Climate change is expected to significantly influence the geographical distribution and impact of infectious diseases worldwide, especially those that require vectors such as mosquitoes and ticks for transmission. However, undernutrition has been identified as the greatest effect of climate change on health.
Now, results from a new study published February 19, 2019, in the Proceedings of the National Academy of Sciences, give a different perspective to this problem. The study (High ambient temperature dampens adaptive immune responses to influenza A virus infection) examines how high temperatures and subsequent reduced food intake affect the adaptive immune response to influenza virus infection.
The researchers housed healthy, young adult female mice in different temperature conditions—a group of mice was kept at refrigerator-cold temperature (4 degrees Celsius or 39.2 degrees Fahrenheit), another group at room temperature (22 C or 71.6 F), and an additional group at high-heat (heat wave) temperature (36 C or 96.8 F). The researchers then infected the mice in the different groups with the influenza virus, and compared their immune responses.
The researchers found that, compared with mice kept at room temperature, high heat-exposed mice reduced their food intake and exhibited a 10% reduction in body weight, although commensal microbiota composition remained intact. In addition, high heat-exposed mice developed impaired immune responses to the influenza virus— these mice failed to stimulate inflammasome-dependent cytokine secretion and migration of respiratory dendritic cell to lymph nodes, and exhibited increased autophagy in lung tissue. In room temperature-exposed mice, induction of autophagy severely impaired virus-specific CD8 T cells and antibody responses.
Heat exposure also impaired immune responses in mice infected with either Zika virus or a pathogenic tick-borne phlebovirus that causes severe fever with thrombocytopenia syndrome. Injection with either glucose or dietary short-chain fatty acids (which are metabolites produced by gut microbes) restored influenza virus-specific adaptive immune responses in high heat-exposed mice.
These findings suggest that outside temperature and host nutritional status may be critical determinants of viral pathogenesis or vaccine efficacy. People often lose their appetite when they feel sick. If someone stops eating long enough to develop a nutritional deficit, that may weaken the immune system and increase the likelihood of getting sick again.
Takeshi Ichinohe, one of the two study co-authors, said in a press release: “People often lose their appetite when they feel sick. If someone stops eating long enough to develop a nutritional deficit, that may weaken the immune system and increase the likelihood of getting sick again.” He added: “Perhaps vaccines and nutritional supplements could be given simultaneously to communities in food-insecure areas. Clinical management of emerging infectious diseases, including influenza, Zika, and Ebola, may require nutritional supplements in addition to standard antiviral therapies.”
It’s fascinating to read about how heat and diet can affect the immune system. The fact that staying in a warmer or cooler area can affect your immune response to fight influenza by affecting the cytokine secretion and migration of very import immune cells such as the dendritic cells. The paper I choose talks about the immune system and how living in different seasons(summer and neutral) and how the body reacts to the temperature change from working affects the immune system(pre work and post work). I think this is Important because this is more of a realist look on daily life and how affects us and the immune system. In this study Living in a hot environment showed an increase in lymphocytes and monocytes. Work had a bigger impact on the leukocytes, lymphocytes, and monocytes. It showed that the environment and the work the body is doing affects the number of immune cells in our body. Even with the temperatures reaching as hot as 37c, all of these saw in increases after the body was stressed with heat and work. But it showed that even though these numbers were elevated they were still within normal range. Respectably having a neglectable impact on the immune system function. What’s very interesting is how the body adjusts to the work so that it limits itself and stays at a stable temperate throughout the day in either season. Without this the Body temperature would have gotten a lot warmer and we could have seen a more significant change in the immune cell count.
as I was reading your comment where you talked about “Living in a hot environment showed an increase in lymphocytes and monocytes”, I thought that this might in fact be a positive effect that warmer temperatures can have on immune system. So I did some research and found a study stating why sometimes its beneficial for the body to raise its temperature (through fever) in order to improve a specific immune response. This study stated that through fever, the body rises its temperature and it causes the dilation of blood vessels (vasodilation) which decreases the blood pressure, increases the blood flow and as a result, the number of lymphocyte cells that have to pass by the HEVs (endothelial venules) increases. Therefore, there would be more lymphocytes present at the lymph node to fight off infections.
I found it very interesting that there is a correlation between the environmental temperature and the nutritional status of the host and that an imbalance of this correlation leads to weakening of the immune system and increase the likelihood of getting sick. The discussion however didn’t talk about low temperature effects on the immune system and mostly focused about the immune responses under heat exposure. In a recent study on the Teleost immune system, the researchers have examined the effects of low environmental temperature on the immune system of this organism. They have found that in low temperatures, the antibody production activity is interfered, as the B cell are no longer able to response to the T-dependent antigens and as a result, are not able to produce antibodies which leads to the suppression of the adaptive immune system. The other findings of this study indicated that low temperature decreases the rate at which T lymphocytes proliferate and as a result, it slows down the activation and the activity of the T cells. This could explain the reason why we catch more colds during the cold weather as our immune systems are weakened and their activity is interrupted.
In the article, it talks about complement proteins which are the major components of the innate immune system. They talk about the 30 proteins like classical and lectin. They are used for the vital role that targets cells and microbes and released cleavage products that help in inflammation. It is fascinating to see that lower temperature or average temperatures don’t seem to have an effect on the number of these proteins for this critical part of the immune system. The research suggested that cold stress might not affect upregulation while fighting microbes. It would be exciting to see research done on the pathways the fish uses to combat the temperature of its environment and still regulated these important proteins.
As I was reading the comment and the corresponding reply, I started thinking more about how temperature and cytokine production have a reciprocal relationship. When we are sick and our innate immune system is activated, through a process of cytokine production and release, inducing inflammation, our bodies develop a fever to fight off the infection. Accordingly, I started thinking about other external factors, which can affect cytokine production and/or release.
I found this study, which looked at the changes in pathway markers for inflammation as a result of pulsed electromagnetic field treatment (PEMF treatment). Following PEMF treatment, there was a decrease in the levels of mRNA of interleukin-1 beta and TNF-alpha, which are associated with pro-inflammatory pathways, in addition to an increase in mRNA levels of interleukin 10, which is associated with anti-inflammatory pathways.
The findings suggest that PEMF treatment results in changes to gene expression of the factors involved in regulating inflammation. Changes in mRNA levels of enzymes associated with heme catabolism and removal of reactive oxygen species were also noted. More studies are needed to confirm this and understand the underlying mechanism of action of PEMF.
The findings are significant because it shows the therapeutic potential of PEMF treatment for chronic inflammation.
I agree it’s fascinating the effects of the environment, in this case, the climate can have on various organisms. The article I chose discusses various cases of amphibians reaction to environmental stress and linking the survival and decline of these organisms to diseases caused by compromises to their immune system. This is important to know especially now, seeing as how we face various devastating climate changes in most corners of the world. These are not only affecting lower organisms but we as a more advanced species. Knowing the causes and strategizing to solve some of these problems would improve the survival rate of various organisms and allow for a better ecosystem.
The information in this article was very interesting especially since we are experiencing such extreme climate change now. However, I did not think of the impact of climate change, or nutrition, on immune function. The article I chose looks at the impact of global climate change on immune reactivity, with emphasis on its impact on child health. The impact on child health is a perspective that was not discussed in the article above. However, the importance of this is evident since climate change greatly affects the upcoming generations. As a result of macronutrient deficit, under-nutrition is the primary cause of secondary immune suppression in children around the world. This deficit causes a decrease in complement activation, phagocytosis, antibody secretion and cytokine production, as well as lymphatic organ atrophy in young children. In addition to this, severe protein-energy malnutrition (PEM) can lead to leucopenia (decreased white blood cell count) and decreased T cell counts (both helper and cytotoxic T cells). This would impact children’s ability to fight off pathogens they naturally come into contact with, as well as those they encounter via vaccines, decreasing their efficacy. Thus, the rapidly changing climate conditions, along with limited access to nutrients, can cause a drastic change in immune health, especially in the younger generations.
While I was reading your comment, you have mentioned that macronutrient deficit may cause a decrease in T lymphocytes counts in young children. So, I found it quite interesting to know how climate change impact on T cells count on the blood of a child. Thus, I found an article after some research, stating that decrease on peripheral blood T-lymphocytes in children leads to sleep apnea-hypopnea syndrome which is due to CD4+/CD8+ T lymphocytes ratio in blood was reduced and nocturnally awakening the child. This factor leads to pathophysiologic changes in the body of the child, weakening the immune system of the child which increases the disease factors and recurrent instability of the child’s health and so does the release of inflammatory signals could lead to cerebral damage due to blood flow obstruction.
I am very interested in this blog because it uses nutrition as a medium to explain the relationship between climate change and immunity: Outdoor temperatures can affect people’s nutritional intake. Lack of nutrition can lead to a weakened immune system. As we know, adequate sleep is as important to health as adequate nutrition. Since blogs use a nutritional perspective to show the relationship between climate change and immunity, I suspect that climate change can further affect the immune system in our body by affecting sleep. As it known, climate changes such as air deterioration and temperature discomfort can affect our sleep. In order to find the relationship between sleep and immunity, I started a further explore. I found an article, The Sleep-Immune Crosstalk in Health and Disease. This article describes the relationship between sleep and immunity in detail, which can be a strong support for my guess hypothesis: in this article, the author explains that sleep can affects various immune linked with a lower infection risk and a better infection responses or vaccination responses. A better sleep can inducted a hormonal constellation that supports immune functions. What’s more, sleep influences inflammatory homeostasis through effects on some inflammatory mediators like cytokines. The information in this article fully proved that sleep has an important influence on immunity. The information in this article is ample proof that sleep has an important impact on immunity and helps me build a bridge between climate change and immunity. Just like the blog’s point of view, “Climate change can affect the body’s nutritional intake to affect immunity.” Climate change can also affect immunity by affecting sleep.
I found it interesting that you were able to find a connection between sleep deprivation and nutritional intake. Both of these factors play a role in weakening the immune system. I was wondering if there was any correlation between the amount of sleep one gets and appetite levels. The Health Care Food Research Laboratories in Tokyo, Japan did a study where they gave individuals different amounts of sleep to determine if this would affect appetite levels. The two conditions used included a 3.5 vs. 7 hour sleep night for three consecutive nights. This was then followed by a 7 hour recovery night. They also monitored energy expenditure, core body temperature and carbohydrate and fat utilization. They found that though sleep deprivation did not affect energy expenditure or carbohydrate and fat utilization, the core body temperature was significantly lower in individuals who only received 3.5 hours of sleep. They also found that they had an increase in appetite because gastric hormone levels were significantly lower. This is important because over longer periods of time this puts people at risk for weight gain. More research should be done in order to determine the ideal number of hours of sleep needed to maintain a healthy weight. Also it would be interesting to find a study that looks at how weight gain affects immune response.
I had learned that certain diseases could spread easier depending on the climate in certain areas. But I hadn’t thought about how this, paired with the loss of appetite people usually feel when sick, could have such a drastic effect on general health. I believe that this article would go very well with the information presented in this post. Climate change is a huge issue we are dealing with in the present time. When it comes to changes in climate, we can expect to see large fluctuations in temperature and its stability. This article shows how low temperatures and humidity can increase the spread of influenza between groups of guinea pigs. It was found that the virus spread most efficiently in colder temperatures that had a low relative humidity. As we saw this year, we had multiple polar vortexes pass through the United States. This drop in temperature during the peak months of influenza would have made it much easier for the virus to spread. Temperature’s effect on our health and the spreading of illnesses, paired with the decrease in nutrition because of this is undoubtedly worrying. This adds truth to the phrase, “An apple a day keeps the doctor away.”
Climate change is definitely an issue environmentally but it is especially interesting how climate change is an issue in regards to human health. The immune system is not only affected by microorganisms such as bacteria, pathogens, and viruses but is also affected by external temperature. The paper I chose to cite looks into how the effects of climate change would change the way that those living in rural areas receive health treatment. I thought this paper uniquely tied in economic healthcare in with the topic of how climate change affects human health. Because people living in rural communities already have sparse access to proper healthcare, this paper raises the question as to how the health of these communities would change even more, which I believe is a topic worth researching more into.
Do global warming affect our health? I sometimes think about this question because I feel that during seasonal change or dramatic temperature change, people is easy to get flu. Luckily, this blog shows that high temperature is harmful to our immune system. The article mentioned in the blog indicates hot or even warm temperature don’t benefit our immunity. It combines nutrition status as a cofactor with temperature as well as shows that what parts of immune response are influenced. However, warm or cold temperate may not as good as what mentions in this article. A article published in 2017 also use mouse to do similar experiment. Their study shows cold environment suppressing humoral immunity but advance innate immunity and did not affect cellular immunity. Their study is more complex than the study mentioned in the post blog. I think people may control nutrition intake by themselves so we also need to study our immunity with food stress to see ether warmer temperature or nutrition counts and studying the amount of antibody as this article mentioned may be a good choice.
It would have never occurred to me that an increase in temperature would in turn affect our immune system and in turn enable us to be more prone to getting viral infections like the influenza virus as well as the Zika virus. On the other side however, I could see how a change in diet would affect the immune system, however I would never have thought the two to have a correlation. We know that a lack of proper nutrition and diet can lead to a weakened immune system by the body not being able to produce the essential nutrients that is needed in order for the body to do its natural processes. I supposed the decrease in the immune response due to high temperatures stems from the fact that an increase in temperature outside can cause an increase in temperature inside our bodies as well. this can lead to a number of temperature specific pathways going awry in our bodies thus making our immune system less sufficient. A study done by Brian Boag, et. al. exemplifies the notion that an increase in temperature also affects the rate in which we get parasitic infections as well.
I believe this is similar to basic homeostasis in the physiology of an organism. With normal temperature and a steady diet, the organisms thrive but when that situation is challenged, we expect to see changes with the condition of the organisms. In this case, the response observed is a cry for help by the immune system as it is trying to maintain homeostasis as it was, depending on the organism. The increased or decreased temperature affects the diet and progressively, the change in the diet affects the immune system of that organism. Even similar organisms share some differences that could have an impact on how different the immune system would react to the same changes in temperature and diet. This point is proved in the article in the link below as the researchers conducted experiments to see how global temperatures affect the performance of insect herbivores, both directly and indirectly and confirm that the response is trait-specific.
I found this blog post to be very intriguing because many people today still do not want to believe in climate change and global warming. The results from the study shown in the blog post, tells us that high temperatures and reduced food intake could leave human very vulnerable to viral infections. I was astonished to discover from the blog post, that mice kept at high heat temperatures, stopped eating food and resulted in a 10% reduction in weight. It was also surprising that the mice in hot temperatures experienced a failure to stimulate inflammasome-dependent cytokine secretion and that the respiratory dendritic cells were unable to migrate to the lymph nodes and initiate an adaptive immune response. Furthermore, the mice put in high temperatures reported to exhibit increased autophagy in the lung tissues, which is interesting because it means that cells are being formed from destroying other cell organelles and it is responsible for cellular homeostasis. This blog post allows us to realize the harmful effects that can arise from climate change and global warming. People living near the equator and places where food and resources are limited (like Africa) have shown to be at the highest risk for viral infection. Due to the increase in temperature around the world and malnutrition, researchers have reported that vaccine efficiency might be reduced, which will result in many people becoming ill. Climate change is a serious threat to not only humans, but to many plants and animals around the world, I have attached an article which goes into detail about the health and well being of populations around the world.
Maybe we don’t need to worry much about the temperature that affects the success rate of vaccination. I think people living near the equator may have better resistant to heat so that vaccination still be useful for them. And for us, I think now we spend most of our time inside, therefore temperature’s effect have been reduced. I also find a study that focus on temperature and vaccination in fish, which indicate low temperature is not good. So some of people in the world may need certain temperature.
Here is the link:
Maybe we don’t need to worry much about the temperature that affects the success rate of vaccination. I think people living near the equator may have better resistant to heat so that injection still be useful for them. And for us, I guess now we spend most of our time inside. Therefore temperature’s effect has been reduced. From our immunology class, the antibody would switch mainly to IGg, and the amount of antibody increased a lot when exposed to the same pathogen several times, which means if the vaccine is not as effective as before, we could repeat injections. I also find a study that focuses on heat and vaccination in fish, which indicate the low temperature is not suitable to some extent. By the way, some of the people in the world may need a specific temperature.
Here is the link: https://www.ncbi.nlm.nih.gov/pubmed/29226986
It was very interesting to find out that there is a correlation between nutrition, environmental temperature, and the effect it has on someone’s immune system. The adult female mice exposed to high-heat consumed less and also developed an impaired immune response in comparison to mice at room temperature. I wish the study would have explained the effects of refrigerator-cold temperature in relation to nutrition and immune response, and how it compared to the mice exposed to room temperature. In a recent article, it states that both cold and dry air would provide favorable conditions for the occurrence of influenza. However, in the presence of cold seasons, the dry polar and moist tropical weather types are significantly associated with increasing influenza likelihood, while dry tropical and moist tropical significantly decrease the occurrence of influenza; this would make sense as to why “flu season” is usually dominant within the cold months of the year. I believe a beneficial add-on to this experiment would be to examine the effects of nutrition and temperature of the refrigerator cold mice and if they provided favorable conditions for the occurrence of influenza.
In response to Omolola, I find that interesting how there are so many articles that are being geared more towards the effects of climate on how these organisms are functioning and their infect-ability. In my previous post I highlighted a study that demonstrated the effect of high temperatures has on parasitic infections. This article highlights the effects of climate change on infectious diseases as a whole.
I find it very interesting how outside ambient temperature can affect the effectiveness of the immune system. However, it begs the question of why and how do these phenomena happen? One thing to note is that the temperature of the group was close to a standard mammal’s body temperature. This brings up an interesting point, was the high temperature affecting the immune system differently or was the high temperature degrading many other body functions as well. Since the temperature was so high, I would be thinking about if the mice were being hydrated as well. Since high temperatures can cause some adverse effects that can affect the body. One issue that I would think about is what is the body temperature of a mouse.
I believe this is similar to basic homeostasis in the physiology of an orgasm. With normal temperature and a steady diet, organisms thrive, but when that situation is challenged, we expect to see changes with the condition of different systems in the body, especially the immune system. There is a clear relationship between nutritional status and environmental temperature. This imbalance leads to constant and frequent sickness. In the article linked below, it was observed that low temperatures lead to low immunological functions because B cells fail to respond to T cells, and in return, this cascades to a chain complication and or malfunction, where antibodies aren’t being produced efficiently as they should.
It was very interesting to find out that there is a correlation between nutrition, environmental temperature, and the effect it has on someone’s immune system. The adult female mice exposed to high-heat consumed less and also developed an impaired immune response in comparison to mice at room temperature. Overall, I wish the study would have spoken about the age of the mice during this experiment. I say this because it is a proven fact that when you are older, your immune response is weaker, even with the help of vaccinations. This article speaks of elderly people and why vaccinations don’t help in protecting them from influenza. Vaccines usually deal with the body’s ability to adapt to antigenically distinct epitopes on emerging strains of a virus. The reduced efficacy in the influenza vaccine for the elderly is due to the fact that there is a significant decrease in the capacity of antibodies that are able to target the viral glycoprotein. This reduced adaptability means that most B cells activated in the elderly target highly conserved but less potent epitopes. I feel like knowing this information, it would be interesting to see the effect of temperature on older mice who already have a weaker immune system and observe the differences in how they respond to temperature with a vaccine and without one.
I found this article interesting because it discusses how climate change could potentially have great effects on the immune system as the temperature continues to rise. I found a study where they looked at the effects of heat stress on Malabari goats and how the expression of cytokines changed. Over a 45 day period, they kept one group of goats at comfortable conditions, while the other group was kept in a hot environment. What they found was that expression of IL-18, TNF-α, IFN-β, and IFN-γ were lower in the heat stressed goats than in the control group goats. This is important because IL-18 induces cell mediated immunity which allows for activation of macrophages. As macrophages are phagocytes, if they are not activated, pathogens won’t be engulfed and broken down. Also, B cells and T cells cannot be activated by macrophages if the immune system becomes overwhelmed. IL-18 also stimulates natural killer cells to release cytokine IFN-γ. IFN-γ is necessary in the immune response because it induces expression if MCH II allowing for activation of macrophages. IFN-β plays a role in the innate immune system as it produces an antiviral response. Once macrophages are activated, TNF-α can be synthesized and they are responsible for inducing apoptosis of cells. A low level of all these cytokines is dangerous because the adaptive immune response essentially cannot get started without stimulation of these cytokines. This is important to understand because as seen in the goats, humans could also potentially begin expressing lower level of these necessary cytokines, as climate change continues to cause high temperatures. If this happens humans will be subjected to delayed and weaker immune responses if infected. I would be interested find research to see if there is any other way to activate these cytokines because unless all countries take initiative to reverse climate change, this may be an option to help strengthen the immune response.