{"id":976,"date":"2025-11-28T23:44:26","date_gmt":"2025-11-28T23:44:26","guid":{"rendered":"http:\/\/littleheroesfoundation.org\/?p=976"},"modified":"2025-11-28T23:44:26","modified_gmt":"2025-11-28T23:44:26","slug":"perhaps-the-most-important-advance-in-postgenomics-for-schistosomiasis-has-been-the-successful-application-of-rna-interference-rnai-to-schistosomes-2082","status":"publish","type":"post","link":"https:\/\/littleheroesfoundation.org\/?p=976","title":{"rendered":"\ufeffPerhaps the most important advance in postgenomics for schistosomiasis has been the successful application of RNA interference (RNAi) to schistosomes (20,82)"},"content":{"rendered":"

\ufeffPerhaps the most important advance in postgenomics for schistosomiasis has been the successful application of RNA interference (RNAi) to schistosomes (20,82). improved understanding of the immune response to schistosome infection, both in animal models and in humans, suggests that development of a vaccine may be possible. This review considers aspects of antischistosome protective immunity that are important in the context of vaccine development. The current status in the development of vaccines against the African (Schistosoma mansoniandS. haematobium) and Asian (S. japonicum) schistosomes is then discussed, as are new approaches that may improve the efficacy of available vaccines and aid in the identification of new targets for immune attack. == INTRODUCTION == In 1852, Theodor Bilharz described for the first time a tropical parasitic disease (bilharzia, later termed schistosomiasis) caused by blood-dwelling trematode fluke worms of the genusSchistosoma.Five schistosome species infect humans; they areSchistosoma mansoni,S. japonicum,S. mekongi,S. intercalatum, andS. haematobium. The first four species have well-described associations with chronic hepatic and intestinal fibrosis and their attendant consequences.S. haematobiuminfections cause fibrosis, stricturing, and calcification of the urinary tract. A number of animal-specific schistosome species (e.g.,S. bovisorS. margrebowiei) may occasionally Sugammadex sodium accidentally infect humans. The cercaria-stage parasites of a large number of other nonhuman (particularly bird)-infecting schistosomes (e.g.,Trichobilharziasp.) may penetrate human skin but then die. These can give rise to an allergic condition called swimmer’s itch, or cercarial dermatitis, a reaction caused by the release of antigens by the dying parasites in the skin. Approximately 200 million people in 74 countries are infected with schistosomes; 120 million are symptomatic, and 20 million suffer severe illness (31,129). Schistosomiasis is the most important human helminth infection in terms of morbidity and mortality; a recent meta-analysis assigned 2 to 15% disability weight to the disease (78). There is also emerging evidence that schistosome infections may impact the etiology and transmission of human immunodeficiency virus\/AIDS (HIV\/AIDS) (22,23,72,73,80), tuberculosis (23,42-44), and malaria (14,19,39,96,119,153), and vice versa. In particular, the possible interaction between schistosomiasis and HIV\/AIDS is receiving increasing attention, given the role of immune responses in both diseases and the geographic overlap in distribution; low CD4+T-cell counts resulting from HIV infection may increase susceptibility to schistosome infection and influence egg excretion Sugammadex sodium (54,56,74). Thus, schistosomiasis imposes a high socioeconomic burden on many affected developing countries. S. mansonioccurs in much of sub-Saharan Africa, northeast Brazil, Surinam, Venezuela, the Caribbean, lower and middle Egypt, and the Arabic peninsula.S. haematobiumis present in much of sub-Saharan Africa, the Nile valley in Egypt and Sudan, the Maghreb, and the Arabian peninsula.S. japonicumis endemic along the central lakes and River Yangtze in China, in Mindanao, Leyte, and some other islands in the Philippines, and in small pockets in Indonesia.S. mekongioccurs in the central Mekong Basin in Laos and Cambodia, andS. intercalatumis found in pockets in west and central Africa (56). Comprehensive reviews of the biology, epidemiology, diagnosis, treatment, and control of schistosomiasis Sugammadex sodium are available (47,48,56,78,111,129-131,149,179). == BIOLOGY, LIFE CYCLE FEATURES, AND TRANSMISSION == The schistosome life cycle is depicted in Fig.1. Unlike other trematodes, schistosomes are dioecious (i.e., they have separate sexes), with the adults having a cylindrical body of 7 to 20 mm in length featuring two terminal suckers, a complex tegument, a blind digestive tract, and reproductive organs. The male’s body forms a groove, or gynaecophoric channel, in which it holds the longer and thinner female (56,129). AllSchistosomainfections follow direct contact with freshwater harboring free-swimming larval forms of the parasite known as cercariae. Cercariae utilize an elastase proteolytic enzyme produced in the head region to Sugammadex sodium penetrate the skin Sugammadex sodium<\/a> of humans or, in the case ofS. japonicum, other Rabbit Polyclonal to Actin-pan<\/a> mammalian hosts (domestic livestock such as buffaloes [Bubalus bubalis], pigs, sheep, and dogs). They shed their bifurcated tails and enter capillaries and lymphatic vessels en route to the lungs. After several days, the young worms, or schistosomula, migrate to the portal venous system, where they mature and unite. These worm pairs then migrate to their ultimate vascular bed, i.e., superior mesenteric veins (S. mansoni), inferior mesenteric and superior hemorrhoidal veins (S. japonicum), or the vesical plexus and veins draining the ureters (S. haematobium). Egg production commences 4 to 6 6 weeks after infection and continues for the life of the worm, which can be up to 15 years in the definitive host. Eggs are deposited in the vein lumen. The females produce hundreds (S. mansoni,S. haematobium, andS. intercalatum) to thousands (S. japonicumandS. mekongi) of eggs per day. Eggs pass into the host tissues, and then many pass through the intestinal or bladder mucosa.<\/p>\n","protected":false},"excerpt":{"rendered":"

\ufeffPerhaps the most important advance in postgenomics for schistosomiasis has been the successful application of RNA interference (RNAi) to schistosomes (20,82). improved understanding of the immune response to schistosome infection, both in animal models and in humans, suggests … <\/p>\n

Continue reading “\ufeffPerhaps the most important advance in postgenomics for schistosomiasis has been the successful application of RNA interference (RNAi) to schistosomes (20,82)”<\/span><\/a><\/div>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[50],"tags":[],"class_list":["post-976","post","type-post","status-publish","format-standard","hentry","category-death-domain-receptor-associated-adaptor-kinase"],"_links":{"self":[{"href":"https:\/\/littleheroesfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/976","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/littleheroesfoundation.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/littleheroesfoundation.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/littleheroesfoundation.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/littleheroesfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=976"}],"version-history":[{"count":1,"href":"https:\/\/littleheroesfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/976\/revisions"}],"predecessor-version":[{"id":977,"href":"https:\/\/littleheroesfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/976\/revisions\/977"}],"wp:attachment":[{"href":"https:\/\/littleheroesfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=976"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/littleheroesfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=976"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/littleheroesfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=976"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}