Characterizing T-cell epitopes in vaccine candidates.

T-cell clones can be used to test in vitro whether synthetic peptides associate with major histocompatibility complex (MHC) antigens - a necessary condition for the peptides to be immunogenic. Generally, the T-cell clones have been obtained from immune donors, but J.R.L. Pink and F. Sinigaglia argue here that non-immune, human leukocyte antigen (HLA)-typed donors are a useful source of clones and antigen-presenting cells that can be used to assay systematically peptide-MHC associations.