Question

Which of the following statements is correct about type I interferon?

a. They belong to the same class (family) as IFN-γ.
b. They are only secreted by NK cells, CD8 T cells, and cells.
c. Their secretion is a direct response to a viral infection.
d. There is only one isotype of type I interferon.
e. None of the above are correct, they are all false statements.

Answer 1

The correct statement about type I interferon is that their secretion is a direct response to a viral infection. Options a), b), and d) are incorrect as they misstate the family classification, cell sources, and isotype numbers of type I interferons, respectively.

Step-by-step explanation:

The correct statement about type I interferon is c. Their secretion is a direct response to a viral infection. Type I interferons, which are indeed a class of early-acting cytokines, are released by cells in response to viral infections.

Their primary function is to alert neighboring cells to the presence of the virus and to activate various immune responses to inhibit viral replication and facilitate tumor surveillance.

These interferons signal uninfected cells to produce antiviral compounds, promote apoptosis in infected cells, and activate immune cells such as macrophages.

Considering the other options: a) Type I interferons are not in the same family as IFN-γ, which is a type II interferon. b) Type I interferons are not only secreted by NK cells and CD8 T cells but by a variety of cell types in response to viral infections. d) There are multiple isotypes of type I interferons, not just one.