Name: interferons block viral replication
Uploaded: 2026-03-12T13:36:03.000Z
Duration: 1 min 30 s
Channel: JoVE

Interferonlar, viral protein sentezini engelleyerek viral çoğalmayı baskılayan doğal antiviral maddelerdir.Pegile interferonlar, polietilen glikolün interferonlara bağlanmasıyla oluşturulan bir rekombinant interferon türüdür.Bu interferonlar sağlıklı konak hücrelerindeki reseptörlere bağlanır ve interferonla uyarılan genlerin ekspresyonunu tetikler.Bu genler, başlangıçta inaktif bir durumda bulunan birkaç antiviral proteinin sentezini indükler.Bunlardan üçü, protein kinaz R, oligoadenylat sentetaz ve RNase L, viral mRNA çevirisini kesmede önemli bir rol oynar.Viral enfeksiyonda, viral çift zincirli RNA'nın varlığı bu proteinleri aktive eder.Aktif protein kinaz R, ökaryot çeviri başlatma faktörü 2⍺'yu fosforile ederek hem viral hem de konak mRNA'nın translasyonunu engeller.Ayrıca, oligoadenilat sentetaz, RNase L'yi aktive eden kısa adenilat molekül zincirlerini sentezler.Aktif RNaz L, viral ve koşuk mRNA'yı bozur ve enfekte hücrelerde protein sentezini durdurur. Bu, hücre ölümünü teşvik eder ve viral çoğalmayı sınırlar.

viral protein sentezinin İnhibörü

Inhibitors of Viral Protein Synthesis

Protein sentezi, viral çoğalma için vazgeçilmezdir; çünkü virüsler bu süreç için gerekli hücresel mekanizmaya sahip değildir ve konakçının translasyon mekanizmasını ele geçirmek zorundadır. Buna karşılık, konak hücreler, viral yayılmayı engellemede merkezi rol oynayan özel sitokinler olan interferonları içeren kritik doğuştan gelen bir bağışıklık savunması uygular.Viral tespit edildiğinde, enfekte hücreler bitişik enfekte olmayan hücrelerdeki reseptörlere bağlanan interferonlar salgılar; bu da JAK-STAT sinyal yolunu aktive eder ve interferonla uyarlanan genlerin (ISG) ifadesini tetikler. Bu ISG'ler, üç ana antiviral proteinin ekspresyonu indükler: protein kinaz R (PKR), 2',5'-oligoadenylat sentetaz (OAS) ve RNase L. Enfeksiyonla ilişkili moleküler bir desen olan viral çift zincirli RNA (dsRNA) doğrudan PKR ve OAS'yi aktive eder.Aktive edilmiş PKR, ökaryot çeviri başlatma faktörü 2'nin (eIF2α) alfa alt birimini fosforile eder, mRNA çevirisini durdurur ve hem viral hem de konak protein sentezini baskılar. Aynı zamanda, OAS, RNase L'yi aktive eden 2',5' bağlantılı oligoadenilat üretimini katalize eder. Aktif RNase L, ribozomal RNA dahil olmak üzere viral ve hücresel RNA'yı parçalar, böylece protein sentezinin kapanmasını zorlaştırır ve hücre içindeki antiviral durumu artırır.Rekombinant İnterferonların Klinik UygulamalarıGüçlü antiviral özellikleri nedeniyle, rekombinant interferonlar çeşitli viral hastalıkların klinik yönetiminde kullanılmıştır:<ul><li>Antiviral tedavi: Interferon-alfa (IFN-α), kronik hepatit B ve C enfeksiyonlarının tedavisinde tarihsel bir temel taşı olmuş, viral yükü azaltmış ve hastalık ilerlemesini geciktirmiştir. Hepatit C'de, doğrudan etkili antivirallerin (DAA'lar) ortaya çıkmasından önce standart tedavi yöntemiydi ve bu ilaçlar şimdi üstün etkinlik ve tolere edilebilirlik sunmaktadır. IFN-α ayrıca insan papilloma virüsü (HPV) ile ilişkili lezyonlar ve HIV ile bağlantılı Kaposi sarkomunu tedavi etmek için de kullanılır.</li><li>Onkoloji: IFN-α, tüylü hücreli lösemi ve kronik miyeloid lösemi, kötü huylu melanom ve böbrek hücreli karsinom gibi bazı hematolojik malignitelerde immünomodülatör bir ajan olarak görev yapar.</li><li>İmmünoloji: İnterfon-beta (IFN-β), multipl sklerozu yönetmekte yaygın olarak kullanılır, nüks sıklığını azaltır ve engelliliğin ilerlemesini geciktirir.</li></ul>Klinik faydalarına rağmen, interferon tedavileri grip benzeri semptomlar, yorgunluk, depresyon ve hematolojik anormallikler gibi yan etkilerle ilişkilidir ve bu durum bazı hastalarda kullanımlarını sınırlayabilir. Buna rağmen, bu çeşitli uygulamalar, interferonların antiviral, onkoloji ve immünolojik alanlardaki çok yönlülüğünü ve klinik önemini vurgulamaktadır.

Viral Protein Sentezinin İnhibörü

Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's ...

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interferons block viral replication

Interferons block viral replication by shutting down protein synthesis and activating the cell’s antiviral defenses. Viruses need the host cell’s translational machinery to make proteins, because they do not have the machinery to do this on their own. When a virus is detected, infected cells release interferons, which are cytokines, or signaling proteins, that warn nearby uninfected cells.

Interferons bind to receptors on nearby cells and activate the JAK-STAT signaling pathway. This turns on interferon-stimulated genes, or ISGs. These genes lead to the production of three key antiviral proteins: protein kinase R (PKR), 2',5'-oligoadenylate synthetase (OAS), and RNase L.

Viral double-stranded RNA, or dsRNA, helps activate PKR and OAS. PKR phosphorylates the alpha subunit of eukaryotic translation initiation factor 2, called eIF2alpha. This blocks the start of mRNA translation and slows both viral and host protein synthesis. At the same time, OAS makes 2',5'-linked oligoadenylates, which activate RNase L.

Active RNase L breaks down viral and cellular RNA, including ribosomal RNA. This deepens the shutdown of protein synthesis and strengthens the antiviral state in the cell. Recombinant interferons have also been used in medicine, especially for chronic hepatitis B and C, HPV-associated lesions, and Kaposi's sarcoma linked to HIV.

Interferon-alpha, or IFN-alpha, was a historical treatment for hepatitis C before direct-acting antivirals became available. Pegylated interferon with ribavirin was once standard therapy for hepatitis C. IFN-alpha is also used in some cancers, including hairy cell leukemia, chronic myeloid leukemia, malignant melanoma, and renal cell carcinoma.

Interferon-beta, or IFN-beta, is used to manage multiple sclerosis. It can reduce relapse frequency and slow disability progression. Interferon treatments can also cause flu-like symptoms, fatigue, depression, and blood-related abnormalities, which may limit their use.

Interferons Block Viral Replication

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key terms and concepts

Learn how interferons stop viral replication by turning on PKR, OAS, and RNase L, and see their uses in hepatitis, HPV, cancer, and multiple sclerosis.

Interferons Block Viral Replication | JoVE K12

JoVE Core Microbiology provides an engaging introduction to the microbial world and its influence on health, industry, and the environment. This comprehensive collection covers key concepts such as microbial structure, metabolism, genetics, and ecology. It introduces essential laboratory techniques and microscopy methods through visually engaging animations. Corresponding scientist-in-action videos bridge classroom concepts with real-world research and applications.

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Interferons Block Viral Replication

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