Studies on the regulation of gene expression in lymphoid cells.

美日免疫学研讨会于1月底在加利福尼亚州蒙特雷举行，为期2天。9名美国和7名日本免疫学家介绍并讨论了他们的最新结果。本研究从淋巴细胞定向分化相关基因、T细胞对抗原的加工和识别、超抗原、细胞因子及其受体、免疫功能紊乱等方面，利用基因打靶技术制备了RAG-1和RAG-2缺陷小鼠。由于完全缺乏淋巴细胞，小鼠表现出严重的联合免疫缺陷，证实这些基因参与了IG和T细胞受体基因的重组。超抗原可以激活大量携带靶V β的T细胞，这可能导致疾病，如中毒性休克。EB病毒是一种超抗原，在类风湿性关节炎等自身免疫性疾病中可能参与T细胞的活化，并讨论了EB病毒细胞因子受体的独特结构。IL-6和IL-5受体均由两条多肽链组成，即配体结合链和信号转导子。信号转导子通常用于几种细胞因子受体系统，如：例如，IL-5、IL-3和GM-CSF利用相同的信号转换器，IL-6和LIF利用相同的gp 130作为信号转换器。这种独特的系统可能能够解释多效性和冗余的细胞因子。

The US-Japan Immunology Symposium was held for 2 days at the end of January at Monterey, CA. Nine US and seven Japanese immunologists presented and discussed their up-to-date results. The discussion was focused on the topics i) genes involved in the commitment of lymphoid cells, ii) antigen processing and recognition by T cells, iii) superantigens iv) cytokines and their receptors and v) immune disorders.The RAG-1 and RAG-2 deficient mice were prepared by gene targeting technology. The mice showed a severe combined immune deficiency due to the total lack of lymphoid cells confirming the involvement of these genes in the recombination of the Ig and T cell receptor genes.The class I MHC epitope of a bacterial pathogen which is a nonamer peptide, was identified. Superantigens can activate large number of T cells bearing the target V beta and this can lead to diseases, such as toxic shock. EB virus was shown to make a superantigen and suggested to be involved in the activation of T cells in autoimmune diseases such as rheumatoid arthritis.An unique structure of cytokine receptors was discussed. Both IL-6 and IL-5 receptors consist of two polypeptide chains, a ligand binding chain and a signal transducer. Signal transducers are common by utilized between several cytokine receptor systems, i. e., IL-5, IL-3 and GM-CSF utilize the same signal transducer and IL-6 and LIF utilize the same gpl30 as a signal transducer. This unique system may be able to explain pleiotropy and redundancy of cytokines.