PBL offers four rat interferon proteins spanning two interferon classes: two Type I IFN-alpha subtypes and one Type I IFN-beta, all mammalian-cell expressed, plus a Type II IFN-gamma expressed in E. coli. Type I and Type II interferons use different receptors and different signaling complexes, so the choice between them depends on the biology being studied, not just the species.
Rat IFN-Alpha 1 is a Type I interferon expressed in mammalian cells, with activity measured on rat epithelial-like (RATEC) cells. It is one of at least two distinct rat IFN-alpha subtypes available as purified recombinant protein, alongside IFN-Alpha 14, reflecting the same subtype diversity seen in the mouse and human IFN-alpha gene families.
Rat IFN-Alpha 14 is a second, distinct rat IFN-alpha subtype, also expressed in mammalian cells and assayed on RATEC cells. Because IFN-alpha subtypes can differ in potency and induce distinct interferon-stimulated gene patterns despite signaling through the same receptor, having both Alpha 1 and Alpha 14 available supports subtype-comparison studies rather than assuming one rat IFN-alpha protein represents the whole family.
Rat IFN-Beta is a Type I interferon expressed in CHO cells and supplied without carrier protein. Like IFN-alpha, it signals through the heterodimeric Type I IFN receptor (IFNAR), activating JAK1 and TYK2 and driving STAT-dependent induction of antiviral genes; it is produced mainly by fibroblasts and pathogen-exposed dendritic cells, macrophages, and endothelial cells in response to viral infection and Toll-like receptor stimulation.
Rat IFN-Gamma is a Type II interferon, biologically distinct from the Type I proteins above despite the shared "interferon" name. It is expressed in E. coli, originally derived from rat leukocytes, and produced primarily by T lymphocytes and natural killer cells rather than by cells responding directly to infection. It signals through a separate receptor, IFNGR1/IFNGR2, activating JAK1 and JAK2 to form a STAT1 homodimer that drives a different set of target genes than the Type I pathway, and it plays a central role in macrophage activation and MHC class I and II upregulation rather than direct antiviral defense alone.