{"id":3813,"date":"2021-01-22T12:56:59","date_gmt":"2021-01-22T11:56:59","guid":{"rendered":"https:\/\/www.mc-praha.cz\/mcp\/?p=3813"},"modified":"2021-01-22T16:23:02","modified_gmt":"2021-01-22T15:23:02","slug":"britska-mutace-viru-sars-cov-2","status":"publish","type":"post","link":"https:\/\/www.mc-praha.cz\/mcp\/britska-mutace-viru-sars-cov-2\/","title":{"rendered":"Britsk\u00e1 mutace viru SARS-CoV-2"},"content":{"rendered":"

V\u00a0prosinci 2020 byla ve Velk\u00e9 Brit\u00e1nii zji\u0161t\u011bna nov\u00e1 mutace koronaviru SARS-CoV-2 ozna\u010den\u00e1 SARS-CoV-2 VOC 202012\/01 (Variant of Concern, year 2020, month 12, variant 01) nebo tak\u00e9 UI-202012\/01, linie B.1.1.7 a 20B\/501Y.V1. Ud\u00e1v\u00e1 se, \u017ee tato \u201ebritsk\u00e1 varianta\u201c se oproti t\u00e9 sou\u010dasn\u011b dominuj\u00edc\u00ed \u0161\u00ed\u0159\u00ed rychleji, je tedy v\u00edce virulentn\u00ed.<\/p>\n

Mutace SARS-CoV-2 VOC 202012\/01 se vyskytuje v N501Y a zahrnuje 23 mutac\u00ed (samostatn\u00fdch nukleotidov\u00fdch substituc\u00ed), kter\u00e9 vedou ke zm\u011bn\u00e1m viru. Osm z\u00a0t\u011bchto mutac\u00ed je ve spike (S) proteinu, dev\u011bt dal\u0161\u00edch m\u011bn\u00ed aminokyselinovou sekvenci protein\u016f jinde v genomu viru a \u0161est mutac\u00ed, kter\u00e9 tuto sekvenci protein\u016f jinde v genomu viru nem\u011bn\u00ed. Dal\u0161\u00ed varianta viru SARS-CoV-2 zji\u0161t\u011bn\u00e1 v\u00a0Ji\u017en\u00ed Africe se ozna\u010duje 501Y.V2 a m\u00e1 tak\u00e9 mutaci v N501Y. Fylogenetick\u00e1 anal\u00fdza uk\u00e1zala, \u017ee i p\u0159esto, \u017ee maj\u00ed SARS-CoV-2 VOC 202012\/01 z Velk\u00e9 Brit\u00e1nie a 501Y.V2 z Ji\u017en\u00ed Afriky mutaci v N501Y, jde o r\u016fzn\u00e9 varianty viru.<\/p>\n

\"\"<\/p>\n

Obecn\u011b se ud\u00e1v\u00e1, \u017ee evolu\u010dn\u00ed tlak vede k takov\u00fdm mutac\u00edm, kter\u00e9 zvy\u0161uj\u00ed afinitu k receptoru nebo usnad\u0148uj\u00ed vstup viru do c\u00edlov\u00e9 lidsk\u00e9 bu\u0148ky. U britsk\u00e9 i jihoafrick\u00e9 varianty viru SARS-CoV-2 se uv\u00e1d\u00ed, \u017ee jsou p\u0159enosn\u011bj\u0161\u00ed, tedy rychleji se \u0161\u00ed\u0159\u00ed v\u00a0populaci ne\u017e sou\u010dasn\u00e1 nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00ed varianta viru SARS-CoV-2. Jedn\u00edm z\u00a0d\u016fvod\u016f je siln\u011bj\u0161\u00ed vazba viru s\u00a0ACE2 (angiotensin konvertuj\u00edc\u00ed enzym 2) receptorem na povrchu bun\u011bk. Glykoproteiny S, kter\u00e9 vy\u010dn\u00edvaj\u00ed z povrchu viru, maj\u00ed oblast zvanou receptorov\u00e1 vazebn\u00e1 dom\u00e9na (RBD), kter\u00e1 je tvo\u0159ena aminokyselinami. Tato dom\u00e9na je m\u00edstem vazby s ACE2 receptorem. Mezi t\u011bmito dv\u011bma proteinov\u00fdmi partnery existuje mnoho interakc\u00ed. Britsk\u00e1 varianta viru m\u00e1 mutaci N501Y v receptorov\u00e9 vazebn\u00e9 dom\u00e9n\u011b, kde do\u0161lo ke zm\u011bn\u011b aminokyseliny asparagin (N) na aromatick\u00fd tyrosin (Y). RBD m\u00e1 pak o jednu aromatickou aminokyselinu v\u00edce. Podle strukturn\u00ed anal\u00fdzy Y501 (RBD) interaguje s Y41 (ACE2) a tvo\u0159\u00ed aromaticko\u2013aromatick\u00e9 interakce. Komplex ACE2\u2013RBD m\u00e1 v\u00a0t\u00e9to nov\u00e9 interakci v\u00edce vazebn\u00e9 energie a zaji\u0161\u0165uje siln\u011bj\u0161\u00ed vazbu viru na bu\u0148ky.<\/p>\n

Jihoafrick\u00e1 varianta viru m\u00e1 krom\u011b mutace N501Y dal\u0161\u00ed dv\u011b mutace \u2013 K417N a E484K. Mutace K417N poskytuje m\u00e9n\u011b odpudiv\u00e9 s\u00edly mezi ACE2\u2013RBD. Lysin (K) je pozitivn\u00ed stejn\u011b jako histidin (H) v ACE2 a vytv\u00e1\u0159\u00ed mezi sebou lehce odpudiv\u00e9 s\u00edly. Zm\u011bna lysinu na asparagin mutac\u00ed tuto interakci odstran\u00ed a ACE2 na povrchu bun\u011bk se m\u016f\u017ee l\u00e9pe v\u00e1zat k\u00a0S proteinu viru. Posledn\u00ed mutace, E484K, poskytuje lysin, kter\u00fd slou\u017e\u00ed jako \u00fanikov\u00fd mutant proti imunitn\u00edmu syst\u00e9mu, proto\u017ee interferuje se schopnost\u00ed lidsk\u00fdch s\u00e9rov\u00fdch protil\u00e1tek v\u00e1zat se na tuto oblast RBD.<\/p>\n

Dal\u0161\u00edm z\u00a0faktor\u016f rychlej\u0161\u00edho \u0161\u00ed\u0159en\u00ed britsk\u00e9 a jihoafrick\u00e9 varianty viru je intenzivn\u00ed p\u0159enos, ke kter\u00e9mu doch\u00e1z\u00ed b\u011bhem po\u010d\u00e1te\u010dn\u00ed f\u00e1ze epidemie zp\u016fsoben\u00e9 danou lini\u00ed.<\/p>\n

Koronaviry b\u011b\u017en\u011b proch\u00e1zej\u00ed mnoha mutacemi, kter\u00e9 \u010dasto nejsou rozhoduj\u00edc\u00ed pro jejich biologick\u00e9 chov\u00e1n\u00ed a v\u00fdznamn\u011b nem\u011bn\u00ed strukturu viru.\u00a0Tento jev se vyskytuje tak\u00e9 u SARS-CoV-2. Je vysoce pravd\u011bpodobn\u00e9, \u017ee britsk\u00e1 varianta viru, jej\u00ed\u017e v\u00fdskyt byl ji\u017e prok\u00e1z\u00e1n i na \u00fazem\u00ed n\u011bkter\u00fdch dal\u0161\u00edch zem\u00ed, nenaru\u0161\u00ed ochranu z\u00edskanou o\u010dkov\u00e1n\u00edm. Bylo ov\u011b\u0159eno, \u017ee po aplikaci mRNA vakc\u00edny BNT162b2 (Pfizer\/BioNTech) organismus vytvo\u0159\u00ed ekvivalentn\u00ed titry neutraliza\u010dn\u00edch protil\u00e1tek proti nov\u00fdm variant\u00e1m viru stejn\u011b jako proti sou\u010dasn\u00e9 nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00ed variant\u011b viru. Je na m\u00edst\u011b p\u0159edpokl\u00e1dat, \u017ee v\u00a0sou\u010dasnosti pou\u017e\u00edvan\u00e9 i vyv\u00edjen\u00e9 typy vakc\u00edn budou fungovat i proti britsk\u00e9 variant\u011b viru.<\/p>\n

Britsk\u00e1 varianta viru m\u016f\u017ee m\u00edt vliv na spolehlivost n\u011bkter\u00fdch diagnostick\u00fdch PCR test\u016f, kter\u00e9 c\u00edl\u00ed na gen S. V\u011bt\u0161ina celosv\u011btov\u011b pou\u017e\u00edvan\u00fdch PCR test\u016f je v\u0161ak zam\u011b\u0159ena na v\u00edce c\u00edl\u016f, a proto se nep\u0159edpokl\u00e1d\u00e1 v\u00fdznamn\u00fd dopad britsk\u00e9 varianty na diagnostiku.<\/p>\n

Dle n\u00e1zoru v\u011bdc\u016f vykazuje britsk\u00e1 varianta, kter\u00e1 zvy\u0161uje virovou z\u00e1t\u011b\u017e, srovnateln\u00fd pr\u016fb\u011bh onemocn\u011bn\u00ed i \u00fa\u010dinky na respira\u010dn\u00ed trakt jako nyn\u00ed nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00ed varianta SARS-CoV-2. Pod\u00edl t\u011b\u017ek\u00fdch p\u0159\u00edpad\u016f je tak\u00e9 zhruba stejn\u00fd jako u\u00a0d\u0159\u00edv\u011bj\u0161\u00edch variant viru. Laboratorn\u00ed testy s\u00e9rov\u00fdch protil\u00e1tek po prod\u011bl\u00e1n\u00ed onemocn\u011bn\u00ed COVID-19 jsou v\u0161ak na tuto novou variantu viru m\u00e9n\u011b citliv\u00e9.\u00a0Ve sv\u011btle v\u00fd\u0161e uveden\u00e9ho mus\u00ed b\u00fdt v\u011bdeck\u00e1 komunita v pohotovosti, proto\u017ee v\u011bt\u0161\u00ed variace v S proteinu by mohly uniknout t\u011blesn\u00fdm protil\u00e1tk\u00e1m vyvolan\u00fdm vakc\u00ednami, kter\u00e9 se zat\u00edm jev\u00ed slibnou pomoc\u00ed s potenci\u00e1lem zachr\u00e1nit miliony \u017eivot\u016f.<\/p>\n

 <\/p>\n

22.1.2021<\/p>\n

RNDr. Martina \u0160indelkov\u00e1<\/p>\n

—<\/p>\n

 <\/p>\n

https:\/\/www.who.int\/csr\/don\/31-december-2020-sars-cov2-variants\/en\/<\/p>\n

https:\/\/pubmed.ncbi.nlm.nih.gov\/33377359\/<\/p>\n

https:\/\/gov.wales\/sites\/default\/files\/publications\/2020-12\/technical-brief-viral-variant-voc-20201201-23-december-2020_0.pdf<\/p>\n

https:\/\/riojournal.com\/article\/62936\/<\/p>\n

https:\/\/www.biorxiv.org\/content\/10.1101\/2021.01.07.425740v1.full<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

V\u00a0prosinci 2020 byla ve Velk\u00e9 Brit\u00e1nii zji\u0161t\u011bna nov\u00e1 mutace koronaviru SARS-CoV-2 ozna\u010den\u00e1 SARS-CoV-2 VOC 202012\/01 […]<\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"image","meta":{"_uag_custom_page_level_css":""},"categories":[1],"tags":[],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"boldthemes_grid":false,"boldthemes_grid_11":false,"boldthemes_grid_22":false,"boldthemes_grid_21":false,"boldthemes_grid_12":false,"boldthemes_latest_posts":false,"boldthemes_grid_gallery":false},"uagb_author_info":{"display_name":"Jbednar","author_link":"https:\/\/www.mc-praha.cz\/mcp\/author\/jbednar\/"},"uagb_comment_info":0,"uagb_excerpt":"V\u00a0prosinci 2020 byla ve Velk\u00e9 Brit\u00e1nii zji\u0161t\u011bna nov\u00e1 mutace koronaviru SARS-CoV-2 ozna\u010den\u00e1 SARS-CoV-2 VOC 202012\/01 […]","post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.mc-praha.cz\/mcp\/wp-json\/wp\/v2\/posts\/3813"}],"collection":[{"href":"https:\/\/www.mc-praha.cz\/mcp\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mc-praha.cz\/mcp\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mc-praha.cz\/mcp\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mc-praha.cz\/mcp\/wp-json\/wp\/v2\/comments?post=3813"}],"version-history":[{"count":3,"href":"https:\/\/www.mc-praha.cz\/mcp\/wp-json\/wp\/v2\/posts\/3813\/revisions"}],"predecessor-version":[{"id":3823,"href":"https:\/\/www.mc-praha.cz\/mcp\/wp-json\/wp\/v2\/posts\/3813\/revisions\/3823"}],"wp:attachment":[{"href":"https:\/\/www.mc-praha.cz\/mcp\/wp-json\/wp\/v2\/media?parent=3813"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mc-praha.cz\/mcp\/wp-json\/wp\/v2\/categories?post=3813"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mc-praha.cz\/mcp\/wp-json\/wp\/v2\/tags?post=3813"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}