Study on the expression of SAP (SLAM associated protein) and SLAM (signaling lymphocyte activation molecule), and the reactivation of EBV (Epstein-Barr virus)

(1) SAP/SLAM的表达和EBV的活化：(1)我们在8株EBV阳性和阴性的Burkitt淋巴瘤（BL）、5株其他B和T细胞以及2株胃上皮细胞株中表征了SLAM和SAP的表达。SLAM在所有细胞系中均有表达，而SAP仅在Daudi、Akata、Jurkat、MT-4和胃上皮细胞系GT38中表达。在Akata、Daudi和GT38细胞中分析EBV再激活后SAP的表达。抗人免疫球蛋白（Ig）可显著降低Daudi和Akata细胞中SAP的表达。TGF-β1在Daudi和GT-38细胞中也能降低SAP表达，诱导EBV再激活，而在缺乏TGF-β受体II的Akata细胞中，TGF-β1既不抑制SAP，也不诱导EBV再激活。这些结果表明，EBV的再激活信号如抗人Ig和TGF-β1与SAP信号相互作用，EBV的再激活与SAP的抑制同时发生（修订后可接受；Virology J. ... More）。(2) SLAM信号抑制细胞生长和IL-4基因表达：我们发现EBV阳性淋巴样细胞株OB表达SLAM和抗SLAM抗体诱导细胞生长和IL-4表达抑制，但不抑制干扰素y的表达。这些结果提示SLAM在B细胞（制剂）中具有免疫调节剂的功能。(3)赤田和道迪无性系中SAP的表达差异：赤田和道迪无性系中SAP的表达差异较大。低表达SAP的克隆比高表达SAP的克隆（待制备）更能激活EBV。(2) EBV再激活信号：(1)Akata细胞通过TGF-β受体II的缺陷介导的TGF-1介导的EBV再激活存在缺陷。(2) AKT/PI3激酶通路上调细胞生长和EBV的自发再激活。(3) EA-D分子为58、50、48和44 kDa的络合物。58和50 kDa分子为磷酸化形式，48和44 kDa分子为去磷酸化形式，并在EBV再激活的细胞中积累。(4) 38丝裂原活化蛋白激酶（MAPK）调控IL-10基因在BL细胞株中的表达。我们在4个期刊上发表了这些结果。(3)今后研究的新进展：(2)测定了EBV- lmp1基因的c端核苷酸序列，并对日本EBV分离株的序列变异进行了分析。结果表明，日本EBV分离株与非洲BL分离株差异较大，但与中国EBV主要分离株中国1号亲缘关系密切。(2)日本和中国分离株的中国1号菌株分别具有不同的特征突变。少

(1) Expression of SAP/SLAM and EBV reactivation : (1) We characterized the expression of SLAM and SAP in 8 EBV-positive and -negative Burkitt's lymphoma (BL), 5 other B and T, and 2 gastric epitherial cell lines. SLAM was expressed in all tested cell lines, but SAP was expressed in only Daudi, Akata, Jurkat, MT-4 and a gastric epitherial cell line GT38. The SAP expression was analyzed upon reactivation of EBV in Akata, Daudi and GT38 cells. The expression of SAP was reduced dramatically in Daudi and Akata cells by treatment with anti-human immunoglobulins (Ig). TGF-β1 also reduced SAP expression and induced EBV reactivation in Daudi and GT-38 cells, while TGF-β1 did neither suppress SAP nor induce EBV reactivation in Akata cells, which lack TGF-β receptor II. These results indicate that the EBV-reactivation signals such as anti-human Ig and TGF-β1 cross-talk with the SAP signal and that EBV is reactivated simultaneously with the suppression of SAP (acceptable with revison ; Virology J. … More ). (2) SLAM signal suppresses cell growth and IL-4 gene expression : We found that an EBV positive lymphoid cell line OB expressed SLAM and anti-SLAM antibody induces the inhibition of cell growth and IL-4 expression but not interferon y expression. These results suggest that SLAM functions an immunological modulator in B cell (in preparation). (3) Diferential expression of SAP in Akata and Daudi clones : We found that SAP expression was different in each clones of Akata and Daudi. The EBV was reactivated by anti-Ig more highly in clones with lower expression of SAP than those of higher expression of SAP (in preparation).(2) EBV-reactivation signaling : (1) Akata cells have defectiveness of TGF-1 mediated EBV reactivation by the defectiveness of TGF-β receptor II. (2) The AKT/PI3 kinase-pathway up regulates cell growth and spontaneouse EBV reactivation. (3) EA-D molecule is a complex with 58,50,48 and 44 kDa. The 58 and 50 kDa molecules are phosphorilated form, and 48 and 44 kDa molecules are dephosphorilated form and accumurate in EBV reactivated cells. (4) 38 mitogen-activated protein kinase (MAPK) regulates IL-10 gene expression in BL cell lines. We published these results in 4 journals.(3) A new progress for our future : (2) We determined the C-terminal nucleotide sequences of EBV-LMP1 gene and characterized the sequence variation of Japanese EBV isolates. The results indicate that the Japanese EBV isolates greatly different from the African BL isolates but closely related to the China 1, which is a major strain of Chinese EBV isolates. (2) The China 1 strains of Japanese and Chinese isolates are different with characteristic mutations, respectively. Less