The Innate and the Acquired Immune Responses - Essay Example

Source: The Innate and the Acquired Immune Responses Innate immunity is the first defense line of the body against bacteria.It is a non-specific host form defense that works against microorganisms that invade the body. The innate immunity components include; anatomical barriers, tissue bactericides such as complement, intact normal flora, as well as, the ability to experience inflammatory, and, phagocytic responses. The innate immunity identifies bacteria, removes the cells that are dead, and recruits cells to the infection site. In the case that the innate immunity has failed, the organism can be detected by the adaptive immunity mechanisms which then attack them. The adaptive immunity is antigen-specific and thus only reacts with the response induced organism (Aricibasi et al. 84). It displays immunological memory through which it recalls having encountered an invading organism thus reacting more rapidly on the same organism on subsequent exposure. This paper is a discussion that compares and contrasts the innate and the acquired immune responses. When a person comes into contact with an infectious agent, the first defenses to counter the infection are physical, as well as, chemical barriers like; antimicrobial proteins that are secreted at mucosal surfaces, which deny the microbes from getting into the body. In the case that these barriers are overwhelmed, or dodged, other immune system components get into action. The complement system is able to recognize the foreign organisms, as well as, phagocytic white blood cells like the innate immune system macrophages and neutrophils, and destroy them immediately (Minnicozzi 115) In contrast, the acquired immune response, also referred to as the adaptive immune system, develops in days. It is, however, able to eliminate infections in a more efficient way due to the lymphocytes exquisitely recognition functions that are specific. These cells are able to respond to every antigen through antigen receptors that are highly specialized which are present on the lymphocytes surface. The lymphocytes present in the body in their billions, possess a vast range of antigen receptors collectively, which make it possible for the immune system to identify, and take action to virtually any antigen an individual may be exposed to. This enables the adaptive immunity to focus on overcoming the pathogens that have eluded or overcome the innate immunity. Additionally, the innate immunity defense systems are effective in battling many pathogens. However, they are constrained by their reliance on germline-encoded receptors in order for them to identify microorganisms that have the ability to evolve more rapidly than the infected host. This is why they are able to only identify microorganisms that bear surface molecules, which are common to most pathogens conserved over the evolution course. Most pathogenic bacteria contain a protective capsule that has evolved that makes it possible for them to hide these molecules making it difficult for them to be recognized and phagocytosed. Viruses do not carry invariant molecules like those of bacteria, and the macrophages rarely recognizes them. However, viruses, as well as, encapsulated bacteria may nevertheless be picked by dendritic cells via the macropinocytosis nonreceptor-dependent process. This may then reveal the molecules that mask their infectious nature activating the dendritic cell to present the antigens that belong to them to lymphocytes. (Kobayashi et al. 5123). All the blood cellular elements such as the red blood cells which transport oxygen, platelets for triggering blood clot in tissues that are damaged, and the immune system white blood cells, originate from the bone marrow’s hematopoietic stem cells. Since these stem cells have the ability to produce every different blood cell types, they are mainly referred to as pluripotent hematopoietic stem cells. They give rise to additional limited developmental potential that are the instant progenitors of platelets, red blood cells, and the two major white blood cells categories, the lymphoid, as well as, myeloid lineages. Macrophages are resident in close to all the tissues, and they are the monocytes mature form that circulates in the blood migrating into tissues continually where they differentiate. Monocytes and macrophages formulate one of among the three phagocytes type within the immune system. The others include granulocytes, and dendritic cells. Throughout the innate immune system response, the macrophages perform several varying functions, and they are the cells that are relatively long-lived. One function is to engulf invading microorganisms and killing them. They are an important initial defense in the phagocytic innate immunity role, and they dispose pathogens, as well as, cells that are infected that are targeted by the adaptive immune response. Monocytes and macrophages are both phagocytic, but the occurrence of most infections is in the tissues, and thus it is macrophages that primarily perform the vital protective function. Additionally, macrophages other crucial role is to arrange immune responses. They assist the induction of inflammation, as well as, secrete signaling proteins which activate other cells of the immune system recruiting them into an immune response. Macrophages also act as the body’s general scavenger cells that clear dead cells, as well as, cell debris (Mendes et al. 287). The granulocytes contain densely staining granules within their cytoplasm and are referred to as polymorphonuclear leukocytes due to their oddly nuclei shape. Granulocytes are three types, which include neutrophils, eosinophils, and basophils. They are normally distinguished by their different granules staining properties. They are relatively short-lived compared to macrophages as they survive only for a number of days, and they are formed in great numbers during the immune response, when they migrate from the blood to infection or inflammation sites. They are the most vital and numerous cells present in the innate immune responses. They take up different microorganisms by phagocytosis and destroy them efficiently in intracellular vesicles, with the use of enzymes that are degradative, as well as, other stored antimicrobial substances in the cytoplasmic granules (Murphy 50). Eosinophils and basophils are fewer than neutrophils, but they also contain granules that have various enzymes, as well as, toxic proteins that are released with the activation of the cells. They are believed to be chiefly vital in the defense against parasites that are too large to for ingestion by macrophages or neutrophils. They are also capable of contributing to inflammatory allergic reactions where their effects are more damaging as opposed to protective. Mast cells contain blood-borne precursors that are not well defined. These cells differentiate in the tissues. They are best recognized for their allergic responses orchestrating role and are thought to contribute in the protection of the body’s internal surfaces against pathogens, and are also involved in the parasitic worms’ response. They contain large granules in the cytoplasm which are released in the activation of the mast cell, which helps in the inflammation induction. Common lymphoid progenitor within the bone marrow causes the adaptive immune system antigen-specific lymphocytes, as well as, another lymphocyte type that responds to the infection presence though not specific to antigen and is, therefore, taken as part of the innate immune system. The latter is a distinctive granular cytoplasm large cell known as natural killer cell. These cells are usually null cells, and they are not a type of T cells. Null cells represent a small proportion of the population of lymphocyte. With the stimulation of the antibody presence, they have the ability to attack some cellular targets directly. They are known to kill tumor or cells that are viral-infected, but not with the same specificity as that of cytotoxic T cells (Murphy 80). Cytokine generally refers to protein that is secreted by the cells affecting the behavior of the cells nearby with appropriate receptors. Chemokines are proteins that are secreted which act as chemoattractants and they attract cells that bear appropriate receptors like, neutrophils and monocytes, from the bloodstream and into the tissue that is infected. Inflammation is initiated by the cytokines and chemokines that are released by the activated macrophages. It is beneficial in combating infection through the recruitment of proteins and cells from the blood stream and into the infected tissue assisting in the direct destruction of the pathogen. Inflammation also increases the lymph flow carrying with it microbes and antigen presenting cells from the tissue that is infected to the nearby lymphoid tissues, where lymphocytes are activated initiating the adaptive immune response. Following the triggering of the adaptive immunity, inflammation recruits the components that are effective for the adaptive immune stem, which are antibody molecules, as well as, effector T cells, to the infection site (Aricibasi et al. 84). Complement is a group of plasma proteins whose activation can trigger local inflammation, as well as, invading bacteria phagocytosis. The complement system activation by bacterial surfaces results in a cascade of reactions that are proteolytic which coat microbe with complement fragments, but not the cell’s own body. Microbes that are complement-coated are identified and bound by complement receptors that are specific on macrophages picked by phagocytosis and destroyed. Although the progression of tumor involves processes like the invasion of tissue that may cause inflammatory responses to activate, the immune system ignores disseminated cancer or tolerates it. The mechanisms that are responsible for blocking the immune responses initiation during cancer are understood poorly. The Stat-3 constitutive activation, which is an oncogenic signaling pathway that is common, suppresses the proinflammatory tumor expression mediators. In tumor cells, blocking Stat-3 increases the expression of proinflammatory cytokines, as well as, the chemokines which are responsible for activating the innate immunity, as well as, the dendritic cells resulting to tumor-specific responses of T-cell. Additionally, the activity of constitutive Stat-3 induces the production of pleiotropic factors which inhibit the functional maturation of dendritic cells. Tumor-derived factors hinder the cell maturation of dendritic cells in the progenitor cells through Sta-3 activation. Therefore, the antitumor immunity inhibition involves a Stat-3 activation cascade propagating from the tumor to the dendritic cells. The Stat-3 activity of tumor can mediate the immune evasion through blocking the production, as well as, the inflammatory signal sensors by the immune system multiple components. Histamine plays a vital role in most allergic, as well as inflammatory processes. Its source is in the mast cell tissues. Apart from the allergic reactions, it has significant effects most immune reactions aspects through binding to its various group of are variously expressed on T lymphocytes, macrophages, dendritic, and various hematopoietic cells. Interferon refers to proteins that are produced and later released by the cells to an appropriate stimulus in response to the pathogens presence like bacteria, parasites, viruses, or tumor cells. They play a very vital role in the line of first defense against infections that are viral. They fall in the category of the non-specific immune system and are normally induced early in the viral infection stage before the immune system has had the opportunity to respond. Additionally, an allergy is referred to the reaction of the immune system over something that does not necessarily bother others. It is exaggerated because the foreign substances are viewed by the body as harmless and thus no response occurs in those who are non-allergic. However, in those who are allergic the body notices a foreign substance and cause the immune system to generate a response. Allergens, which are allergy producing substances are; pollen, dust mites, insect stings, some types of medicine, or some types of food (Murphy 58). Early innate response defense system highly depends on invariant recognition receptor patterns, which detect pathogens common features. However, innate defenses though they are critical, can be overcome or eluded by many pathogens and do not result in immunological memory. Identifying a particular pathogen and responding through enhanced protection against reinfection is exclusive acquired immunity response. The adaptive immunity is antigen-specific and thus only reacts with the response induced organism. It displays immunological memory through which it recalls having encountered an invading organism thus reacting more rapidly on the same organism on subsequent exposure. Works Cited Aricibasi, Merve, Arne Jung, E D. Heller, and Silke Rautenschlein. “Differences in Genetic Background Influence the Induction of Innate and Acquired Immune Responses in Chickens Depending on the Virulence of the Infecting Infectious Bursal Disease Virus (ibdv) Strain.” Veterinary Immunology and Immunopathology. 135 (2010): 79-92. Print. Kobayashi, Y, A Iwata, K Suzuki, A Suto, S Kawashima, Y Saito, T Owada, M Kobayashi, N Watanabe, and H Nakajima. “B and T Lymphocyte Attenuator Inhibits Lps-Induced Endotoxic Shock by Suppressing Toll-Like Receptor 4 Signaling in Innate Immune Cells.” Proceedings of the National Academy of Sciences of the United States of America. 110.13 (2013): 5121-5126. Print. Mendes, Luisa, Theunis Piersma, Dennis Hasselquist, Kevin D. Matson, and Robert E. Ricklefs. “Variation in The Innate And Acquired Arms of The Immune System Among Five Shorebird Species.” Journal of Experimental Biology 209.2 (2006): 284-291. Print Minnicozzi, Michael, Richard T. Sawyer, and Matthew J. Fenton. “Innate Immunity In Allergic Disease.” Immunological Reviews 242.1 (2011): 106-127. Print. Murphy, Kenneth, Paul Travers, Mark Walport, and Charles Janeway. Janeway's Immunobiology. New York: Garland Science, 2008. Print. Read More