41. Immune System

What is the difference between an epitope and an antigen?

Which of the following statements is not true?a. An antibody has more than one antigen-binding site.b. A lymphocyte has receptors for multiple different antigens.c. An antigen can have different epitopes.d. A liver or muscle cell makes one class of MHC molecule.

One of the key difficulties in the development of anti-HIV drugs is the fact that HIV only infects humans. This precludes the testing of drugs in animals and instead requires that drugs be tested on volunteer human subjects. The developing world (particularly sub-Saharan Africa and Southeast Asia) has the highest rates of HIV infection. Consequently, drug companies frequently conduct studies in these regions. Some people decry such tests, fearing that drug companies may profit hugely from the use of economically disadvantaged people. Others counter that such tests are the only way to find new and cheaper drugs that will ultimately help everyone. What do you think are the ethical issues surrounding trials of anti-HIV drugs in the developing world? Which side do you think has the more morally compelling argument?

Which of the following is a characteristic of adaptive immunity?

Why is HIV a dangerous pathogen?

Why does our immune system not usually attack our own healthy tissues?

New flu shots are needed every year to protect against infection because of __________.

Besides helper T cells, what are two other types of cells that HIV infects?

When searching for a donor for an organ transplant, doctors try to match the __________ of the donor and recipient as closely as possible.

The idea behind vaccination is to induce __________ without requiring the vaccinated individual to get sick.

A vaccine may contain __________.

A type of cell that makes immunizations effective is the __________.

How do antibodies to foreign blood groups come to exist in the body?

What do the antibodies secreted by plasma cells (the effector cells of humoral immunity) do to attack their targets?

What is the role of dendritic cells in the primary immune response?