Skin test and lymphocyte stimulation in delayed hypersensitivity against Staphylococcus aureus antigens. Development of hypersensitivity.

The development of delayed hypersensitivity against staphylococcal antigens in guinea pigs was observed from day 3 to day 50 after sensitization with staphylococcal homogenate in Freund's incomplete (FIA) and Freund's complete adjuvant (FCA). Skin test reactivity, stimulation of lymph node lymphocytes, and peripheral blood lymphocytes and the titre of precipitating antibodies were followed during this period. Maximal skin test reactivity as well as maximal lymphocyte responsiveness occurred at day 21 after sensitization in FCA-sensitized guinea pigs. In FIA-sensitized animals highest skin reactivity was observed at day 14 and maximal lymphocyte stimulation 35 days after sensitization. Precipitating antibodies reached a plateau at day 20 in plasma of animals sensitized with FCA and at day 35 in FIA-sensitized animals.