BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Immune System

Health and Disease in a New Light

Microbiota are groups of organisms that live on and in some mammals. Animals, such as humans, who live in a state of mutualism with these organisms have them mostly on parts of their body with large surface areas. This includes skin and the intestinal tract. The human gut microbiome is a complex community of organisms that have been studied over the past decades and most intensely within the past fifteen years. So far the information on the human gut microbiome is limited and the research on it is somewhat inconclusive, raising more questions than it answers questions; however, that is a side effect of most research that is just beginning to be analyzed more in depth. The idea that we are just now starting to study and understand these organisms that have lived on and in us for centuries is a topic that is cutting edge and very interesting.

Microbiota

A short coverage of information about microbiota in the intestinal tract includes the following. In mammalian animals, these organisms play an important role in the formation of intestinal mucosa as well as a healthy systematic immune system. Animals that lack microbial cells contain abnormal numbers of several immune cell types and immune cell products, as well as have deficits in local and systemic lymphoid structures. Therefore, their spleens and lymph nodes in them are poorly formed and their intestinal mucosa, deficient. Mice with a lack of microbiota were known to have a lower amount of plasma producing cells – which make antibodies of a certain type. This is due to the fact that the microbiota is regulated by the plasma cells in mammals and it is found unnecessary to have a large amount of them in animals lacking the organisms. These mice also exhibited an impaired ability to regulate cytokine levels – any of a number of substances, such as interferon, interleukin, and growth factors, which are secreted by certain cells of the immune system.

In 2010 there was a study done that was comprised of making cultures of these organisms and bacteria in the human intestinal tract outside of the human body because we do not have the necessary technology to study the microbiota in their hosts. This study yielded the publication of a paper titled “Gut Microbiota in Health and Disease” which gives a detailed overview of the findings of this study. Briefly, a colonization of mice lacking microbiota with altered Schaedler flora (ASF) was insufficient to promote differentiation of Th17 cells (which play an important role in defense against infection), despite the fact that ASF includes a number of bacteria from the Bacteroidetes phylum (microbiota). Researchers concluded the there is no way to be sure of the affects of microbiota. Meaning although there was no lack of microbiota, the mice still had an immune system deficiency in the same way that mice lacking any microbiota did. Since the health and abundance of microbiota in the gut microbiome is so closely related with the ability of the immune system of the host, it is concluded that changes in the microbiome can lead to onset of diseases/illnesses in the host. These factors can also change with environmental changes such a dietary choices of the host. Understanding the dynamics of the gut microbiome under different conditions will help us diagnose and treat many diseases that are now known to be associated with microbial communities.

Analyzing the affects of microbiota in the human gut can reveal topics about human pathology that we did not know before. Therefore, scientists look forward to the development of studies on this topic.

Don’t Kill Me Immune System! I’m a Friend.

Believe it or not, but not all bacteria is out to get you, especially some of your gut bacteria. These helpful bacteria can aid in digestion and overall healthy, but the question is, why doesn’t your immune system kill them just like harmful bacteria? In other words, how does the immune system differentiate between good and bad bacteria? For now, we are not really sure, but a study from March of this year by Immunologist Ivaylo Ivanov and his team at Columbia University could bring us closer to understanding this form of cell signaling.

The study focuses particularly on the interaction between T cells and segmented filamentous bacteria in the gut. Normally, the immune system would produce antibodies that would bind to antigens on the foreign cell’s surface. As a result, the cell would be marked for destruction by the immune system. However, through an experiment on mice, the researchers found that although the T cells were activated by the segmented filamentous bacteria, the T cells did not destroy the bacteria.

These gut bacteria located in human, mouse, and fish intestines cling themselves to the gut wall and have antigens. So why aren’t they killed? Well, the antigens are packaged in tiny vesicles located near the tip of the hook-like appendage that the bacteria uses to cling to the gut wall: the holdfast. Sorry, that’s about all I can give you. The rest is speculation at this point.

Nonetheless, Ivanov and his team discovered something previously unnoticed by finding these vesicles that hold antigens in segmented filamentous bacteria. They speculate that the T cells read antigens in different ways based on whether or not it’s exposed on the outside of the cell or packaged in a vesicle. In the end, this a big discovery that peaks my interest, especially for its implications on the study of cell signaling. What’s your hypothesis as to why the T cells don’t attack the gut bacteria?

Does Exposure to Toxins In the Environment Affect One’s Offspring’s Immune System?

A study has recently surfaced stating that maternal exposure to industrial pollution may harm the immune system of one’s offspring and that this impairment is then passed from generation to generation, resulting in weak body defenses against viruses.

Paige Lawrence, Ph.D., with the University of Rochester Medical Center’s Department of Environmental Medicine, led the study and conducted research in mice, which have similar immune system functions as humans. Previously, studies have shown that exposure to toxins in the environment can have effects on the respiratory, reproductive, and nervous system function among generations; however, Lawrence’s research is the first study to declare that the immune system is also impacted.

“The old adage ‘you are what you eat’ is a touchstone for many aspects of human health,” said Lawrence. “But in terms of the body’s ability to fights off infections, this study suggests that, to a certain extent, you may also be what your great-grandmother ate.”

“When you are infected or receive a flu vaccine, the immune system ramps up production of specific kinds of white blood cells in response,” said Lawrence. “The larger the response, the larger the army of white blood cells, enhancing the ability of the body to successfully fight off an infection. Having a smaller size army — which we see across multiple generations of mice in this study — means that you’re at risk for not fighting the infection as effectively.”

In the study, researchers exposed pregnant mice to environmentally relevant levels of a chemical called dioxin, which is a common by-product of industrial production and wast incineration, and is also found in some consumer products. These chemicals eventually are consumed by humans as a result of them getting into the food system, mainly found in animal-based food products.

The scientists found the production and function of the mice’s white blood cells was impaired after being infected with the influenza A virus. Researchers observed the immune response in the offspring of the mice whose mothers were exposed to dioxin. Additionally, the immune response was also found in the following generations, as fas as the great-grandchildren (or great- grandmice). It was also found that this immune response was greater in female mice.  This discovery now allows researchers to have more information and evidence to be able to more accurately create a claim about this theory.

As a result of the study, researchers were able to state that the exposure to dioxin alters the transcription of genetic instructions. According to the researchers, the environmental exposure to pollutants does not trigger a genetic mutation. Instead, ones cellular machinery is changed and the immune response is passed down generation to generation. This discovery explains information that was originally unexplainable. It is obviously difficult to just avoid how much toxins you are exposed to in the environment, but it is definitely interesting to see the extent of the immune responses in subsequent generations. We can only hope that this new information, and further discoveries, help people adjust what they release into this world that results in these harmful toxins humans are exposed to, and their offsprings.

 

 

 

Stem Cells and CRISPR

Many cells can reproduce but there are a few types of cells that are not able to reproduce. One of these types are nerve cells, the cells that cary messages from your brain to your body.  There are many ways nerve cells can be destroyed or damaged, by trauma or drug use.  Millions of people are effected by losing nerve cells and for so long no one could think of a way to recreate them; until the discovery of stem cells.

After fertilization, and when the newly formed zygote is growing, it is made up of a sack of cells.  Some of these cells are stem cells which develop according to their environment. Because of the behavior of stem cells, scientists theorized that if they placed stem cells in the brain or spinal chord, two areas that have an abundance of neurons, the stem cells would turn into a neuron because of the environment it was in.  But, when they tried introducing stem cells into the body, the immune system treated them as an foreign body, as it should. Our immune system has to treat anything that does not come from our body as an enemy or we could get extremely sick.  However, the downside is organ transplants, blood transfusions, etc. are dangerous because they could cause a serious immune rejection.

Someone experiencing a spleen transplant rejection

Cells have a surface protein that displays molecular signals to identify if it is self or foreign.  Removing the protein causes NK (natural killer) cells to target the cell as foreign. Scientist haven’t been able to figure out how to make a foreign cell not seem foreign until Lewis Lanier, chair of UCSF’s Department of Microbiology and Immunology, and his team found a surface protein that, when added to the cell, did not cause any immune response.  The idea would be to use CRISPR/cas9 to edit the DNA of the stem cells, and in doing so would remove the code for the current surface protein and add the code for the new surface protein.

After the scientists had edited the stem cells, to have the correct signal protein, they released them into a mouse and observed that there was no immune rejection. Truly amazing. Maybe brain damage could be helped by this science one day. Tell me your thoughts on Stem Cells in the comments!

For more information, please go check out the primary source of this article.

 

 

Message Intercepted – Commence attack on bacteria!

Tevenphage – Photo credit to Wikimedia Commons

While experimenting, a group of scientists noticed that a A virus, VP882, was able to intercept and read the chemical messages between the bacteria to determine when was the best time to strike. Cholera bacteria communicate through molecular signals, a phenomenon known as quorum sensing, to check their population number.  The signal in question is called DPO.  VP 882, a subcategory of bacteria’s natural predator, the bacteriophage, waits for the bacteria to multiply and is able to check for the DPO.  Once there is enough bacteria, in the experiment’s case they observed cholera, the virus multiples and consumes the bacteria like an all-you-can-eat buffet. The scientists tested this by introducing DPO to a mixture of the virus and bacteria not producing DPO and found that that the bacteria was in fact being killed.

The great part about VP 882 is it’s shared characteristic with a plasmid, a ring of DNA that floats around the cell. This makes it easier to possibly genetically engineer the virus so that it will consume other types of bacteria. This entails it can be genetically altered to defeat other harmful bacterial infections, such as salmonella.

Ti plasmid – Photo credit to Wikimedia Commons

Current phage therapy is flawed because phages can only target a single type of bacteria, but infections can contain several types of different bacteria.  Patients then need a “cocktail” with a variety of phages, which is a difficult due to the amount of needed testing in order to get approved for usage.  With the engineering capability of using a single type of bacteria killer and the ability to turn it to kill bacteria, phage therapy might be able to advance leaps and bounds.

As humans’ storage of effective antibiotics depletes, time is ticking to find new ways to fight bacterial infections.  Are bacteriophages and bacteria-killing viruses like VP 882, the answers?

Strong Genes Equal Strong Immune System

Although scientists have long agreed that antibodies are in integral part of building up the body’s immune system, there is new evidence that strongly suggests genetic factors play a large role in determining how well the immune system builds and uses these antibodies when fighting disease.

https://commons.wikimedia.org/wiki/File:Redhead_twins.jpg

In a recent study, “researchers from James Cook University’s Australian Institute of Tropical Health and Medicine (AITHM) and the University of Queensland’s (UQ) Diamantina Institute have analyzed blood samples from 1835 twins and thousands of their siblings.” The team looked at the body’s immune response to “six common human viruses, including the Human Herpes virus, Parvovirus, Epstein Barr virus and the Coxsackie virus.” The team determined that genes passed down by parents are the major factor in how powerfully an immune system responds to diseases. “These genes determine whether you mount an intense or weak immune response when confronted with a viral infection,” says Associate Professor Miles.

“Demonstrating that antibody response is heritable is the first step in the eventual identification of individual genes that affect antibody response.” The researchers’ next goal is to identify the superior genes in order to, “imitate ‘super defenders’,” and “design next generation vaccines.”

 

We Didn’t Start the Fire…Gut Microbes Did.

Many scientists have hypothesized that infants’ gut microbiota could influence the development of their immune system. Recently, a test led by Drs. Christine C. Johnson at the Henry Ford Health System in Detroit and Susan Lynch at the University of California, San Francisco, but this theory to test. Specifically, they set out to examine the relationship between an infant’s gut microbiota and their relative risk of atopy and asthma. The researchers inspected the composition of gut microbes in stool samples from almost 300 infants—all part of a diverse study group born in and around Detroit between 2003 and 2007—by means of examining sequence variation within ribosomal RNA. Ultimately, the team found that the infants could be divided into 3 separate groups, each with distinct bacterial and fungal gut microbiota.

When blood samples obtained from the infants at 2 years of age were tested for sensitivity to allergens, the 3 microbiota groups had significantly different risks for allergen sensitivity. The “high-risk” microbiota group had a relatively lower abundance of certain bacteria and a higher level of some fungi, and was more likely to be diagnosed with asthma at 4 years of age. This seeming link between gut microbiota and allergy and asthma was also manifested when other factors associated with allergic disease—such as breastfeeding—were controlled. Moreover, the researchers found that the high-risk group had a distinct set of metabolites that lacked anti-inflammatory fatty acids and breast milk-derived oligosaccharides that were found in children in the low-risk microbiota group, increasing vulnerability to inflammation.

File:500px photo (56342660).jpeg

Neonatal gut microbiota play a huge role in health and disease (Credit: Eric Atkins)

The researchers also mixed immune cells from healthy adult donors in solutions containing metabolites extracted from the infant’s stool samples. The high-risk group’s metabolite samples increased the amount of allergy-promoting immune cells interleukin-4, a cell-signaling protein associated with allergies, and also reduced T-regulatory cells, an essential group of immune cells that suppress allergic responses. This reduction in T-regulatory cells was also spurred by a lipid that the team identified, called 12,13-DiHOME, that was found at high levels in the high-risk group. Discussing this finding, Lynch expressed to The Scientist, “That for me is incredibly exciting as it suggests that microbial-associated metabolites in the neonatal gut may represent an important driver of early-life immune cell phenotypes associated with disease development in childhood.”

The team plans to conduct a similar study that will focus on environmental factors and how they may affect the development of the gut microbiota. According to Lynch, “Understanding the basis of human-microbial development may prove critical to unraveling the basis of allergy and asthma and to developing preventative therapeutic strategies.”

New Research Uncovers Bat Super Immunity

Recent research has discovered a unique ability in bats to carry diseases but remain symptom free.  This ‘super immunity’, as it has been called by researchers, is currently a mystery to scientists but could one day provide methods for achieving super immunity in humans.

Bats are know to carry many diseases that are deadly to humans like the Ebola virus, Hendra virus, and MERS (Middle Eastern Respiratory Syndrome).  For some reason, their immune system allows them to not get sick or show any signs of the disease.  Research published in the journal Proceedings of the National Academy of Sciences might allow us to better understand why this strange phenomenon occurs in bats.  These researchers looked deep into the immune system of bats, especially into the interferons.  An interferon is defined as “a protein released by animal cells, usually in response to the entry of a virus, that has the property of inhibiting virus replication.”  According to the research, bats only have three interferons, which is less than a quarter of the number of interferons possessed by humans.  “This is surprising given bats have this unique ability to control viral infections that are lethal in people and yet they can do this with a lower number of interferons” says Dr. Michelle Baker, an immunologist at CSIRO’s Australian Animal Health Laboratory. Researchers also found another notable difference in how bat immune systems work as a whole.  While most mammals only activate their immune systems when they are infected by something, bats seem to always have active immune systems. Having the immune system active at all times can be dangerous in most animals because it can be toxic to cells, but bats seem to be perfectly fine.

Myotis yumanensis (Yuma myotis)

Image Source: http://bit.ly/1T4Qn0r

While information on bat super immunity may be limited at the moment, future research could prevent outbreaks like the Ebola virus in West Africa.  Dr. Baker describes the potential of this research well by saying, “If we can redirect other species’ immune responses to behave in a similar manner to that of bats, then the high death rate associated with diseases, such as Ebola, could be a thing of the past.”

Article Source: http://www.biologynews.net/archives/2016/02/22/bat_super_immunity_could_help_protect_people.html

Further reading: http://mashable.com/2016/02/24/bat-super-immunity/#_6DA21uIkiqU

 

My Gut is Telling Me To Exercise

Researchers at the University of Colorado Boulder have recently discovered that early life exercise can improve the activity of the gut microbiome. The gut microbiome is the next big thing in scientific research as scientists discover its affect on both general health and disease progression.

“Our gut microbiota contains tens of trillions of microorganisms, including at least 1000 different species of known bacteria with more than 3 million genes”. Microbiota, found in the intestine, help with a range of bodily functions such as digesting foods that the stomach is unable to, producing vitamins, and helping the immune system.

https://en.wikipedia.org/wiki/Escherichia_coli#/media/File:EscherichiaColi_NIAID.jpg

https://en.wikipedia.org/wiki/Escherichia_coli#/media/File:EscherichiaColi_NIAID.jpg

‘Exercise affects many aspects of health, both metabolic and mental, and people are only now starting to look at the plasticity of these gut microbes,”. Bacteria reside in infants’ intestinal tracts after birth to assist digestion and immune development. Exercise increases the effectiveness of these bacteria, and a  healthy gut biome promotes better brain function and causes antidepressant effects.

Scientists studied exercise and its effects on the gut microbiome using juvenile rats and proved this theory. The rats that exercised during their early lives developed a better microbial structure. The adult rats that exercised could not catch up to the rats that exercised as juveniles.

Do you think that this is an obvious or an unexpected idea, that early life exercise strengthens the gut microbiome? Does metabolic health usually coincide with mental health? Why would the gut microbiome be related to gene-making?

Other Sources

http://www.ncbi.nlm.nih.gov/pubmed/26647967

http://www.medicalnewstoday.com/articles/290747.php 

http://www.scientificamerican.com/article/the-guts-microbiome-changes-diet/

 

 

Junk Food Encourages Disease

According to a recent discovery posted in Science News, a typical American diet, consisting of poorly nutritional foods, leaves one prone to getting sick by weakening their immune system. Interestingly enough, this issue is rooted in cells that are not your own. In your gut microbiome, there are countless varieties and numbers of bacteria, all working away at the food that passes through your gut. Now, these bacteria are actually quite manipulative, and besides from feeding off of the food that you eat, teach your immune system what to attack, like an instructor or tutor for your immune system, albeit a biased one. These bacteria have colonized your body. They’re not just going to let some pathogen get in the way of their free meal ticket.

(What it looks like in there)

What happens when you eat certain foods, like junk foods, is that your gut microbiome changes. Different bacteria thrive on the fatty or sugary foods while other bacteria that survive off of more complex starches and carbs fade away, changing the demographic of your gut microbiome. This limited variety also limits the amount of invaders your immune system knows as hostile, or understands how to deal with, and therefore, you are more susceptible to disease, or medical complications.

(Actual photo of a biofilm found in the gut)

This was proven by taking samples from fit and obese humans and inserting them in otherwise sterile mice. Their resulting microbiomes grew, and the mice with the obese implant suffered more medical problems than the mice with the fit implant. This is because there were not enough “trainer” bacteria in the first mice’s gut to help train it to fend off disease, and thus it got sick more easily. So don’t go blaming your immune system the next time you get sick. It may be your fault for avoiding real, nutritional food (not just salad), and not taking care of it.

The moral of the story is to eat your vegetables and serve the bacterial overlords that have taken host in your body.

They’re good for you.

Trust me.

 

How Intestinal Microbiota Could Prevent Asthma

There are trillions of microbiota living in the average human intestine.  These microorganisms have formed a mutualistic relationship with humans and take on a number of functions including digestion, vitamin production, and the prevention of harmful bacteria growth.  In addition to these essential roles, new research shows that four types of these organisms may prevent asthma

Bacteria

 

The four types of bacteria are Faecalibacterium, Lachnospira, Veillonella, and Rothia.  Currently, some scientists think that these bacteria, FLVR for short, help prevent asthma by creating chemical byproducts.  These byproducts are thought to help train the immune system to attack harmful germs and to prevent inflamation.  Having these microorganisms is essential for the development of children. It is possible that the absence of the bacteria can lead to many health problems for people, including asthma.  Stuart Turvey, a pediatric immunologist at the University of British Columbia and a co-author of the study, thinks that being exposed to the FLVR microorganisms at very young ages is essential for preventing asthma and has said “Having the right bacteria in place at the right time is really important, especially in those early months of life.”  Despite their research, scientists do not know much about why the immune system possibly malfunctions when it is not exposed to the bacteria.  However they do know that the immune system becomes “confused” and creates inflammation in the lungs.

These new findings on asthma could possibly explain why asthma’s prevalence has tripled to quadrupled in first world countries in the past 30 years.  The advanced medical knowledge and technology in these countries could possibly be creating an over sterilized world.  Due to more and more doctors treating common sicknesses with antibiotics, human intestines are starting to become too clean and they lack the essential microorganisms including FLVR.  The absence of of these FLVR bacteria is likely to put more people at risk of developing asthma.  One study showed that many Canadian school children had very low levels of FLVR bacteria, putting them at high risk of developing asthma. Another study performed on mice strengthens the viewpoint that these bacteria prevent asthma.  The study examined new born mice by exposing some to FLVR and leaving the rest without the bacteria.  The results showed that the mice exposed to the FLVR at very young ages had much lower rates of inflammation in the airways.

Original Article

The Harm Stress Causes

http://upload.wikimedia.org/wikipedia/commons/c/c6/DNA_double_helix_45.PNG

https://www.sciencenews.org/article/chronic-stress-can-wreak-havoc-body

Recently scientists have begun to discover why stress can have a negative effect on the human body. Although stress is needed when dealing with situations which require hormones to trigger a fight or flight, consistent stress can lead to a multitude of health problems. Chronic stress can lead to mental instability, and an increased risk in heart attacks, strokes, infection, etc. The decrease in health is due to inflammation and warped genetic material caused by epigenetics (chemical interactions that activate and deactivate regions of a genome to carry out specific functions). Recently scientists have discovered that  changes in epigenetics can affect activity levels in genes which directly change responsibilities of certain cells including immune cells. The stress causes a genetic response that deactivates certain areas of a genome which stops an immune cell from working properly, which of course leads to an increase in diseases that cannot be properly taken care of. Hopefully, as we continue to understand epigenetics, we will be able to take appropriate steps that will both further our understanding of the human genome, as well as help increase the longevity and immune system of individuals.

A Baby’s Immune System Might Be Stronger Than We Think

Lymphocyte_activation_simple

Mothers are often extremely protective of their newborn. Most moms are fearful that everything could potentially make their baby sick. Unfortunately though, there is no absolutely sure way to keep a child from getting sick. The immune system plays a huge role in keeping humans well. Two important parts of the immune system are antibodies and memory cells. Antibodies help kill harmful germs while memory cells help the immune system respond quickly to an infection and prevent disease. In fact, recent studies prove that the Immune system of newborn babies are stronger than people previously believed.

Scientists involved in a study led by King’s College London, are reporting that newborn immune T cells can trigger an inflammatory response to bacteria. Originally, it was believed that babies immune systems were immature and therefore couldn’t trigger the same inflammatory response adults normally demonstrate. The team discovered that whilst T cells in newborn babies manufacture a potent anti-bacterial molecule known as IL8. It activates neutrophils to attack the body’s foreign invaders.

In addition, Dr. Deena Gibbons, Lead author in the Department of Immunobiology at King’s College London believes that this “mechanism by which the baby protects itself in the womb from infections of the mother.” Next, she plans to better understand the reasons that there are many differences between the immune cells in newborns and those in adults.

The T Cell activity demonstrated by newborns could be used for future treatments to boost the immune system or neonates in intensive care (place with major risk of infection).

This article is very interesting and important because it is vital to keep newborn babies as healthy and safe as we possibly can. Sometimes it can be as simple as following common measures such as hand washing, avoiding people who are most likely to be sick, snotty noses or hacking coughs. A mother should try to do anything she can to limit the demands placed and a baby’s immune system in the early months to keep her baby healthy.

I chose this article because I know what it is like to be a patient in a Hospital and the precautions that doctors take to prevent further sickness when the immune system is not fully developed or strong.

Image links: 

Häggström, Mikael. “Medical gallery of Mikael Häggström 2014“. Wikiversity Journal of Medicine 1 (2). DOI:10.15347/wjm/2014.008ISSN 20018762. – Image:Lymphocyte_activation.png

http://en.wikipedia.org/wiki/Immune_system

Article: King’s College London. “Immune system of newborn babies stronger than previously thought.” ScienceDaily. ScienceDaily, 21 September 2014. <www.sciencedaily.com/releases/2014/09/140921145104.htm>.

http://www.sciencedaily.com/releases/2014/09/140921145104.htm

Other Sources:

http://en.wikipedia.org/wiki/Immune_system

http://www.wellness.com/reference/allergies/newborn-immune-system

http://www.nobelprize.org/educational/medicine/immunity/immune-detail.html

Weak Immune Systems Are Good?

 

http://commons.wikimedia.org/wiki/File:Baby_on_Back.jpg

http://commons.wikimedia.org/wiki/File:Baby_on_Back.jpg

In a recent article published, it is said that baby’s weak immune systems are  good because they let in good bacteria. A recent study suggests that babies are deliberately vulnerable to bacterial infections in the months after birth. This vulnerability allows good microbes to enter the baby’s gut, skin, mouth and lungs. Perhaps we could use this system to treat infections in infants and change the way babies are vaccinated.

To test this theory that the weak immune systems let in good bacteria, scientist Sing Sing Way proposed a experiment. Coming from an infectious-disease background, the pediatrician from Cincinnati Children’s Hospital used mice to test this theory. He compared the immune cells in week-old mice to those in adult mice. The younger mice had a higher proportion of red blood cells. With this, he found that these cells suppress the immune response by making the enzyme arginase. 

Sing Sing Way then gave the young mice antibodies that removed the red blood cells and stopped the production of arginase. When infected with Listeria Monocytogenes the mice’s immune systems fended off the bacterium. However without the arginase, the mice’s intestinal cells became inflamed. Ofer Levy, from Boston Children’s Hospital, concluded that reducing the inflammation must be the body’s reason for initially suppressing the immunity- “If there were no mechanisms to dampen inflammation, the newborn would fall apart”. What do you think of Levy’s conclusion and this new study?

 

 

Osmosis Jones: Fact vs. Fiction

 

The Cells of the Immune System
Photo from: http://commons.wikimedia.org/wiki/File:Innate_Immune_cells.jpg

Osmosis Jones is the story of a white blood cell police officer, Ozzy, who teams up with a cold pill, Drix, to save Frank from a deadly virus. Of course being a children’s movie Osmosis Jones isn’t a completely accurate depiction of the human immune system, or body in general, but just how accurate is it?

In the movie the major conflict arises when Frank, the human, eats an unsanitary egg. On this egg lives the virus, Thrax, who is a deadly pathogen. So far the movie checks out. In the human immune system the first line of defense are barriers between the inside of the body and the outside world. Some of these barriers include the skin, mucus membranes, tears, saliva, sweat and stomach acid. In the movie the virus does penetrate one of these barriers, in this case the mouth, to enter the body. This is accurate to how a virus may enter the human body.

After this the movie becomes less and less accurate to how the human immune system functions. Although there is detection of a pathogen the only response Frank’s immune system has in the movie is through the use of the police force, the white blood cells. This is completely inaccurate to how the human body fights off a pathogen. When the body detects a pathogen (virus or bacteria) mast cells release histamines to dilate the blood vessels (this is never shown in the movie, especially because the blood vessels are shown as highways, but thats another matter altogether). The next step in the immune response is macrophages come and engulf infected and dead cells and they release cytokines that attract other immune cells to the area. Neutrophils and natural killer cells then kill the infected cells. The closest thing to this second line of defense is the police force and their communication. They have radios and ways to communicate to call for backup, although it is extremely inaccurate to the way the immune system really functions.

The third line of defense that the Human body uses is specific defense. This includes B and T cells and the steps taken to target the pathogen specifically and the infected cells. Through the processes of Cell-mediated response and Antibody-mediated response the immune system targets the infection and destroys it. Both of these processes are not depicted in the movie in any form. This along with the ending (don’t worry I won’t spoil it) are both inaccurate to anything that could happen in the human body.

So Osmosis Jones isn’t the most scientifically accurate movie of all time, but that doesn’t stop it from making a great movie. The inaccuracies in the film can be excused by the fact that it is a children’s movie and not a new theory about the immune system. I mean how many kids would want to sit though a movie that was 100% accurate? You would lose all of the car chases, the drama, the suspense, the mucus filled dams, and the explosions. Overall I really enjoy Osmosis Jones, although I don’t recommend using it to study for your next science test.

 

 

Doing Nothing is Still Doing Something

If you’re like me, you hate taking medication: it’s at times completely unnecessary, and who wants the hassle of having to remember actually take the meds?  Well, I have good news for us “lazy” ones: at times when we’re sick doing nothing is actually the best medication!

Have you ever noticed that whenever we have a problem, we tend to think that it can be fixed with some type of medication? Headache? Tylenol or Advil.  Tummy hurts?  A lovely dose of the horrendously pink Pepto should do.  Sore throat? Oh it must be the early symptoms of strep throat–here’s some antibiotics.  Let’s just forget about all medications that exist today–it’d be like how cavemen lived.  They had no medications, no drugs, simply their bodies which kept them alive and healthy for most of the time.  We need to give our bodies more credit–after all, they are made to maintain homeostasis.

According to an article written my Dr. Danielle Ofri, a professor of medicine at NYU, sometimes not taking any medication to alleviate a “medical condition” is actually the best medication for our bodies.  Doctors have the tendency to prescribe medication when they find that something is “wrong” with a patient, and patients likewise want something done when something is “wrong.”  Like everything else in the world, every action a doctor makes has a reaction.  Most frequently, this reaction that occurs from the physician prescribing an additional medication is a reaction within the body of the patient.  Often, especially in elders, there are multiple doctors to one patient, as a result, prescribe multiple prescriptions which sometimes causes detrimental affects to the health of the patient because the medications react with each other and create further problems for the patient, which leads to the prescribing of even more medications.

So, rather than acting immediately, let’s just stop and think for a moment…is it perhaps better to just chill and see what happens? Uh, yeah.  There are some doctors (the super smart ones) who practice this “doing nothing,” and believe “If the patient is doing fine right now, why rock the boat?”  This method is called clinical inertia, which is generally looked down upon, but why?  Dr. Ofri wrote “doctors who tend toward inertia might actually benefit their patients by protecting them from overzealous medical intervention.”  In an article from the American Medical Association, which focused on diabetes, cholesterol and hypertension, it was found that in these three diseases, it is perceived that “lower” is better, but it was found that lower levels in sugar or pressure are associated with higher death rates.

So…what’s the lesson?  Of course not all patients are the same, but when it comes to “fixing” a “problem,” your doctor should understand that there is room to stop and think for a second.  We’re all like balances, and little illnesses act as stones put on one side of the scale creating a bit of an imbalance, and rather than balancing the scale out with medication, we should sometimes allow our bodies to do their thing and balance it out themselves.

Photo taken by Gianluca Neri

 

 

Always Sick? It may not be your fault

I feel like I get sick more than most of my friends. I always come up with excuses as to why I am sick like: “I must have caught it from my sister”, “I’m just really stressed” or “my lack of sleep lowers my immune systems ability to fight off infection.” But now I have a new excuse: my genes.

A recent article immediately peaked my interest because it may not be my fault I am more susceptible to illnesses. An experimental study involved seventeen healthy individuals who were infected with a strain of seasonal flu (H3N2). Nine out of the seventeen got sick. The researchers drew blood before the individuals were infected and every eight hours for the next five days. Then examined the activity of 22,000 genes in each blood sample. Patterns in gene activity could predict how sick people would get.

Our immune systems respond to “foreign invaders.”  Surprisingly  the immune systems of the people who got sick and did not get sick acted similarly. Those who got sick activated “immune chemicals” that trigger inflammation and stress responses, and those who did not get sick still had an active immune response but “repressed the stress response [and] activated anti-inflammation and antioxidant genes.”

This study illustrates that gene activity analysis might be able to help doctors determine the patients who are in danger of getting seriously sick.

Despite these findings I think the researchers need to determine whether the different patterns of responses depend only on a persons genes. In this study in particular the properties of the specific virus that the individuals were infected with could have played a role in the findings, and maybe a different strain of flu would yield different results.

Still, the next time I get sick I might be blaming the genes I inherited. Thanks Mom and Dad.

 

 

 

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