SARS-COV-2 Infection Induces Antibodies Capable of Killing Infected Cells Regardless of Disease Severity

Drawing on epidemiological field studies and the FrenchCOVID hospital cohort coordinated by Inserm, teams from the Institut Pasteur, the CNRS and the Vaccine Research Institute (VRI, Inserm/University Paris-Est Créteil) studied the antibodies induced in individuals with asymptomatic or symptomatic SARS-CoV-2 infection. The scientists demonstrated that infection induces polyfunctional antibodies. Beyond neutralization, these antibodies can activate NK (natural killer) cells or the complement system, leading to the destruction of infected cells. Antibody levels are slightly lower in asymptomatic as opposed to symptomatic individuals, but polyfunctional antibodies were found in all individuals. These findings show that infection induces antibodies capable of killing infected cells regardless of the severity of the disease. The research was published in the journal Cell Reports Medicine.

Nearly half of those infected with SARS-CoV-2 do not develop symptoms. Yet, the immune response induced by asymptomatic forms of COVID-19 remains poorly characterized. The extent of the antiviral functions of SARS-CoV-2 antibodies is also poorly characterized. Antibodies are capable of both neutralizing the virus and activating “non-neutralizing” functions. The latter include antibody-dependent cellular cytotoxicity (ADCC) and complement activation, which are major components of the immune response and play a key role in the efficacy of some vaccines. ADCC is a two-stage process in which infected cells are first recognized by antibodies, then destroyed by NK cells. The complement system consists of a series of plasma proteins that also enable the elimination of cells targeted by antibodies. The ability of antibodies to activate these non-neutralizing functions has been little described for SARS-CoV-2 infection so far.

The teams from the Institut Pasteur, the CNRS and the VRI (Inserm/University Paris-Est Créteil) initially developed new assays to measure the various antibody functions. They produced assays to study cell death induced by NK cells or by complement in the presence of antibodies. By analyzing cultures in real time using video microscopy, the scientists showed that NK cells kill infected cells in the presence of antibodies, demonstrating new antiviral activity employed by SARS-CoV-2 antibodies.

The scientists then examined the serum of patients with symptomatic or asymptomatic forms of COVID-19 with their new assays. They also used methods previously developed at the Institut Pasteur, such as the S-Flow assay, to detect SARS-CoV-2 anti-spike antibodies, and the S-Fuse assay, to measure the neutralization capacity of these antibodies

“This study demonstrated that individuals infected with SARS-CoV-2 have antibodies that are capable of attacking the virus in different ways, by preventing it from entering cells (neutralization) or by activating NK cells to kill infected cells (via ADCC). We therefore use the term polyfunctional antibodies,” explains Timothée Bruel, co-last author of the study and a scientist in the Institut Pasteur’s Virus & Immunity Unit[1] and at the VRI.

By comparing different groups of patients, the scientists then showed that asymptomatic individuals also have polyfunctional antibodies and that their response is slightly weaker than those of patients with moderate forms of COVID-19.

“The study reveals new mechanisms of action of SARS-CoV-2 antibodies and suggests that the protection induced by an asymptomatic infection is very close to that observed after a symptomatic infection,” concludes Olivier Schwartz, co-last author of the study, head of the Virus & Immunity Unit and at the VRI.

Source: Institut Pasteur

Study: Music Can Speed Your Way to Sleep – Lullaby Effect

Cara Murez wrote . . . . . . . . .

Music hath charms to soothe you off to slumber, new research suggests.

The study found that calming tunes at bedtime seem to help older people struggling with insomnia.

“We found music therapy was effective for older adults with sleep disturbance,” said study co-author Yen-Chin Chen, an associate professor of nursing at National Cheng Kung University in Tainan, Taiwan.

That’s one of three takeaways from the study.

“Second, listening to sedative music is more effective than listening to rhythmic music,” Chen said. “And listening to music for longer than four weeks is more effective for older adults with sleep disturbance.”

Getting enough sleep can improve a person’s thinking and memory function, as well as energy levels, Chen said.

The findings were published online in the Journal of the American Geriatrics Society.

The study authors noted that adults aged 60 and up appear to sleep better when they listen to music for 30 minutes to an hour at a time, and that they see the greatest benefit by trying tunes for at least a month.

For the review, the researchers looked at five studies with 288 participants.

About half of the participants listened to bedtime music. The rest either had other treatments for their sleep problems or none at all. The research compared different treatments to music, and rhythmic music to calming music.

Listening to calming music, which has a slower tempo and smoother melody, resulted in better sleep, the investigators found. By slowing your heart rate and breathing, and lowering your blood pressure, calming music can lower your stress and anxiety, the researchers theorized.

Older adults need seven to nine hours of sleep each night, according to the U.S. National Institute on Aging.

About 40% to 70% of older adults have sleep problems, and about 40% experience insomnia, waking often during the night or too early in the morning, the study authors noted in the report.

Sleep problems can contribute to irritability and depression, cause memory problems, and lead to falls and accidents.

Dr. Alayne Markland, an associate professor of medicine in the division of gerontology, geriatrics, and palliative care at the University of Alabama, Birmingham, reviewed the findings.

“I think this is novel work,” she said, adding that more work remains, especially with older adults who have thinking and memory issues. The study did not include people with Alzheimer’s disease, Parkinson’s disease or other neurologic conditions.

“This could be a good thing to try — we just don’t have that data,” Markland said. Music could be a very effective sleep aid for some folks, as long as they don’t leave it on all night long, she added.

Sleep is an important driver of metabolism, activity levels, social interaction and mental health for seniors, so getting recommended amounts is important, Markland stressed.

It’s hard to say based on these findings alone who might be better suited to other strategies, such as cognitive behavioral therapy for insomnia (CBTI) with a trained professional, Markland said. CBTI can target behaviors around falling asleep and staying asleep.

According to a research summary from the American Geriatrics Society, one limitation of the study was that people who listened to music received more attention from researchers, which could be why their sleep improved. Also, all of the study participants had similar sleep problems, so this music strategy many not help folks who are struggling with sleep for other reasons.

Dr. Rafael Pelayo, a sleep specialist at Stanford Sleep Medicine Center in California, noted that most older people who are healthy don’t have any sleep issues at all. Some have poor sleep as a result of other medical conditions, he added.

For example, someone with cataracts may sleep poorly because less light goes into their eyes, which can influence their sleep-wake cycles, he explained. Menopause, depression, sleep apnea, thyroid issues or iron deficiency can also cause sleep issues.

And over time, poor sleep can become a habit, Pelayo pointed out.

People who experience chronic pain or post-traumatic stress disorder have particular sleep challenges, but there are tools to help with even those sleep issues, according to Pelayo.

“There are many reasons an older person may sleep poorly,” he said. “Having said that, most of the conditions will improve when addressed correctly.”

Pelayo sees the greatest potential for music as a sleep aid in those whose sleep issues are stress-related. The predictability of music can help these folks get into the right state of mind and promote serenity, he said.

“People should go to bed, feeling safe, comfortable and loved. That’s the state of mind you want to be in: safe, comfortable and loved,” Pelayo said. “That’s how our children sleep and that’s what we hope to provide our kids and you need to provide for yourself. If you go to bed thinking ‘How bad will it be tonight?’ that will make you sleep lighter.”

Source: HealthDay

Lamburgers a la Grecque with Cilantro-mint Chutney

Ingredients

Cilantro-mint Chutney

1/3 cup plain yogurt
2 tablespoons chopped yellow onion
1-1/2 fresh jalapeno chilies, stemmed, seeded, and chopped
1-1/2 tablespoons chopped fresh ginger root
3/4 cup fresh cilantro (coriander) leaves
1/3 cup fresh mint leaves
1 large garlic clove, chopped
1/2 teaspoon salt, preferably kosher
pinch of sugar

Lamburgers

1 pound lean ground sirloin
1 pound lean ground lamb
1 garlic clove, minced
1/2 cup crumbled feta cheese (about 2 ounces)
1/3 cup minced pitted Kalamata olives
1 teaspoon salt, preferably kosher
6 medium-sized pita breads, preferably thicker variety
1/4 cup fruity olive oil, preferably extra-virgin
1 teaspoon ground cumin mixed with 1 teaspoon ground coriander
vegetable oil for brushing on grill rack

Condiments

tomato slices
thin red onion slices
red leaf lettuce leaves

Method

  1. To make the chutney, combine all the ingredients in a blender or food processor and blend thoroughly. Cover and chill for at least several hours or as long as 24 hours.
  2. In a grill with a cover, prepare a medium-hot fire, preferably with natural hardwood charcoal, for direct-heat cooking.
  3. To make the burgers, combine the sirloin, lamb, garlic, cheese, olives, and salt in a large bowl. Handling the meat as little as possible to avoid compacting it, mix well. Divide the mixture into 6 equal portions and form the portions into round patties to fit the pica breads. Brush the patties with the olive oil and then sprinkle with the cumin mixture.
  4. When the fire is ready, brush the grill rack with vegetable oil.
  5. Place the patties on the grill, cover, and cook until browned on the bottom, about 4 minutes.
  6. With a wide spatula, turn the patties and cook until done to preference, about 4 minutes longer for medium-rare.
  7. During the last few minutes of cooking, place the pica breads on the outer edges of the grill and turn to toast lightly on both sides.
  8. Place the patties inside the pica bread pockets and add the chutney.
  9. Offer the condiments at the table.

Makes 6 servings.

Source: Burgers


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