Question

cytotoxic t cells destroy infected cells by releasing toxins that form pores in the cell membrane, causing the cell to burst. why is this method particularly effective at stopping a viral infection?
it signals regulatory t cells to end the immune response immediately.
it allows the t cell to consume the infected cell for energy.
it captures the viruses and presents their antigens to helper t cells.
it destroys the host cell \factory,\ preventing the viruses inside from replicating and spreading further.

a patient requires a kidney transplant. doctors search for a donor with the most similar major histocompatibility complex (mhc) proteins. why is this matching process critical for the success of the transplant?
similar mhc proteins ensure the new kidney can connect properly to the recipients lymphatic vessels.
mhc proteins are necessary for the innate immune systems general phagocytosis of all foreign material.
the recipients immune system will identify a kidney with different mhc proteins as
on - self\ and mount an attack against it.
a close mhc match ensures the new kidney will be able to produce the correct antibodies for the recipient.

Explanation:

1. Viruses replicate inside host cells. By destroying the infected host cell, cytotoxic T - cells eliminate the environment where viruses can replicate and spread, thus stopping the viral infection.
2. MHC proteins are crucial for the immune system to recognize self and non - self. If the donor's MHC proteins are different from the recipient's, the recipient's immune system will recognize the transplanted kidney as foreign and attack it, leading to transplant rejection.

Answer:

1. It destroys the host cell "factory," preventing the viruses inside from replicating and spreading further.
2. The recipient's immune system will identify a kidney with different MHC proteins as "non - self" and mount an attack against it.