title: Universal epitopes for human CD4+ cells on tetanus and diphtheria toxins.
abstract: Previous studies suggested that tetanus and diphtheria toxoids (TTD and DTD, respectively) contain "universal" epitopes for human CD4+ cells (residues 632-651 and 950-969 of TTD and 271-290, 321-350, 351-370, 411-430, and 431-450 of DTD). To investigate whether CD4+ cells of 100 randomly selected subjects recognized those sequences, the proliferation of CD4+ cell-enriched blood lymphocytes to TTD and DTD and individual synthetic universal epitopes was measured. CD4+ cells of 98 subjects recognized both toxoids, those of 1 subject only TTD, and those of 1 only DTD. The TTD peptides and DTD peptides 271-290 and 331-350 were recognized by >/=80% of the toxoid-sensitized subjects. The other DTD sequences were recognized by 63%-71% of subjects. DR-homozygous subjects recognized several universal epitopes less frequently than did DR-heterozygous subjects. The intensity of responses to the epitope peptides correlated with that to TTD or DTD, consistent with recognition of the peptides by CD4+ cells specific for the cognate toxoid.
authors.affiliation: Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Twin Cities Campus, St. Paul, MN 55108, USA.
authors.forename: B M
authors.initials: BM
authors.lastname: Diethelm-Okita
authors.forename: D K
authors.initials: DK
authors.lastname: Okita
authors.forename: L
authors.initials: L
authors.lastname: Banaszak
authors.forename: B M
authors.initials: BM
authors.lastname: Conti-Fine
mesh_terms: D000328:Adult; D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004167:Diphtheria Toxin / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte; D005260:Female; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D013744:Tetanus Toxin / Q000276:immunology*
chemical_list: D004167:Diphtheria Toxin; D018984:Epitopes, T-Lymphocyte; D013744:Tetanus Toxin