Nav: Home

Candida-specific helper T cells are preferential and early targets of HIV

June 09, 2016

Candida yeasts normally live on human skin and mucous membranes without causing disease. In individuals with a weakened immune system, however, they are a major cause of opportunistic infections. A study published on June 9th in PLOS Pathogens shows how HIV soon after infection specifically targets and destroys the very immune cells that keep Candida in check.

Opportunistic infections--clinically relevant diseases caused by usually harmless microbes--are a hallmark of HIV/AIDS and thought to be caused by a progressively weakening immune system that loses the ability to suppress even known pathogens. It is known that CD4 helper T cells, the primary target of HIV, are a key part of the immune response to many opportunistic microbes. However, HIV-positive individuals do not suddenly become susceptible to all sorts of infections. Instead, there is a consistent sequence in the vulnerability to different opportunistic pathogens during the progression of HIV-infected individuals to AIDS.

Haitao Hu, from the University of Texas Medical Branch in Galveston, USA, and colleagues, are interested in the reasons for this differential vulnerability, including the question why the common opportunistic infections with Candidaalbicans occur early during HIV/AIDS progression. The researchers had previously discovered that human C. albicans-specific CD4 helper T cells are more permissive to HIV infection in vitro compared to CD4 helper T cells specific for cytomegalovirus (CMV), another opportunistic pathogen but one that usually causes disease at late stages of HIV/AIDS.

In this study, they examine how HIV targets these two groups of pathogen-specific CD4 T-cells in HIV-infected individuals over time. The researchers used consecutive blood samples from 20 HIV-infected individuals who had C. albicans-specific and CMV-specific CD4 helper T cells, experienced progressive loss of overall numbers of CD4 helper T cells over time, and who had not yet started antiretroviral treatment (ART). Compared to CMV-specific cells, the researchers found, C. albicans-specific CD4 T cells were more susceptible to HIV in vivo and preferentially depleted earlier in the HIV-infected individuals.

It is known that C. albicans-specific CD4 T helper cells come in two different 'flavors'. Some of them produce mainly two immune stimulators called IL-17 and IL-22 (and are referred to as Th17 cells), whereas others, so-called Th1 cells, produce predominantly interferons, another type of immune signaling molecule. In the HIV-infected individuals, the researchers saw a sequential dysfunction for C. albicans-specific CD4 T cell response, with an earlier and more profound depletion of Th17 cells. This suggests that these Th17 cells are the ones that primarily prevent C. albicans from causing disease in healthy individuals.

"Based on an ART naïve HIV infection cohort", the authors summarize, "we comparatively investigated the dynamic impact of HIV on C. albicans- and CMV specific CD4 T-cell immunity in HIV non-controllers. We identified a sequential dysfunction and preferential depletion of C. albicans-specific CD4 T cell response during progressive HIV infection". Their results, they suggest, "may provide an immunological basis for early loss of immune control over mucosal candidiasis in HIV-infected individuals and also suggest a potential mechanism for pathogen-specific immune failure in AIDS".
In your coverage please use this URL to provide access to the freely available article in PLOS Pathogens:

Please contact if you would like more information.

Funding: The work was supported by National Institutes of Health Grant 1R21AI110214 (to HH) ( and the Robert Mapplethorpe Foundation grant (to HH) ( The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing Interests: The authors have declared that no competing interests exist.

Citation: Liu F, Fan X, Auclair S, Ferguson M, Sun J, Soong L, et al. (2016) Sequential Dysfunction and Progressive Depletion of Candidaalbicans-Specific CD4 T Cell Response in HIV-1 Infection. PLoS Pathog 12(6): e1005663. doi:10.1371/journal.ppat.1005663


Related Hiv Articles:

The Lancet HIV: Severe anti-LGBT legislations associated with lower testing and awareness of HIV in African countries
This first systematic review to investigate HIV testing, treatment and viral suppression in men who have sex with men in Africa finds that among the most recent studies (conducted after 2011) only half of men have been tested for HIV in the past 12 months.
The Lancet HIV: Tenfold increase in number of adolescents on HIV treatment in South Africa since 2010, but many still untreated
A new study of more than 700,000 one to 19-year olds being treated for HIV infection suggests a ten-fold increase in the number of adolescents aged 15 to 19 receiving HIV treatment in South Africa, according to results published in The Lancet HIV journal.
Starting HIV treatment in ERs may be key to ending HIV spread worldwide
In a follow-up study conducted in South Africa, Johns Hopkins Medicine researchers say they have evidence that hospital emergency departments (EDs) worldwide may be key strategic settings for curbing the spread of HIV infections in hard-to-reach populations if the EDs jump-start treatment and case management as well as diagnosis of the disease.
NIH HIV experts prioritize research to achieve sustained ART-free HIV remission
Achieving sustained remission of HIV without life-long antiretroviral therapy (ART) is a top HIV research priority, according to a new commentary in JAMA by experts at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.
First ever living donor HIV-to-HIV kidney transplant
For the first time, a person living with HIV has donated a kidney to a transplant recipient also living with HIV.
More Hiv News and Hiv Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...