Antigen-specific anti-phosphocholine antibodies: binding site studies.
The present investigation extends our initial evaluation of the evolution of antigen selection mechanisms for antibodies of a "single" specificity. The binding sites of 11 mouse anti-PC antibodies produced in response to the bacterium P. morganii or the nematode A. suum were characterized for both hapten and hapten plus carrier specificity. All of the anti-P. morganii HP belonged to the M603 anti-PC antibody family, whereas all the A. suum HP belonged to the M511 family. Of the eight anti-P. morganii HP, six exhibited a fine specificity profile for PC and choline analogues only slightly different from M603 Id+ HP induced by S. pneumoniae and PC-protein. These six and a seventh HP, whose hapten binding profile was unique, were also unusual in showing strong reactivity for a soluble PC containing extract from P. morganii. All three anti-A. suum-specific HP studied in detail had hapten-binding profiles remarkably similar to each other, a finding that is in contrast to M511 Id+ HP to S. pneumoniae and PC-protein. All three HP also showed evidence for preferential binding activity for A. suum, although this was not as dramatic as that seen with the anti-P. morganii HP. These data support our hypothesis that antigen selection of anti-PC antibodies occurs not so much for PC itself as it does for the carrier (microbial) determinants to which PC is attached.
Claflin
J L
JL
Hudak
S
S
Maddalena
A
A
Bender
T
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000145:classification*; D000942:Antigens, Bacterial / Q000276:immunology; D000946:Antigens, Fungal / Q000276:immunology; D001200:Ascaris / Q000276:immunology; D001666:Binding Sites, Antibody; D002794:Choline / Q000031:analogs & derivatives*; D000939:Epitopes / Q000276:immunology*; D006825:Hybridomas / Q000276:immunology; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D010767:Phosphorylcholine / Q000276:immunology* / Q000378:metabolism; D011511:Proteus / Q000276:immunology
D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D000946:Antigens, Fungal; D000939:Epitopes; D007130:Immunoglobulin Idiotypes; D010767:Phosphorylcholine; D002794:Choline