THE FORMATION AND PROPERTIES OF POLIOVIRUS-NEUTRALIZING ANTIBODY : III. SEQUENTIAL CHANGES IN ELECTROPHORETIC MOBILITY OF 19S AND 7S ANTIBODIES SYNTHESIZED BY RABBITS AFTER A SINGLE VIRUS INJECTION

Rabbits injected intravenously with a single high dose of poliovirus (type 1) produced two major 19S and two 75 type neutralizing antibody populations, with different electrophoretic mobilities. The first 2 to 2½ days after immunization the antibody was of the 19S type and migrated as a single component in the β-region. In contrast, the major 19S antibody synthesized from day 3 on was a γ(1)-globulin. 7S type antibody, appearing on day 4, was contained only in the γ(1)-region, while 10 to 14 days following immunization the 7S antibody was associated with both γ(1)- and γ(2)-globulins. The electrophoretic distribution of antibody in 2-week sera revealed the presence of at least four antibody populations (19S β, 19S γ(1), 7S γ(1), and 7S γ(2)). Serum samples collected 1 or 2 weeks following antigenic stimulation often contained small amounts of antibody which sedimented at a rate (11S to 15S) intermediate to that of 7S and 19S antibodies. The neutralizing activity of the 19S type antibodies and the intermediately sedimenting antibody was destroyed by incubation with 0.1 M (5 days) or 0.2 M (1 day) 2-mercaptoethanol at 3°C. The 7S antibody activity was un-affected by treatment with from 0.1 to 0.8 M mercaptan.