Interferons

About interferons

Interferons are dominant inducible effector molecules that are produced by all nucleated animal cells. They are responsible for the modification of basic biochemical processes in a reversible fashion. It thus plays an important role in the proper functioning of the organisms and also contributes to the prevention and treatment of diseases.

Discovery

• Isaac and J. Lindenmann first discovered the existence of chick interferon in 1957. They invented its ability to induce resistance against viral infections. They are a sort of glycoproteins produced by our body cells in response to a viral infection. According to them, the discovery of double-stranded RNA was an efficient inducer in vitro and in vivo.
• The first discovery revealed that interferons are responsible for slowing down the rate of cell multiplications. This discovery was made in 1962.
• Later in 1973, it was reported that interferons could interfere with the level of certain cellular enzymatic activities. It also affects the expression of cellular genes and the immune functioning of the body.
• Again around 1981, scientists revealed that interferons have the potential to modify the cell structures and act as physiologic regulators.
• Interferons were later on regarded as complex, possessing highly regulated cellular mechanisms. They play a major role in cell growth and defense mechanisms against viruses and specifically, neoplastic cells.

 Early experiments

Early experiments with interferons started in the 1950s. Researchers conducted experiments to understand how cells interact with each other and their response to foreign particles, like viruses or bacteria.

To study these observations, scientists developed a technique called “interferon induction”. It involved exposure of the cell cultures to radiations that would stimulate them to produce proteins known as interferons.

Such experiments helped researchers to understand more about the role of interferons in immune response and disease prevention. It provided insight into potential therapeutic applications and their use against viral infections and cancer.

In addition, these studies laid the groundwork for further research on interferon-based therapies that are now used to treat various diseases today.

Scientific contribution

Interferons are proteins that play an important role in the immune system. Some of the key contributions include:

1. Interferons help to regulate the body’s response to infection by activating certain cells within the immune system, such as natural killer cells and macrophages.
2. They inhibit viral replication by blocking virus-specific enzymes or interfering with other aspects of viral life cycles.

Role in the immune system

• Exhibit antiviral properties such as it provides immunity against the vestibular stomatitis The cells are cultivated in a suitable nutritional medium and are treated with interferon at different concentrations. It is then infected with the virus.
• Interferons also help in inducing the synthesis of protein and the degradation of cellular RNA.
• Interferons suppress the proliferation of a number and malignant cells. For example – normal and malignant keratinocytes.
• The combination of interferons with the other two types of interferons helps in potentiating its antiproliferative activity.
• Interferons are responsible for maintaining the stimulation of cellular immunity. It is done by activation of effector cells like macrophages, Helper T cells, etc.

Types of interferons

Type I

Type 1 interferons (IFN-α and IFN-β) belong to a family of cytokines that play an important role in the immune system.

Function

They are produced in response to viral infections like natural killer cells and macrophages. They also exhibit antiviral activity that protects against infection. Additionally, type 1 interferons help in regulating cell growth and inflammation.

Characteristics

Type 1 Interferons are divided into alpha and beta interferons.

• It helps in the stimulation of other cells to produce more cytokines to fight off infection.
• It possesses antiviral properties, thus protecting against infections.
• Type 1 IFNs induce apoptosis which works to eliminate the infected cells from the body.

Type II interferons (IFN-γ)

They are cytokines, produced by T cells and natural killer cells. It binds to the receptor complex such as IFNGR1 and IFNGR2. Hence, it helps in promoting the phosphorylation of STAT1 via JAK1 and JAK2.

Functions

They play an essential role in the immune system, as they help in the activation of other cells like macrophages and dendritic cells. It also possesses antiviral properties that protect against viral infections

Characteristics

• It helps in the activation of immune cells like macrophages and dendritic cells.
• They also help in the stimulation of inflammatory molecules like tumor necrosis factor alpha (TNFα).
• Activation of apoptosis of the cancerous cells.
• It helps in the protection of damages caused by viruses or bacteria.

Type III

Type III interferons are the proteins produced in response to the immune system against infectious agents.

Function

Type III IFNs or IFN-λ have an essential role in increasing the production of other inflammatory cytokines such as TNFalpha, that helps fight viral infection.

Characteristics

• They generally activate natural killer cells that target infected cells to remove infections from the body.
• It also increases the production of cytokines like TNF-alpha, which helps in fighting viral infection.

Comparison Of The Types of Interferons

 Mechanism of action

Interferons are protein molecules that play an important role in generating the body’s immune response.

They act as signaling molecules, sending messages to other cells and activating them to fight off infections. Hence, they work by binding to receptor molecules with target cells.

It therefore triggers a series of events, thus leading to increased production of antiviral proteins. These antiviral proteins protect against various infections. Moreover, they stimulate the activation of natural killer cells. They are specialized white blood cells that attack virus-infected cells and provide immunity to our body.

Importance of interferons in the immune response

• Are great at generating the immune response.
• First of all, they are responsible for activating other cells of the immune system like natural killer cells and macrophages, that fight off infections.
• Secondly, they help stimulate an inflammatory response by increasing cytokine production and inhibiting the replication of viruses.
• Finally, they also induce apoptosis to prevent further damage to neighboring cells.

Clinical applications

• They are used to treat a variety of antiviral infections, cancer, and autoimmune diseases.
• Stimulation of the body’s immune system to fight off infection or disease-causing agents.
• Also have shown effective results in the treatment of chronic hepatitis C virus (HCV) infection. It has been proven to reduce HCV levels in patients.
• It acts as an adjuvant therapy for certain types of cancers such as melanoma and renal cell carcinoma.

Q&A

1. What is interferon and its function?

They are dominant inducible effector molecules that are produced by all nucleated animal cells. They play a major role in cell growth and defense mechanisms against viruses and specifically, neoplastic cells.

2. Do interferons fight viruses?

They inhibit viral replication by blocking virus-specific enzymes or interfering with other aspects of viral life cycles.

3. What are the three types of interferons?

Classified as Type I, Type II, and Type III interferons.

4. What is the difference between cytokines and interferons?

Interferons are protein molecules that belong to a group of cytokines whereas cytokines are molecules produced by the immune cells to target the infected cells.

Summary

• Interferons are dominant inducible effector molecules that are produced by all nucleated animal cells.
• They are responsible for the modification of basic biochemical processes in a reversible fashion.
• It plays an important role in the proper functioning of the organisms and also contributes to the prevention and treatment of diseases.
• The first discovery revealed that interferons are responsible for slowing down the rate of cell multiplications. This discovery was made in 1962.
• Later on regarded as complex, possessing highly regulated cellular mechanisms.
• It plays a major role in cell growth and defense mechanisms against viruses and specifically, neoplastic cells.
• Interferons are classified as Type I, Type II, and Type III interferons.
• Type 1 IFNs induce apoptosis which works in eliminating the infected cells from the body.
• Type II IFNs help in the stimulation of inflammatory molecules like tumor necrosis factor alpha (TNFα).
• Type III interferons are the proteins produced in response to the immune system against infectious agents.
• Interferons have shown effective results in the treatment of chronic hepatitis C virus (HCV) infection. It has been proven to reduce HCV levels in patients.
• It acts as an adjuvant therapy for various cancers like melanoma carcinoma.

References

1. https://link.springer.com/chapter/10.1007/978-3-319-07758-1_7
2. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.0105-2896.2004.00204.x
3. https://books.google.com/books?hl=en&lr=&id=fFZIOM03QO4C&oi=fnd&pg=PP1&dq=interferons&ots=xs7zfMzykm&sig=WEvZ0WBGZ3gxV3MzOx1aA2Nlvss
4. https://onlinelibrary.wiley.com/doi/abs/10.1111/bpa.12955
5. https://link.springer.com/article/10.1186/s13075-019-1878-y
6. https://journals.asm.org/doi/abs/10.1128/JVI.00985-20

Written By: Sushmita Mukhopadhyay