A bicellular mechanism in the immune response to chemically defined antigens. II. Immunological tolerance

Spleens of mice which had been made tolerant to RSA were explanted to organ cultures and stimulated with DNP-RSA. No anti-DNP antibodies were produced. Such cultures did form antibodies to DNP when stimulated with α-DNP-poly-l-lysine. Mice tolerant to RSA were injected, prior to explantation, with either RSA or Hcy in Freund's adjuvant. When the first group was stimulated in vitro with DNP-RSA no antibodies were detected. When the second was stimulated with DNP-Hcy, a high response to DNP was measured. Cultures of RSA-tolerant spleens, treated with DNP-RSA 3 hr prior to the application of α-DNP-poly-l-lysine, did not produce anti-DNP antibodies. Hence, functional receptors for DNP on the APC do exist in carrier-tolerant animals. Tolerance, in this system, seems to be based on the inactivation of ASC.