Chronic proliferative arthritis of mice induced by Mycoplasma arthritidis. II. Serological responses of the lost and effect of vaccines.

Complement-fixing antibodies were first detected in mice 7 days after intravenous injection with Mycoplasma arthritidis. Peak titers were observed at 21 days, and high levels of antibody persisted through 293 days. The metabolism-inhibiting antibody response was minimal. On fractionation of mouse sera, only 7S antibody was detected which first appeared at 12 days after injection and persisted throughout the experiment. In contrast, serum taken from rats injected with M. arthritidis contained predominantly 19S antibodies in the early stages of the disease which were gradually replaced with 7S antibodies. The intravenous injection of mice with M. arthritidis culture supernatant fluid had no effect upon their subsequent susceptibility to the arthritogenic effects of M. arthritidis, but this procedure appeared to delay the onset of abscess formation after the subcutaneous injection of M. arthritidis. Formalin-killed cells of M. arthritidis partially protected mice against the arthritis induced by M. arthritidis. Previous infections with M. arthritidis conferred partial immunity against the arthritogenic effects of the organism. Serum taken from convalescent mice at 41 days had a partial protective effect when used to immunize passively normal mice against M. arthritidis. However, rabbit anti-M. arthritidis serum which possessed higher complement-fixing and metabolism-inhibiting antibodies was without significant protective properties.