Protection of rats against adjuvant arthritis by bacterial lipoplysaccharides

Lipopolysaccharides from both gram-negative and gram-positive bacteria in incomplete adjuvant caused rats to become resistant to mycobacterial (complete) adjuvant arthritis. Lipopolysaccharides h protected rats when they were administered in adjuvant did not protect when administered in saline. Mycobacterial wax D in saline was protective, while in adjuvant it produced arthritis. The degree of stimulation of a common tissue reaction may determine whether the result is protection or disease.