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 macrophages 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 hr of in vitro culture, the remaining antigen persists qualitatively unchanged throughout further culture. However, coincident immunogenicity of the macrophage-associated NDP-GPA progressively deccreases, 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 inaccessible to antibody.