Study finds ‘important implications’ to understanding immunity against COVID-19

New research from Emory University indicates that nearly all people hospitalized with COVID-19 develop virus-neutralizing antibodies within six days of testing positive. The findings will be key in helping researchers understand protective immunity against SARS-CoV-2 and in informing vaccine development. The test that Emory researchers developed also could help determine whether convalescent plasma from COVID-19 survivors can provide immunity to others, and which donors' plasma should be used. The antibody test developed by Emory and validated Read more

Emory plays leading role in landmark HIV prevention study of injectable long-acting cabotegravir

Emory University played a key role in a landmark international study evaluating the safety and efficacy of the long-acting, injectable drug, cabotegravir (CAB LA), for HIV prevention. The randomized, controlled, double-blind study found that cabotegravir was 69% more effective (95% CI 41%-84%) in preventing HIV acquisition in men who have sex with men (MSM) and transgender women who have sex with men when compared to the current standard of care, daily oral emtricitabine/tenofovir disoproxil fumarate Read more

Yerkes researchers find Zika infection soon after birth leads to long-term brain problems

Researchers from the Yerkes National Primate Research Center have shown Zika virus infection soon after birth leads to long-term brain and behavior problems, including persistent socioemotional, cognitive and motor deficits, as well as abnormalities in brain structure and function. This study is one of the first to shed light on potential long-term effects of Zika infection after birth. “Researchers have shown the devastating damage Zika virus causes to a fetus, but we had questions about Read more

checkpoint inhibitors

Transition to exhaustion: clues for cancer immunotherapy

Research on immune cells “exhausted” by chronic viral infection provides clues on how to refine cancer immunotherapy. The results were published Tuesday, Dec. 3 in Immunity.

Scientists at Emory Vaccine Center, led by Rafi Ahmed, PhD, have learned about exhausted CD8 T cells, based on studying mice with chronic viral infections. In the presence of persistent virus or cancer, CD8 T cells lose much of their ability to fight disease, and display inhibitory checkpoint proteins such as PD-1 on their surfaces. PD-1 is targeted by cancer immunotherapy drugs, such as pembrolizumab and nivolumab, which allow CD8 T cells to regain their ability to attack and kill infected cells and cancers.

Those drugs are now FDA-approved for several types of cancer, yet some types of tumors do not respond to them. Studying exhausted CD8 T cells can help us understand how to better draw the immune system into action against cancer or chronic infections.

In previous research, Ahmed’s lab found that exhausted cells are not all alike, and the diversity within the exhausted T cell pool could explain variability in responses to cancer immunotherapy drugs. Specifically, they observed that a population of “stem-like” cells proliferated in response to PD-1-blocking drugs, while a more differentiated population of exhausted cells stayed inactive. The stem-like cells are responsible for maintaining the exhausted T cell population, but cannot kill virus-infected or tumor cells on their own.

The current paper defines a transitional stage in between the stem-like and truly exhausted cells. The truly exhausted cells are marked by a molecule called CD101, and are unable to migrate to sites of infection and contain lower amounts of proteins needed to kill infected or tumor cells.

“The transitional cells are not completely exhausted,” says postdoctoral fellow Will Hudson, PhD, first author of the Immunity paper. “They are still capable of proliferating and performing their ‘killer cell’ functions. In our experiments, they contribute to viral control.”

The transitional cells, lacking CD101, could be a good marker for response to PD-1 blocking drugs, Hudson says. Enhancing the proliferation or survival of these cells, or preventing their transition to lasting exhaustion, may be a novel therapeutic strategy for cancer. Read more

Posted on by Quinn Eastman in Immunology Leave a comment

Immunotherapy for triple negative breast cancer

Treatments that unleash the immune system against cancer have been a hot topic for the last few years, but they do not appear in our recent feature on breast cancer for Winship Cancer Institute’s magazine.

Partly, that’s because decent avenues for treatment exist for most types of breast cancer, with improvements in survival since the 1980s. Immunotherapy’s successes have been more dramatic for types of cancer against which progress had been otherwise meager, such as lung cancers and metastatic melanoma.

Jane Meisel, MD with patient

Winship oncologist Jane Meisel, MD with patient

However, for “triple-negative” breast cancer (TNBC) in particular, immunotherapy could be a good match, because of the scarcity of targeted treatments and because TNBC’s genomic instability may be well-suited to immunotherapy.

Winship oncologists Jane Meisel and Keerthi Gogineni inform Lab Land that several early-phase clinical studies open to breast cancer patients, testing “checkpoint inhibitor” agents such as PD-1 inhibitors, are underway. More are pending.

Meisel’s presentation at Winship’s Sea Island retreat says that immunotherapy is “not yet ready for prime time, but a very promising experimental approach for a subset of patients for whom current therapies are not sufficient. We need to better understand which subsets of patients are most likely to benefit, and how we can use other therapies to enhance efficacy in patients who don’t initially respond.”

Read more

Posted on by Quinn Eastman in Cancer Leave a comment

Why checkpoint inhibitors fall short for some types of cancer

The big news from the recent American Society of Clinical Oncology meeting has been largely about immunotherapy drugs, also known as checkpoint inhibitors. These drugs have been shown to be effective in prolonging life in patients with some types of cancer, such as lung cancer and melanoma, but not others, such as colorectal and prostate cancer.

Lab Land asked oncologist Bradley Carthon and immunology researcher Haydn Kissick why. Both Carthon’s clinical work and Kissick’s lab research on prostate cancer are featured in the new issue of Winship magazine, but the prostate feature just touches on checkpoint inhibitors briefly.

Carthon says the reason checkpoint inhibitors haven’t moved the needle with prostate cancer is “likely due to the absence of infiltration of the prostatic tissue by tumor-associated lymphocytes.”

Checkpoint inhibitors are supposed to unleash the immune system, but if the immune cells aren’t in contact with the cancer cells so that the drugs can spur them into action, they won’t help much. Carthon says: “The answer may be to ‘prime’ the prostate with an agent, then introduce the checkpoint inhibitors.” Read more

Posted on by Quinn Eastman in Cancer, Immunology Leave a comment