Dai R, van Rooijen N, Dijkstra C D, Streilein J W
Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts 02114, USA.
Cell Immunol. 1995 May;162(2):265-74. doi: 10.1006/cimm.1995.1078.
Splenic dendritic cells resemble epidermal Langerhans cells in the sense that when both cell types are placed in culture for 1 or more days they undergo a functional transformation that equips them to activate unprimed syngeneic T cells. Among Langerhans cells, this transformation has been ascribed to contaminating keratinocytes that are present in cell suspensions prepared from epidermis. Cytokines released from cultured keratinocytes, particularly GM-CSF and IL-1, have been implicated in mediating the functional transformation observed among cultured Langerhans cells. The present experiments have examined the nature of the cytokines responsible for functional conversion of fresh to cultured dendritic cells harvested from spleens of normal mice and have attempted to identify among the cultured cells the cellular source(s) of these factors. The results indicate that splenic dendritic cells acquire unique accessory properties for activation of naive T cells when placed in vitro because factors generated within the culture, especially GM-CSF and IL-1 beta, are present. Our evidence shows that splenic T cells and phagocytic cells, presumably macrophages, contribute to the presence of these conversion-promoting factors. Thus, this evidence suggests that splenic dendritic cells within the spleen of normal mice, like Langerhans cells within the epidermis of normal, unperturbed skin, exist in vivo in a proactive state with respect to the capacity to induce priming among naive T cells. Acquisition of unique accessory cell function depends upon other cell types within spleen, such as T cells and macrophages that secrete GM-CSF and IL-1 beta. These cytokines, as well as other undefined factors, enable dendritic cells to acquire the accessory properties required to activate resting T cells.
脾脏树突状细胞类似于表皮朗格汉斯细胞，因为当这两种细胞类型在培养中放置1天或更长时间时，它们会经历功能转变，从而具备激活未致敏的同基因T细胞的能力。在朗格汉斯细胞中，这种转变被归因于从表皮制备的细胞悬液中存在的污染角质形成细胞。培养的角质形成细胞释放的细胞因子，特别是粒细胞-巨噬细胞集落刺激因子（GM-CSF）和白细胞介素-1（IL-1），被认为介导了在培养的朗格汉斯细胞中观察到的功能转变。本实验研究了负责将从正常小鼠脾脏收获的新鲜树突状细胞转变为培养树突状细胞的细胞因子的性质，并试图在培养细胞中鉴定这些因子的细胞来源。结果表明，脾脏树突状细胞在体外培养时获得了激活幼稚T细胞的独特辅助特性，因为培养物中产生的因子，特别是GM-CSF和白细胞介素-1β（IL-1β）存在。我们的证据表明，脾脏T细胞和吞噬细胞，可能是巨噬细胞，促成了这些促进转变因子的存在。因此，这一证据表明，正常小鼠脾脏内的脾脏树突状细胞，就像正常未受干扰皮肤表皮内的朗格汉斯细胞一样，在体内对于诱导幼稚T细胞启动的能力处于主动状态。获得独特的辅助细胞功能取决于脾脏内的其他细胞类型，如分泌GM-CSF和IL-1β的T细胞和巨噬细胞。这些细胞因子以及其他未定义的因子，使树突状细胞能够获得激活静止T细胞所需的辅助特性。
