A UNIQUE RESPONSE TO STAPHYLOCOCCAL-ENTEROTOXIN-B BY INTRAHEPATIC LYMPHOCYTES AND ITS RELEVANCE TO THE INDUCTION OF TOLERANCE IN THE LIVER

It has been reported that the intrahepatic lymphocyte (IHL) population is somewhat differently constituted from lymphocytes in other lymphoi d tissues. Staphylococcal enterotoxin B (SEB) is a superantigen which can induce T-cell tolerance in mice. The authors investigated the in v itro and in vivo responses of mouse IHL to SEB. An intravenous injecti on of SEB did not result in the augmentation of the proliferative resp onse of IHL, while mesenteric and splenic lymphocytes (mLNC and SPC, r espectively) had augmented responses. Interleukin-2 (IL-2) mRNA was cl early detected in mLNC and SPC by reverse transcriptase-polymerase cha in reaction (RT-PCR) shortly after the administration of SEB, but it w as scarcely expressed in IHL. The expression of CD25 (IL-2 receptor) w as also augmented in mLNC and SPC in the early period, while it was no t changed in IHL. These findings suggested that the time required for tolerance induction is different locally and that the loss of augmenta tion of IL-2 and IL-2, receptor production by IHL may be relevant to t he rapid induction of T-cell tolerance in the liver.