Role of Fever in Immunity - Essay Example

Role of Fever in Immunity Name Institution Date Introduction According to Evans, Repasky & Fisher, (2015), fever is a medical hallmark or symptom of infection and disease. It is an increase in body temperature that is caused by cytokine-induced upward shift of the average position of the hypothalamic thermoregulatory center. The presence of fever is always related to the response of immune in an organism. Thompson (2005) further defines temperature as an adaptive reaction to viral and bacterial contagions or to tissue injuries which results in inhibited growth of microorganisms and enhanced immune function. Delves & Roitt (2000), defines an immune system as an association of cells and molecules within an organism, with specified roles in defending against infection. They further argue that immune system is of two types of responses; innate (natural) responses and adaptive (acquired) responses. Innate responses are mostly experienced when the contagious agent is encountered while on the other hand learned response is as a result of repeated exposure of an organism to an infection. In innate responses, phagocytic cells (neutrophils, monocytes, and macrophages), that secrete inflammatory mediators, and ordinary killer cells are used as stated by Delves & Roitt (2000). Acquired responses are basically characterized by the production of antigen-specific B and T cells, found when the external receptors of these cells bind to an antigen. An antigen can be termed as any external substance that triggers a response from the two white blood cells (T cells and B cells). Antigen-presenting cells display the antigen to lymphocytes and join with them in the reaction to the antigen. B cells secrete immunoglobulin, the antigen-specific antibodies that remove the extracellular microorganisms. T cells together with the B cells can make antibodies. They can also destroy intracellular pathogens by triggering macrophages and also through the killing of virally infected cells. In conclusion innate and adaptive responses work together in fighting antigens. An increase in temperature improves the efficiency of individual immune cells. (Evans et al., 2015) argued that thermal factor of fever affect the inflammatory process taking place in the time of infection by stimulating most workings of innate and adaptive immunity. Repasky (2011) on her research stated that “although increase in temperature of an organism is known to be widely associated with disease infection and inflammation over time, it plays an important role in an immune system in that it triggers most of the immune responses”. She further supports her statement by giving an example of how cold-blooded animals move to the warmer places in times of their illness or when infected with fever. In her findings this helps the cold-blooded animals since the warm temperatures enhance the immune system of these animals. Contrary (Evans et al., 2015) explained that increase in temperature can also have an adverse impact in that it may destroy the body tissues. These tissues especially the lymphoid tissues that produce and send out lymphocytes whose principal role is to destroy antigen found in foreign invaders. Other lymphoid tissues work differently in that they recognize the antigens in the blood stream and then command the lymphocytes into action. Though this might be seen as a negative impact of fever in our immunity, Wherry (2009) emphasized the importance of knowing how and when to treat mild fever. According to Dr. Amesh, a fever should not be ignored because high fever especially above 102 degrees Fahrenheit should be addressed because it might cause mental illness to children. Scientists have argued that having a fever is, in fact an adequate immune response. Given the above contributions it can be concluded that high temperatures help in providing immune to infections in that it triggers answers to the antigens and also hardens our immune system. It should also be noted that not all fevers especially the mild fevers should be treated since they might be playing this very paramount role to our immunity. On the contrary, one should not ignore high temperatures bearing in mind the risks that come along with especially the destruction of the body tissues that lower the immunity of an organism. Moreover, fever enhances the functionality of our immune system. Although it had been believed that many infectious microbes cannot replicate well when one has a fever, Wherry (2009) argued that increase in body temperature temporarily enhances the functionalism of the immune system. According (Mace et al., 2011) generation and differentiation of a particular kind of lymphocyte, known as a "CD8+ cytotoxic T-cell" , that is capable of destroying virus-infected cells and tumor cells, is improved by small range fever hyperthermia. In this test researchers injected mice with an antigen and observed how CD8+ cytotoxic T-cells triggered to respond to the antigen. When the body temperature of half the mice was by around 2oC,it was proven that the CD8+ cytotoxic T-cell were in large numbers in the warmed mice compared to the one they maintained in the normal body temperature indicating that this lymphocyte replicated in number under the influence of high temperatures. In general it can be concluded that an increase in temperature experienced when one has fever plays an important role in the response of the innate system of immunity in that it provides a suitable environment for the functioning of these defensive cells as well increasing their replication rate. Despite the beliefs that have existed through enhancement of the functionality of the cells involved in immune and also through the multiplication of these cells it is important to note that temperature rise plays a significant role in the functionalism of the immune tissues. Moreover, most of these cells survive best in an environment of slightly higher temperatures which comes across with mild fevers. As a result temperature should not be viewed in the negative part alone but also considered giving a defense to infections. Furthermore, fever relates directly to the immunity since a rise in temperature can help kill some microbes. Harden et al., 2015 cited that fever and the sickness behaviors are mostly caused by the complicated inflammation processes. This inflammation occurs as an immediate natural response to the infection-causing pathogens. Launey et al., 2011 approximates a 50% of all reported and treated fever to be of a non-infectious source. Though the consequences of this inflammation are uncomfortable i: e pain swellings greatly assist in innate immune response as well as help in faster healing of wounds. Given the evolutionary preservation of fever and natural immunity, Rosenspire, Kindzelskii& Petty (2002) in their study hypothesized that fever's thermal element has a possibility of broad supplement innate immune function particularly neutrophil activation. Besides, (Mantovani et al., 2011) argued that neutrophils are used in the initiation, monitoring and in playing the effector roles of both inborn and acquired immune cells. They further emphasized that neutrophils play a critical part in the pathogenesis of a broad range of infections, inclusive of those caused by intracellular pathogens, autoimmunity, chronic inflammation and cancer. On their study of the impact of febrile temperature on neutrophil activation at a single cell level, they found that reactive oxygen intermediates and that febrile temperatures, for both non stimulated as well as LPS- stimulated supporter human neutrophils, does not support release of the immunity response. It can be drawn from their study that increase in temperature is a broad-based system used in enhancing the innate immune system. With this in mind it therefore crucial for one to wisely choose the methods of treating fever whether the physical means or the pharmacological means. For instance treating an illness with the physical cooling weakens most of the innate immunity component since cooling exposes the organism to low temperatures which apparently lowers down their functioning. In summary, even though according pharmaceutical commercials, high temperatures are dangerous, they in fact have a paramount role in immune function and the recovery progression of the body. The ability of Fever to influence the character and level of functional temperature rise associated with the unfamiliar effects on diverse functional temperatures which may have upon model immune responses in vitro. According to Hannson (1997), the above association can help to explain the evolutionary management of the fevered reaction to diseases or infection. In his study he further added that the increased temperatures contribute in regulating the emergence of immune responses rather than restricting the functionalism of the already existing immune responses. As a result, Hannson (1997) argued that biological purpose of fever in relation to the immune system is the removal of lower peripheral tissue temperatures instead of boosting of fundamental temperatures. Contrarily, some functions are augmented by the core temperature changes while others are selectively controlled by peripheral tissue temperature transitions. According to Duff (1986), behavioral fever in cold-blooded mammals has shown little mortality associated with infections. In his study, he further states that biology of interleukin-1 and other cytokines has permitted the testing, in vitro, of workings of mammalian host resistance (e.g. immune cell function). Blattaies (1986) experimentally argues that a lizard that was infected with a live bacterium proved fever enhanced its survival according to a data he collected on the lizard. From this, it can be concluded that increased temperature can support the survival of organisms primarily when infected with a virus. In his findings, he adds that certain leukocyte functions have been improved in vitro at high temperatures. Where an in vitro study is the one carried out in an organism that involves tens of thousands of cells which simplifies the study since the researcher can concentrate on a small component compared to the larger part. Though fever helps fight infections, very high internal temperatures of above 105 degrees F, can expose the body fats and proteins into temperature stress. This heat stress alters the proper functioning of these fats and proteins. In summary from the in vitro study of heat it shows that high or excess temperatures influences the immune system of a bacterium while mild fever or slightly higher temperatures help to trigger or enhance the functioning of the immune system. Conclusion From the above findings, one would blindly think that fever only affects our immune system negatively but this is not the case. Increased temperature has both advantages as well as a disadvantage to the immune functioning. As seen from the above study the benefits outweigh the disadvantages. The mild fever should not always be taken as an infection, but one should be careful on any fever infections to avoid damage to the body tissues. It has also been shown that immune responsive cells replicate faster in a higher temperature this indicates that heat promotes replication or increment of the numbers of cells that help in the defense of infection. Immune responses and temperature are inseparable in that these responses are the one that cause fever in times as the cells fight against the infectious microbes. Fever also makes the body unfavorable for replication of viruses and bacteria. It might be uncomfortable to have a fever, but one should be careful in treating it especially the mild illnesses. Of the two fundamental responses of the immune system, it has been found that the natural or the innate response correlates positively with the increase in temperature as opposed to the adaptive or acquired immune response. In a nutshell, any symptom of fever stimulates an immune response that helps in preventing infections in our body systems and ensures the proper or normal functioning of the body tissues and antigens. As human beings, we should have an insight of fever before looking for ways of treating it. REFERENCES Delves, P. & Roitt, M. (2000). the Immune System. The New England Journal of Medicine, Vol. 343, pp. 37 – 49 Evans, S. Repasky, A. & Fisher, T. (2015). Fever and the thermal regulation of immunity. Nature Reviews Immunology, Vol. 15, pp. 335 – 349 Mantovani, A. Cassatella, MA. Costantini, C. & Jaillon, S. (2011).Neutrophils in the activation and regulation of innate and adaptive immunity. Nature Review Immunology. Vol. 11(80), pp. 519 – 531 Hannson, DF. (1997). Fever,temperature and the immune response. Annals of New York Academy of Sciences, Vol. 813, pp. 453 – 464 Blatteis, CM. (1986). Fever: is it beneficial? The Yale Journal of Biology in Medicine, Vol. 59(2), pp. 107 - 116 Duff, DW. (1986). is fever beneficial to the host in a clinical perspective? The Yale Journal of Biology and Medicine, Vol. 59(2), pp. 125 - 130 Mace, A.Zhong, L. Kilpatrick, C. Zynda, E. Lee, C.….. &Repasky, A. Differentiation of CD8+ T cells into effector cells is enhanced by range physiological hyperthermia. Journal of Leukocyte Biology, Vol. 90, pp. 951- 962 Rosenspire, AJ. Kindzelskii, AL. & Petty, HR. (2002). Fever-associated temperatures enhance neutrophil responses to lipopolysaccharide in a potential mechanism involving cell metabolism. Journal of immunology, Vol. 169(10), pp. 5396 – 5400 Thompson, J. (2005). Fever: A Concept Analysis. Journal of Advanced Nursing, Vol. 51(5), pp. 484 – 492 Wherry, J. (2009).Healthy Living. Journal of Leukocyte Biology, Vol. 20, pp.50 - 100 Read More