Acute cutaneous graft-versus-host disease to minor histocompatibility antigens in a murine model. Evidence that large granular lymphocytes are effector cells in the immune response.

We studied the morphologic and immunophenotypic characteristics of inflammatory infiltrates in the skin of mice with acute graft-versus-host disease induced by bone marrow transplantation between strains differing only in minor histocompatibility antigens. The strain combinations employed (B10.Br - greater than CBA) have been shown to produce a lethal graft-versus-host disease with clinical severity proportional to the number of T lymphocytes added to the donor marrow inoculum. Transplant recipients developed pronounced clinical signs of graft-versus-host disease, including copious diarrhea and weight loss, and histologic alterations in skin strikingly similar to this disease in humans. Our findings indicate that the preponderant mononuclear cell in lesional skin from these animals has phenotypic characteristics of a natural killer cell. This cell was often found in apposition with necrotic epidermal cells. The origin, function, and potential relevance of natural killer cells in lesion formation in this experimental model are discussed.