Scientists say checking cervical lesions is better than blood test to measure immune cell response to HPV treatment
Preliminary results of a small clinical trial show that a vaccine used to treat women with high-grade precancerous cervical lesions triggers an immune cell response within the damaged tissue itself. The Johns Hopkins scientists who conducted the trial said the finding is significant because measuring immune system responses directly in the lesions may be a more accurate way to evaluate so-called “therapeutic” vaccines than by the conventional means of blood analysis.
“It’s difficult to measure immune cell responses to therapeutic vaccines, but we believe that clinical studies could tell us more about the value and function of the vaccines if we check for the response in the lesions, where the immune system is fighting precancerous cells,” says Connie Trimble, MD, associate professor of gynecology and obstetrics, oncology and pathology at Johns Hopkins’ Kimmel Cancer Center.
Results of the first 12 women enrolled at Johns Hopkins on a clinical trial led by Trimble are reported online in the January 27, 2014 issue of Science Translational Medicine. Each of the women was diagnosed with high-grade precancerous cervical lesions linked to a strain of the human papillomavirus (HPV16) most commonly associated with cervical cancer. In a bid to treat the lesions and prevent cervical cancer, they received three vaccine injections in the upper arm over an eight-week period.
Two types of vaccines were used for the study: one constructed with genetically engineered DNA molecules that teach immune system cells to recognize premalignant cells expressing HPV16 E7 proteins, and one that is a non-infectious, engineered virus that targets and kills precancerous cells marked by HPV16 and HPV18 E6 and E7 proteins.
Seven weeks after the third vaccination, the investigators surgically removed cervical lesions from all of the women. Blood samples and cervical tissue were collected from each patient at the beginning and end of the trial, letting scientists compare immune cell responses before and after vaccination.
In three of six patients treated with the highest dose of the vaccine, and one patient in each of the two groups receiving lower doses of the vaccine, the cervical lesions disappeared. The first patient was treated in 2008, and the 12th in 2012. None of the 12 patients has, so far, developed more lesions.
Among those vaccinated, the investigators found significant increases of CD8 T-cells, the “killer” cells of the immune system, in cervical tissue. Blood samples failed to show as strong a pre- and postvaccination effect. The investigators also said the vaccine did not have the unwanted consequence of altering the number of T-regulatory cells, which suppress immune system responses.
“We found striking immune system changes within cervical lesions, which were not as evident in the patients’ peripheral blood samples,” says Trimble.
The investigators also measured gene expression of post-vaccinated cervical cells in three of the patients and found increased expression of several genes associated with activation of the immune system. They found many similarities in T-cell receptors in the cervical tissue of two of the vaccinated patients, “suggesting that the T-cells are seeing the same thing,” says Trimble.
The Johns Hopkins team says it plans to enrol some 20 more patients, testing a combination of the vaccines and a topical cream to enhance the immune response locally.
Trimble explains that the location of cervical lesions gives scientists an advantage in their vaccination approach. “It’s important that we can monitor these cervical lesions closely,” says Trimble.
She says that the conventional practice of measuring vaccine effectiveness via blood tests probably began with mouse models used for immunotherapy research. “But the way that HPV and the immune system behave in humans may be far different,” she says.
HPV causes nearly all cervical, anal, vaginal, and penile cancers and nearly two-thirds of oral cancers. In the cervix, about 20 to 25% of high-grade lesions will disappear spontaneously. Because there is no standard way to predict lesions that will disappear, the current standard of care for these lesions is surgical removal. Current preventive vaccines for HPV are not effective on women already exposed to the ubiquitous virus.
Brain uses serotonin to perpetuate chronic pain
Setting the stage for possible advances in pain treatment, researchers at The Johns Hopkins University and the University of Maryland report they have pinpointed two molecules involved in perpetuating chronic pain in mice. The molecules, they say, also appear to have a role in the phenomenon that causes uninjured areas of the body to be more sensitive to pain when an area nearby has been hurt. A summary of the research was January 23 in the journal Neuron.
“With the identification of these molecules, we have some additional targets that we can try to block to decrease chronic pain,” says Xinzhong Dong, Ph.D., associate professor of neuroscience at the Johns Hopkins University School of Medicine and an early career scientist at Howard Hughes Medical Institute. “We found that persistent pain doesn’t always originate in the brain, as some had believed, which is important information for designing less addictive drugs to fight it.”
Chronic pain that persists for weeks, months or years after an underlying injury or condition is resolved afflicts an estimated 20 to 25% of the population worldwide. It can be caused by everything from nerve injuries and osteoarthritis to cancer and stress.
In their new research, the scientists focused on a system of pain-sensing nerves within the faces of mice, known collectively as the trigeminal nerve. The trigeminal nerve is a large bundle of tens of thousands of nerve cells.
Each cell is a long “wire” with a hub at its centre; the hubs are grouped together into a larger hub. On one side of this hub, three smaller bundles of wires – V , V2 and V3 – branch off. Each bundle contains individual pain-sensing wires that split off to cover a specific territory of the face. Signals are sent through the wires to the hubs of the cells and then travel to the spinal cord through a separate set of bundles. From the spinal cord, the signals are relayed to the brain, which interprets them as pain.
When the researchers pinched the V2 branch of the trigeminal nerve for a prolonged period of time, they found that the V2 and V3 territories were extra sensitive to additional pain. This spreading of pain to uninjured areas is typical of those experiencing chronic pain, but it can also be experienced during acute injuries, as when a thumb is hit with a hammer and the whole hand throbs with pain.
To figure out why, the researchers studied pain-sensing nerves in the skin of mouse ears. The smaller branches of the trigeminal V3 reach up into the skin of the lower ear. But an entirely different set of nerves is responsible for the skin of the upper ear. This distinction allowed the researchers to compare the responses of two unrelated groups of nerves that are in close proximity to each other.
To overcome the difficulty of monitoring nerve responses, Dong’s team inserted a gene into the DNA of mice so that the primary sensory nerve cells would glow green when activated. The pain-sensing nerves of the face are a subset of these.
When skin patches were then bathed in a dose of capsaicin – the active ingredient in hot peppers – the pain-sensing nerves lit up in both regions of the ear. But the V3 nerves in the lower ear were much brighter than those of the upper ear. The researchers concluded that pinching the connected-but-separate V2 branch of the trigeminal nerve had somehow sensitized the V3 nerves to “overreact” to the same amount of stimulus.
Applying capsaicin again to different areas, the researchers found that more nerve branches coming from a pinched V2 nerve lit up than those coming from an uninjured one. This suggests that nerves that don’t normally respond to pain can modify themselves during prolonged injury, adding to the pain signals being sent to the brain.
Knowing from previous studies that the protein TRPV1 is needed to activate pain-sensing nerve cells, the researchers next looked at its activity in the trigeminal nerve. They showed it was hyperactive in injured V2 nerve branches and in uninjured V3 branches, as well as in the branches that extended beyond the hub of the trigeminal nerve cell and into the spinal cord.
Next, University of Maryland experts in the neurological signaling molecule serotonin, aware that serotonin is involved in chronic pain, investigated its role in the TRPV1 activation study. The team, led by Feng Wei, M.D., Ph.D., blocked the production of serotonin, which is released from the brain stem into the spinal cord, and found that TRPV1 hyperactivity nearly disappeared.
Says Dong: “Chronic pain seems to cause serotonin to be released by the brain into the spinal cord. There, it acts on the trigeminal nerve at large, making TRPV1 hyperactive throughout its branches, even causing some non-pain-sensing nerve cells to start responding to pain. Hyperactive TRPV1 causes the nerves to fire more frequently, sending additional pain signals to the brain.”
Depression in pregnant mothers may alter pattern of foetal brain growth
Depression is a serious mental illness that has many negative consequences for sufferers. But depression among pregnant women may also have an impact on their developing babies.
Children of depressed parents are at an increased risk of developing depression themselves, a combination of both genetic and environmental factors. These children also display alterations in the amygdala, a brain structure important for the regulation of emotion and stress. However, prior work in this area has assessed children years after birth, which means that the timing of these alterations has remained unidentified.
Researchers led by Dr Anqi Qiu at the National University of Singapore now have the answers, with their new work published in the December 2013 issue of Biological Psychiatry.
They set out to perform a direct analysis of prenatal maternal depression and variation in the foetal development of the amygdala. To do so, they recruited 157 pregnant women who completed a depression questionnaire during their 26th week of pregnancy. Later, within two weeks of birth, newborns underwent magnetic resonance imaging scans to ascertain the structure of their amygdala and diffusion tensor imaging scans to determine the integrity of the amygdala’s pattern of neural connections.
The volume of the amygdala did not differ between the infants regardless of their mothers’ depression status. However, the researchers found significantly reduced structural connectivity (i.e., lower fractional anisotropy and lower axial diffusivity) in the right amygdala of infants of mothers with high levels of depression symptoms.
In other words, the amygdala’s microstructure (e.g., its “wiring”) was abnormal in the infants born to depressed mothers.
This important finding suggests that a propensity for abnormal amygdala function, a feature of mood and anxiety disorders, may be transmitted from mother to child during foetal life. This finding suggests one new path that a history of maternal depression might contribute to a life-long increase in the vulnerability to mental illness.
This study provides added evidence supporting the notion that mental health screening should be included among the medical evaluations that women undergo when they discover that they are pregnant. Indeed, the authors conclude that their study supports that “interventions targeting maternal depression should begin early in pregnancy”.
Research shows childhood influences may affect adult eating habits
New research has examined the influence of advertising on adult eating habits and suggests that exposure to beloved characters of our childhood are still influencing our food choices as adults. Popular and long-standing food advertising characters include Ronald McDonald, the Laughing Cow and Tony the Tiger.
The research, led by Dr Paul Connell of Cass Business School in Dubai, part of City University London, suggests that adults could have a positive bias toward brands with which they had an affinity as kids.
The research has important implications in the Gulf region where consumption of junk food is extremely high and obesity poses a real health burden. World Health Organisation statistics suggest 20 to 30% of people in the Middle East are obese and addressing the exposure to unhealthy brands as children could offer an interesting approach in tackling the condition.
Increased consumption of more energydense, nutrient poor foods with high levels of sugar and saturated fats (fast foods), in combination with reduced physical activity, have led to obesity rates that have risen three-fold or more since 1980 in many areas globally, including the ME, according to the WHO.
Dr Connell comments: “People should check the labels of the products they’ve loved since childhood. It’s possible that affectionate feelings for brand characters mean they are overlooking relevant nutritional information. Many advertising characters have been around for decades, so parents should be mindful that their judgment of products associated with ads they saw as children themselves, might be clouded, particularly when making dietary choices for their children.”
The research also suggests that public health and safety campaigns aimed at children may affect them throughout their lives, suggesting that governments and schools have a responsibility to educate children from a young age on the importance of nutrition.
Dr Connell adds: “We recommend that health-oriented media campaigns targeted at children should aim to relate to children on an emotional level, for example, by emphasizing loveable characters and fun narratives.”
Further research by Dr Connell and his colleagues also discovered a link between exposure to healthy images and a decrease in consumption of junk food. The team found that when individuals are exposed to healthy images and words, they were more able resist unhealthy snacks later in the day.
The research poses an interesting approach to affecting eating habits and could be explored in the regions schools as a tactic to positively influence children’s mealtime choices. The results also have a wider significance, informing those who play a vital role in improving public health; food marketers, the media and the government.
Professor Connell said: “The timings of healthy advertisements and public service messages can be optimised in order to help people adhere to healthier lifestyles by boosting their levels of self-regulation over the course of the day.”
Fit teenagers are less likely to have heart attacks in later life
Researchers in Sweden have found an association between a person’s fitness as a teenager and their risk of heart attack in later life. In a study of nearly 750,000 men, they found that the more aerobically fit men were in late adolescence, the less likely they were to have a heart attack 30 or 40 years later.
The study, published online 8 January 2014 in the European Heart Journal found that the relationship between aerobic fitness and heart attack occurred regardless of the men’s body mass index (BMI) when they were teenagers. However, fit but overweight or obese men had a significantly higher risk of a heart attack than unfit, lean men.
Professor Peter Nordström, of Umeå University, Umeå, Sweden, who led the research, said: “Our findings suggest that high aerobic fitness in late adolescence may reduce the risk of heart attack later in life. However, being very fit does not appear to fully compensate for being overweight or obese in respect to this risk. Our study suggests that it’s more important not to be overweight or obese than to be fit, but that it’s even better to be both fit and a normal weight.”
Prof Nordström and his colleagues analysed data from 743,498 Swedish men who underwent medical examinations at the age of 18 when they were conscripted into the Swedish armed forces between 1969- 1984. Aerobic fitness was measured by a cycle test where the resistance was gradually increased until they were too exhausted to continue.
The researchers found that every 15% increase in aerobic fitness was linked to an approximately 18% reduced risk of a heart attack (myocardial infarction or MI) 30 years later after adjusting for various confounding factors including socioeconomic background and BMI. The results also suggested that regular cardiovascular training in late adolescence was independently associated with an approximately 35% reduced risk of an early heart attack in later life.
“There were 7,575 myocardial infarctions in 620,089 men during the total follow-up time where aerobic fitness was measured, which means the cumulative incidence was about 1222 per 100,000 men,” explained Prof Nordström. “There were 271,005 men (43.7%) who were normal weight or lean, and who had an aerobic fitness that was better than the average. Among these lean, fit men there were 2176 MIs, resulting in a cumulative incidence of about 803 MIs per 100,000 men. Thus, the cumulative incidence of MIs was reduced by about 35% in this group.”
However, he warned that the study showed only that there was an association between fitness and a reduction in heart attacks, and it could not show that being aerobically fit caused the reduced risk of heart attack.
“The relationship between aerobic fitness and heart disease is complex and may well be influenced by confounding factors that were not investigated in this study. For instance, some people may have a genetic predisposition to both high physical fitness and a low risk of heart disease. In a recent study of twins, we found that 78% of the variation in aerobic fitness at the time of conscription is related to genetic factors.”
Prof Nordström said: “As far as we know, this is the first study to investigate the links between an objective measure of physical fitness in teenagers and risk of heart attack in the general population. Further studies are needed to investigate the clinical relevance of these findings, but given the strong association that we have found, the low cost and easy accessibility of cardiovascular training, and the role of heart disease as a major cause of illness and death worldwide, these results are important with respect to public health.”
New combination treatment offers breakthrough for Hep C therapy
Efforts to cure hepatitis C, the liver-damaging infectious disease, are about to get simpler and more effective, according to new research at Johns Hopkins and elsewhere.
In a study reported in the January 16 2014 issue of the New England Journal of Medicine, researchers say combination treatments involving a pair of experimental, oral antiviral drugs, daclatasvir and sofosbuvir, were safe and highly effective in the treatment of hepatitis C. The combination therapy worked well even in the patients who are hardest to treat, in whom the conventional “triple therapy” with hepatitis C protease inhibitors, telaprevir or boceprevir, plus peginterferon and ribavirin had failed to cure the infection.
“This research paves the way for safe, tolerable and effective treatment options for the vast majority of those infected with hepatitis C,” says study leader Mark Sulkowski, MD, medical director of the Johns Hopkins Center for Viral Hepatitis. “Standard treatments for the disease are going to improve dramatically within the next year, leading to unprecedented advances for the treatment of patients infected with the hepatitis C virus.”
The research was conducted on 211 men and women with any of the three major types of the disease who were treated at 18 medical centres across the United States and Puerto Rico. Among patients with genotype 1 – the most common strain of the infection in the United States – 98% of the 126 previously untreated patients and 98% of 41 patients whose infections remained even after the triple therapy were considered cured, with no detectable virus in their blood three months after the treatment had stopped. Results were similar in study participants infected with genotypes 2 or 3, strains which are less common in the United States.
The study participants took a daily combination of 60 milligrams of daclatasvir and 400 milligrams of sofosbuvir, with or without ribavirin.
In December last year, the US FDA approved sofosbuvir in combination with peginterferon and ribavirin for the treatment of genotype 1 infection and in combination with only ribavirin for genotype 2 and 3 infection. Daclatasvir has not yet been approved by the FDA.
Sulkowski says that if declatasavir and other new drugs for hepatitis C win approval from the FDA, the dreaded weekly injections of peginterferon will be a thing of the past.
Sulkowski, a professor at the Johns Hopkins University School of Medicine, also says that the so-called “pill burden” of what had been standard therapy for genotype 1 could go down from some 18 pills per day and one injection per week to as few as one or two pills per day and no injections. Side effects from the new pill combination were generally mild, but included fatigue, headache and nausea, a safety profile that Sulkowski says compares favourably with that of the peginterferon-based therapy, which is tied to severe side effects which may include fatigue and depression.
The new study is one of the first to show that hepatitis C can be cured without the use of ribavirin, which is known to cause anemia.
New test for meningitis
A new test for meningitis – which could help deliver faster and more effective treatments for patients – has been developed through University of Strathclydeled research.
The onset of meningitis is often rapid and severe, particularly when a bacterial infection is the cause – and the latest research could speed up diagnosis, leading to better outcomes for patients.
Dr Karen Faulds, a Reader in Strathclyde’s Department of Pure and Applied Chemistry, led the study. She said: “Meningitis is a hugely virulent and, in some forms, potentially highly dangerous infection. The type of antibiotic used to treat it depends on the strain of meningitis, so it is essential to identify this as quickly as possible.”
Several types of bacteria cause meningitis and each is sensitive to different antibiotics. Dr Faulds and PhD student Kirsten Gracie, from the Centre for Molecular Nanometrology at Strathclyde – with partners at the University of Manchester – used a spectroscopic imaging technique known as SERS (surface enhanced Raman scattering) to identify which bacteria were present in a single sample, with a view to analysing cerebral spinal fluid from patients suspected to have meningitis.
Dr Faulds said: “The great advantage of the SERS technique is that it gives sharp, recognisable signals, like finger printing, so we can more easily discriminate what analytes – or chemical substances – are present in a mixture.”
A series of DNA probes, containing dyes detectable by SERS, made it possible to single out the different pathogens, three types of which Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidisis were tested for. The faster the type of bacteria can be identified by DNA analysis, the faster patients can receive the most effective antibiotic for their condition.
This also reduces the need for broadband antibiotics, overuse of which is increasing bacterial resistance. Combining the SERS technique with chemometrics – data-driven extraction of information from chemical systems – means the amount of bacteria in a sample can be measured whilst simultaneously identifying the bacteria. The chemometrics work was carried out in collaboration with Professor Roy Goodacre at the University of Manchester.
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