Masten B J, Lipscomb M F
Department of Pathology, University of New Mexico, Albuquerque, NM 87131, USA.
J Immunol. 1999 Feb 1;162(3):1310-7.
Dendritic cells (DCs) are specialized APCs that are important in priming naive T cells and can be manipulated in vitro and in vivo to enhance immunizations against microorganisms and tumors. A limitation in the development of suitable immunotherapeutic vaccines for the lung is incomplete information on the role of DCs and other potential APCs in the lung in priming naive T cells. In the current study, we analyzed the relative contributions of murine lung DCs and B cells to process and present OVA to naive CD4+ OVA323-339-specific (DO11.10) T cells in vitro. We also examined their expression of MHC class II and accessory molecules before and after maturation in culture. Similar to DCs from other sites, freshly isolated lung DCs can process OVA, spontaneously up-regulate MHC class II and accessory molecules during overnight culture, and stimulate naive T cells in an Ag-specific manner. In contrast, freshly isolated lung B cells were unable to both process and present native OVA. Furthermore, under conditions of limited OVA323-339 peptide exposure, B cells had a significantly diminished capacity to stimulate T cells, and this correlated with a decreased density of both MHC class II and important costimulatory molecules as compared with lung DCs.
树突状细胞（DCs）是特殊的抗原呈递细胞（APCs），在启动初始T细胞方面很重要，并且可以在体外和体内进行调控，以增强针对微生物和肿瘤的免疫接种。开发适用于肺部的免疫治疗疫苗的一个限制是，关于肺部DCs和其他潜在APCs在启动初始T细胞方面的作用信息不完整。在当前研究中，我们分析了小鼠肺部DCs和B细胞在体外处理OVA并将其呈递给初始CD4+ OVA323-339特异性（DO11.10）T细胞的相对贡献。我们还检测了它们在培养成熟前后MHC II类分子和辅助分子的表达。与来自其他部位的DCs相似，新鲜分离的肺部DCs能够处理OVA，在过夜培养期间自发上调MHC II类分子和辅助分子，并以抗原特异性方式刺激初始T细胞。相比之下，新鲜分离的肺部B细胞既不能处理也不能呈递天然OVA。此外，在OVA323-339肽暴露有限的条件下，B细胞刺激T细胞的能力显著降低，这与肺部DCs相比，MHC II类分子和重要共刺激分子的密度降低有关。
