Bodmer H, Viville S, Benoist C, Mathis D
Laboratoire de Génétique Moléculaire des Eucaryotes du CNRS, Strasbourg, France.
Science. 1994 Mar 4;263(5151):1284-6. doi: 10.1126/science.7510069.
The invariant chain (Ii) binds nascent major histocompatibility complex (MHC) class II molecules, blocking peptide binding until the complex dissociates in the endosomes. This may serve to differentiate the MHC class I and II antigen presentation pathways and enable class II molecules to efficiently bind peptides in the endosomes. This hypothesis was addressed by probing spleen cells from a combination of knock-out and transgenic mice with a large panel of T cell hybridomas. The Ii molecule blocked the presentation of a range of endogenously synthesized epitopes, but some epitopes actually required Ii. Thus, the influence of Ii on presentation does not follow simple rules. In addition, mice expressing Ii were not tolerant to epitopes unmasked in its absence, a finding with possible implications for autoimmunity.
恒定链（Ii）与新生的主要组织相容性复合体（MHC）II类分子结合，阻止肽段结合，直到该复合体在内体中解离。这可能有助于区分MHC I类和II类抗原呈递途径，并使II类分子能够在内体中有效结合肽段。通过用大量T细胞杂交瘤探测基因敲除和转基因小鼠组合的脾细胞，对这一假说进行了研究。Ii分子阻断了一系列内源性合成表位的呈递，但有些表位实际上需要Ii。因此，Ii对呈递的影响并不遵循简单的规则。此外，表达Ii的小鼠对在其缺失时暴露的表位不耐受，这一发现可能对自身免疫有影响。
