What Is Interferon?
Apr 13, 2022
Source: Cainiu Health
Dr. Qi Zhirong
Introduction
Interferons are secreted glycoproteins produced by host cells in response to viral infection or other inducing agents. Based on differences in structure, function, and the cell types that produce them, interferons are classified into Type I, Type II, and Type III interferons. Interferons exhibit broad-spectrum antiviral activity and can induce homologous cells to synthesize antiviral proteins, thereby establishing an antiviral state.
Interferons (IFNs) are a critical class of cytokines primarily used in the treatment of viral infections and malignancies, exhibiting diverse biological functions including antiviral and antitumor activities. The following provides a detailed analysis:
Interferons are secreted glycoproteins produced by host cells upon stimulation by viruses or other inducers. Based on structural features, functional properties, and cellular sources, interferons are classified into three types: Type I, Type II, and Type III. Type I interferons—including IFN-α, IFN-β, and IFN-ω—are predominantly produced by virus-infected cells. Type II interferon refers exclusively to IFN-γ, which is mainly secreted by activated T lymphocytes and natural killer (NK) cells. Type III interferons—comprising IFN-λ1, IFN-λ2, and IFN-λ3 (also known as IL-29, IL-28A, and IL-28B, respectively)—are primarily generated by virus-infected mucosal epithelial cells.
Interferons possess broad-spectrum antiviral activity. They induce neighboring cells to synthesize antiviral proteins, thereby establishing an “antiviral state” that restricts further viral replication and spread. Interferons effectively suppress the replication of numerous viruses, including influenza virus, respiratory syncytial virus (RSV), adenovirus, and herpes simplex virus (HSV). Additionally, interferons inhibit tumor cell proliferation, induce tumor cell apoptosis, modulate immune function, and enhance the host’s cytotoxic response against tumor cells. Moreover, they suppress tumor angiogenesis, thereby slowing tumor growth.
Clinically, interferons hold extensive therapeutic value and are widely employed in treating viral infections, cancers, and immune-mediated disorders. Dosage and administration regimens must be individualized according to the patient’s clinical condition and specific disease. Generally, sustained administration over a defined period is required to achieve optimal therapeutic efficacy. Throughout treatment, strict adherence to physician-prescribed dosing is essential to avoid both underdosing and overdosing.
Prior to initiating interferon therapy, a thorough medical history review and physical examination must be conducted to confirm patient suitability for treatment.
