Booze inhibits more than just your judgement: it impairs your immune system’s ability to fight off pathogens, according to a study published last week in the journal BMC Immunology. Researchers exposed human monocytes, a type of white blood cell vital for a functioning immune system, to an amount of alcohol equivalent to a blood alcohol concentration of 0.1 (around the legal level in most states). Compared to booze-free cells, monocytes exposed to both short- and long-term levels of alcohol produced significantly less type 1 interferons, chemicals the help recruit immune cells to stage an antiviral response (and also have anti-tumor activity). Excessive drinking has long been thought to interfere with the body’s ability to fight disease, and boozing is an important risk factor for hepatitis C and barrier to treatment in HIV. But not much had been known about the mechanisms behind the effect.

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Scientists have now sequenced the genome of the Atlantic cod, revealing something unusual: the cod is missing an important component of the adaptive immune system found in almost all jawed vertebrates. In particular, when the researchers compared the cod’s genome to that of the stickleback (a closely related fish that has already been sequenced), they saw that the Atlantic cod does not have genes that code for the proteins MHC II, CD4, and invariant chain, all of which work together to help the body recognize and fight off invading bacteria and parasites.

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Could Neanderthal DNA have protected our ancestors from diseases?

What’s the News: While we humans have certainly outlasted our hominin cousins, new research shows that Neanderthal and Denisovan genes may have helped us spread far and wide. By mating with the two species, our ancestors acquired genes that allowed them to adapt to diseases outside of Africa far quicker than would have been otherwise possible, according to Peter Parham, a professor of microbiology and immunology at Stanford University.

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Mouse embyronic stem cells

What’s the News: Reprogrammed stem cells—cells taken from an adult and turned back into stem cells—can be rejected by the body, at least in mice, suggests a new Nature study. Donated tissues and organs are often attacked by a patient’s immune system, since reprogrammed stem cells can be made from a patient’s own skin, researchers had hoped these cells offered a way to avoid such rejection by letting patients, in essence, donate tissue to themselves. But the new finding may be a significant setback to what is a promising line of treatment.

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Metastatic melanoma cells

What’s the News: Souped-up cells from a patient’s own immune system could one day be used to treat advanced melanoma, according to a preliminary study published in Science Translational Medicine investigating the safety of the technique. The researchers manipulated a patient’s immune system cells to better recognize cancer cells in the lab and then re-introduced those cells into the body—an approach called “adoptive T-cell therapy.”

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Earlier this week at a scientific conference in Boston, HIV researchers announced a remarkable success in countering the virus’ drain on the immune system. But this early step is far from a cure.

Why it’s exciting:

Carl June and colleagues tested six male patients who already had HIV and were taking a standard antiviral regimen. Like many HIV patients, the drugs helped them, but their counts of immune cells stayed low. June’s team tested a therapy created by Sangamo BioSciences in Richmond, California, that alters a patient’s actual white blood cells to make them more HIV-resistant.

Researchers removed a sample of CD4⁺ T cells, the type of immune cells affected by HIV, from each man and used Sangamo’s enzyme to disrupt the CCR5 gene, which encodes a protein that HIV uses to enter CD4⁺ cells. The engineered cells were then infused back into the patients. Immune-cell counts subsequently rose for five of the six patients who received the therapy. “It’s very exciting,” says John Rossi, a molecular biologist at the City of Hope’s Beckman Research Institute in Duarte, California. “If they did this several times in a given patient, you could establish a high percentage of resistant cells.” [Nature]

The idea came from the “Berlin Patient,” who we’ve written about before at 80beats. He became famous after receiving a donation of bone marrow from someone who carried a mutation in CCR5 that made them resistant to HIV.

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Talk about early intervention. One day, a fetus with a genetic disease may be able to get treatment before it even leaves the womb–and that treatment will come in the form of an extra gift from mom. While this scenario will only come to pass if new mouse research can be translated to humans, the finding are exciting.

The new work solves a medical mystery. When researchers realized they could diagnose a fetus with certain genetic illnesses as early as the first trimester, they plunged into the search for in utero treatments. Ailments like sickle cell anemia and some immune disorders might be treatable with blood stem cells taken from a donor’s bone marrow, researchers thought: the transplanted cells would multiply and populate the fetus’s bone marrow with healthy blood-forming cells, and the fetus’s immature immune system wouldn’t reject the foreign entities. But when researchers tried such transplants, they didn’t work.

“The fact that fetal stem cell transplantation has not been very successful has been puzzling, especially given the widely accepted dogma that the immature fetal immune system can adapt to tolerate foreign substances,” said co-senior author Qizhi Tang…. “The surprising finding in our study is that the mother’s immune system is to blame.” [press release]

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Suppose that Alzheimer’s disease, like a bacterial or viral infection, inspires the immune system to take action and defend the body. If this is true, then there must be antigen proteins that are specific to the disease, which the body recognizes as foreign and which triggers the mustering of a defense. Could doctors catch a glimpse of that process and diagnose the disease earlier? That’s the hope behind a study out this week in Cell, led by Thomas Kodadek.

Many new efforts to speed up diagnosis of Alzheimer’s are ongoing, with some, like Kodadek’s, looking for a signal in the bloodstream. The problem is, scientists don’t know what antigens are the signature of the disease, nor which antibodies the immune system raises to go after them. So they set a trap.

On a slide, Kodadek’s team assembled thousands of different shapes of peptoids—molecules that are slight variations of the peptide molecules found in our bodies—and exposed them to blood samples from people with Alzheimer’s and without. The idea was, if particular peptoids bound only to antibodies from people with Alzheimer’s and not to antibodies of people without, then those antibodies they snagged could be considered a signature of Alzheimer’s in the bloodstream.

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A new study is providing insights into the 2009 swine flu epidemic, and why more serious complications arose in healthy middle-aged people than expected. The researchers say the culprit may be antibodies to seasonal flu found in the seriously ill patients, which might have caused an immune system overreaction in the lungs.

“Nobody really had a good explanation for why middle-aged people seemed to have more severe disease than would have been expected,” says Richard Scheuermann, an immunologist at the University of Texas Southwestern Medical Center in Dallas. “This explanation is the first one that I’ve seen that actually makes sense.” [Nature News]

Normally, severe flu illness happens in the very young (who haven’t been previously exposed to the flu and don’t have protective immunity) and the elderly (who have weakened immune systems). Instead of affecting these groups, the 2009 pandemic H1N1 “swine flu” primarily caused severe reactions in middle-aged adults.

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In recent weeks we’ve covered new experimental treatments that involve injecting stem cells into patients to treat conditions like stroke and spinal injury. But in a new study, British researchers have pinpointed the possibility—in rats at least—of stimulating the body’s own stem cells to repair the chronic damage brought on by multiple sclerosis.

In MS patients, the immune system mistakenly attacks what’s called the myelin sheath, the protective layer around the axons of nerve cells.

The loss of myelin in MS sufferers leads to damage to the nerve fibres in the brain that send messages to other parts of the body, leading to symptoms ranging from mild numbness to crippling paralysis. [AFP]

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From Ed Yong:

The vast majority of people who are infected with HIV go on to develop AIDS. Their bodies become riddled with the virus, their immune systems falter, and they are besieged by life-threatening infections. But not everyone shares the same fate. Around 1 in every 300 people infected with HIV carry genetic trump cards that allow them to resist and control the virus. These “HIV controllers” can live with the virus for years. They never develop AIDS and they live long, healthy lives, even if they never take any medication. Their genetic secrets are slowly being revealed.

Researchers studying thousands of people with HIV, some with the controllers and some without, found something surprising:

Amazingly, every single one of these variants sits within a specific part of our sixth chromosome, among a set of genes called class I HLA genes. The proteins they produce form part of the internal security checks that defend us from infections. They grab small pieces of other proteins from inside our cells and display them on the outside, waving them under the noses of passing T-cells. If the T-cells recognise these pieces as parts of bacteria, viruses or other foreign invaders, they tell the infected cell to self-destruct and set the immune system on red alert.

Check out the rest of this post at DISCOVER blog Not Exactly Rocket Science.

Related Content:
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80beats: Good News: Anti-Microbial Gel Cuts HIV Infection Rates for Women
80beats: New HIV Hope? Researchers Find Natural Antibodies That Thwart the Virus
80beats: Gene Therapy Hope for HIV: Engineered Stem Cells Hold Promise
80beats: Did the Eradication of Smallpox Accidentally Help the Spread of HIV?

Image: Wikimedia / HIV Budding

The snowy, wind-blown Scottish archipelago of St. Kilda may be inhospitable, but because it is inhospitable,  it is an ideal natural laboratory. The last people left this place behind nearly a century ago, but the sheep stayed. And the in absence of human interference in their breeding, the sheep of St. Kilda have shown scientists something peculiar.

It has to do with the relationship between the immune system and reproduction. Andrea Graham and colleagues have studied the islands’ Soay sheep for years and years, and found the average lifespan of the ewes to be about 6 years. However, there’s great variation in there: Some lived just a few years, and some as many as 15.

The short-lived ewes had lower concentrations of antibodies than the longer-lived ones, which suggested why their lives were so short. But why was natural selection not weeding them out? Dr. Graham said the researchers found this to be a puzzle: “What are all these sheep doing with low antibody concentrations?” [The New York Times]

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As the deadly facial cancer that has drastically reduced the population of Tasmanian devils continues to spread through the species, the main hope for scientists trying to save them from extinction has been to hunt for devils that might be resistant to the disease, and to try to take advantage of that immunity. Reporting in the Proceedings of the Royal Society B, Kathy Belov and her team say they may finally have done just that: Some devils from northwest Tasmania, they say, are genetically distinct from the rest and could be resistant to the disease.

Belov says that most Tasmanian devils have immune systems so closely related that they’re all susceptible to the disease, which spreads when the devils bite each other on the face and leave behind tumor cells. The bitten devils’ immune systems don’t recognize the tumor cells as foreign, allowing them to take hold. Scientists have given the iconic marsupial as little as 25 years left if efforts are not made to solve the cancer riddle. The population has dwindled by a whopping 70 per cent since the first reported case of devil facial tumour disease in 1996 [Sydney Morning Herald]. Previous research showed that the marsupials are more socially linked that researchers initially believed, which is bad news for those trying to contain the disease.

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In very rare cases, the womb is a dangerous place for a developing fetus. Researchers have found that pregnant women can pass on cancer cells to their unborn babies, if those cancer cells carry a particular genetic mutation. The new study resolves a longstanding puzzle, because in theory any cancer cells that manage to cross the placenta into the baby’s bloodstream should be targeted for destruction by the child’s immune system. But there are records of 17 cases of a mother and baby appearing to share the same cancer – usually leukaemia or melanoma [BBC News].

In the study, which will be published in Proceedings of the National Academy of Sciences, researchers used a genetic “fingerprinting” technique to match the cancer cells found in a mother and baby. The case, involving a Japanese mother aged 28 and her daughter, revealed that both patients’ leukaemic cells carried the identical mutated cancer gene BCR-ABL1 even though the infant had not inherited this gene [The Times]. This meant that the child, who was diagnosed with cancer at the age of 11 months, could not have developed leukemia independently.

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Breaking news from the “Great–one more thing to worry about” file! Microbiologists have looked inside showerheads and found that the dark and damp crannies provide perfect conditions for the growth of bacterial film. A new study in the Proceedings of the National Academy of Sciences looked at showerheads in nine cities and found that they harbor colonies of Mycobacterium avium in particular, a type of microbe that can cause lung ailments. “If you are getting a face full of water when you first turn your shower on, that means you are probably getting a particularly high load of Mycobacterium avium, which may not be too healthy,” says lead author Norman Pace [CNET].

These findings may sound alarming, but the researchers stress that bacteria is everywhere–in the air we breathe and the water we drink–and for the most part, these microbes pose little danger. Study coauthor Leah Feazel says of the shower findings: “This really shouldn’t concern average, healthy people. The main concern is for people who are immune-compromised” [Reuters]. People with AIDS or other immune system disorders should consider getting metal showerheads, which harbor less bacteria than plastic, and changing them often. Anybody else who feels uncomfortable with the idea of a bacterial shower has a couple of options–they can let the shower run for 30 seconds or so before stepping in to flush out some of the microbes, or they can take a bath.

Related Content:
80beats: Your Belly Button Is a Lush Oasis for Bacteria, and That’s a Good Thing
80beats: Researchers Find a Unique Bacterial Ecosystem—In Your Mouth
80beats: Whoops! Anti-Bacterial Wipes Can Spread Disease

Image: flickr / stevendepolo