Quantitative and immunologic aspects of the handling of 2,4 dinitrophenyl guinea pig albumin by macrophages

Studies correlating quantitative aspects of the handling of dinitrophenyl guinea pig albumin (DNP GPA) by guinea pig microphages with the potential of cell associated antigen to initiate proliferation of immune T lymphocytes have examined the nature of immunologically relevant antigen. After the loss of 75% of cell bound DNP GPA during the first 24 h of in vitro culture, the remaining antigen persists qualitatively unchanged throughout further culture. However, coincident immunogenicity of the macrophage associated DNP GPA progressively decreases, suggesting loss of accessibility of the antigen to responding immune lymphocytes. There is a small, stable, surface antigen pool but these studies suggest that the immunologically critical fraction of DNP GPA, as regards guinea pig T cell activation, is resistant to trypsinization and inaccesible to antibody.