Regulation of antibody synthesis against Escherichia coli endotoxin. 3. Induction of immunological paralysis in non-immune and pre-immunized mice.

Normal mice injected with a paralysing dose of endotoxin are unresponsive to an immediate subsequent injection of an immunogenic dose of the corresponding bacteria. In pre-sensitized mice the injection of a paralysing dose of endotoxin suppresses the immune response after a lag period of 80–90 hours during which the responding cells appear normally. The suggested explanation to this was that antigen-sensitive cells once triggered by the antigen divide and produce antibodies for a certain time period and thereafter disappear. During this period they are unaffected by the paralysing dose of antigen. It is suggested that the cells amenable to suppression are those from which the antibody producing cells are recruited, e.g. the antigen sensitive cells. The kinetics of suppression of an active immune response was the same whether antiserum or a paralysing dose of antigen was used as suppressive agent. This finding further supported the conclusion that actively antibody producing cells are antigen independent.