Many Vaccines Now Include Highly Purified,recombinant,or Synthetic Peptide Antigens

question 5

Multiple Choice

Many vaccines now include highly purified,recombinant,or synthetic peptide antigens.Given alone,the antigens in these vaccines would be less immunogenic than vaccines containing intact killed or live microbes.Adjuvants are substances added to purified protein or peptide vaccines to enhance their ability to elicit T cell immune responses.Which of the following statements about these adjuvants is NOT correct?

• A)They induce local inflammation,thereby increasing the number of antigen-presenting cells (APCs)at the site of immunization.
• B)They stimulate the expression of costimulators on local APCs.
• C)They enhance local production of cytokines that promote T cell activation.
• D)They prolong the expression of peptide-MHC complexes on the surface of APCs.
• E)They bind to T cell antigen receptors and promote their proliferation.