Canadian health authorities lifted Wednesday what was effectively a ban on gay men giving blood, announcing new rules making men who have not had sex with men in the past five years eligible.
HIV & AIDS May 22, 2013 | not rated yet | 1
Coenzyme Q10 decreases all cause mortality by half, according to the results of a multicentre randomised double blind trial presented today at Heart Failure 2013 congress. It is the first drug to improve heart failure mortality ...
1 hour ago | not rated yet | 4
Heart failure accelerates the aging process and brings on early andropausal syndrome (AS), according to research presented today at the Heart Failure Congress 2013. AS, also referred to as male 'menopause', was four times ...
1 hour ago | not rated yet | 1
(AP)—Department of Justice lawyers have again asked a federal appeals court in New York to delay lifting age restrictions and prescription requirements on an emergency contraceptive popularly known as the morning-after ...
1 hour ago | not rated yet | 0
Mortality and length of stay are highest in heart failure patients admitted in January, on Friday, and overnight, according to research presented today at the Heart Failure Congress 2013. The analysis of nearly 1 million ...
1 hour ago | not rated yet | 0
20 hours ago | 3.7 / 5 (3) | 2 |
Two mutations central to the development of infantile myofibromatosis (IM)—a disorder characterized by multiple tumors involving the skin, bone, and soft tissue—may provide new therapeutic targets, according to researchers ...
18 hours ago | 3 / 5 (2) | 0 |