Question

Interferons combat viral infection by
A) Inhibiting viral packaging directly
B) Increasing the binding of antibodies to viruses.
C) Binding to the virus and agglutinating them.
D) Restricting viral spread to the neighbouring cells by inhibiting viral replication.

Answer 1

Hint:Interferons are one of the important modulators of the immune system. These kinds of complexes are produced by the body's cells as a defensive response to viruses. These interferons increase antigen presentation.

Complete answer:
Virus-infected and tumour cells of our body are specialised to synthesize glycoproteins which protect the non-infected cells of our body from pathogen's attack, they are known as interferons. These interferons activate macrophages that are the phagocytic cells which are natural killer cells, preventing viral replication. These compounds work by increasing antigen presentation to lymphocytes. Interferons were named so due to their ability to interfere with viral proliferation. The various forms of interferon are the body's most rapidly produced and important defence against viruses.

Now let us gather information about given options :
A) Inhibiting viral packaging directly : interferons do not directly inactivate the viruses. The direct inhibition is a kind of antibody-antigen interaction. Antibodies called opsin get attached to the surface of the pathogen and do this.
B) Increasing the binding of antibodies to viruses : it is also a kind of antigen-antibody interaction. It is a kind of precipitation in which soluble antigen is picked up by the antibody and increases binding.
C) Binding to the virus and agglutinating them : it is also a kind of antigen-antibody interaction. Clumping of micro-organism typically due to an antigen antibody reaction and is termed as agglutination.
D) Restricting viral spread to the neighbouring cells by inhibiting viral replication : Interferons were named so due to their ability to interfere with viral proliferation. The various forms of interferon are the body's most rapidly produced and important defence against viruses.
Our required option is d that is Restricting viral spread to the neighbouring cells by inhibiting viral replication.

Hence the correct answer is option ‘D’.

Note:Three forms of interferon have been observed that are —alpha (a), beta (B), and gamma (y) classified into two types: type I-a and ß forms and type II - y form based on the type of cell that produces the interferon and the functional characteristics of the protein.