最近剛好有醫師問到interferon alfacon-1，所以我簡單找了一些他的介紹如下：
DESCRIPTION
Interferon alfacon-1 is a recombinant non-naturally occurring type-I interferon.
The 166-amino acid sequence of Interferon alfacon-1 was derived by scanning
the sequences of several natural interferon alpha subtypes and assigning
the most frequently observed amino acid in each corresponding position.1
Four additional amino acid changes were made to facilitate the molecular
construction, and a corresponding synthetic DNA sequence was constructed
using chemical synthesis methodology. Interferon alfacon-1 differs from
interferon alfa-2b at 20/166 amino acids (88% homology), and comparison with
interferon-beta shows identity at over 30% of the amino acid positions. Interferon
alfacon-1 is produced in Escherichia coli (E. coli) cells that have been genetically
altered by insertion of a synthetically constructed sequence that codes for
Interferon alfacon-1. Prior to final purification, Interferon alfacon-1 is allowed to
oxidize to its native state, and its final purity is achieved by sequential passage
over a series of chromatography columns. This protein has a molecular weight
of 19,434 daltons.
INFERGEN is a sterile, clear, colorless, preservative-free liquid formulated with
100 mM sodium chloride and 27 mM sodium phosphate at pH 7.0 ± 0.2. The
product is available in single-use vials containing 9 mcg and 15 mcg Interferon
alfacon-1 at a fill volume of 0.3 mL and 0.5 mL, respectively. INFERGEN vials
contain 0.03 mg/mL Interferon alfacon-1, 5.9 mg/mL sodium chloride, and
3.8 mg/mL sodium phosphate in Water for Injection, USP. INFERGEN is to be
administered undiluted by subcutaneous (SC) injection.
CLINICAL PHARMACOLOGY
General
Interferons are a family of naturally occurring, small protein molecules with
molecular weights of 15,000 to 21,000 daltons that are produced and secreted
by cells in response to viral infections or to various synthetic and biological
inducers. Two major classes of interferons have been identified (i.e., type-I and
type-II). Type-I interferons include a family of more than 25 alpha interferons
as well as beta interferon and omega interferon. While all alpha interferons
have similar biological effects, not all the activities are shared by each alpha
interferon and, in many cases, the extent of activity varies substantially for each
interferon subtype.
All type-I interferons share common biological activities generated by binding of
interferon to the cell-surface receptor, leading to the production of several
interferon-stimulated gene products. Type-I interferons induce pleiotropic biologic
responses which include antiviral, antiproliferative, and immunomodulatory
effects, regulation of cell surface major histocompatibility antigen (HLA class I
and class II) expression and regulation of cytokine expression. Examples
of interferon-stimulated gene products include 2´5´ oligoadenylate synthetase
(2´5´ OAS) and [1]-2 microglobulin.
The antiviral, antiproliferative, natural killer (NK) cell activation, and gene-induction
activities of INFERGEN have been compared with other recombinant alpha
interferons in in vitro assays and have demonstrated similar ranges of activity.
INFERGEN exhibited at least 5 times higher specific activity in vitro than
Interferon alfa-2a and Interferon alfa-2b.2 Comparison of INFERGEN with a
WHO international potency standard for recombinant alpha interferon (83/514)
revealed that the specific activity of INFERGEN in both an in vitro antiviral cytopathic
effect assay and an antiproliferative assay was 1 x 109 U/mg. However,
correlation between in vitro activity and clinical activity of any interferon is
unknown.
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