Accumulation of T cells and local anti-PPD antibody production in lymphokine-mediated chronic peritoneal inflammation in the guinea pig

Abstract

The role of lymphokines in chornic peritoneal inflammation in the guinea pig has been investigated. A model of chronic inflammation was used in which a large intraperitoneal accumulation of macrophages and lymphocytes occurred, following repeated local injection of PPD into FCA-immunised animals. Activity attributable to the lymphokine, MIF could be demonstrated in chronic peritoneal exudate fractions even after several weeks of continuous stimulation. Characterisation of the lymphoid infiltrates revealed a large predominance of T cells. Very high percentages but low absolute numbers of T lymphocytes were also found in chronic peritoneal exudates of non-preimmunised, continuously stimulated guinea pigs. Ectopic lymphoid foci were found only in the peritoneal lining tissue of the preimmunised animals and were shown to contain many anti-PPD antibody producing cells. These lymphoid foci may have been induced by the continuous local generation of lymphokines. Their presence suggests that significant local, specific antibody production is particularly likely to occur in chornic inflammation with a delayed hypersensitivity component.