Primary immune response of mice to sheep erythrocytes during the course of infection with Listeria monocytogenes.

The influence of an infection with a sublethal dose of viable Listeria monocytogenes on the primary antibody-forming potential of mice against sheep erythrocytes (SE) was monitored by means of counting plaque-forming cells (PFC) in the spleen and measuring circulating antibodies against SE. Additionally, the course of infection was followed by determination of viable bacteria in the spleen. As against the injection of killed L. monocytogenes, infection with viable bacteria did not display any significant influence on the immune response against SE when the immunogenic stimulus was given either stimultaneously with the bacteria or on day 4 or 13 of infection, respectively. Vice versa, the immunization with the particulate antigen had no measurable influence on either course of outcome of infection with the parasite.