Bacterial superantigen staphylococcal enterotoxin B induces interstitial pneumonia in SCID mice reconstituted with peripheral blood mononuclear cellsfrom collagen vascular disease patients

To investigate whether superantigens induce interstitial pneumonia associat ed with collagen vascular disease (CVD), staphylococcal enterotoxin B (SEB) was intratracheally administered to SCID mice reconstituted with periphera l blood mononuclear cells (PBMCs) from CVD patients that suffered lung comp lications. Although a slight accumulation of inflammatory cells into the pe rivascular area was seen in the lungs of SCID mice injected with PBMCs from CVD patients or healthy donors, SEE administration significantly increased the severity of inflammation in the lungs of SCID mice that received CVD p atient PBMCs. Furthermore, human leukocytes were detected by immunohistoche mistry in the lungs of SCID mice that received SEE after reconstitution wit h PBMCs from CVD patients but not in other groups of SCID mice. CD45RO(+) m emory T cells comprised the majority of infiltrating human leukocytes. Thes e results suggest the possibility that external superantigens may induce th e development of interstitial pneumonia in patients that have a genetic bac kground predisposition to autoimmune disease. (C) 2000 Academic Press.