{"id":748,"date":"2021-05-25T18:10:16","date_gmt":"2021-05-25T12:25:16","guid":{"rendered":"http:\/\/immunologynotes.com\/?p=129"},"modified":"2021-08-10T14:30:29","modified_gmt":"2021-08-10T08:45:29","slug":"factors-affecting-immunogenicity","status":"publish","type":"post","link":"https:\/\/microbenotes.com\/factors-affecting-immunogenicity\/","title":{"rendered":"Factors affecting Immunogenicity"},"content":{"rendered":"<p><span style=\"color: #000000;\">Immunogenicity is determined by:<\/span><\/p>\n<p><span style=\"color: #000000; font-size: 18pt;\"><strong><u>A. Properties of Immunogen <\/u><\/strong><\/span><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_65 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title \" >Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #0a0a0a;color:#0a0a0a\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #0a0a0a;color:#0a0a0a\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/microbenotes.com\/factors-affecting-immunogenicity\/#foreignness\" title=\"Foreignness\">Foreignness<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/microbenotes.com\/factors-affecting-immunogenicity\/#molecular-size\" title=\"Molecular Size\">Molecular Size<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/microbenotes.com\/factors-affecting-immunogenicity\/#chemical-nature-and-heterogeneity\" title=\"Chemical Nature and Heterogeneity\">Chemical Nature and Heterogeneity<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/microbenotes.com\/factors-affecting-immunogenicity\/#physical-form\" title=\"Physical form\">Physical form<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/microbenotes.com\/factors-affecting-immunogenicity\/#susceptibility-to-antigen-processing-and-presentation\" title=\"Susceptibility to antigen processing and presentation\">Susceptibility to antigen processing and presentation<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/microbenotes.com\/factors-affecting-immunogenicity\/#b-biological-system-of-host\" title=\"B. Biological System of Host\">B. Biological System of Host<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"foreignness\"><\/span><span style=\"color: #000000;\"><strong>Foreignness<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">An antigen must be a foreign substance to the animal or recognized as non-self by the biological system to elicit an immune response. E.g. Bovine serum albumin, a common experiment antigen is not immunogenic when injected to the cow but strongly immunogenic when injected to the rabbit. However there are some exceptions, some macromolecules such as <strong>collagen and cytochrome c<\/strong> have been conserved during evolution hence are weakly immunogenic but some self-components <strong>like sperm and corneal tissues<\/strong> are sequestered from immune system hence are strongly immunogenic even when injected to the animal from which they are originated.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"molecular-size\"><\/span><span style=\"color: #000000;\"><strong>Molecular Size<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">The most active immunogens tend to have a molecular mass of 14,000 to 6, 00,000 Da, <strong>usually &gt;1, 00,000 Da<\/strong>. g. tetanus toxoid, egg albumin, thyroglobulin are highly antigenic. Generally, substances with molecular mass <strong>less than 5,000 to 10,000 Da<\/strong> are <strong>poor immunogens<\/strong>. E.g. Insulin (5,700 Da) is either non-antigenic or weakly antigenic.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"chemical-nature-and-heterogeneity\"><\/span><span style=\"color: #000000;\"><strong>Chemical Nature and Heterogeneity<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">Antigens are mainly proteins and some are polysaccharides. In general, chemically more complex the substance is the more immunogenic it will be. Synthetic <strong>homopolymers <\/strong>(Multiple copies of single sugar or amino acids) tends to lack immunogenicity regardless of size while <strong>heteropolymers<\/strong> are usually more immunogenic than homopolymers. It is presumed that presence of an aromatic radical is essential for rigidity and antigenicity of a substance.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"physical-form\"><\/span><span style=\"color: #000000;\"><strong>Physical form<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">In general particulate antigens are more immunogenic than soluble ones. Denatured antigens are more immunogenic than the native form. Large, insoluble or aggregated molecules are more immunogenic than small, soluble ones.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"susceptibility-to-antigen-processing-and-presentation\"><\/span><span style=\"color: #000000;\"><strong>Susceptibility to antigen processing and presentation<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">Development of immune response (Both humoral and cell-mediated) requires interaction of T-cells and antigen that has been processed and presented together with MHC molecules. Antigens that cannot be processed and presented by MHC are poor immunogens. Antigens that are <strong>easily phagocytosed<\/strong> are generally more immunogenic. E.g. D-amino acids are stereoisomers of naturally occurring L-amino acids. As antigen-presenting cells can only process and present L-amino acids, D-amino are poor immunogens.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-130\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/02\/Factors-affecting-Immunogenicity.jpg\" alt=\"Factors affecting Immunogenicity\" width=\"650\" height=\"340\" \/><\/p>\n<h2><span class=\"ez-toc-section\" id=\"b-biological-system-of-host\"><\/span><span style=\"color: #000000;\"><strong><u>B. Biological System of Host<\/u><\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ol>\n<li><span style=\"color: #000000;\"><strong>Genotype of Recipient Animal: <\/strong>It is a major factor that determines immune responsiveness. Some substances are immunogenic in one species but not in another .Similarly, some substances are immunogenic in one individual but not in others. <strong>MHC gene products<\/strong> which function in processing and presenting of antigen influence response towards antigen. <strong>Genes that codes B-cell and T-cell receptor<\/strong> also influences immunogenicity. Also, the <strong>genes coding proteins<\/strong> for various regulatory mechanisms influences it.<\/span><\/li>\n<li><span style=\"color: #000000;\"><strong>Dosage and Route of administration: <\/strong>An insufficient dosage of immunogen will not elicit immune response (Either it fails to elicit immune response or lead to state of tolerance). Conversely, excessively high dose will also lead to <strong>unresponsiveness or tolerance<\/strong>. There is a dose of antigen above or below which the immune response will not be optimal. A single experimental dosage is not sufficient to develop immune response however <strong>booster dose<\/strong> over a period of time enhances immunogenicity. Administration route strongly influence immune response. Sub-cutaneous route is better than the intravenous or intragastric routes.<\/span><\/li>\n<li><span style=\"color: #000000;\"><strong>Adjuvants: <\/strong>These are substances that when mixed and injected with antigen enhances the immunogenicity of antigen. E.g. Aluminium potassium sulphate (Alum) is an adjuvant that enhances immunogenicity by increasing persistence of antigen (Releasing antigen slowly from injection site) and enhancing phagocytosis of antigen. Adjuvants enhance immunogenicity by: <\/span>\n<ol>\n<li><span style=\"color: #000000;\">Prolonged persistence of antigen.<\/span><\/li>\n<li><span style=\"color: #000000;\">Co-stimulatory signals are prolonged.<\/span><\/li>\n<li><span style=\"color: #000000;\">Local inflammatory response is increased.<\/span><\/li>\n<li><span style=\"color: #000000;\">Non-specific proliferation of lymphocytes is increased.<\/span><\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<p><span style=\"color: #000000;\">The use of adjuvants, however, is often hampered by undesirable side effects such as fever and inflammation.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Immunogenicity is determined by: A. Properties of Immunogen Foreignness An antigen must be a foreign substance to the animal or recognized as non-self by the biological system to elicit an &#8230; <a title=\"Factors affecting Immunogenicity\" class=\"read-more\" href=\"https:\/\/microbenotes.com\/factors-affecting-immunogenicity\/\" aria-label=\"Read more about Factors affecting Immunogenicity\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":636,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1026],"tags":[1086,1164,1248,1249,1385],"custom":{"td_video":"","featured_image":"https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/02\/Factors-affecting-Immunogenicity.jpg","author":{"name":"Sagar Aryal","avatar":"https:\/\/secure.gravatar.com\/avatar\/862472ea06500d4318f1ad82addb608e?s=96&d=mm&r=g"},"categories":[{"term_id":1026,"name":"Immunology","slug":"immunology","term_group":0,"term_taxonomy_id":1026,"taxonomy":"category","description":"<strong>Immunology is an emerging branch of medical science that deals with studies related to different aspects of the immune system like the cells, structure, function, response against antigens, and disorders.<\/strong>\r\n<ul>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The immune system consists of a collection of cells, chemicals, processes, and mechanisms that function to protect the body from foreign antigens, such as microbes (organisms such as bacteria, fungi, and parasites), viruses, cancer cells, and toxins.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Beyond, the structural and chemical barriers which protect us from infection, the immune system consists of two lines of defense; innate immunity and adaptive immunity.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The innate immunity represents the first line of defense against the antigen, and it is an antigen-independent defense mechanism used by the host immediately or within hours of encountering an antigen.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">On the other hand, adaptive immunity is antigen-dependent and antigen-specific and, therefore, includes a lag time between exposure to the antigen and maximal response.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Studies conducted in immunology are related to the measurement of physiological functioning of the immune system in both healthy and disease conditions, malfunctioning of the system in the case of disorders, and physical, chemical, and physiological characteristics of the cells of the immune system.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Immunology is fast becoming an important branch of clinical medicine as it has a close relationship with organ transplantation, oncology, virology, bacteriology, and even dermatology.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Immunology is focused on certain organs of the body like the bone marrow and the lymphatic system and the white blood cells found in the blood.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">These cells or organs producing these cells are responsible, directly or indirectly, for the defense mechanism of the body against a pathogenic agent or other antigens.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">These cells keep on circulating throughout the body via blood or lymph so that they can detect antigens entering the body from different sources.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">An important aspect of immunology is immunotherapy, where components of the immune system or antigens are used to treat a disease or disorder as a form of treatment.<\/span><\/li>\r\n<\/ul>","parent":0,"count":115,"filter":"raw","cat_ID":1026,"category_count":115,"category_description":"<strong>Immunology is an emerging branch of medical science that deals with studies related to different aspects of the immune system like the cells, structure, function, response against antigens, and disorders.<\/strong>\r\n<ul>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The immune system consists of a collection of cells, chemicals, processes, and mechanisms that function to protect the body from foreign antigens, such as microbes (organisms such as bacteria, fungi, and parasites), viruses, cancer cells, and toxins.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Beyond, the structural and chemical barriers which protect us from infection, the immune system consists of two lines of defense; innate immunity and adaptive immunity.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The innate immunity represents the first line of defense against the antigen, and it is an antigen-independent defense mechanism used by the host immediately or within hours of encountering an antigen.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">On the other hand, adaptive immunity is antigen-dependent and antigen-specific and, therefore, includes a lag time between exposure to the antigen and maximal response.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Studies conducted in immunology are related to the measurement of physiological functioning of the immune system in both healthy and disease conditions, malfunctioning of the system in the case of disorders, and physical, chemical, and physiological characteristics of the cells of the immune system.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Immunology is fast becoming an important branch of clinical medicine as it has a close relationship with organ transplantation, oncology, virology, bacteriology, and even dermatology.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Immunology is focused on certain organs of the body like the bone marrow and the lymphatic system and the white blood cells found in the blood.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">These cells or organs producing these cells are responsible, directly or indirectly, for the defense mechanism of the body against a pathogenic agent or other antigens.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">These cells keep on circulating throughout the body via blood or lymph so that they can detect antigens entering the body from different sources.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">An important aspect of immunology is immunotherapy, where components of the immune system or antigens are used to treat a disease or disorder as a form of treatment.<\/span><\/li>\r\n<\/ul>","cat_name":"Immunology","category_nicename":"immunology","category_parent":0}]},"_links":{"self":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/748"}],"collection":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/comments?post=748"}],"version-history":[{"count":0,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/748\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media\/636"}],"wp:attachment":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media?parent=748"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/categories?post=748"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/tags?post=748"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}