title: Genetic control of the immune response to staphylococcal nuclease. III. Time-course and correlation between the response to native nuclease and the response to its polypeptide fragments.
abstract: The progression of the Ir gene-controlled antibody response to staphylococcal nuclease in mice with repeated immunizations has been examined. H-2-linked control of the response to a single immunization with 100 mug of nuclease in complete Freund's adjuvant was confirmed. However, among strains of the high responder H-2a haplotype, the response of the A/J mice was about 10-fold higher than that of the B10.A, indicating additional non-H-2-linked control. In addition, the low responder C57BL/10 (H-2b) strain produced antibody levels as high as or higher than those of the congenic high responder B10.A (H-2a) strain when both strains were repeatedly immunized, indicating complexity even in the H-2-linked control of the response to this small monomeric protein. Polypeptide fragments of nuclease were also studied as immunogens. The antibody response to one fragment (residues 99-149) was found to follow the same pattern among five strains tested as that to whole nuclease. However, in this case the C57BL/10 was found to be a nonresponder rather than a low responder, failing to develop a response despite repeated immunizations. In contrast, the C57BL/10 showed a low but significant response to another fragment (residues 1-126) of nuclease. These results suggest that the apparent H-2-linked control of the response to whole nuclease is a reflection of the ability to recognize a determinant(s) in the region from residues 99 to 149, and that the eventual response of the C57BL/10 strain after hyperimmunization reflects the recognition of other determinants. If these observations reflect the common recognition of a determinant on native nuclease and on a random-conformation fragment, they have implications about the conformational specificity of the receptors, or the flexibility of the determinants, involved in H-2-linked Ir-gene control. In addition, evidence is presented for a possible second H-2-linked gene (or genes) controlling the response to other determinants of nuclease expressed on the polypeptide fragments.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D000917:Antibody Formation; D005260:Female; D005796:Genes; D008040:Genetic Linkage; D006649:Histocompatibility Antigens; D007156:Immunologic Memory; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008836:Micrococcal Nuclease / Q000276:immunology*; D010455:Peptides / Q000276:immunology; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial; D006649:Histocompatibility Antigens; D010455:Peptides; D008836:Micrococcal Nuclease