ABSTRACT
I. CLASSIFICATION OF INTERFERONS Interferons (IFNs) are classified into three major groups, a, 13, and y, on the basis of their antigenicity and the relatedness of their nucleotide sequences. IFNs were previously named according to the cell preparations from which they are derived. IFN-a was known as leukocyte, or lymphoblastoid, IFN, and IFN-/3 as fibroblast IFN. IFN-y was known as immune IFN, because it had been derived from immunologically stimulated T lymphocytes. Type I IFNs comprise IFN-a and IFN-0, both of which bind to the same cell receptor, the type I IFN receptor. Type II IFN, IFN-y, binds with type II receptor.
