The Immune System – Immunity
The Immune system is a structure of body safeguarding to protect human body from antigens such as infectious and venomous agents . This system concedes, processes, and then eliminates antigens. Based on the descriptions and memory, the immune system deterrent is categorized into two which are the innate and adaptive immunity. The coordination and development of the well-adjusted mechanism to obliterate the pathogens are both shared by both of the systems. Particular elements acclimate themselves to each and every classes of new illness encountered and hence able to assemble pathogen-specific immunity whereas nonspecific components act as an extinguisher or chemical mediators of pathogens regardless of antigenic specificity. Innate immunity also called non-specific immunity because it is always described inasmuch of its potential to remove antigens at first line without preceding revealed to this specific antigen.
This category of immune system is incorporated of epithelial barriers, molecules and cells of innate immunity for examples NK cell, neutrophils, basophils, eosinophils, and monocytes-macrophages. Apart from that , adaptive immunity which is known as specified immunity needs antigen-designation and secondary reaction to be stronger. Memory is the other crucial element that causes the retaliation enhancement in adaptive immunity. Besides ,there are two majors of protection based on the work area which are cellular mediated and humoral mediated adaptive immunity. In addition to this, the cellular mediated adaptive immunity is mostly controlled by the coordination of APCs, adaptive T helper cells and effector cells. The examples of antigen presenting cells are dendritic cells monocytes, macrophages, and residential macrophages lymphocytes.
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According to JLM Carrillo (2017) , the immune system made up of a few chains of effector mechanism which can destroy the pathogens such as bacteria , fungi , viruses and parasites effectively. The innate immune system is composed typically of somatic barriers such as mucous membranes and skin , chemical agent , through the reaction of antimicrobial peptides and sort of reactive oxygen , innate immune cells , and soluble conciliator such as the complement structure, innate antibodies, and corresponding cytokines. On top of that , the fundamental purpose of the innate immune system are to avoid the introduction of pathogens into the body via physical and chemical barriers , to prevent the proliferation of infections through the complement network, to eliminate pathogens through the process of phagocytosis, to initiate the adaptive immune system throughout the process of synthesis of several cytokines and antigen presentation to T cells and B cells. Apart from that , the cells of the innate system have a few concern that are important to protect human body from pathogens. Some cells induce physical barriers that delay infections. However , some of the cell classification indicate the miscellaneous pattern recognition receptors that concede pathogen-associated molecular patterns and damaged-associated molecular patterns which are respond by creating inflammatory cytokines to destroy microorganism or infected cells. These kind of cells consists of myeloid cells , non-myeloid cells and some lymphoid cells.
In addition , non-myeloid cells incorporate of fibroblast and epithelial cells which is usually include the formation of a barrier between the internal and external circumstances. The sort of cells produce antimicrobial material that inhibit the entry of pathogens. Besides , these antimicrobial stuff are known as antimicrobial peptides , and the are important elements of the innate immune reaction, which promote the first line of shelter against infections. Meanwhile , myeloid cells contains dendritic cells , neutrophils, eosinophils, basophils, mast cells, platelet and macrophages. All these cells have their own specific functions to protect human body from invading microorganism especially when someone is having a wound, these cells will be stimulated by our body innate immunity system to protect us from infection that enter our body through open wound. Other than that one , lymphoid cells consists the natural killer cells , and innate lymphoid cells . Innate lymphoid cells are a novel derivation of hematopoietic reactor that aid preservative roles in innate immune response to infectious pathogens , in lymphoid tissue development , in tissue remodelling after impairment caused by injury or infection and in the homeostasis process of tissue stromal cells.
The existence of pathogens happens through cells necessitate in the innate immunity reaction by nonspecific materials that are usually shared by many pathogens called pathogens-associated molecular patterns. Pathogens-associated molecular patterns are highly sustained products and are made of variety of microorganisms. These pathogens-associated molecular patterns do not show particular form with antigenic volatility, and host cells do not share the identical molecular design with pathogens , resulting in remembrance of the immune system, able to differentiate between self and non self. Among the pathogens-associated molecular patterns that available the pathogens are peptidoglycan , lipopolysaccharide, lipoteichoic acid , unmethylated cytosine phosphor-guanine motifs, double stranded ribonucleic acid virus, and the cell wall element of yeast. Lipopolysaccharide represents the prime element of Gram-negative bacteria , as peptidoglycan represent the crucial constituent of Gram-positive bacteria. Acknowledgement of these pathogen-associated molecular patterns is moderate via pattern recognition receptors, primarily assign to the family of Toll-like receptors.
As cited by Janeway. Jr. CA (2002) ,the induction of adaptive immune response starts when a microorganisms is consumed by an immature dendritic cell in the infected tissue. These specific phagocytic cells are dwelling in most tissues and are comparatively long-lived, turning over at a moderate rate. They obtain from the same bone marrow pioneer as macrophages, and roam from the bone marrow to their peripheral stations, where their part is to observe the particular environment for pathogens. Ultimately, all tissue-resident dendritic cells move via the lymph to the regional lymph nodes where they associate with recirculating natural lymphocytes. If the dendritic cells unable to be activated, they persuade sufferance to the antigens of self that they convey. Besides ,the immature dendritic cell brings receptors on its superficial that acknowledge ordinary features of many pathogens, such as bacterial cell wall proteoglycans. As with macrophages and neutrophils, attachment of a bacterium to these receptors restorative the dendritic cell to deluge the pathogen and prostitute it intracellularly. Immature dendritic cells are also frequently taking up extracellular evidence, embrace any virus molecules or bacteria that may be exist, through the receptor-independent mechanism of macropinocytosis.
The province of dendritic cells, however, is not primarily to demolish pathogens but to bear pathogen antigens to peripheral lymphoid organs and then present them to T lymphocytes. Apart from that , pathogen in infected tissue will be taken by dendritic cell so it can be activated , and migrate to the surrounding lymph node. On activation , a highly beneficial antigen-presenting cell formed by the evolve of the dendritic cell and experience changes that empower it to activate pathogen – specific lymphocytes that it confronts in the lymph node. In addition , an activated dendritic cells produce cytokines that effect both innate and adaptive immune responses, making these cells important gatekeepers that regulate whether and how the immune system responds to the existence of infectious agents. We shall compare the maturation of dendritic cells and their central part in available antigens to T lymphocytes.
According to Russel .R. ( n.d ) , adaptive immunity called specific immunity because it’s ability to identify and protect itself against definite attackers and their outcomes. On top of that , adaptive immunity known as a smart structure whose memory allows it to react immediately to a second experience with a pathogen. There are few elements of specific immunity involved which are obtained over time , antigens trigger specialized immune response , many types of cells , tissues and organs are element of specific immunity including B and T lymphocytes with certain receptors , lymphatic recirculation system , interactions with circulatory , nervous and endocrine system and interactions with non – specific system such as antigen presentation. Plus , there are five classes of immunoglobulin in adaptive immunity such as IgA , IgG , and IgM which are usually produced after viral infection, IgE which involved in activation of basophils and mast cells against parasites and allergens while IgD is type of B-cell receptor. In addition , there are two category of specific immunity is obtained during an individual’s life which are naturally acquired as a immune response that attack pathogens confronted in daily life and artificially acquired that react to pathogens in a vaccine further eminent as either active or passive. Furthermore , an active response invigorating our own immune system such as through vaccination and produce our own immunity while passive response already made in our body which gain from mother via placenta or colostrum.
When evaluating immune response to patient on the infection episodes , the immune system has developed to deal with infectious antigens. There are a few lines of host defence such as mechanical barriers act as a important first defence , disturbance of drainage such as tears , saliva , bile , pancreatic , mucus and even sebaceous excretion help protect the superficial they flow over , and obstruction is corresponding with infection , secretions that contain a number of enzymes and factors which help to slow down bacterial growth , normal microbial flora helps to impede the overwhelming of pathogenic bacteria.
According Fink L. S. and Cooksonn T.B (2005) , in most cases , cell death considered as either apoptosis or necrosis. Apoptosis defined as an active programmed activity of autonomous cellular demolish to prevent obtaining inflammation. Apoptosis has been to describe a significant morphological model of cell death observed as cells were dismissed during embryonic growth , normal cell transformed in healthy adult tissue , and atrophy upon hormone was releasing. Apoptosis process characterized by nuclear and cytoplasmic condensation and cellular fragmentation becomes membrane – bound fragments which becomes atrophy by phagocytosis process. Necrosis is described as a passive activity , the cell death occurs unexpectedly due to environmental perturbation with uncontrolled emancipate of inflammatory cellular materials. On the other hand ,necrosis also usually used to designated the current dead tissues and the amount of changes happened in the body cells after they have died. Therefore , as the phagocytosis absence in this process , an apoptotic body might lose their integrity and becomes necrosis. Necrosis cell death happened as a reaction to injury such as trauma and infarction which are significantly the result of a pathological process.”