Preferential pairing of T and B cells for production of antibodies without covalent association of T and B epitopes.
T cell from H-2b mice recognize at least 12 sequence regions on the Torpedo acetylcholine receptor (TAChR) alpha, gamma and delta subunits. Immunization of C57BL/6 mice with individual synthetic TAChR sequences known to contain CD4+ epitopes resulted in most cases (10 out of 12 peptides) in anti-peptide antibody (Ab) production, indicating that short TAChR sequences contain both CD4+ and B epitopes. Immunization of C57BL/6 mice with a mixture of a CD4+ epitope peptide, from the TAChR or from an unrelated protein, plus another TAChR sequence forming a "pure" B epitope (T alpha 63-80), induced in most cases anti-peptide Ab and CD4+ cell sensitization only against the peptide containing the CD4+ epitope. However, when the T epitope peptide T alpha 360-378 was co-injected with the B epitope, Ab were also produced against the B epitope peptide. Injection of the individual peptides T alpha 360-378 and T alpha 63-80 at different and distant sites along the back of mice elicited sensitization of CD4+ cells and Ab production only against peptide T alpha 360-378. Therefore, when optimal cooperation between T and B cells occurs, spatial proximity but not covalent association of the B and the CD4+ epitope is necessary for production of Ab against the B epitope.
Bellone
M
M
Department of Biochemistry, College of Biological Sciences, University of Minnesota, St. Paul 55108.
Karachunski
P I
PI
Ostlie
N
N
Lei
S
S
Conti-Tronconi
B M
BM
D000595:Amino Acid Sequence; D000818:Animals; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology / Q000502:physiology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002450:Cell Communication; D000939:Epitopes; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology; D011950:Receptors, Cholinergic / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology*
D000939:Epitopes; D010446:Peptide Fragments; D011950:Receptors, Cholinergic