Stem-cell Inactivation in Mixed Spleen Cell Cultures

Abstract

A NUMBER of attempts have been made to understand the interactions possible between immunologically active cells. In vitro, transformation of lymphocytes in response to other antigenically different lymphocytes has been noted¹ as have similar reactions involving cells explanted from spleens². The reactions of immune lymphocytes with their target cells have often been studied. The work of Hellström et al.³ has led to consideration of the notion of allogeneic inhibition during which it is implied that the activity of a cell may be inhibited simply by the presence of a foreign cell antigen. All such work is relevant to an increase in our understanding of the possible importance of immunological reactions between cells in vivo. These experiments describe the effects of the presence of foreign cells on the capacity of mouse spleen cells, first to respond to antigenic stimulation, and second to give rise to haematopoietic cell colonies. The effect of irradiation on one of the components of the cell mixture is described. A preliminary account of this method has already been published⁴.