Keino H, Matsumoto I, Okada S, Kurokawa M, Kato T, Tokuhisa T, Usui M, Taniguchi M, Nishioka K, Sumida T
Division of Immunology, Rheumatology, and Genetic Program, Institute of Medical Science, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan.
Microbiol Immunol. 1999;43(6):577-84.
The T-cell receptor (TCR) BV gene of human TCR AV24+ double-negative (DN) T cells, a novel subset of natural killer (NK) T cells, was investigated by single-cell sorting and single-cell polymerase chain reaction (PCR) methods. Seven of eleven TCR AV24+ DN T-cell clones utilized TCR BV8, three BV9, and one BV6. Six of seven TCR AV24/BV8+ DN T-cell clones had identical TCR beta and alpha chains, indicating that they were the same clone. All three TCR AV24/BV9+ DN T-cell clones also demonstrated the same amino acids in the CDR3 region. These findings strongly suggest that the usage of TCR beta and alpha chains on TCR AV24+ DN T cells is extremely restricted, supporting the notion that these cells recognize highly limited T-cell epitopes on antigens. All TCR AV24+ clones expressed the NKR-P1A mRNA, and so were true NK T cells. IL-2 and IL-4 mRNAs were detected in all clones, suggesting that the majority of these cells were Th0-type T cells. Six clones overexpressed Fas-ligand (Fas-L) mRNA and Fas antigen was detected on all clones at the mRNA level. In conclusion, TCR AV24+ DN T cells might recognize restricted T-cell epitopes on antigens and function as Th0-type T cells, inducer cells to Th1- or Th2-type T cells (regulatory T cells), and as Fas-L-positive cytolytic T cells.
采用单细胞分选和单细胞聚合酶链反应（PCR）方法，对人类T细胞受体（TCR）AV24⁺双阴性（DN）T细胞（自然杀伤（NK）T细胞的一个新亚群）的TCR BV基因进行了研究。11个TCR AV24⁺ DN T细胞克隆中有7个利用TCR BV8，3个利用BV9，1个利用BV6。7个TCR AV24/BV8⁺ DN T细胞克隆中有6个具有相同的TCRβ和α链，表明它们是同一克隆。所有3个TCR AV24/BV9⁺ DN T细胞克隆在互补决定区3（CDR3）区域也显示出相同的氨基酸。这些发现强烈表明，TCR AV24⁺ DN T细胞上TCRβ和α链的使用极其受限，支持了这些细胞识别抗原上高度有限的T细胞表位这一观点。所有TCR AV24⁺克隆均表达NKR-P1A mRNA，因此是真正的NK T细胞。在所有克隆中均检测到白细胞介素-2（IL-2）和白细胞介素-4（IL-4）mRNA，表明这些细胞中的大多数是Th0型T细胞。6个克隆过度表达Fas配体（Fas-L）mRNA，并且在所有克隆的mRNA水平上均检测到Fas抗原。总之，TCR AV24⁺ DN T细胞可能识别抗原上受限的T细胞表位，并作为Th0型T细胞、Th1或Th2型T细胞（调节性T细胞）的诱导细胞以及Fas-L阳性溶细胞性T细胞发挥作用。
