NKT cells Research Paper Example | Topics and Well Written Essays - 1000 words

NKT cells - Research Paper Example Immunologists have been striving to unearth the connection between NKT cells and the inflammatory characteristics of asthma, in a bid to design new intervention strategies. This paper will review the biology of Natural Killer T cells and the prevention strategies of asthma and allergic diseases. Biology of NKT Cells Natural Killer T cells form a subset of lymphocytes as scientists have described. Depending on the T-cell receptor repertoires, NKT cells fall into three categories. The first type of NKT cells is the classical NKT cells that exhibit conserved T-cell receptors (Akbariet al 2006). Immunologists have been described type 1 NKT cells in mice and humans, with those in humans named invariant NKT cells. Type 2 is also available in both mice and humans but have a diverse range of T-cell receptors. However, type 2 faces a restriction from CD1d. The third type forms the independent category of NKT cells characterized as expressing either Ly49 or NK1.1 (CD161 in humans). Moreover, i t proved quite difficult to isolate this type of NKT cells. Immunologists have succeeded in isolating type 1 and associating it with the development of asthma. NKT cells present numerous similarities to Th2 Cells, which trigger the processes that cause the development of asthma. ... However, the two types of cells exhibit different activation processes (Wohlleben&Erb, 2006). Processes Leading to the Development of Asthma and related Atopic Diseases Experts seeking to understand the immunologic processes that lead to the development of asthma, have described the process in detail. Asthma results from the Th2 responses taking place in the lungs. The production of Th2 responses result from the action of allergen specific CD4+. The basis of asthma development is that there must be activation of transcription factors from the downstream factors resulting to the production of Th2 effector cells. The effect of these processes is the production of cytokines such as interleukins IL-4, IL-5, IL-9, and IL-13. Moreover, these processes trigger the recruitment of eosinophils and allergen specific immunoglobulin E by beta cells (Mallevaey et al, 2006). Granulation of eosinophils and mast cells occurs with as they indulge in a cross-linking with immunoglobulin E (igE). This ca uses the production of mucous and airway hyper-reactivity and a chronic inflammation of the airway. These are the central attributes of asthma.Processes that trigger Th2 responses often lead to airway hyper-reactivity and inflammation. Immunologists have highlighted that Th1 responses do not trigger this hyper-reactivity and inflammation defining asthma and other atopic diseases. There is evidence suggesting that children contacting bacterial infections that trigger Th1 responses in their earlier years have a less likelihood of developing asthma. NKT Cells and Asthma There is evidence that NKT cells have the potential to trigger Th2 responses that often lead to development of asthma and other atopic diseases. This is because of their ability to recognize glycolipid

Sundiata Essay Example | Topics and Well Written Essays - 750 words

Sundiata - Essay Example Therefore, the study of myths and their interrelationship with the real-life is of the paramount importance for the deeper understanding of the very nature of any human society. As a perfect example for this purpose we may investigate the book written by D. T. Niane "Sundiata: An Epic of Old Mali", which is one of the most well-known traditional narratives of West Africa that provides an account of Sundiata Keita, a historical heroic figure renowned as the founder of the Mali Empire. This book contains important insights into the mythical component of the human perception of history, and exposes the intimate connection that the present always has with the past. Let us take a closer look at this narrative and examine the function of memory as the bridge connecting heroes of the book with the world they live in. Among the numerous personages of the epic, the story of the relationship between the great king of Mali Sundiata and his griot Balla Fasseke takes perhaps the central place in terms of its importance for the whole narrative. Griots can be seen as professional storytellers and public speakers, but the significance of their social role was much deeper in the African societies than it could seem from this superficial description. On the most fundamental level, a griot was perceived as the vessel of historical memory of a social group. Every king had a griot beside him whose task was to instruct his patron in such a way as to procure the inheritance of traditions of ancestors. Therefore, griots role was naturally wide-ranging, as they were speaking for their kings, were tutoring their children, and in this way aimed to ". . . bring to life the deeds and exploits of kings for younger generations" (Niane, 1995, p.1). By the way, to prove that griots could rely on orally transmitted tradit ions we may for instance consider such a stable phenomenon as proverbs, which are referred to in the narrative in the following way: "Mens wisdom is contained in proverbs, and when children wield proverbs it is a sign that they have profited from adult company" (Niane, 1995, p.29). In the full accordance with the elevated status of griots, Balla Fasseke becomes a close tutor of the prospective king Sundiata yet from his early childhood. Balla educates and instructs Sundiata on the rules of behavior, so that ". . . between his mother and the griot, the child got to know all that needed to be known" (Niane, 1995, p.23). Thus, from the very beginning of the story of Sundiata the role of his guardian angel is assigned to Balla. In his turn, Balla was very devoted to his patron, which can be seen from his faithfulness to Sundiata even during his exile at the court of a powerful sorcerer king Soumaoro. But for Sundiata the absence of the griot does not simply mean the loss of a counselor, but in essence signifies the disconnection of Sundiata from the memory of his ancestors. Such a deprivation of him of the link with the mythical ancestors is the sufficient reason even for war, and in the narrative one of the first signs of the imminent war between Sundiata and Soum aoro is symbolized by the proclamation of Balla Fasseke by Soumaoro as of his new griot. At the same time, the respect that Soumaoro had for Balla proves that the memory of the past is indispensable for all, including such a seemingly powerful personage as the sorcerer