Description
Interferon-alpha 2 (IFN-α2), also known as leukocyte interferon, is a type I interferon with potent antiviral and immunomodulatory properties [1, 2]. Type I interferons are a family of highly related proteins (>95% amino acid sequence homology) that signal through the interferon-α receptor (IFNAR), composed of two subunits: IFNAR1 (~125 kDa), which contributes to ligand binding and signal transduction, and IFNAR2 (~100 kDa), the primary ligand-binding chain [3]. Human IFN-α2 exists in three allelic variants: IFN-α2a, IFN-α2b, and IFN-α2c. Recombinant human IFN-α2a (rhIFN-α2a), commonly produced in E. coli, is a single non-glycosylated polypeptide of 165 amino acids with a molecular mass of ~19.3 kDa. The IFN-α2a gene was originally cloned from human leukocytes, and the recombinant protein is purified using proprietary chromatographic techniques [1]. Functionally, IFN-α2 activates the JAK-STAT signaling pathway, leading to 1. Antiviral defense-inhibition of viral replication and enhancement of cellular resistance to infection [2, 4]. 2. Antiproliferative activity-suppression of tumor cell growth and induction of apoptosis [4, 5]. 3. Immunomodulation-upregulation of class I MHC, activation of NK cells and cytotoxic T lymphocytes, and modulation of B-cell antibody production [2, 6]. 4. Synergy with other cytokines – amplification of immune signaling networks [2]. Recombinant IFNα2a is widely used as a therapeutic agent for viral infections (e.g., hepatitis B and C) [7, 8], hematologic malignancies (e.g., hairy cell leukemia, chronic myeloid leukemia) [9], and solid tumors (e.g., malignant melanoma, renal cell carcinoma) [10, 11]. UniProt ID: P01563