Recombinant human B7.2 IgV-like domain expressed in bacteria maintains its co-stimulatory activity in vitro

OBJECTIVE: To investigate which of the two immunoglobulin (Ig)-like domains, the immunoglobulin variable region homologous domain IgV (hB7.2 IgV) and the immunoglobulin constant region homologous domain IgC (hB7.2 IgC) on the human B7.2 molecule contains receptor binding sites, and to evaluate whether the B7.2 protein expressed in bacteria has biological activity in vitro. METHODS: Three fragments of hB7.2 IgV,hB7.2 IgC and the complete extracellular region of human B7.2 containing both the IgV and IgC domains,hB7.2 Ig (V+C), were amplified by PCR and subcloned into pGEM-Teasy. Three recombinants,pGEX-4T-3-hB7.2 IgV,pGEX-4T-3-hB7.2 IgC and pGEX-4T-3-hB7.2 Ig (V+C), were generated by cloning the fragments into a prokaryote expression plasmid (pGEX-4T-3) and transformed into the host strain E. coli DH5alpha. The relevant target fusion proteins consisting of GST and hB7.2 IgV,hB7.2 IgC and hB7.2 Ig (V+C), were identified by SDS-PAGE and Western blotting. With the presence of the first signal imitated by anti-CD3 antibody, T cell activation was observed by exposing purified T lymphocytes to each soluble form of the three bacterially-produced human B7.2 fusion proteins by [(3)H]-TdR incorporation. RESULTS: Three recombinant fusion proteins of human B7.2, GST-hB7.2 IgV, GST-hB7.2 IgC and GST-hB7.2 Ig (V+C) were produced and detected in inclusion body form from engineered bacteria. With the first signal present,T lymphocytes proliferated when co-stimulated by bacterially-produced either GST-hB7.2 Ig (V+C) or GST-hB7.2 IgV fusion proteins, but not by GST-hB7.2 IgC. CONCLUSIONS: Functional human B7.2 fusion protein can be produced in bacteria. The IgV-like domain of human B7.2 is sufficient for B7.2 to interact with its counter-receptors and co-stimulate T lymphocytes.

Effects of“Moxibustion Serum”on Proliferation and Phenotypes of Tumor Infiltrating Lymphocytes

Tumor infiltrating lymphocytes (TIL) were cultured with “moxibustion serum”(MS), and the results were examined by flow cytometry. The results indicated that MS could enhance the proliferation of TIL,accelerate it to reach the exponential growth phase, and assist recombinant interleukin 2 (rIL-2) to enhance successively the percentage of CD3^+ positive cells, maintain the number of CD4^+ positive T cells, promote greatly the percentage of CD8^+ positive T cells among TILs, and reverse the CD4^+/CD8^+ ratio. Such cooperative effects rely on relative specificity of acupoints. It is suggested that MS is beneficial to the growth of TIL both in the aspects of proliferation and phenotypes.

Fas/FasL系统与卵巢肿瘤的免疫逃逸的研究

目的 :检测Fas、FasL在上皮性卵巢癌及其肿瘤浸润淋巴细胞 (TIL)中的表达 ,探讨Fas系统在卵巢癌免疫逃逸中的作用。方法 :用流式细胞术检测了 31份上皮性卵巢癌、2 0份卵巢良性肿瘤、10份正常卵巢组织以及 31份卵巢癌TIL、12份卵巢良性肿瘤TIL的Fas及FasL的表达。结果 :卵巢癌组织的Fas表达明显低于卵巢良性肿瘤及正常卵巢组织 ,P <0 0 1;而其FasL表达明显高于后者 ,P <0 0 1。卵巢良性肿瘤及正常卵巢组织的Fas、FasL表达差异无显著意义 ,P >0 0 5。卵巢癌组织中含有丰富的TIL ,其Fas及FasL的表达明显高于卵巢良性肿瘤TIL ,差异有显著意义 ,P <0 0 5。卵巢癌组织Fas的表达与临床分期、组织学分级及淋巴结转移无关 ,P >0 0 5。FasL的表达与临床分期无关 ,但随组织学分级的升高而增加 ,P <0 0 5 ,有淋巴结转移者FasL的表达明显高于无淋巴结转移者 ,P <0 0 5。卵巢癌TIL中Fas及FasL的表达与各临床病理参数无关 ,P >0 0 5。结论 :上皮性卵巢癌组织中存在Fas表达的下调和FasL表达的增加 ,FasL高表达者预后不良。肿瘤细胞可能通过FasL的过度表达 ,逃避免疫监视 ,诱导Fas敏感的TIL凋亡 ,发生浸润和转移。

重组人FLT3配基对人脐血CD_(34)^+细胞的体外扩增作用

目的观察重组人ＦＬ（ｒｈＦＬ）对脐血ＣＤ＋３４细胞的体外扩增作用。方法用磁性细胞分离仪富集人脐血ＣＤ＋３４细胞。在ＣＤ＋３４细胞体外液体培养中加入不同的细胞因子，在不同时间取样测试ＣＤ＋３４细胞阳性百分率、晚期造血祖细胞（粒细胞巨噬细胞集落生成单位及红系爆增式集落形成单位）并计数细胞总数。结果用磁性细胞分离仪可快速富集脐血ＣＤ＋３４细胞，纯度高达８０％以上。ｒｈＦＬ可协同白细胞介素（ＩＬ）－３、ＩＬ－６、粒－巨噬细胞集落刺激因子及促红细胞生成素促进ＣＤ＋３４细胞总数在７天时扩增３．４倍，无ｒｈＦＬ的对照组ＣＤ＋３４细胞只扩增１．５倍，但对晚期造血祖细胞的扩增无明显协同作用。结论用排除法证实ｒｈＦＬ主要扩增了早期造血祖细胞。