Augmentation of Natural Killer Cell Activity by Anti‐Host Delayed‐Type Hypersensitivity during the Graft‐versus‐Host Reaction in Mice

Abstract

During a graft-versus-host (GVH) reaction in unirradiated F1 hybrid mice there is a generalized activation of natural killer (NK) cells. We have examined whether the enhanced NK activity is due to an F1 resistance mechanism directed at the parental cells used to induce the GVH reaction. Spleen cells of C57BL/10 origin induce much more NK cell activation in B10F1 hybrids than the opposite parental type, despite a similar intensity of systemic GVH reactions. However, this does not correlate with in vivo resistance of mice with GVH reaction to a local challenge dose of B10 cells. NK cell activation in (CBA X BALB/c)F1 mice with GVH reaction involves both host and donor cells and is preceded by an anti-host delayed-type hypersensitivity (DTH) response. B10 cells have a greater ability to induce DTH in B10F1 mice than cells from the opposite parent. We propose that NK cells are one group of non-specific effector cells recruited by DTH in a GVH reaction and may contribute to the tissue pathology.

Experimental studies of immunologically mediated enteropathy. Development of cell mediated immunity and intestinal pathology during a graft-versus-host reaction in irradiated mice.

“…Interestingly, this occurred after the sudden cessation of CCPR and no significant villus alterations were found before the initial increase in CCPR. Thus, the intestinal damage during the GvHR in irradiated mice is characterised by an early, proliferative stage of crypt hyperplasia and increased (CBAXBALB/C) Fl MICE WITH GVHR The evolution of the antihost immune response in GvHR was followed by assessing specific antihost cytotoxic T lymphocyte activity and by measuring the level of splenic natural killer cell activity, which we have shown previously to reflect the non-specific effects of antihost delayed type hypersensitivity.7 15 The splenic natural killer activity of F1 mice was virtually eliminated by the dose of irradiation used and remained very low throughout the seven days of study (Fig. 4b).…”