PRIMARY B-CELL RESPONSE TO NEUROPEPTIDE-Y AND BOVINE PANCREATIC-POLYPEPTIDE

An analysis of the murine primary response to protein epitopes has been made with two small highly structured proteins, neuropeptide Y (NPY) and bovine pancreatic polypeptide (BPP), both of 36-amino acid residue length and containing helical structures. A group of cell lines producing monoclonal IgM antibody have been prepared consisting of six anti-NPY and two anti-BPP. The V(H) nucleotide sequences have been determined and characterized as germ-line either by identity to established germ-line sequences or by inference from the germ-line character of the D and J(H) segments. The intrinsic association constants for the homologous ligands have been estimated to range from 10(4) to 10(7) M-1 based on competitive ELISA. No severe restriction in the utilization of V(H) families, D segments or J(H) segments appears to be involved in this response. Among the eight cell lines, three V(H) families were represented as well as all three families of D segments and all of the J(H) segments, although some preference for J(H)3 was indicated. The length of the N(D)N sequences was also not subject to restriction, ranging from 9 to 29. Two unusual features of the CRD3s were noted, one involving the utilization of an uncommon DSP2 segment and the other the apparent occurrence of a D-D fusion.