Cytotoxic T lymphocytes, including radiation GI syndrome, GvHD disease, inflammatory disease and autoimmune disease, by administering a therapeutically effective amount of an antibiotic that kills Gram-negative bacteria together with anti-ceramide antibody or anti-ceramide mimetic It has been found that many diseases mediated by sphere (CTL) -induced killing and / or damage to the endothelial microvasculature are treated and prevented. [Selection] Figure 8抗セラミド抗体又は抗セラミド模倣剤と共に、グラム陰性細菌を殺傷する抗生物質を治療上有効量投与することにより、放射線GI症候群、GvHD疾患、炎症性疾患及び自己免疫疾患を含む、細胞傷害性Tリンパ球（CTL）誘発性殺傷及び／又は内皮微小血管系に対する損傷が媒介する多くの疾患を治療及び予防されることを見出した。【選択図】図8
