Kuberekana kwemavhairasi mumasero emugadziri
Mavhairasi zvinhu zvinotapukira zvisingaonekwe zvakanaka zvisingagone kurarama nekuberekana zviri zvega. Kusiyana nemabhakitiriya kana fungi, ane masisitimu awo ekugadzirisa muviri, mavhairasi anovimba zvakanyanya nemasero emuviri kuti agadzire zvikamu zvitsva. Nokudaro, maitiro ekuberekana kwehutachiona—maitiro ayo mavhairasi anokopa majini awo uye kuunganidza zvidimbu zvitsva zvehutachiona—anogara achiitika mukati memasero emuviri. Kunzwisisa matanho ekuberekana kwehutachiona kwakakosha mubiology, mushonga, uye hutano hweveruzhinji, sezvo nzira dzakawanda dzekudzivirira nekurapa dzakagadzirirwa kudzivirira chimwe chezvikamu zvakakosha zvedenderedzwa iri.
Maumbirwo ehutachiona uye kuvimba kwahwo nehutachiona hwahwo
Kazhinji, mavhairasi anoumbwa nezvinhu zvemajini (nucleic acid), zvinogona kuva DNA kana RNA, zvinodzivirirwa neprotein coat inonzi capsid. Mamwe mavhairasi ane layer yekuwedzera, envelopu inobva ku host cell membrane, ine mapuroteni epamusoro ekubatanidza kumasero anotarisirwa. Mavhairasi haana ribosomes, mitochondria, kana ma enzymes akazara e metabolic. Nekuda kweizvozvo, kuti abereke, mavhairasi anofanira "kupamba" michina yemasero e host, kusanganisira ma replication enzymes, transcription-translation systems, uye manyuko esimba nezvinhu zvakagadziriswa.
Kunyangwe mavhairasi akasiyana-siyana, kudzokororwa kwawo kunogona kunzwisiswa kuburikidza nematanho akati wandei akakosha: kunyudzwa (kubatanidzwa), kupinda (kupinda), kusunungurwa (kuburitswa kwezvinhu zvemajini), kudzokororwa uye kugadzirwa kweprotein, kuungana, uye kuburitswa. Kusiyana kunoenderana nerudzi rwemavhairasi genome (DNA/RNA, ine tambo imwe chete/ine tambo mbiri) uye kuvapo kana kusavapo kweenvelopu.
1. Kunyudzwa kwehutachiona: kunamatira kwehutachiona kumasero emuviri
Danho rekutanga mukudzokororwa kwemasero i adsorption, iyo nzira iyo hutachiona hunoziva uye hunonamatira pamusoro pesero rinopinda. Kubatanidzwa uku hakusi kwega; mavhairasi ane mapuroteni akasarudzika (akadai sekukwira kwemamwe mavhairasi akaputirwa) anosunga kune ma receptors chaiwo pa membrane yesero. Ma receptors aya anogona kuva mapuroteni, ma glycoprotein, kana zvimwe zvikamu pamusoro pesero.
Kubatana kwehutachiona nereceptor kunoratidza tropism yehutachiona, kureva kuti, mhando dzipi dzemasero kana tishu dzahunogona kutapurira. Semuenzaniso, mamwe mavhairasi anogona kutapurira masero ekufema nekuti mareceptor anodiwa anowanikwa akawanda munyama iyoyo. Ichi ndicho chimwe chikonzero nei hutachiona huchigona kurwisa nhengo dzakananga uye kukonzera zviratidzo zvinoonekwa.
2. Kupinda: kupinda kwehutachiona musero
Mushure mekunamira, vhairasi inofanira kupinda musero. Nzira dzekupinda dzinosiyana zvichienderana nerudzi rwevhairasi:
1. Kusanganiswa kweMembrane: mumavhairasi akaputirwa, vhairasi inogona kubatana nemembrane yesero remugadziri, zvekuti nucleocapsid inopinda mu cytoplasm.
2. Endocytosis: masero "anomedza" mavhairasi nekugadzira ma vesicles (endosomes). Mavhairasi mazhinji anoshandisa nzira iyi, yakaputirwa uye isina kuputirwa.
3. Kubaiwa majini: kunowanikwa mubhakitiriya (mavhairasi anokonzera mabhakitiriya). Virusi rinonamira pamadziro esero rebhakitiriya robva raisa nucleic acid yaro musero.
Danho iri rekupinda mumuviri rinowanzova chinangwa chekugadzirwa kwemishonga, nekuti kana hutachiona hukatadza kupinda, kutenderera kwehutachiona hakugone kuenderera mberi.
3. Kubvisa chifukidziro: kuburitswa kwezvinhu zvemajini zvehutachiona
Kana yapinda musero (ingava mu cytoplasm kana mu endosome), vhairasi inobuda isina kuvharwa, inova kuburitswa kwe capsid yayo, zvichiita kuti majini ayo awane mukana wekubereka. Mune mamwe mavhairasi, shanduko mu pH mukati me endosome dzinokonzera shanduko muchimiro chemapuroteni e capsid, zvichiita kuti genome yevhairasi iburitswe. Mune mamwe mavhairasi, ma enzymes emasero emumba kana ma enzymes evhairasi anobatsira kubvisa capsid.
Kubvisa chifukidziro idanho rakakosha: kana genome risina kuburitswa zvakanaka, kuberekana hakugone kuitika. Uyezve, padanho iri, dziviriro yesero inogona kutanga kuona kuvapo kwehutachiona, semuenzaniso kuburikidza nemasensa eRNA/DNA ekunze anokonzera mhinduro yemuviri yekudzivirira chirwere.
4. Kubatanidzwa kwemajini uye kugadzirwa kwemapuroteni ehutachiona
Danho rinotevera ndiro musimboti wekuberekana: hutachiona hunoshandisa sero rinopinda mumuviri kuti riitewo magene aro uye rigadzire mapuroteni ehutachiona. Maitiro acho anokanganiswa zvakanyanya nerudzi rwemagene ehutachiona.
a. Mavhairasi eDNA
Mavhairasi mazhinji eDNA anopinda munucleus yesero remunhu achishandisa maenzymes eDNA replication yesero uye michina yekunyora. DNA yehutachiona inoshandurwa kuita mRNA neRNA polymerase yemunhu, iyo inozoshandurwa kuita mapuroteni ehutachiona ne ribosomes. Mamwe mavhairasi makuru eDNA ane maenzymes awo, zvichiita kuti azvigadzirire, asi achiri kuda masero.
b. Mavhairasi eRNA
Mavhairasi eRNA anowanzo berekana mu cytoplasm nekuti masero evanhu haana ma enzymes anogona kuburitsa RNA kubva kuRNA. Nokudaro, mavhairasi eRNA anowanzo takura kana kunyora enzyme inonzi RNA-dependent RNA polymerase (RdRp). Iyi enzyme inoita makopi eRNA yehutachiona uye inogadzira mRNA yekugadzira mapuroteni.
Mavhairasi eRNA anogona kuva:
– Pfungwa yakanaka (+) RNA ine tambo imwe chete: genome yayo inogona kushanda zvakananga semRNA uye inoshandurwa ipapo ipapo.
– Pfungwa isina kunaka (-) RNA ine tambo imwe chete: inofanira kutanga yakopwa kuita RNA yepfungwa yakanaka kuti ishandurwe.
– RNA ine tambo mbiri (dsRNA): inoda enzyme yakakosha kuti igadzire mRNA.
c. Retrovirus
MaRetrovirus ane genome yeRNA asi anoshandisa enzyme reverse transcriptase kushandura RNA kuita DNA. DNA iyi inobva yabatanidzwa mugenome yesero remugadziri wemasero nerubatsiro rwe enzyme integrase. Kana yabatanidzwa, zvinhu zvemajini ehutachiona zvinogona "kunyarara" kana kushanda, zvichigadzira mRNA itsva uye majenomu ehutachiona. Iyi nzira yekubatanidza inoita kuti hutachiona hwe retrovirus huome kubvisa zvachose.
Pamusoro pekudzokororwa kwemajini, masero emuviri anomanikidzwawo kugadzira mapuroteni emuviri (capsid, mapuroteni eenvelopu) uye mapuroteni asina kuvakwa (maenzyme ekugadzira, mapuroteni, zvinhu zvinodzora). Mavhairasi mazhinji anogadzira mapuroteni muchimiro chemapolyprotein marefu, ayo anobva apatsanurwa kuita mayuniti anoshanda nemavirusi protease.
5. Kuungana uye kukura kweganda
Kana genome nemapuroteni zvapera, hutachiona hunopinda muchikamu chekuungana. Mapuroteni eCapsid anoungana kuita maumbirwo chaiwo (semuenzaniso, icosahedral kana helical) uku achirongedza genome rehutachiona. Maitiro aya anogona kuitika mu cytoplasm kana nucleus, zvichienderana nehutachiona.
Mamwe mavhairasi anoda nguva yekukura kuti atange kutapurirana. Kukura kunogona kusanganisira kupatsanurwa kwemapuroteni neproteases, kuchinja kwechimiro checapsid, kana kuwedzerwa zvimwe zvikamu. Pasina kukura, zvidimbu zvevhairasi zvinogona kuoneka zvisina kukuvadzwa asi hazvigone kukanganisa masero anotevera.
6. Kuburitswa kwemavhairasi matsva kubva mumasero emuviri
Danho rekupedzisira kuburitswa kwema virions (zvikamu zvevhairasi zvakakwana) kubva musero kuti zvitapukire mamwe masero. Maitiro acho anosanganisira:
1. Cell lysis: sero rinoputika rofa, richiburitsa ma virion akawanda panguva imwe chete. Rinowanikwa mumavhairasi asina kuvharwa uye mune mamwe hutachiona hwakasimba hunokuvadza tishu.
2. Kutumbuka: Mavhairasi akaputirwa anobuda nekutora chikamu chemembrane yesero rinopinda mumuviri senzvimbo inoputirwa. Maitiro aya haawanzo kuuraya sero ipapo ipapo, asi anogona kukanganisa mashandiro esero uye kukonzera kuzvimba.
3. Exocytosis: mamwe mavhairasi anoshandisa nzira inoburitsa sero kuti abude nepama vesicles.
Kutenderera uku kunogona kukurumidza (kubva maawa kusvika mazuva) kana kunonoka uye kunogona kuperekedzwa nechikamu chekuvanda, zvichienderana nehunhu hwehutachiona uye mhinduro yehutachiona.
Kukanganiswa kwekuwanda kwehutachiona pamasero nemuviri
Kuwanda kwemavhairasi kunogona kukonzera kukuvara kwemasero nenzira dzakasiyana-siyana: nekuderedza simba remasero, kukuvadza mamembrane nema organelles, kukonzera kufa kwemasero (apoptosis), kana kukonzera kushushikana kwemuviri. Padanho renyama, kukuvara nekuzvimba zvinotungamira kuzviratidzo zvechirwere.
Kune rumwe rutivi, masoja emuviri anoedza kumisa kuberekana kwema interferon, masero anouraya echisikigo, ma antibodies, uye masero ane chepfu anonzi cytotoxic T. Zvisinei, mavhairasi ane nzira dzakasiyana-siyana dzekunzvenga, dzakadai sekudzivisa ma interferon signaling, kuchinja nekukurumidza, kana kuvanda muchikamu chakavanzika.
Kudzokorora sechinangwa chekurapa nekudzivirira
Mishonga yakawanda inorwisa mavhairasi yakagadzirirwa kunanga matanho chaiwo, semuenzaniso:
- inodzivisa kupinda kwemavhairasi,
- inodzivisa ma enzymes ekudzokorora (RdRp, reverse transcriptase),
- inodzivisa mapuroteni kudzivirira kuibva,
- inodzivirira kuburitswa kwema virion.
Majekiseni anoshanda zvakanyanya nekugadzira immune system kuti ikwanise kuziva hutachiona nekukurumidza isati yatanga kupararira zvisingadzoreki. Nekudzivirira ma antibodies uye mhinduro yakasimba yemasero eT, hutachiona hunogona kudzivirirwa kuti husabatane, kupinda, kana kupararira zvakanyanya.
Penutup
Kuberekana kwemavhairasi mumasero emuviri ibasa rinoitwa nenzira inongwarira, ine matanho akawanda, kubva pakubatanidzwa kusvika pakuburitswa kwemavhairasi matsva. Kunyangwe mavhairasi achiita seari "nyore," kugona kwawo kushandisa masisitimu emasero kunoita kuti ashande zvakanyanya pakuparadzira nekukonzera zvirwere. Kunzwisisa nzira idzi dzekuberekana hakungokoshi chete mudzidzo asiwo kwakakosha pakugadzirwa kwemishonga inorwisa mavhairasi, majekiseni, uye nzira dzekudzora denda. Nekutarisa zvinhu zvakakosha muhupenyu hwemavhairasi, vanhu vanogona kuderedza migumisiro yehutachiona uye kuvandudza kusimba kwehutano hweveruzhinji.
