Peritoneal exudation of macrophages by irritants and its effect on immune responses against sheep erythrocytes and Listeria monocytogenes.

Relation between the degradation of antigenic substances by peritoneal exudate macrophages induced by different irritants and subsequent induction of immune responses against SRBC or Listeria monocytogenes were studied. Delayed footpad reaction and antibody production to SRBC were both suppressed by pretreatment with thioglycollate or with killed Corynebacterium parvum. In contrast, delayed footpad reaction and acquired cellular resistance to Listeria were augmented by pretreatment with thioglycollate. When pretreated with C. parvum, however, such augmentations in immune responses to Listeria were not observed but these responses were suppressed. It was suggested that the amount of antigenic stimuli was determined by the mutual relationship between the level of macrophage activity as scavenger cells and the susceptibilities of the antigenic substances to degradation by macrophages, and that induction of immune responses were affected by this mutual relationship.