UCLA-engineered stem cells seek out and kill HIV in living organisms

Expanding on previous research providing proof-of-principal that human stem cells can be genetically engineered into HIV-fighting cells, a team of UCLA researchers have now demonstrated that these cells can actually attack HIV-infected cells in a living organism.

The study, published April 12 in the journal PLoS Pathogens, demonstrates for the first time that engineering stem cells to form immune cells that target HIV is effective in suppressing the virus in living tissues in an animal model, said lead investigator Scott G. Kitchen, an assistant professor of medicine in the division of hematology and oncology at the David Geffen School of Medicine at UCLA and a member of the UCLA AIDS Institute.

"We believe that this study lays the groundwork for the potential use of this type of an approach in combating HIV infection in infected individuals, in hopes of eradicating the virus from the body," he said.

In the previous research, the scientists took CD8 cytotoxic T lymphocytes - the "killer" T cells that help fight infection - from an HIV-infected individual and identified the molecule known as the T cell receptor, which guides the T cell in recognizing and killing HIV-infected cells. However, these T cells, while able to destroy HIV-infected cells, do not exist in great enough quantities to clear the virus from the body. So the researchers cloned the receptor and used this to genetically engineer human blood stem cells. They then placed the engineered stem cells into human thymus tissue that had been implanted in mice, allowing them to study the reaction in a living organism.

The engineered stem cells developed into a large population of mature, multi-functional HIV-specific CD8 cells that could specifically target cells containing HIV proteins. The researchers also discovered that HIV-specific T cell receptors have to be matched to an individual in much the same way an organ is matched to a transplant patient.

In this current study, the researchers similarly engineered human blood stem cells and found that they can form mature T cells that can attack HIV in tissues where the virus resides and replicates. They did so by using a surrogate model, the humanized mouse, in which HIV infection closely resembles the disease and its progression in humans.

In a series of tests on the mice's peripheral blood, plasma and organs conducted two weeks and six weeks after introducing the engineered cells, the researchers found that the number of CD4 "helper" T cells - which become depleted as a result of HIV infection - increased, while levels of HIV in the blood decreased. CD4 cells are white blood cells that are an important component of the immune system, helping to fight off infections. These results indicated that the engineered cells were capable of developing and migrating to the organs to fight infection there.

The researchers did note a potential weakness with the study: Human immune cells reconstituted at a lower level in the humanized mice than they would in humans, and as a result, the mice's immune systems were mostly, though not completely, reconstructed. Because of this, HIV may be slower to mutate in the mice than in human hosts. So the use of multiple, engineered T cell receptors may be one way to adjust for the higher potential for HIV mutation in humans.

"We believe that this is the first step in developing a more aggressive approach in correcting the defects in the human T cell responses that allow HIV to persist in infected people," Kitchen said.

The researchers will now begin making T cell receptors that target different parts of HIV and that could be used in more genetically matched individuals, he said.

Other study authors are Bernard R. Levin, Gregory Bristol, Valerie Rezek, Sohn Kim, Christian Aguilera-Sandoval, Arumugam Balamurugan, Otto O. Yang and Jerome A. Zack, all of UCLA.

The National Institutes of Health, the California HIV/AIDS Research Program, the California Institute for Regenerative Medicine, the UC Multicampus Research Program and Initiatives from the California Center for Antiviral Drug Discovery, and the UCLA Center for AIDS Research (CFAR) funded this study.

The UCLA AIDS Institute, established in 1992, is a multidisciplinary think tank drawing on the skills of top-flight researchers in the worldwide fight against HIV and AIDS, the first cases of which were reported in 1981 by UCLA physicians. Institute members include researchers in virology and immunology, genetics, cancer, neurology, ophthalmology, epidemiology, social sciences, public health, nursing and disease prevention. Their findings have led to advances in treating HIV, as well as other diseases, such as hepatitis B and C, influenza and cancer.

Most Popular Now

Amgen announces Repatha® (evolocumab) significantl…

Amgen (NASDAQ:AMGN) has announced that the FOURIER trial evaluating whether Repatha® (evolocumab) reduces the risk of cardiovascular events in patients with clinically ev...

Read more

Vitamin D discovery could prove key to new treatme…

A team led by Motonari Uesugi, professor and deputy director of Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS), found that a vitamin D metabol...

Read more

Nuts can inhibit the growth of cancer cells

Roasted and salted, ground as a baking ingredient or fresh from the shell - for all those who enjoy eating nuts, there is good news from nutritionists at Friedrich Schill...

Read more

The drugs don't work, say back pain researchers

Commonly used non-steroidal anti-inflammatory drugs, such as ibuprofen, used to treat back pain provide little benefit, but cause side effects, according to new research ...

Read more

An alternative theory on how aspirin may thwart ca…

Studies abound that point to a role for plain old aspirin in keeping deadly cancers at bay. While aspirin is not yet part of mainstream treatment for any cancer, it is re...

Read more

Novo Nordisk enters collaboration with University …

University of Oxford and Novo Nordisk today announced a landmark research collaboration focused on type 2 diabetes. The partnership will enable scientists from Novo Nordi...

Read more

Relationship expert teams up with Pfizer to addres…

Nationally-recognized relationship expert and author, Logan Levkoff, Ph.D., has partnered with Pfizer Inc. (NYSE:PFE) to fill a void in information available to people li...

Read more

Pfizer reports fourth-quarter and full-year 2016 r…

Pfizer Inc. (NYSE: PFE) reported financial results for fourth-quarter and full-year 2016 and provided 2017 financial guidance. Pfizer manages its commercial operations th...

Read more

Anti-inflammatory diet could reduce risk of bone l…

Anti-inflammatory diets - which tend to be high in vegetables, fruits, fish and whole grains - could boost bone health and prevent fractures in some women, a new study su...

Read more

Sex, drugs, and rock and roll chemistry in the bra…

The same brain-chemical system that mediates feelings of pleasure from sex, recreational drugs, and food is also critical to experiencing musical pleasure, according to a...

Read more

Drug shows promise for treating alcoholism

UCLA researchers have found that an anti-inflammatory drug primarily used in Japan to treat asthma could help people overcome alcoholism. Their study is the first to eval...

Read more

Novartis delivered solid 2016 performance

Novartis announced today that the net sales were USD 48.5 billion (-2%, 0% cc) in the full year, as volume growth of 6 percentage points was offset by the negative impact...

Read more

Pharmaceutical Companies

[ A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Z ]