Abantu ngebengekho ngaphandle iintsholongwane kuba iprotheni yentsholongwane idlala indima ephambili ekuphuhliseni umntu umbungu. Nangona kunjalo, ngamanye amaxesha, babeka izoyikiso ezikhoyo ngendlela yezifo njengakwimeko yobhubhani we-COVID-19. Umnqa, iintsholongwane zibandakanya ~ 8% ye-genome yethu, efunyenwe ngexesha lokuziphendukela kwemvelo, isenza "phantse i-chimera".
Elona gama lidume kakubi kwaye loyikeka kunyaka ka-2020 ngaphandle kwamathandabuzo 'intsholongwane'. Inoveli intsholongwane ye-Corona unoxanduva lwesifo esingazange sabonwa ngaphambili se-COVID-19 kunye nokuphantse ukuwa koqoqosho lwehlabathi. Konke oku kubangwa lisuntswana elincinane elingajongwanga njengeliphila 'ngokupheleleyo' ngenxa yokuba likwimeko engasebenziyo ngaphandle komsingathi, ngelixa liqhubeleka ngaphakathi ekosuleni umamkeli. Eyona nto imangalisayo kwaye iyothusa yinto yokuba abantu bebethwele “imfuza” yentsholongwane ukusukela kumaxesha amandulo kwaye ngoku iijini zentsholongwane zenza ~ 8% ye umntu igenome (1). Ukubeka nje oku ngokwembono, kuphela ~ 1% umntu i-genome isebenza ngokusebenzayo inoxanduva lokwenza iiproteni ezimisela ukuba singoobani.
Ibali lobudlelwane phakathi abantu kwaye iintsholongwane yaqala kwi-20-100 yezigidi kwiminyaka eyadlulayo xa ookhokho bethu bosulelwa ngu iintsholongwane. Usapho ngalunye lwe-endogenous retrovirus luvela kwintsholongwane enye yeeseli ze-germline yi-retrovirus yangaphandle eya kuthi emva kokudibanisa kukhokho wethu, yandiswa kwaye yavela (2). Ukusasazwa okulandelwa kukudluliselwa okuthe tye ukusuka kubazali ukuya kwinzala kwaye namhlanje sinazo ezi genomes zentsholongwane ezifakwe kwiDNA yethu njenge umntu i-endogenous retroviruses (HERVs). Le yinkqubo eqhubekayo kwaye kusenokwenzeka ukuba iyenzeka okwangoku. Ekuhambeni kwexesha lokuzivelela, ezi HERVs zafumana utshintsho, zazinziswa kwi umntu genome kwaye baphulukana namandla abo okubangela isifo. I-endogenous ii-retroviruses azikho kuphela kwi abantu kodwa zikho kuzo zonke izinto eziphilayo. Zonke ezi retroviruses endogenous zidityaniswe kwiindidi ezintathu (Class I, II and III) ezenzeka kwiintlobo ezahlukeneyo zezilwanyana zibonisa ubudlelwane bephylogenetic ngokusekelwe kulandelelwano lokufana (3) njengoko kubonisiwe kuMfanekiso ongezantsi. Ii-HERVs zeqela le-Class I.
Kwiintlobo ngeentlobo ze-retroviruses ezifakwe kwi- umntu igenome, umzekelo weklasi ofanele ukukhankanywa apha, ngulowo weprotein ye-retroviral eneprotein yemvulophu ene-fusogenic ebizwa ngokuba yi-syncytin, (5) umsebenzi wayo wokuqala intsholongwane yayikukuxuba neeseli ezibambayo ukuze kubangele usulelo. Le proteni ngoku ilungiselelwe ngaphakathi abantu ukwenza i-placenta (ukudityaniswa kweeseli zokwenza iiseli ezine-multinucleated) ezingaboneleli nje kuphela ngokutya kwi-fetus evela kumama ngexesha lokukhulelwa kodwa kwakhona ikhusela usana olungekazalwa kukhuselo lomzimba lukamama ngenxa yendalo ye-sycytin ye-immunosuppressive. Le i-HERV ibonakalise ukuba luncedo kwi umntu uhlanga ngokuchaza ubukho balo.
Ii-HERVs nazo ziye zabandakanyeka ekuboneleleni ngokhuseleko lwangaphakathi kumamkeli ngokuthintela usulelo olongezelelweyo olunxulumeneyo iintsholongwane okanye ukunciphisa ubukhali besifo xa ususuleleke kwakhona ngohlobo olufanayo lwe iintsholongwane. Uphononongo luka-2016 luka-Katzourakis no-Aswad (6) luchaza ukuba i-endogenous iintsholongwane inokusebenza njengezinto ezilawulayo kwiijini ezilawula ukusebenza kwe-immune, ngaloo ndlela kukhokelela ekuphuhlisweni kokuzikhusela. Ngaloo nyaka, i-Chuung et al (7) ibonise ukuba ii-HERV ezithile zisebenza njengeziphuculi ezilawulayo ngokumodareyitha ukubonakaliswa kwe-IFN (i-interferon) i-genes inducible ngaloo ndlela inikezela ukugonywa kwemvelo. Iimveliso ze-HERV zokubonisa nazo zinokusebenza njengeepateni ze-molecular ezihambelana ne-pathogen (i-PAMPs), ezibangela i-receptors yeselula enoxanduva lokusingatha umgca wokuqala wokukhusela (8-10).
Enye into enika umdla yee-HERVs kukuba ezinye zazo zibonisa iipolymorphisms zokufakelwa, okt inani leekopi ezahlukeneyo ezikhoyo kwigenome ngenxa yeziganeko ezifakiweyo. Uphononongo lwezifundo ze-20 eziphuma kumaqela eentlanga ezahlukeneyo zibonise iipateni zokufakwa kwe-polymorphism phakathi kwe-0-87% kuzo zonke izifundo (11). Oku kunokuba nefuthe ekudaleni izifo ngokusebenza kofuzo oluthile oluthe cwaka.
Ezinye ii-HERVs nazo zibonakaliswe ukuba zidibene nokuphuhliswa kokuphazamiseka kwe-autoimmune ezifana ne-multiple sclerosis (12). Ngaphantsi kweemeko eziqhelekileyo ze-physiological, i-HERV ibonakaliso ilawulwa ngokuqinileyo ngelixa iphantsi kweemeko ze-pathological ngenxa yokutshintsha kwendawo yangaphandle / yangaphakathi, utshintsho lwe-hormonal kunye / okanye ukusebenzisana kwe-microbial kunokubangela ukuxhatshazwa kwe-HERV expression, ekhokelela kwizifo.
Ezi mpawu zingentla zee-HERVs zibonisa ukuba hayi ubukho bazo kuphela umntu I-genome ayinakuthintelwa kodwa banamandla okulawula i-homeostasis yesistim somzimba sokuzikhusela nokuba sisebenze okanye siyicinezele, ngaloo ndlela kubangele iziphumo ezahlukeneyo (ukusuka ekubeni luncedo ukuya ekubangeleni isifo) kwimikhosi.
Ubhubhani we-COVID-19 ukwabangelwa yi-retrovirus ye-SARS-nCoV-2, eyeyentsapho yomkhuhlane, kwaye kunokuba sengqiqweni ukuba, ngexesha lokuzivelela kwezinto, iigenomes ezinxulumene nolu sapho iintsholongwane idityanisiwe kwi umntu genome kwaye ngoku zikhona njenge-HERVs. Kuqikelelwa ukuba ezi HERVs zinokubonisa iipolymorphisms ezahlukeneyo, njengoko kukhankanyiwe ngasentla, phakathi kwabantu bezizwe ezahlukeneyo. Ezi polymorphisms zinokuba luhlobo lwenombolo yekopi eyahlukileyo yezi HERVs kunye / okanye ubukho okanye ukungabikho kweenguqu (utshintsho kulandelelwano lwe-genome) eziqokelelwe kwixesha elithile. Oku mahluko kwii-HERV ezihlanganisiweyo kunokunika ingcaciso ngokwahluka kwamazinga okusweleka kunye nobuzaza besifo se-COVID-19 kumazwe ahlukeneyo abangelwa ngubhubhane.
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