| Abstract: | The immunogenicity of antigens associated with peritoneal exudate cells was compared with the immunogenicity of free antigens for the induction of delayed hypersensitivity. Oil induced peritoneal exudate cells were incubated with antigens labelled with radioactive iodine, washed and injected intraperitoneally into recipient guinea-pigs. Comparable amounts of free antigens were also injected. All sixteen inbred guinea-pigs given human or bovine gamma-globulin associated with peritoneal exudate cells gave positive reactions (greater than 5 mm) while the eighteen guinea-pigs given free antigens failed to show a reaction. Similar results were obtained with serum albumins in inbred guinea-pigs. The increased immunogenicity of antigens associated with peritoneal exudate cells was also seen in outbred guinea-pigs. Pretreatment with Freund's complete adjuvant did not depress the immunogenicity of antigens associated with peritoneal exudate cells and actually increased the induration of the 24-hour reaction to picrylated human serum albumin and human serum albumin associated with peritoneal exudate cells. |
