Graft versus host reaction in tissue culture. I. Lysis of monolayers of embryo mouse cells from strains differing in the H-2 histocompatibility locus by rat lymphocytes sensitized in vitro.

Rat lymphocytes cultured on mouse embryo cell monolayers produced large pyroninophilic cells (LPC) which lysed the mouse cells. The LPC that developed on monolayers of any particular strain of mouse (originator monolayers) were tested, by transfer, for their ability to lyse monolayers of other mouse strains. The distribution of lysis among the various strains of mouse revealed a definite pattern of specificity. Analysis of the H-2 allelic complement of the mouse strains tested suggests that the lymphocytes were sensitized upon exposure to the mouse embryo monolayers against one or more of the antigens determined by the H-2 locus. The presence or absence of one or all of the antigens in other strains determined whether monolayers of these strains were lysed completely, partially, or not at all. It was concluded that the cultures obtained are an reflection of the graft host immune reaction. It was produced in the tissue culture as a primary response by normal lymphocytes.