Richter M, Trudel I, Talor E
Department of Pathology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
Scand J Immunol. 1990 Dec;32(6):611-22. doi: 10.1111/j.1365-3083.1990.tb03203.x.
The splenic mononuclear cells (MNC) of rabbits 7-14 and 30-48 days following primary intravenous immunization with sheep erythrocytes generated large numbers of antibody-secreting or plaque-forming cells (PFC) in secondary immune responses induced in vitro, whereas the splenic MNC obtained from rabbits 18-30 days following primary intravenous immunization generated poor secondary immune responses (few PFC) in vitro. However, these latter splenic MNC depleted of T cells consistently generated many PFC in the secondary immune response in vitro. Furthermore, the splenic MNC of rabbits thymectomized prior to day 3 following primary intravenous immunization also generated good secondary immune responses in vitro, irrespective of the time of killing post-immunization, whereas the splenic MNC of rabbits thymectomized after day 7 following primary immunization generated poor secondary immune responses in vitro. These results indicate that the depressed ability of the splenic MNC, obtained from rabbits killed between days 18 and 30 post-primary immunization, to generate significant secondary immune responses in vitro is due to suppressor T cells. The suppressor cells are referred to as immune spleen suppressor cells or ISSC. It was demonstrated that the suppression by the ISSC is antigen-specific and that the ISSC secrete an antigen-specific suppressor factor referred to as immune spleen suppressor factor or ISSF. It is concluded that the ISSC are generated in the thymus within a few days following primary immunization, that they migrate to and infiltrate the spleen between days 3 and 7 following primary immunization, and that they suppress or down-regulate further antibody synthesis via the secretion, locally of ISSF.
用绵羊红细胞对家兔进行初次静脉免疫后7 - 14天以及30 - 48天的脾单核细胞（MNC），在体外诱导的二次免疫反应中能产生大量分泌抗体或形成蚀斑的细胞（PFC），而初次静脉免疫后18 - 30天的家兔脾MNC在体外产生的二次免疫反应较差（PFC较少）。然而，这些去除了T细胞的后一组脾MNC在体外二次免疫反应中始终能产生许多PFC。此外，在初次静脉免疫后第3天之前进行胸腺切除的家兔脾MNC在体外也能产生良好的二次免疫反应，与免疫后处死的时间无关，而在初次免疫后第7天之后进行胸腺切除的家兔脾MNC在体外产生的二次免疫反应较差。这些结果表明，初次免疫后18至30天处死的家兔脾MNC在体外产生显著二次免疫反应的能力下降是由于抑制性T细胞。这些抑制细胞被称为免疫脾抑制细胞或ISSC。已证明ISSC的抑制作用具有抗原特异性，并且ISSC分泌一种抗原特异性抑制因子，称为免疫脾抑制因子或ISSF。得出的结论是，ISSC在初次免疫后几天内在胸腺中产生，它们在初次免疫后第3天至第7天之间迁移并浸润脾脏，并且它们通过在局部分泌ISSF来抑制或下调进一步的抗体合成。
