Components of the Adaptive Immune System<\/h2>\n
The main players in adaptive immunity are white blood cells called lymphocytes. The two major types are:<\/p>\n Both B and T cells have antigen-specific receptors on their surface. Each cell is specific for a particular antigen, ensuring the response is targeted.<\/p>\n Adaptive immunity includes both humoral and cell-mediated responses:<\/p>\n A key feature of adaptive immunity is immunological memory. After the initial exposure to an antigen, memory B and T cells are formed. These cells can survive for years, allowing the immune system to “remember” the pathogen and mount a faster, stronger response upon re-exposure. This is the basis for long-lasting immunity after an infection or vaccination.<\/p>\n Adaptive immune responses are triggered when pathogens evade or overcome innate immune defenses. Antigen-presenting cells like dendritic cells and macrophages display pieces of the pathogen to lymphocytes, along with co-stimulatory signals to activate them. This process, along with cytokines produced during the innate immune response, stimulates the proliferation and differentiation of antigen-specific B and T cells to fight the infection.<\/p>\n the adaptive immune system provides powerful, specific, and long-lasting protection against pathogens. Its ability to generate a vast repertoire of lymphocytes, each with a unique antigen receptor, allows it to recognize virtually any pathogen. Immunological memory then provides enhanced protection if that pathogen is encountered again. Together, the innate and adaptive immune systems work to defend the body against the wide range of infectious threats it faces.<\/p>\n Adaptive immunity, also known as\u00a0acquired immunity\u00a0or specific immunity, is a subsystem of\u00a0the overall immune\u00a0system that provides\u00a0a tailored defense\u00a0against specific\u00a0pathogens. Unlike\u00a0the innate immune\u00a0system which\u00a0offers broad protection, the adaptive\u00a0immune system\u00a0is highly specialized to fight each\u00a0particular pathogen the body\u00a0encounters.<\/p>","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","_seopress_robots_follow":"","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"","_seopress_social_fb_title":"","_seopress_social_fb_desc":"","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"","_seopress_social_twitter_desc":"","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"","_seopress_redirections_param":"","_seopress_redirections_type":0,"_seopress_analysis_target_kw":"","_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"categories":[83,71],"tags":[154,174,81,206],"class_list":["post-200331","post","type-post","status-publish","format-standard","hentry","category-mscs","category-stem-cells","tag-cd4","tag-immune-system","tag-stem-cells","tag-t-cells"],"featured_image_src":{"landsacpe":false,"list":false,"medium":false,"full":false},"_links":{"self":[{"href":"https:\/\/cell-lavie.com\/zh\/wp-json\/wp\/v2\/posts\/200331","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cell-lavie.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cell-lavie.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cell-lavie.com\/zh\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/cell-lavie.com\/zh\/wp-json\/wp\/v2\/comments?post=200331"}],"version-history":[{"count":1,"href":"https:\/\/cell-lavie.com\/zh\/wp-json\/wp\/v2\/posts\/200331\/revisions"}],"predecessor-version":[{"id":200952,"href":"https:\/\/cell-lavie.com\/zh\/wp-json\/wp\/v2\/posts\/200331\/revisions\/200952"}],"wp:attachment":[{"href":"https:\/\/cell-lavie.com\/zh\/wp-json\/wp\/v2\/media?parent=200331"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cell-lavie.com\/zh\/wp-json\/wp\/v2\/categories?post=200331"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cell-lavie.com\/zh\/wp-json\/wp\/v2\/tags?post=200331"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"B](\"https:\/\/cdn.kastatic.org\/ka-perseus-images\/6f1b5994f49a400f970287aef6b0f8a5a061c140.svg\")
<\/figure>\n\n
Humoral vs Cell-Mediated Immunity<\/h2>\n
\n
Immunological Memory<\/h2>\n
![\"\"\/](\"https:\/\/cdn.kastatic.org\/ka-perseus-images\/35f34499ee5f0add4b2ec8291b653978eca909f6.svg\")
<\/figure>\nActivation of Adaptive Immunity<\/h2>\n
Innate Immunity vs. Adaptive Immunity: A summary<\/h2>\n
\n\n
\n \nAttribute<\/th>\n Innate Immunity<\/th>\n Adaptive Immunity<\/th>\n<\/tr>\n<\/thead>\n \n Response Time<\/td>\n Fast: minutes or hours<\/td>\n Slow: days<\/td>\n<\/tr>\n \n Specificity<\/td>\n Only specific for molecules and molecular patterns associated with general pathogens or foreign particles<\/td>\n Highly specific! Can discriminate between pathogen vs. non-pathogen structures, and miniscule differences in molecular structures<\/td>\n<\/tr>\n \n Major Cell Types<\/td>\n Macrophages, Neutrophils, Natural Killer Cells, Dendritic Cells, Basophils, Eosinophils<\/td>\n T cells, B cells, and other antigen presenting cells<\/td>\n<\/tr>\n \n Key Components<\/td>\n Antimicrobial peptides and proteins, such as toxic granules<\/td>\n Antibodies<\/td>\n<\/tr>\n \n Self vs. Nonself Discrimination<\/td>\n Innate immunity is based on self vs. nonself discrimination, so it has to be perfect<\/td>\n Not as good as the innate immune system, but still pretty good at determining which is which. Problems in self vs. nonself discrimination result in autoimmune diseases<\/td>\n<\/tr>\n \n Immunological Memory<\/td>\n None<\/td>\n Memory used can lead to faster response to recurrent or subsequent infections<\/td>\n<\/tr>\n \n Diversity and Customization<\/td>\n Limited: Receptors used are standard and only recognize antigen patterns. No new receptors are made to adapt the immune response<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>","protected":false},"excerpt":{"rendered":"