Anti-receptor antibody. I. Isolation and characterization of the immunoglobulin receptor for phosphorylcholine.

We have demonstrated a phosphorylcholine-binding protein in lysates from radioiodinated splenocytes of immunized mice. Immunoprecipitation with anti-receptor antibody of lysates from splenocytes obtained from animals undergoing a primary response or from mice immunized 4 to 6 months earlier with antigen demonstrated that this protein contained H and L chains. Therefore, we have isolated an antigen-specific receptor from the surface of spleen cells from both immunized and "memory" animals. This receptor Ig comprises approximately 10% of total cell surface Ig.