Jackman R M, Moody D B, Porcelli S A
Lymphocyte Biology Section, Brigham and Women's Hospital, Boston, MA 02115, USA.
Crit Rev Immunol. 1999;19(1):49-63.
CD1 is a family of cell surface glycoproteins that are related in structure and evolutionary origin to the major histocompatibility complex (MHC)-encoded antigen-presenting molecules. In contrast to MHC-encoded antigen-presenting molecules, CD1 binds and presents lipid and glycolipid antigens for specific recognition by T cell antigen receptors. Recent work shows that several CD1 family members colocalize with MHC class II proteins within the endocytic system of antigen-presenting cells. Detailed studies of the intracellular trafficking of CD1 proteins reveal new mechanisms controlling delivery of antigen-presenting molecules to particular compartments within cells. The combination of overlapping yet distinct trafficking routes for the various CD1 family members, combined with emerging information on the heterogeneity of CD1-presented lipid antigens, suggest a model whereby different members of the CD1 family could present antigens that occur in various cellular compartments. Furthermore, the CD1 family as a group may present antigens from pathogens that are not normally accessible to or efficiently surveyed by the MHC Class I or II systems. The discovery of this third pathway for antigen presentation, together with the appreciation of a previously unrecognized universe of nonpeptide lipid antigens for T cell responses, are likely to have broad implications for our understanding of the cell-mediated immune response and its role in health and disease.
CD1是一类细胞表面糖蛋白，在结构和进化起源上与主要组织相容性复合体（MHC）编码的抗原呈递分子相关。与MHC编码的抗原呈递分子不同，CD1结合并呈递脂质和糖脂抗原，以供T细胞抗原受体进行特异性识别。最近的研究表明，几个CD1家族成员在抗原呈递细胞的内吞系统中与MHC II类蛋白共定位。对CD1蛋白细胞内运输的详细研究揭示了控制抗原呈递分子向细胞内特定区室递送的新机制。各种CD1家族成员重叠但又不同的运输途径，再加上关于CD1呈递的脂质抗原异质性的新信息，提示了一种模型，即CD1家族的不同成员可以呈递存在于各种细胞区室中的抗原。此外，作为一个整体的CD1家族可能呈递来自病原体的抗原，而这些抗原通常无法被MHC I类或II类系统接触到或有效检测到。这第三条抗原呈递途径的发现，以及对T细胞反应中以前未被认识的非肽脂质抗原世界的认识，可能会对我们理解细胞介导的免疫反应及其在健康和疾病中的作用产生广泛影响。
