ACCESSORY CELL LYMPHOCYTE-T INTERACTIONS - ANTIGEN-DEPENDENT AND ANTIGEN-INDEPENDENT CLUSTERING
ACCESSORY CELL LYMPHOCYTE-T INTERACTIONS - ANTIGEN-DEPENDENT AND ANTIGEN-INDEPENDENT CLUSTERING
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DOI:
10.1084/jem.163.2.247
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发表时间:
1986-02-01
影响因子:
15.3
通讯作者:
STEINMAN, RM
中科院分区:
文献类型:
--
作者:
INABA, K;STEINMAN, RM
Previous work documented the capacity of dendritic cells (DC) to stimulate primary immune responses and to physically cluster with the responding lymphocytes. Rapid cell-cell aggregation assays were used here to study the interaction of DC and other types of APC with T lymphocytes. Graded doses of APC were sedimented with T cells that had been primed to alloantigens, soluble proteins, or lectin, and then labeled with carboxyfluorescein diacetate. The number of clustered T cells was measured after 10 min at 4 or 37.degree. C. At 4.degree., binding was antigen-dependent and included > 50% of the added T cells. Clustering was mediated by all types of APC tested, including DC, macrophages, B lymphocytes, and fresh Langerhans cells, although DC were the most effective. Specificity was evident in the findings that alloreactive T lymphoblasts bound to allogeneic but not syngeneic APC; KLH- and OVA-reactive T cells bound to syngeneic APC in the presence of specific protein: and Con A blasts needed lectin to cluster. A 30 min pretreatment with chloroquine, a drug known to inhibit APC activity, markedly blocked the specific binding of alloreactive and protein-specific T blasts should specifically recognize Ia, presentation of Ia seems to be altered by chloroquine. Binding assays at 37.degree. C gave similar results to those performed at 4.degree. C, with one exception. When DC were used as APC, striking antigen-independent clustering occurred. DC could efficiently cluster primed T cells in the absence of alloantigen, soluble protein, or lectin. We suggest that antigen-independent binding contributes to the distinctive capacity of DC to prime T cells in the afferent limb of the immune response, whereas antigen-dependent binding between other APC and sensitized lymphocytes is critical in the efferent limb.