HPV blood test shows promise for tracking head and neck cancer after treatment

A new blood test developed by University of North Carolina Lineberger Comprehensive Cancer Center researchers shows promise for tracking HPV-linked head and neck cancer patients to ensure they remain cancer-free after treatment.

Researchers will present preliminary findings at the 60th Annual Meeting of the American Society for Radiation Oncology in San Antonio on Tuesday, Oct. 23. Their study evaluated a blood test for HPV-linked oropharyngeal squamous cell carcinoma, which is a cancer of the back of the throat. The findings demonstrated the test could be an effective and less costly alternative for monitoring for cancer recurrence after radiation treatment.

"The goal of this study was to evaluate whether this test can be used to track patients who are completely asymptomatic, and thought to have no active cancer," said UNC Lineberger's Gaorav P. Gupta, MD, PhD, assistant professor in the UNC School of Medicine Department of Radiation Oncology. "We already knew that our test was very sensitive and specific, but we did not know the degree to which it would be useful in early detection of disease recurrence in patients who are otherwise thought to be disease-free."

HPV, or the human papillomavirus, is the most common cause of sexually transmitted infection in the United States, according to the U.S. Centers for Disease Control and Prevention. Infection with certain strains of HPV can cause cervical cancer in women, genital cancers in both men and women, and cancer of the oropharynx, which is the back of the throat, including the base of the tongue and tonsils. The CDC estimates that approximately 70 percent of oropharyngeal cancer cases diagnosed in the United States are probably caused by HPV, which accounts for nearly 13,000 cases per year.

Gupta and his colleagues developed a blood test that can detect fragments of HPV's genetic material that have been released into the blood by dying cancer cells.

"We realized it is important to distinguish HPV DNA that's being released by dying tumor cells from the natural HPV DNA that is present during a viral infection," Gupta said. "Our method accomplishes this feat, thus making it a more sensitive and specific test for cancer."

For their study, the researchers followed 89 patients with HPV-associated oropharyngeal squamous cell carcinoma who received chemotherapy and radiation treatment. They administered the blood test before and during treatment, and then during follow-up visits. The patients received scans three months after treatment, and then came back for clinical exams every two to four months during the first two years, and then every six months in years three through five. Patients received X-rays or CT scans every six months, and again if they had positive HPV results.

"We are detecting subclinical disease with this blood test, and the imaging patients received confirmed those findings," said UNC Lineberger's Bhishamjit S. Chera, MD, associate professor in the UNC School of Medicine Department of Radiation Oncology and the study's co-corresponding author. Chera presented the findings from the study at the ASTRO meeting.

Of the 70 patients whose blood tests were negative three months after treatment, none developed recurrence. Nineteen patients had positive blood tests, and eight of those patients developed recurrence. Physicians are continuing to monitor the remaining eleven who had positive blood tests but no evidence of recurrence.

"The most striking finding of our study is that of the patients who did not have any signal using our blood test, none of them developed disease recurrence," Chera said. "That raises the question: Do we need to be scanning these patients? Scans come with a lot of cost, and because of the cost, we're not able to do it as frequently. Patients end up having a lot of anxiety from one scan to the next, wondering if their cancer has come back. This blood test could spare patients the need for additional imaging and potentially alleviate some anxiety."

The researchers say the next steps will involve investigating whether the test can be used prospectively to monitor patients and to make decisions that could avoid unnecessary imaging, thereby reducing costs. They also see additional applications for the blood test, including monitoring for other HPV-linked cancers, including cervical cancer.

"We are confident this blood test will be translatable to other cancers driven by HPV, and as a monitoring tool for cancer diagnosis," Chera said. "We strongly believe that this test may also have a role in screening, not just for oropharyngeal cancer, but also cervical or anal cancers, possibly in a general population setting, or at least in patients who may be at higher risk of developing these conditions."

In addition to Chera and Gupta, other authors include Sunil Kumar, PhD; Colette Shen, MD, PhD; Robert Amdur, MD; Roi Dagan, MD; Jared Weiss, MD; Juneko Grilley-Olson, MD; Adam Zanation, MD; Trevor Hackman, MD; Jeff Blumberg, MD; Samip Patel, MD; Brian Thorp, MD; Mark Weissler, MD; Nathan Sheets, MD; and William Mendenhall, MD.

The study was supported by the University Cancer Research Fund, Burroughs Wellcome Fund, the University of North Carolina School of Medicine Department of Radiation Oncology, UNC Lineberger and the University of Florida School of Medicine Department of Radiation Oncology.

Intellectual property related to the test and held by the University of North Carolina at Chapel Hill has been licensed to Naveris, a company in which Chera and Gupta hold equity stakes.

Source: https://www.sciencedaily.com/releases/2018/10/181023085744.htm

Registration: https://std-hiv-aids.cmesociety.com/registration

Abstract Submission: https://std-hiv-aids.cmesociety.com/abstract-submission

During HIV infection, antibody can block B cells from fighting pathogens

For the first time, scientists have shown that in certain people living with HIV, a type of antibody called immunoglobulin G3 (IgG3) stops the immune system's B cells from doing their normal job of fighting pathogens. This phenomenon appears to be one way the body tries to reduce the potentially damaging effects of immune-system hyperactivity caused by the presence of HIV, according to the investigators, but in so doing, it also impairs normal immune function.

The research was led by scientists in the Laboratory of Immunoregulation and the Laboratory of Immunogenetics at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

The investigators made their discovery by analyzing blood samples from 83 HIV-uninfected, anonymous donors and 108 people who were living with HIV at various stages of infection. The people living with HIV came from a variety of racial and ethnic backgrounds. Some of these people were being treated for their infection, while others had not yet begun therapy.

The scientists observed that IgG3 appeared on the surface of B cells only under certain conditions. It appeared in people living with HIV, but not in HIV-uninfected people. Also, IgG3 predominantly appeared on B cells of people of African American or black African decent during the chronic phase of untreated HIV infection when the virus was not adequately controlled.

A site on B cells called the B-cell receptor normally binds to foreign entities such as pathogens. This binding stimulates the B cell to produce many copies of the antibody form of the receptor, which can trap a pathogen and mark it for destruction. The scientists found that IgG3 short-circuits this process in certain people living with HIV by docking on the B-cell receptor, blocking it from adequately responding to the pathogen or other intended target. The researchers also demonstrated how other components of the immune system contribute to IgG3 interference with normal B-cell function during HIV infection. Finally, they showed that IgG3 stops binding to B-cell receptors when a chronically infected person starts treatment that controls the virus, illustrating that the IgG3 activity is directly linked to the presence of HIV during chronic infection.

Source: https://www.sciencedaily.com/releases/2018/08/180813125236.htm

Proof-of-concept HIV Immunotherapy study passes Phase 1 safety trial

Preliminary results from a phase I clinical trial have demonstrated the safety and tolerability of a cell therapy involving the ex vivo expansion of T cells and their subsequent infusion into HIV-infected individuals previously treated with antiretroviral therapy (ART). The study appears September 21st in the journal Molecular Therapy.

"This study is focused on finding a way to re-educate the body's immune system to better fight HIV infection," says co-senior study author David Margolis of the University of North Carolina (UNC) at Chapel Hill. "We found that this approach of re-educating the immune cells and reinfusing them was safe, which was the primary goal of the study. The data from this trial will continue to help us design improved immunotherapies against HIV."

A game changer for patients living with HIV, ART has turned what was once a death sentence into a chronically managed disease. But it is not a cure, and the virus continues to persist within a latent reservoir that remains hidden from the immune system. Approaches using pharmacological HIV-latency-reversal agents to induce latent virus to express viral protein could make this reservoir vulnerable to T cells. However, the existing HIV-specific immune response in ART-treated individuals is insufficient to clear persistent infection, even in the presence of latency-reversal agents that induce HIV expression.

One safe avenue for harnessing T cell responses to fight HIV is adoptive cellular therapy. This procedure involves collecting T cells from a patient, growing them in the laboratory to increase their numbers, and then giving them back to the patient to help the immune system fight disease. Earlier adoptive-T-cell-therapy approaches for HIV had limited efficacy as a result of multiple factors. Since these earlier attempts, the adoptive-T-cell-therapy field has made significant advances, largely in the oncology field, that could help to overcome some of the pitfalls encountered with earlier T-cell-therapy approaches for HIV. T cells generated by these sophisticated methods of expansion have been safe and well tolerated, as well as highly effective.

"Before we can combine this approach with treatments meant to bring HIV out from hiding so the improved immune response can clear it from the body, we need to first establish that this immunotherapy approach is safe on its own," says co-senior study author Catherine Bollard of the Children's National Health System. "We have long-standing experience treating patients with virus-specific T cells targeting latent viruses such as Epstein-Barr virus and cytomegalovirus. Therefore, we were extremely excited to work with the UNC team to adapt this virus-specific T-cell-therapy approach to the HIV setting."

In the small proof-of-concept study, Margolis, Bollard, and their collaborators produced ex vivo expanded HIV-specific T cells (HXTCs); their long-term goal was to use HXTCs as part of a strategy to clear persistent HIV infection. The researchers administered two infusions of HXTCs over a 2 week period to six HIV-infected participants whose viral load had been reduced to an undetectable level by ART.

This treatment was well tolerated and had few adverse events. Moreover, two patients exhibited a detectable increase in T-cell-mediated antiviral activity after the two infusions, although the clinical significance of this mild-to-modest impact is unknown. When evaluating participants in aggregate, the research team found no overall enhancement of the magnitude of the HIV-specific immune response. This could be due to the low dose of the two infusions and the lack of strategies to promote the expansion of the T cells once they are in the body.

There was also no decrease in the size of the latent reservoir, most likely because of the absence of therapies such as latency-reversal agents, which are designed to perturb the reservoir and induce recognizable expression of HIV proteins that trigger immune responses. In the future, a critical question will be whether HXTC therapy in combination with latency-reversal agents can deplete the HIV reservoir to an extent that is measurable by current gold-standard assays of HIV latency. A study of HXTC in combination with the latency-reversal agent vorinostat is currently undergoing evaluation in an ongoing clinical trial.

"This is a promising advancement for the field," says first author Julia Sung of UNC, although she also cautions people against over-interpreting the results. "The study did not cure HIV and should not be interpreted as doing so, but we also are very encouraged by the safety data, so it should not be considered discouraging either. This paves the way for the next step, which is to combine this immunotherapy approach with latency-reversal therapy in order to wake up the HIV out of its latent state, where it is invisible to the immune system, then clear it out with the immunotherapy."

A New Method for Removing Cells Infected with the AIDS Virus

With the successful suppression of the AIDS virus (HIV) through medication, the focus turns toward its eradication. Researchers from Kumamoto University in Japan have developed a new compound that is key to the destruction of HIV. When the compound is introduced into infected cells, viral budding (release) is suppressed thereby confining it within the host cells. The cells then die naturally through apoptosis (cell death). This treatment is believed to lead to the complete recovery from AIDS in the near future.

In recent years, multi-drug therapy has made it possible to suppress HIV multiplication in the body when taken properly. This method, however, cannot remove the virus particles of the latent HIV reservoir—non-replicating virus particles that remain dormant in the cells of the body. As soon as drug administration is stopped, the viral load will again increase in the body. Removal of the viral reservoir is currently the top goal in AIDS research.

The "kick and kill" approach, which was developed several years ago, is a strategy for killing reservoir cells. This technique uses a drug that targets the reservoir cells and activates the virus which then allows the immune system to find these cells using the activated virus as a landmark. Although this approach was clinically tested, there is still the problem of not being able to efficiently deactivate the virus after successful activation.

Researchers at Kumamoto University developed a new approach that they call "Lock-in and apoptosis." First, they synthesized the compound L-HIPPO, which binds strongly to the HIV protein Pr55Gag and suppresses viral budding. When L-HIPPO was added to virus-infected cells via a carrier called α-CDE, the virus became confined within the cell and the cell would die through natural apoptosis.

"Unfortunately, this approach is not immediately available for people infected with HIV," said Associate Professor Mikako Fujita of Kumamoto University, one of the leaders of the study. "First, we have to improve upon the drugs that activate the virus and combine them with L-HIPPO to efficiently target the viral reservoir. This would be a big step towards a complete recovery from HIV. We believe that our research will help to completely eradicate AIDS."

Source: https://medicalxpress.com/news/2017-10-method-cells-infected-aids-virus.html