Cyclic development of immunological memory to bacterial lipopolysaccharide

Immunological memory to the lipopolysaccharide of Escherichia coli O113 was generated in strains of inbred mice given a single subimmunogenic dose of either E. coli O113 lipopolysaccharide or the native protoplasmic polysaccharide of E. coli O113. Such memory, which only involved antibody of the immunoglobulin M class, developed in a cyclic manner that was characteristic for the strain of mice used. It involved cell proliferation as well as differentiation and persisted for at least 25 days after priming with a single injection of a subimmunogenic dose of E. coli O113 lipopolysaccharide.