Ulanova M, Tarkowski A, Hahn-Zoric M, Hanson L A
Department of Clinical Immunology, University of Göteborg, Sweden.
Scand J Immunol. 1999 Oct;50(4):387-93. doi: 10.1046/j.1365-3083.1999.00607.x.
Human CD1 molecules, expressed on the surface of professional antigen-presenting cells (including dendritic cells, Langerhans' cells, B cells and activated monocytes) are structurally homologous to major histocompatibility complex (MHC) class I and class II molecules. CD1b and CD1c have been shown to present nonpeptide bacterial antigens to T cells. We hypothesized that CD1 molecules may also be involved in the presentation of bacterial protein antigens. Human peripheral blood mononuclear cells (PBMC) were exposed to two medically important proteins, tetanus toxoid (TT) and purified protein derivative (PPD), with and without murine monoclonal antibodies (MoAbs) specific for CD1a, CD1b and CD1c. All the MoAbs substantially inhibited the proliferative responses of PBMC to TT and PPD. Simultaneous interaction of CD1 and MHC class II molecules was even more inhibitory to these antigen-specific proliferative responses. In contrast, neither mixed lymphocyte reaction nor superantigen and mitogenic responses were affected by CD1-specific antibodies, indicating a certain restriction pattern in antigen presentation. Our findings suggest that, besides MHC class I and II molecules, there is a family of nonpolymorphic cell surface molecules that is able to present certain bacterial protein antigens to T cells.
人类CD1分子表达于专职抗原呈递细胞（包括树突状细胞、朗格汉斯细胞、B细胞和活化的单核细胞）表面，在结构上与主要组织相容性复合体（MHC）I类和II类分子同源。已证实CD1b和CD1c可将非肽类细菌抗原呈递给T细胞。我们推测CD1分子可能也参与细菌蛋白抗原的呈递。将人类外周血单个核细胞（PBMC）暴露于两种医学上重要的蛋白质，破伤风类毒素（TT）和纯化蛋白衍生物（PPD），同时加入或不加入针对CD1a、CD1b和CD1c的鼠单克隆抗体（MoAb）。所有这些单克隆抗体均显著抑制PBMC对TT和PPD的增殖反应。CD1与MHC II类分子的同时相互作用对这些抗原特异性增殖反应的抑制作用更强。相比之下，CD1特异性抗体对混合淋巴细胞反应以及超抗原和促有丝分裂反应均无影响，这表明在抗原呈递过程中存在一定的限制模式。我们的研究结果表明，除了MHC I类和II类分子外，还存在一个非多态性细胞表面分子家族，能够将某些细菌蛋白抗原呈递给T细胞。
