AUGMENTATION OF RAT GRAFT-VERSUS-HOST REACTION BY COLLOIDAL CARBON1

Publisher Website
Google Scholar
Abstract
SUMMARY The effect of colloidal carbon treatment on the rat graft-versus-host reaction, initiated in parental to F1 hybrid strain combinations differing at major histocompatibility determinants, was studied histologically and immunologically by the popliteal lymph node assay. The local graft-versus-host reactivity of parental lymph node cells or thoracic duct lymphocytes was augmented by a prior single injection of colloidal carbon particles into the footpads of F1 hybrid rats. A similar augmenting effect of colloidal carbon on the popliteal lymph node enlargement was also demonstrated when parental thymus cells were injected into F1 hybrid rats. The thymus cells were inactive on their own. The greatest effect in both lymph node cells and thymus cells, was observed in those F1 rats given carbon 1 day prior to or immediately after the parental cell inoculum. Histologically, it was found that the degree of cellular proliferation in the node, characterized by a marked accumulation of large pyroninophilic cells around predominantly carbon-phagocytosed macrophages, was much higher than that of the nontreated carbon side in both the lymph node cell and thymus cell inoculum. When F1 hybrid rats received i.v. lymph node cells from DA donors and were concurrently treated with colloidal carbon, the augmenting effect of the carbon injection was also evaluated by investigating systemic graft-versus-host reaction causing “runting” syndrome. Colloidal carbon alone produced neither great enlargement of the popliteal lymph node or runting syndrome in F1 hybrid rats. The possible nature of the immunological alterations induced by a prior injection of colloidal carbon is discussed. The graft-versus-host reaction (GVHR) was originally considered to represent no more than an attack by parental strain lymphocytes against F1 hybrid strain tissues. Recent investigations of the phenomenon have suggested that this simple explanation is quite untenable, and that the pathological features of the condition reflect the occurrence of a variety of processes. One criticism applicable to many investigations of the GVHR concerns the failure to consider the possibility that cell types other than lymphocyte subclasses, in particular phag-ocytic cells, are involved in the basic cellular interactions. Recently, it has been thought that mononuclear phagocytes can play a regulatory role in immune induction. Several experiments ( 7, 8, 10, 17, 19) showed that macrophages contribute in some way to the T lymphocyte proliferation. Also, factors that enhance or support T lymphocyte function have been found in macrophage cultures ( 7, 8, 10, 17). Of particular interest is the observation of Unanue et al. (19), that culture fluids rich in mononuclear phagocytes contain lymphostimulatory molecules and that in two conditions produced increased secretion of the factors: (1) addition to the cultures of various agents that readily are taken up by macrophages, such as latex particles; or (2) addition of activated lymphocytes. In this paper we present results of experiments that show the relationship between phagocytosed host macrophages with colloidal carbon and graft-versus-host (GVH) reactivity of the parental lymph node cell or thymus cell, as monitored by popliteal lymph node enlargement. The present study establishes that colloidal carbon injection tends to recruit nonspecifically circulating phagocytic host cells in situ and can effect a highly significant augmentation of the GVHR in vivo.

This publication has 0 references indexed in Scilit: