Using peptide mimetopes to elucidate anti-polysaccharide and anti-nucleic acid humoral responses.
Humoral responses against polysaccharide or nucleic acid antigens are often difficult to characterize and to induce. For example, the eliciting antigen for the development of anti-double-stranded(ds)DNA antibodies is unclear. dsDNA is a poor immunogen, yet antibodies to it bear the hallmark of a T cell dependent response. The microbial origin of polysaccharide antigens is, in general, readily known, but these antigens often do not elicit B cell memory responses, which are crucial for vaccine development. This review focuses on the use of peptide mimetopes to better understand humoral responses against non-protein antigens. First we describe a mimetope for dsDNA that was derived by probing a peptide phage library with an anti-dsDNA antibody. We discuss the usefulness of this mimetope in a search for candidate protein antigens and for examining the phenotype of antigen-specific B cells. Next, we discuss two mimetopes for phosphorylcholine (PC), a component of S. pneumoniae C polysaccharide. One was derived through mapping an anti-idiotype epitope and the other by probing a phagodisplay peptide library with an anti-PC antibody. Both of these peptide mimetopes for PC provide useful information regarding the requirements of a protective antibody response against pneumococcal infection, and define a critical role for adjuvant and carrier as well as mimetope.
Caton
M
M
Albert Einstein College of Medicine, Dept of Microbiology and Immunology, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
Diamond
B
B
D000818:Animals; D004247:DNA / Q000276:immunology*; D051379:Mice; D010455:Peptides / Q000276:immunology*; D011008:Pneumococcal Infections / Q000276:immunology / Q000517:prevention & control; D011134:Polysaccharides / Q000276:immunology*
D010455:Peptides; D011134:Polysaccharides; D004247:DNA