“Western cultures have generally regarded bats with superstition and fear; but in China, expressed in art and handicrafts, the bat has achieved respectability as a symbol of happiness and good luck. Too often, popular misconceptions have labeled bats as “dirty,” “disease carriers,” or “blood suckers,” an unenviable—and unjust—reputation to be sure. In reality, the more than 1,300 bat species are vitally important to ecosystems and economies around the world: they perform pest control, they pollinate, and they disperse seeds.”
There is more to bats—bats are the only flying mammals and live very long lives. They do host viruses, though, and some of these viruses are extremely harmful when they infect humans and other animals, as for example Ebola virus, Nipah virus, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses. But how can bats carry so many viruses without suffering from the diseases that these pathogens cause in humans?
Results from a study (Dampened NLRP3-mediated inflammation in bats and implications for a special viral reservoir host) published in the journal Nature Microbiology on February 25, 2019, show that bats are able to limit inflammation. In humans, when properly controlled, the inflammatory response helps fight infection. However, a poorly controlled inflammatory response may contribute to the damage caused by infectious diseases, as well as to aging and age-related diseases. Bats do not react to infection with the typical inflammatory response that often leads to damage.
For the study, researchers compared the responses of immune cells from bats, mice and humans to three different RNA viruses—influenza A virus, MERS coronavirus, and Melaka virus. They found that, when compared to mice and humans, inflammation mediated by the protein NLRP3 (NLR family pyrin domain containing 3) is significantly reduced in bats, even in presence of high viral loads. NLRP3 is the inflammation sensor that normally triggers the body’s response to fight off stress and infection, and has been linked to both viral-induced and age-related inflammation.
More specifically, the researchers found that “transcriptional priming”—a key step necessary for the up-regulation of NLRP3 protein—is reduced in bats when compared to mice and humans. They also found unique, less active variants of NLRP3 only present in bats. These variants are present in two different bat species—Pteropus alecto, a large fruit bat known as the Black Flying Fox, and Myotis davadii, a tiny vesper bat from China. Thus, the variants seem to have been genetically conserved through evolution. Comparison of NLRP3 gene sequences from 10 bat and 17 non-bat mammals confirmed that these variants appear to be bat-specific.
The researchers explain that, in bats, the reduction of inflammation appears to have no impact on the overall viral loads. Rather than being better able to fight infection, bats have a much higher tolerance for it—the dampening of the inflammatory response actually enables them to survive.
Wang Lin-Fa, senior author of the study, said in a press release: “Bats appear to be capable of limiting excessive or inappropriate virus-induced inflammation, which often leads to severe diseases in other infected animals and people. Our finding may provide lessons for controlling human infectious diseases by shifting the focus from the traditional specific anti-pathogen approach to the broader anti-disease approach successfully adopted by bats.”
Prior to reading this intriguing blogspot, I was aware that bats were carriers of so many high profile diseases, but I never once thought to think about how they are able to carry or survive these infectious diseases themselves. The blogpost mentions that bats have an atypical inflammatory response allowing the bats to have a stronger tolerance towards these infectious diseases. In my investigation on understanding the immune systems of bats, and their roles in spreading infectious diseases to humans, I came across an article that focused on bat immune defenses. The article, Immune System Modulation and Viral Persistence in Bats: Understanding Viral Spillover, stated that bats have unique mutations of p53 functional domains. The study also found that the number of interferon variants present in bats is lower than other vertebrates. Interferons in bats stimulate an antiviral effector, RNase-L which is an ISG gene. Overall, the article claims that the studies showed that higher interferon levels, and ISGs prepares bats to have control over viruses (Subudhi et al., 2019). In addition, the article focused on explaining why these unique immune features exist by finding a connection with the flight ability of bats. It was argued that due to a higher metabolism demand needed for flight, there were more oxygen radicals contributing to more damaged DNA. It is believed in the article that bats evolved the mechanism of suppressing their immune response and having reduced inflammation because of damaged DNA associated with flight (Subudhi, et al., 2019). Finding this article helped me add on to the knowledge I gained from the immune responses of bats in the blogpost. The blogpost mentioned the reduced inflammatory response in bats as did the article I found while researching to understand the unique immunology of bats. Not only did the authors of the article mention a reduced inflammatory response in bats; they provided a linkage between this immune mechanism and damaged DNA due to flight.
Reference:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6410205/
APA Citation:
Subudhi, S., Rapin, N., & Misra, V. (2019). Immune system modulation and viral persistence in bats: Understanding viral spillover. Viruses, 11(2), 192.
Ironically, the fact that bats have a dampened immune response to the wide variety of pathogenic zoonotic viral loads they carry, prevents them from succumbing to the viruses themselves. In addition to the reduced expression of the NLRP3 protein mentioned in this article, bats also exhibit a complete loss of the PYHIN gene family, ultimately allowing them to be completely asymptomatic to any virus they may harbor. This is an important family of immune sensors that control regulation of pro-inflammatory cytokine induction. The PYHIN gene family functions as sensors of intracellular self and foreign DNA and activators of the inflammasome and interferon pathways. In an article I read, its suggested that the lack of immune response to such viral loads may not have been an intentional act but rather an adaptation made to lower their metabolic expenses. It’s possible that this was an important adaption to the expensive of flying. Bats increase their metabolic rate up to 34 times over their resting rate and cellular by-products of such an increase in metabolism can lead to harmful side effects such as oxidative DNA damage. In a genomic analysis performed on 10 bat species, altered DNA damage checkpoints and repair pathways were noticed in order to overcome these harmful metabolic side effects. The expense of metabolism is cited for the cause of the complete disappearance of the PYHIN gene family in addition to the altered DNA damage checkpoints. Bats show a strong correlation with the genetic modifications of immune functions and their most prominent characteristic, flying.
Reference
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4764838/
Ironically, the fact that bats have a dampened immune response to the wide variety of pathogenic zoonotic viral loads they carry, prevents them from succumbing to the viruses themselves. In addition to the reduced expression of the NLRP3 protein mentioned in this article, bats also exhibit a complete loss of the PYHIN gene family, ultimately allowing them to be completely asymptomatic to any virus they may harbor. This is an important family of immune sensors that control regulation of pro-inflammatory cytokine induction. The PYHIN gene family functions as sensors of intracellular self and foreign DNA and activators of the inflammasome and interferon pathways. In an article I read, its suggested that the lack of immune response to such viral loads may not have been an intentional act but rather an adaptation made to lower their metabolic expenses. It’s possible that this was an important adaption to the expensive of flying. Bats increase their metabolic rate up to 34 times over their resting rate and cellular by-products of such an increase in metabolism can lead to harmful side effects such as oxidative DNA damage. In a genomic analysis performed on 10 bat species, altered DNA damage checkpoints and repair pathways were noticed in order to overcome these harmful metabolic side effects. The expense of metabolism is cited for the cause of the complete disappearance of the PYHIN gene family in addition to the altered DNA damage checkpoints. Bats show a strong correlation with the genetic modifications of immune functions and their most prominent characteristics.
Reference
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4764838/
Upon reading the article above, I was very interested on the detailed mechanisms of how bats could respond to infection while avoiding severe disease unlike human, but after reading through many articles, it wasn’t clearly identified. Instead, I came across an interesting virus called Marburg virus, which are like the ones in article above where it can survive in the bats and coexist, while it will lead to serious disease in humans.
MARVs causes severe human disease because of the abnormal immune responses. MARVs primarily targets infection of dendritic cells and dysregulates them. Dysregulation of dendritic cells help replication and dissemination of the MARVs which then can result in immunopathology. Unlike in humans, Egyptian rousette bats (ERBs) are the natural reservoirs of Marburg virus (MARVs), and when bats are infected, it only results in virus replication and shedding with asymptomatic control of the virus. In the study, ERBs infected with MARV represented a low level of replication of MARVs in the bone marrow-derived dendritic cells (BMDCs) of ERB. Also, MARV activated the transcription of IFN-related genes in ERB which resulted in showing the highest IFN signaling on the third day of the infection. This is suggesting that there is a strong antiviral response against MARV infection. On the other hand, infection of MARV inhibited cytokines and chemokines and dendritic dell maturation pathway. This shows how the ERB’s immune system respond to MARV by upregulating antiviral pathways to regulate replication of MARV and downregulate adaptive immune response to prevent proinflammatory immunopathogenesis (Prescott et al., 2019). I thought it was interesting to share another virus that can coexist in bats and share the similarities of bat’s response to different virus.
APA Citation:
Prescott, J., Guito, J. C., Spengler, J. R., Arnold, C. E., Schuh, A. J., Amman, B. R., Sealy, T. K., Guerrero, L. W., Palacios, G. F., Sanchez-Lockhart, M., Albariño, C. G., & Towner, J. S. (2019). Rousette Bat Dendritic Cells Overcome Marburg Virus-Mediated Antiviral Responses by Upregulation of Interferon-Related Genes While Downregulating Proinflammatory Disease Mediators. mSphere, 4(6), e00728-19. https://doi.org/10.1128/mSphere.00728-19
I find chiropteran dampening of NLRP3-mediated inflammation to be a beneficial evolutionary adaptation that contributes to overall fitness. It was fascinating to read the study’s detailed description regarding “transcriptional priming,” its mechanisms, and how it differs compared to humans and other mammals. Unlike bats, however, we do not possess this form of increased immune tolerance to the discussed RNA viruses above, rendering us more susceptible to certain zoonotic diseases. Along with expanding urbanization, the prevalence of zoonosis grows with the rapid decline of organismal habitat availability, further forcing unnatural overlap and interaction with wild animal populations. Moreover, a reduction of biodiversity manifests as a consequence of habitat destruction stemming from anthropogenic activity, thereby threatening ecosystemic richness. A study published by Nature (Impacts of Biodiversity on the Emergence and Transmission of Infectious Diseases) endorses the maintenance of healthy biodiversity to mitigate the risks of pathogenic transmission. This biodiversity aids us by providing a more pertinent genetic pool, often described as a dilutional effect. I believe that habitat restoration efforts should be promoted to alleviate biodiversity loss as it also benefits our population by decreasing the risk of infectious diseases reaching us. Though bat species express enhanced viral resilience, they are not immune to the environmental and physiological stresses we impose on them from urban development, deforestation, and depletion of resources.
Please note that the following source was used for the above comment:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7094913/
I find it interesting that bats have immune responses that limit inflammation even when they have high levels of the pathogens in their tissues. It is especially surprising to see the differences between these animals and humans and how they can fight infections more efficiently than humans. In a recent study, researchers found that bats have evolved new mechanisms that allow them to limit the inflammatory responses and expression of inflammatory cytokine. The study also mentions that they are also able to maintain a robust amount of type I IFN responses, which limit the propagation of viruses. This makes me wonder as to why humans have not been able to evolve an immune system like these bats, considering that some of the inflammatory responses that humans have, can lead to death. I believe that as more research is conducted on bats and their immune systems, researchers will be able to find more contributions to human life and how to enhance our immune systems and their responses.
Reference: https://www.ncbi.nlm.nih.gov/pubmed/32117225
This article truly provided me information about bats that I initially lacked. I will admit, I had my own bat stereotypes prior to reading this article and was surprised to realize how much more resilient these creatures are compared to humans. With the pandemic of the Coronavirus going on at the time, it is now more interesting that the cause of the virus spreading is the consumption of bats. In order to find out more about the relationship between bats and viruses I found this article, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356540/ on Pubmed. In this article they mention that bats are the “reservoirs of several emerging viruses.” The reduced transcriptional priming in bats of transcription factors like NLRP3 in bats, allows for viruses to escape detection by immune cells and survive longer in the bats. Not only do bats have a higher viral tolerance, but the article mentions there are periods throughout the year in which the bats have a higher than normal virus reservoir and can thus be more likely to cause spillover transmission to humans and other animals. The study of viruses is entirely relevant for our current society as we work to navigate through the COVID-19 outbreak. However, in the future extensive study in the transmission of these viruses between people as well as in spillover transmission events such as bats to humans will play vital as we develop and learn ways to better combat diseases in the future.
I agree it is quite interesting to see how bats have such a complex system in which they can host so many infectious disease. I think studies such as these are prominent, especially due to the situation we are facing with coronavirus. This topic has been discussed for a while as we are well aware of diseases in bats spilling over in humans and other species activating serious diseases. This serious disease however is not seen in bats due to a unique lack of expression of their inflammatory gene. In a similar study, they compared cell response in humans versus the bats and it was confirmed that the inflammatory response in the bats was not overly activated even though the two species were exposed to the same amount of pathogen. The study emphasized how humans emphasized human cells expressed a numerous amount of RNA for TNF which is a signal protein responsible for inflammation. The same was not discovered in bats which alluded to the idea that bats have a unique way restraining inflammatory response. Understanding this, it is important to make sure we interact safely with bats as their ability to carry deadly diseases and not be affected is amazing and scary at the same time.
Banerjee, A., Rapin, N., Bollinger, T., & Misra, V. (2017). Lack of inflammatory gene expression in bats: a unique role for a transcription repressor. Scientific reports, 7(1), 1-15.
Before reading this post, I never realized the complexity of a bat’s immune system. The fact that they can carry so many diseases, but do not get infected is fascinating. This post made me wonder what specific things and mechanisms contribute to a bat’s advanced immune system. Upon my research, I found that bats contain TLR13, which is a toll-like receptor that is believed to enhance viral recognition. TLR13 is only found in one other mammal, rodents. In addition, it has been reported that bats have “qualitative and quantitative differences in adaptive immune responses and the generation and maintenance of memory.” Meaning, their immune system is much larger and more efficient in comparison to other animals. Also, cell-mediated immunity occurs slower in bats. You would think this would have a negative effect on the immune system of bats because this process activates macrophages, t- lymphocytes, and cytokines to the antigen. However, with the complexities and advanced machinery of a bat’s immune system, I wonder if this provides any benefit to them? Overall, these are just a few differences that contribute to a bat’s immune system. Many other complex mechanisms make a bat’s immune system so strong. Mechanisms that make a bat’s immune system so strong.
Reference:
https://www.ncbi.nlm.nih.gov/pubmed/23302292
I have always heard that bats can carry a variety of diseases and it has been suggested that they be avoided in order to reduce exposure, but I never contemplated why I never heard about a large number of symptomatic bats being a problem. I think that I assumed that bats are just carriers for these diseases and for whatever reason, maybe having to do with DNA or coding, that the bat species could not become infected with the diseases themselves. It is very interesting to learn now that they actually have limited inflammatory responses which can result in higher tolerance for infection. It is even more interesting to find out that these adaptations to the protein NLRP3 are quite unique to the bat species. After reading this article I decided to do more research into the uniqueness of the bat immune response and found a study that transplanted bat cells from bone marrow into a mouse. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5856848/) This study was able to successfully transplant immune cells from a bat into a mouse suffering from immunodeficiency. This experiment was done by transferring bat bone marrow cells into an eight-week old adult mice intravenously and collecting and reviewing the components of blood several weeks later. The study found that the bat bone marrow cells were able to survive, repopulate and expand in a long-term capacity to establish an immune system in this previously defenseless mouse. The results from this study were incredible to me and made me feel even more curious, and hopeful, for the future of immune studies.
Reference:
Yong, Kylie Su Mei, et al. “Bat-Mouse Bone Marrow Chimera: a Novel Animal Model for Dissecting the Uniqueness of the Bat Immune System.” Scientific Reports, Nature Publishing Group UK, 16 Mar. 2018, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5856848/.
Hey Cray, I took a look at the article you referenced and I was stunned myself at the results. For them to have such a success rate at transplanting these cells into a completely different species was truly surprising. After reading this article myself I started thinking about how scientist would consider humans imitating the immune system of the bats in order to be better equipped to fight off pathogens but it never occurred to me to actually ‘take’ it. I know this worked and has some success in the mouse but it got me wondering how this would work for humans or if they even were considering doing that in the future? I looked at a couple of papers and I understand that bone marrow transplants are commonly used now to fight off certain diseases but I wasn’t sure how the human body would react to this. We may not be as strong as the bat in the immune system department but our immune system is pretty smart and protects us from a lot of harm. For example, I came across this study where they tried implanting organs and the immune system rejected it overexpressing Interleukin-8. I mean there are so many different instances where the immune system rejects tissues, organs, and blood from other humans so I couldn’t imagine the risks of using resources from a bat. Not to mention the ethical backlash that this could get. I am interested to see how future research will continue on this opportunity.
Reference: https://www.ncbi.nlm.nih.gov/pubmed/32307138
García-Covarrubias, L., Cedillo, J. S., Morales, L., Fonseca-Sanchez, M.-A., García-Covarrubias, A., Villanueva-Ortega, E., … Queipo, G. (2020, April 16). Interleukin 8 Is Overexpressed in Acute Rejection in Kidney Transplant Patients. Retrieved from https://www.sciencedirect.com/science/article/abs/pii/S0041134519319037?via=ihub
Before reading this article the only know facts about bats that I new about are their roles in the ecosystems and their usefulness as pollinators due to advance biology courses and their recent newfound fame of carrying coronavirus, never did I know that the viruses they carried so many viruses that are incredibly harmful. Yes, can animals have bacteria and viruses that are harmful to humans, this I knew. From the amount of animals we eat in this western culture, we are constantly aware of thee dangerous that uncooked animals can have and are aware that they carry harmful bacteria (salmonella, influenza, and E.coli) and we interact with them anyways and they live normal lives. But the numerous amounts of viruses contained in the bat and the complexity of its immune system was new to me. Stated in the post, Wang Lin-Fa, hypothesized that bats can aid in the shift of controlling infectious diseases”. Though bats are harmful that introduced new ideas for controlling human diseases. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2546865/
Hey Yve, reading this comment made me think upon why bats are cause so many human diseases? A study I found suggests that because bats are reservoirs of many RNA viruses and because RNA viruses have more of a genetic variability. Due to this viruses are able to mutate more than DNA viruses. This is because these viruses are able to things like frameshifting to make larger proteins like RNA dependent RNA polymerase. The article also mentions that viral RNA polymerases lack proofreading capabilities. Another reason is that bats are mammals who have a lot of the same mammalian receptors similar to humans, plus they can cover a large area geographically. All of these factors make why bats carry so many human viruses.
References: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4979447/
This is a very interesting article, especially in the wake of the SARS-Cov-2 pandemic. The danger of the disease targeting the respiratory system and being transmitted as easily as it is. So there are lots of therapies being tested to combat the disease, and one of the major issues that the virus causes is inflammation in the respiratory tissue. Therefore, if the mediated inflammatory response that appears in bats could be adapted as a therapy to humans, then bats could eventually help to treat a disease that they carry.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7171518/
This blog post goes to show how impactful media and society can be on your outlook on simple things. I have never stopped to think about how bats contribute to the environment because they are never spoken of in this light. They are always portrayed as evil, dark, dangerous, and full of diseases. I did however figure that they had some sort of a strong immune system considering they are carriers of so many viruses that harm other specials like us! After reading in this article that the main difference between their immune system and ours is the amount of NLRP3 protein, I wanted to do some research on how this protein actually worked in our body in different situations. I found a couple different studies where they looked at the NLRP3 protein and how it helps a lot of immune threats by aiding and activating the inflammatory response, but I also found studies where a reduction or inhibition of this protein actually helped. For example, in this one study I came across, when the researchers inhibited NLRP3 in mice following ischaemic brain injury, they began to see healing and positive results for repair (Wang, 2020). I understand that this protein, and inflammation in general, is vital for a lot of immune responses to threatening pathogens but what if this pathway is always harming us In other ways? I wonder if it’s the immune response that’s causing varying damage to our body that we are viewing as the pathogen’s doings? I would like to see more studies of the effect of protein at different levels in relation to several different immune threats. It would be nice to see if this protein is causing this problem or the actual pathogens.
Reference: https://www.ncbi.nlm.nih.gov/pubmed/32251636
Wang, H., Chen, H., Jin, J., Liu, Q., Zhong, D., & Li, G. (2020, April 3). Inhibition of the NLRP3 inflammasome reduces brain edema and regulates the distribution of aquaporin-4 after cerebral ischaemia-reperfusion. Retrieved from https://www.sciencedirect.com/science/article/abs/pii/S0024320520303866?via=ihub
The article is very interesting and informative, on the nature of bats. However, the unique things about bets is their ability to withstand inflammatory responses, which indicates a strong immune system. Although, very little is known about bat immune systems. Different bat species show different immune responses; according to this article “Bats: Important Reservoir Hosts of Emerging viruses” it shows that certain bat species have different immune responses. Like as immunoglobulins were purifying from great fruit eating bats, these immunoglobulins include IgG, IgA, and IgM. The Indian flying foxes, showing signs of certain macrophages, B and T lymphocytes in their bone marrows. Bats immunology has a very distinct and broad view. The article also provided information on different viruses that bats most commonly hold, including the rabies virus, Sars- CoV-like viruses, and Henipaviruses, which is a related to the nipah virus. The article also lists 66 different viruses which a bat can be susceptible towards and show no inflammatory responses. “ Some commonly employed evasion strategies include virus-encoded immune-modulating cytokines, decoy soluble cytokine receptors, inhibitors of apoptosis and cellular signaling, inhibitors of antigen processing, and T-cell antagonists.” Bats are known to be immune evasive and virus persistence; however, these aspects can help our understanding for creating antibiotics that can assure some resistance or immune responses in humans. Bats are a vessel for further understanding viruses through a mammalian species.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1539106/
Great read! The article is very through as to how bats cause so many human diseases. Bats are carries how various zoonotic and even vector-borne diseases. They are the most abundant mammals, accompanied with their ability to fly they are able to leave a large geographical footprint. Once way Fruit ear bats cause disease is as they are flying they eat fruit, but when done they just drop their half eaten fruit in whatever area they are flying over. In this case, animals such as pigs and other wild animals they eat those things and get infected. Bats also roost in huge numbers (in millions) in caves and such so if one fat has a virus it is very easy for it to be transmitted to others and quickly. One article I read suggests that because bats are so adapted to flying they have very unique physiology to combat getting infected. They change their body temperature a lot, when flying their body temperature runs very hot which means that viral replication is lower at this time. However, when they are in Torpor “mini-hibernation” their body temperature runs cold, this is when viral replication is high. Due to these fluctuating body temperatures they don’t get the disease. Also, due to all they flying their metabolic rates are extremely high which also yields a lot of metabolic waste that could also suggest them not getting the disease. Lastly, due to bats being mammals and humans also being mammals we both have a lot of receptor similarities therefore, we are more susceptible to viruses that are carried by bats.
Reference:
https://wwwnc.cdc.gov/eid/article/20/5/13-0539_article
Bats have been identified as ideal, hospitable reservoir hosts for viruses. Due to their latent-like infection trait, they can remain persistently infected with an increasing viral load, whilst displaying no pathology or clinical symptoms. This may facilitate continuous shedding of the virus and may result in a phenomena of virus spillover. Especially in areas where disease surveillance is limited, viruses may be spilling over with little to no detection. For example, the well-studied Hendra virus is endemic in Australian fruit bats. It passes from the bats to domestic animals, mainly horses. Within these animals, the virus rapidly amplifies, which is then spread to nearby humans. The virus must persist through multiple levels to successfully transmit. It must survive in the cell, then the host, then the entire population of hosts, and finally the community of the host species and the environment. There are several hierarchical levels in the transmission of the virus from bats to humans. These levels come with many enabling factors that promote transmission. There is the distribution of reservoir hosts, the shedding of the pathogen, the ability of the pathogen to survive outside its host until finding a new host, exposure to a spillover host, and the susceptibility of the spillover host just to name a few. Interrupting in any of these factors may assist in reducing the number of those affected. More research is needed regarding the spillover traits displayed in bats; this may give an upper hand in forecasting and perhaps better controlling pandemics that arise due to such means.
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4262174/
I really enjoyed reading this article because of the current COVID-19 pandemic and the evidence surrounding the idea that the COVID-19 virus originated from a bat. I was aware that bats are a carrier of certain diseases, but I never knew to what extent. After reading this post, I was interested in what mechanism in a bat’s immune system makes it different from humans. Upon further research I found the article, “Going to Bat(s) for Studies of Disease Tolerance” by Mandl. The article posed an interesting question: are humans susceptible to producing dangerous immune responses to RNA viruses because of life history and evolutionary traits or is the specific physiology of bats what allows them to be immunologically tolerant? According to the article, humans are known to harbor DNA viruses (like herpesviruses) more often than RNA viruses, suggesting that humans have a greater immune tolerance to DNA viruses because of the more ancient relationship humans and DNA viruses have. The differences between what pathogens humans and bats have been exposed to can lead to distinct adaptations in the way each’s immune system reacts to certain viruses. In addition, the evolutionary history of exposure can give each species immunological tolerance altogether to certain infections without disease while being susceptible to other diseases. In terms of physiology, bats are the only flying mammals.The ability to fly can allow for a greater spread of viruses and introducing areas to viruses that have never experienced that certain pathogen before, creating more exposure and immunity within different populations. The metabolic pathway that provides the ATP to power flight within bats is also suggested to have overlapping aspects with the innate immune system, indicating that evolutionary adaptations made so that bats could fly may have also affected bat immunity. There is not a clear answer to the previously posed question yet, however, it would be interesting to further investigate. A greater understanding of how bat immune systems can coexist with RNA viruses can potentially provide insight into how to achieve greater immune tolerance and resilience within humans.
Article: https://www.ncbi.nlm.nih.gov/pubmed/30294323
Mandl, J. N., Schneider, C., Schneider, D. S., & Baker, M. L. (2018). Going to Bat(s) for Studies of Disease Tolerance. Frontiers in immunology, 9, 2112. https://doi.org/10.3389/fimmu.2018.02112