Interferons are proteins released by host cells in response to viruses that help activate the immune system and inhibit viral replication. They have various functions including activating immune cells, increasing antigen presentation, and inhibiting tumor growth. Interferon therapy is used to treat multiple sclerosis, some cancers, and hepatitis B and C often in combination with other drugs. Common side effects of interferon therapy include flu-like symptoms. Several types of interferons have been approved for medical use to treat various conditions.

1. Roles of Interferon In
diseases.
Presented by : Poulani Roy
College Roll no. : 19MB0001.
Siliguri College.

2. CONTENT
1.Introduction.
2.Function.
3.Interferon Therapy.
4.Conclusion.

3. INTRODUCTION
Introduction-The various forms of interferon are the body's most rapidly
produced and important defense against viruses. Interferons can also combat
bacterial and parasitic infections, inhibit cell division, and promote or impede the
differentiation of cells.
Roles In Disease- Interferons are a group of signaling proteins made and
released by host cells in response to the presence of several viruses. In a typical
scenario, a virus-infected cell will release interferons causing nearby cells to
heighten their antiviral defenses.

4. Interferon type I (α/β/δ…)
Interferon type I (α/β/δ…)

5. Interferon type I (α/β/δ…)
● The molecular structure of human interferon-alpha IFNs belong to
the large class of proteins known as cytokines, molecules used for
communication between cells to trigger the protective defenses of the
immune system that help eradicate pathogens.Interferons are named
for their ability to "interfere" with viral replication by protecting cells
from virus infections.
● IFNs also have various other functions: they activate immune cells,
such as natural killer cells and macrophages; they increase host
defenses by up-regulating antigen presentation by virtue of
increasing the expression of major histocompatibility complex (MHC)
antigens.
● Certain symptoms of infections, such as fever, muscle pain and "flu-
like symptoms", are also caused by the production of IFNs and other
cytokines.More than twenty distinct IFN genes and proteins have been
identified in animals, including humans.
● They are typically divided among three classes:
Type I IFN, Type II IFN, and Type III IFN. IFNs belonging to all three classes
are important for fighting viral infections and for the regulation of the
immune system.

6. FUNCTION
All interferons share several common effects: they are antiviral agents and they modulate
functions of the immune system. Administration of Type I IFN has been shown experimentally to
inhibit tumor growth in animals, but the beneficial action in human tumors has not been widely
documented. A virus-infected cell releases viral particles that can infect nearby cells. However,
the infected cell can protect neighboring cells against a potential infection of the virus by
releasing interferons. In response to interferon, cells produce large amounts of an enzyme
known as protein kinase R (PKR). This enzyme phosphorylates a protein known as eIF-2 in
response to new viral infections; the phosphorylated eIF2 forms an inactive complex with
another protein, called eIF2B, to reduce protein synthesis within the cell. Another cellular
enzyme, RNAse L—also induced by interferon action—destroys RNA within the cells to further
reduce protein synthesis of both viral and host genes. Inhibited protein synthesis impairs both
virus replication and infected host cells. In addition, interferons induce production of hundreds
of other proteins—known collectively as interferon-stimulated genes (ISGs)—that have roles in
combating viruses and other actions produced by interferon. They also limit viral spread by
increasing p53 activity, which kills virus-infected cells by promoting apoptosis. The effect of IFN
on p53 is also linked to its protective role against certain cancers.

7. FUNCTION
Another function of interferons is to up-regulate major histocompatibility complex
molecules, MHC I and MHC II, and increase immunoproteasome activity. All interferons
significantly enhance the presentation of MHC I dependent antigens. Interferon gamma
(IFN-gamma) also significantly stimulates the MHC II-dependent presentation of
antigens. Higher MHC I expression increases presentation of viral and abnormal
peptides from cancer cells to cytotoxic T cells, while the immunoproteasome processes
these peptides for loading onto the MHC I molecule, thereby increasing the recognition
and killing of infected or malignant cells. Higher MHC II expression increases
presentation of these peptides to helper T cells; these cells release cytokines (such as
more interferons and interleukins, among others) that signal to and coordinate the
activity of other immune cells.
Interferons can also suppress angiogenesis by down regulation of angiogenic stimuli
deriving from tumor cells. They also suppress the proliferation of endothelial cells. Such
suppression causes a decrease in tumor angiogenesis, a decrease in its vascularization
and subsequent growth inhibition. Interferons, such as interferon gamma, directly
activate other immune cells, such as macrophages and natural killer cells.

8. INTERFERON THERAPY
Interferon beta-1a and interferon beta-1b are used to treat and control multiple sclerosis, an
autoimmune disorder. This treatment may help in reducing attacks in relapsing-remitting multiple
sclerosis and slowing disease progression and activity in secondary progressive multiple
sclerosis.
Interferon therapy is used (in combination with chemotherapy and radiation) as a treatment for
some cancers. This treatment can be used in hematological malignancy, such as in leukemia and
lymphomas including hairy cell leukemia, chronic myeloid leukemia, nodular lymphoma, and
cutaneous T-cell lymphoma. Patients with recurrent melanomas receive recombinant IFN-α2b.Both
hepatitis B and hepatitis C are treated with IFN-α, often in combination with other antiviral drugs.
Some of those treated with interferon have a sustained virological response and can eliminate
hepatitis virus. The most harmful strain—hepatitis C genotype I virus—can be treated with a 60-
80% success rate with the current standard-of-care treatment of interferon-α, ribavirin and
recently approved protease inhibitors such as Telaprevir (Incivek) May 2011, Boceprevir (Victrelis)
May 2011 or the nucleotide analog polymerase inhibitor Sofosbuvir (Sovaldi) December 2013.
Biopsies of patients given the treatment show reductions in liver damage and cirrhosis. Some
evidence shows giving interferon immediately following infection can prevent chronic hepatitis C,
although diagnosis early in infection is difficult since physical symptoms are sparse in early
hepatitis C infection. Control of chronic hepatitis C by IFN is associated with reduced

9. INTERFERON THERAPY
Unconfirmed results suggested that interferon eye drops may be an effective treatment
for people who have herpes simplex virus epithelial keratitis, a type of eye
infection.There is no clear evidence to suggest that removing the infected tissue
(debridement) followed by interferon drops is an effective treatment approach for these
types of eye infections.Unconfirmed results suggested that the combination of interferon
and an antiviral agent may speed the healing process compared to antiviral therapy
alone.
When used in systemic therapy, IFNs are mostly administered by an intramuscular
injection. The injection of IFNs in the muscle or under the skin is generally well tolerated.
The most frequent adverse effects are flu-like symptoms: increased body temperature,
feeling ill, fatigue, headache, muscle pain, convulsion, dizziness, hair thinning, and
depression. Erythema, pain, and hardness at the site of injection are also frequently
observed. IFN therapy causes immunosuppression, in particular through neutropenia
and can result in some infections manifesting in unusual ways.

10. INTERFERON THERAPY
Generic name and Trade name-
Interferon alfa -Multiferon
Interferon alpha 2a -Roferon A
Interferon alpha 2b -Intron
Human leukocyte Interferon-alpha (Hu IFN-alpha-Le) -
Multiferon
Interferon beta 1a, liquid form -Rebif
Interferon beta 1a, lyophilized- Avonex

11. INTERFERON THERAPY
Interferon beta 1a, biogeneric (Iran)-Cinnovex
Interferon beta 1b -Betaseron / Betaferon
Interferon gamma 1b -Actimmune
PEGylated interferon alpha 2a -Pegasys
PEGylated interferon alpha 2a (Egypt)- Reiferon Retard
PEGylated interferon alpha 2b- PegIntron
PEGylated interferon alpha 2b (Europe)- Besremi
PEGylated interferon alpha 2b plus ribavirin (Canada) -Pegintron

12. CONCLUSION
Several different types of interferons are approved for use in humans. One was first
approved for medical use in 1986. For example, in January 2001, the Food and Drug
Administration (FDA) approved the use of PEGylated interferon-alpha in the USA; in this
formulation, PEGylated interferon-alpha-2b (Pegintron), polyethylene glycol is linked to the
interferon molecule to make the interferon last longer in the body. Approval for PEGylated
interferon-alpha-2a (Pegasys) followed in October 2002. These PEGylated drugs are
injected once weekly, rather than administering two or three times per week, as is
necessary for conventional interferon-alpha. When used with the antiviral drug ribavirin,
PEGylated interferon is effective in treatment of hepatitis C; at least 75% of people with
hepatitis C genotypes 2 or 3 benefit from interferon treatment, although this is effective in
less than 50% of people infected with genotype 1 (the more common form of hepatitis C
virus in both the U.S. and Western Europe). Interferon-containing regimens may also
include protease inhibitors such as boceprevir and telaprevir.
There are also interferon-inducing drugs, notably tilorone that is shown to be effective
against Ebola virus.