肝癌细胞株SMMC-7721中CD147和MMP-9的表达及意义

目的研究肝癌细胞系SMMC-7721中CD147与基质金属蛋白酶-9（MMP-9）的表达及意义。方法用流式细胞仪检测正常肝细胞L-02与肝癌细胞SMMC-7221中CD147的表达；用免疫组化法检测两种细胞产生的MMP-9的表达。结果正常肝细胞L-02中CD147表达阴性，SMMC-7721中CD147表达呈强阳性（阳性率为98．1％）；MMP-9在正常肝细胞及肝癌细胞中均有表达，但在肝癌细胞中表达明显增高。结论肝癌细胞系SMMC-7721中CD147与MMP-9表达明显增高，与肝癌的侵袭转移潜能有关。     

p73基因在甲氨蝶呤诱导髓性白血病细胞系U937细胞凋亡过程中的表达

为了探讨甲氨蝶呤（MTX）诱导U937细胞凋亡过程中p73 mRNA的表达变化，用MTX诱导U937细胞凋亡，凋亡指标采用细胞形态学、DNA片段电泳、流式细胞术检测DNA含量及细胞周期的变化等方法；采用半定量反转录PCR（RT－PCR）检测p73 mRNA的表达变化。研究结果显示：MTX可诱导U937细胞凋亡。5μmol/L的MTX作用于U937细胞6小时，可见部分细胞体积缩小，染色质明显浓缩和核碎裂。DNA片段电泳，MTX处理组可见清晰的梯形条带。流式细胞仪检测发现MTX作用于U937细胞，6，8，10小时，细胞的凋亡率分别为5．15％，11．43％和14．7％，并使细胞阻滞在G2／M＋S期，而对照组细胞不发生凋亡。半定量RT－PCR结果显示在U937细胞凋亡前后，p73 mRNA的表达无明显变化。结论提示，在MTX诱导U937细胞凋亡过程中，p73的mRNA水平表达差异无显性。     

辛伐他汀对脂多糖诱导人THP-1单核细胞表达MMP-9的影响

【目的】研究辛伐他汀对脂多糖（LPS）诱导人THP-1单核细胞表达基质金属蛋白酶9（MMP-9）的影响,探讨辛伐他汀稳定动脉粥样硬化（AS）斑块的机制。【方法】体外培养人THP-1单核细胞,分为对照组、LPS组、辛伐他汀低、中、高浓度组;辛伐他汀三组加入不同浓度辛伐他汀预孵2h与LPS组均加入LPS刺激24h,应用Western blotting与ELISA分别检测各组细胞蛋白与培养基上清中MMP-9水平。【结果】LPS诱导人THP-1单核细胞MMP-9表达显著增加,辛伐他汀呈浓度依赖性显著抑制LPS诱导人THP-1单核细胞MMP-9表达。【结论】辛伐他汀通过抑制LPS诱导人THP-1单核细胞MMP-9表达,可能是其在炎症状态下稳定AS斑块的机制之一。     

手霉素通过线粒体凋亡途径诱导U937和HL-60细胞凋亡

目的 研究法尼酰基转移酶抑制剂手霉素（Manumycin）诱导白血病细胞凋亡的机制。方法 用2μmol／L手霉素处理白血病细胞系U937和HL-60细胞不同时间，用流式细胞术检测细胞凋亡。免疫印迹技术检测细胞色素C、caspase9、caspase8、caspase3的表达。用荧光染料JC-1检测法测定线粒体膜电位（Δψm），并用caspase抑制剂Z—VAD—fmk阻断caspase的活化，探讨caspase在手霉素诱导白血病细胞凋亡中的作用。结果 2μmol／L手霉素处理U937和HL-60细胞16h，Δψm显著下降，相对值分别是0．51±0．07和0．41±0．06（P〈0．01）。手霉素诱导细胞色素C从线粒体释放到细胞质，激活caspase-9、caspase8和caspase-3。50μmol／L的Z—VAD—fmk可完全阻断caspase激活，但仅部分阻断手霉素诱导的U937和HL-60细胞凋亡，细胞凋亡率分别减少51．69％和56．47％。结论 手霉素通过线粒体途径诱导U937和HL-60细胞凋亡。     

shRNA抑制CD147基因表达对HT29细胞增殖、侵袭和致瘤能力的影响

目的用RNA干扰(RNAi)技术抑制CD147基因的表达,检测其对人结直肠癌细胞系HT29细胞增殖、侵袭和致瘤能力的影响。方法设计合成CD147特异性的RNA干扰表达质粒pYr-mir30-shRNA,稳定转染HT29细胞,分别获得HT29/shRNA-control和HT29/shRNA细胞;RT-PCR和western blot分别检测CD147、MCT1、MCT4 mRNA和蛋白质的表达;明胶酶谱法检测MMP-2和MMP-9的活性;CCK8法分析细胞的增殖能力;Transwell小室检测细胞的侵袭能力;观察结直肠癌裸鼠皮下移植瘤的致瘤能力。结果与空白组比较,RNA干扰后的细胞中CD147、MCT1 mRNA(F分别为99.645和84.985)及蛋白质(F分别为73.675和19.842)的表达水平均降低(P均0.01);MMP-2和MMP-9的活性均降低(P均0.01);细胞增殖(t分别为7.491、15.023、14.584、6.637和11.211,P均0.01)和侵袭(F=330.443,P0.01)能力均降低,使裸鼠荷瘤能力下降(F=365.679,P0.01)。结论 RNA干扰能有效抑制CD147基因的表达,抑制HT29细胞的增殖和侵袭能力。     

基质细胞衍生因子在不同的急性髓系白血病细胞系的迁移、黏附和细胞凋亡中的生物学作用

本研究探讨基质细胞衍生因子（stromal cell derived factor 1，SDF-1）在急性髓系白血病（AML）细胞的迁移、黏附和细胞凋亡中的生物学作用及有关的信号转导。采用流式细胞术检测AML的细胞系KG1a、ML1、U937细胞表面标记物的表达；以免疫荧光技术检测SDF-1对肿瘤细胞膜表面分子的影响；通过微孔细胞转移实验检测SDF-1对AML细胞的趋化作用及磷脂酰肌醇3激酶（P13K）在趋化过程中的作用；用蛋白免疫印记技术检测P13K信号途径有关的细胞凋亡分子BCL—XL在SDF-1活化此途径后的变化。结果表明：3种AML细胞系不同程度表达CD34（KG1a=95．6％、ML1=4．6％、U937=4．8％）、CD45（KG1a=98．3％、U937=97．5％、NIL1=17．8％）、CXCR4（ML1=85．4％、U937=43.6％、KG1a=3．8％）、ICAM（KG1a=75．8％、U937=41．8％、ML1：46.3％）。SDF-1能促进CXCR4高表达的ML1和U937细胞在基质细胞的黏附并能够诱导此类细胞的迁移，上述作用被G蛋白抑制剂pertussistoxin（PTX）、P13K抑制剂渥曼青霉素（wortmannin）明显抑制；而对CXCR4低表达的KG1a细胞则无上述作用。SDF通过此途径还促进肿瘤细胞存活；此作用同样可被P13K抑制剂明显抑制，加用wortman—nin后促肿瘤细胞调亡显著增加。蛋白免疫印记检测phospho—AKT、BCL—XL显示，在SDF组明显增强，加用PTX、wortmannin组则减弱。结论：SDF-1能触发CXCR4高表达的ML1和U937细胞的极化形态的建立及诱导黏附分子的重新分布，从而通过P13K信号途径促进此类AML细胞的迁移，减少肿瘤细胞的调亡，而对CXCR4低表达的KG1a细胞则无上述作用。上述作用可以被P13K信号途径阻断剂和G蛋白抑制剂所阻断。     

唾液腺腺样囊性癌患者的MAPK、MMP-2和MMP-9及CD147表达和价值

目的 探究唾液腺腺样囊性癌患者丝裂原活化蛋白激酶（mitogen activated protein kinase, MAPK）、基质金属蛋白酶-2 (matrix metallo proteinase, MMP-2)、细胞外基质金属蛋白酶诱导因子（extracellular matrix metalloproteinase inducer, CD147）、基质金属蛋白酶-9(matrix metallo proteinase, MMP-9)的表达和价值。方法 选取2020年2月—2022年2月甘肃医学院附属医院接诊的20例唾液腺腺样囊性癌患者为A组,另外选择同期健康体检者20例为B组（正常唾液腺组织）,均进行实验室检查,采用免疫组织化学法测定、分析两组MAPK(p-JNK、p-P38)、MMP-2和MMP-9、MVD、CD147表达水平,以及A组中MVD、CD147、MMP-2、MMP-9与MAPK(p-JNK、p-P38)的相关性分析。结果 A组MMP-2、MMP-9、MVD、CD147表达水平高于B组,MAPK(pJNK、p-P38)表达水平低于B组,差异有统计学意义（P<...     

雷公藤内酯醇对神经胶质瘤U87细胞侵袭性抑制的体外研究

目的 研究雷公藤内酯醇（triptolide）对体外培养的胶质瘤U87细胞侵袭性的抑制作用,并探讨其作用分子机制. 方法 使用MTT法检测雷公藤内酯醇对胶质瘤U87细胞增殖抑制作用, Transwell实验检测雷公藤内酯醇处理后细胞侵袭能力的变化,进一步通过Real-Time PCR和Western印迹法检测雷公藤内酯醇对U87胶质瘤细胞的组织蛋白酶B（Cathepsins B,CB）、基质金属蛋白酶9（MMP-9）表达的影响. 结果 雷公藤内酯醇以剂量-效应方式抑制胶质瘤细胞增殖,同时可减弱U87胶质瘤细胞的侵袭能力,下调其CB、MMP-9表达水平. 结论 在体外实验中雷公藤内酯醇抑制U87胶质瘤细胞侵袭性生长的机制与下调CB及MMP-9的表达,降低胶质瘤细胞水解细胞外基质的能力有关.     

4-1BBL单克隆抗体激发U937细胞NF-κB的核转位及4-1BBL/CD28同型异构分子共定位

本研究探讨共刺激分子4-1BBL逆向信号在人急性单核细胞白血病细胞株U937中的分子机制.选择U937细胞株作为靶细胞,与鼠抗人4-1BBL激发型单克隆抗体1 F1（mAb 1 F1）共培养.应用激光共聚焦显微镜观察U937细胞株上NF-κB核转位及4-1BBL分子与CD28同型异构分子（CD28i）的共定位;使用流式细胞术及RT-PCR检测U937细胞4-1BBL和CD28i的分子表达.结果表明：U937细胞经mAb 1F1刺激后,出现明显的NF-κB核内转位及细胞膜上4-1BBL与CD28i分子的共定位.结论：介导U937细胞生长的4-1BBL逆向信号的传导与NF-κB的核转位相关;CD28i分子可能参与了4-1BBL逆向信号的传导.     

乳腺浸润性导管癌组织中CD147与基质金属蛋白酶-9表达

目的探讨CD147与基质金属蛋白酶（metalloprotease,MMP）-9在乳腺浸润性导管癌组织中的表达及意义。方法应用免疫组织化学SP法检测60份乳腺浸润性导管癌石蜡包埋组织中CD147与MMP-9的表达;采用Western blot方法检测28份乳腺浸润性导管癌及癌旁新鲜组织标本中CD147与MMP-9表达情况。结果免疫组织化学结果显示,CD147主要在癌细胞的胞膜及胞质中表达,在间质中不表达;MMP-9主要在癌细胞的胞质中表达,在间质中不表达;CD147与MMP-9表达在组织学分级及淋巴结转移上差异有统计学意义（P〈0.05）;在年龄、肿块大小及临床分期上差异无统计学意义（P〉0.05）;2种蛋白在乳腺浸润性导管癌组织中表达有明显相关性（r=0.769,P〈0.05）。Western blot结果显示,乳腺浸润性导管癌组织中CD147与MMP-9表达高于癌旁乳腺组织（P〈0.05）,且有淋巴结转移者高于无淋巴结转移者（P〈0.05）。结论 CD147与MMP-9在乳腺浸润性导管癌组织中表达明显增高,可能在乳腺癌发生、发展中发挥重要作用。     

人急性单核细胞白血病细胞系SHI-1在裸鼠体内的高致瘤性及其机制的初步研究

本研究确定人急性单核细胞白血病细胞系SHI-1在裸鼠体内的高致瘤性,并对其成瘤机制进行初步探讨。将SHI-1细胞接种至裸鼠皮下,观察肿瘤生长情况;取肿瘤组织行病理检测、R显带核型分析;RT-PCR检测MLL-AF6融合基因和VEGF基因的转录;明胶酶谱法检测培养上清中基质金属蛋白酶-9（MMP-9）和MMP-2的表达;体外穿膜实验观察迁移能力。结果表明：注射SHI-1细胞的16只裸小鼠均于皮下出现肿块;瘤体由白血病细胞组成;注射的裸鼠中有MLL/AF6融合基因和VEGF基因的转录;在无血清培养上清中MMP-9和MMP-2的表达明显高于对照细胞;SHI-1细胞有较强的迁移能力,MMP-2的阻断抗体可显著抑制其体外迁移能力。结论：SHI-1在裸鼠体内有极高的成瘤率,其机制可能与p53基因的异常、高水平VEGF基因的转录、金属蛋白酶的高表达和较强的体内浸润能力有关。     

尿激酶受体基因反义RNA转移体系的建立及其在白血病研究中的应用

尿激酶受体 (uPAR)表达与肿瘤 /白血病细胞的侵袭与转移能力明显相关。为探讨逆转录病毒载体介导的uPAR基因反义RNA转移体系在抑制白血病细胞表达uPAR中的价值 ,构建了表达反义uPAR基因的逆转录病毒载体LaCD87SN ,用脂质体转染 交互感染策略建立uPAR基因反义RNA转移体系 ,并以双嗜型aCD87病毒转导U937白血病细胞 ;用PCR分析反义uPAR基因的整合和表达 ;用流式细胞术和明胶酶谱分别检测白血病细胞CD87表达和基质金属蛋白酶 (MMP)活性。结果显示 :通过转染 交互感染获得上清中病毒滴度为 6 .3× 10 5cfu/ml的双嗜型病毒产生细胞Am12 /aCD87;aCD87病毒感染的U937/aCD87细胞内存在aCD87原病毒的整合 ,并高水平表达uPAR基因反义RNA。此外 ,与载体对照的U937/NeoR细胞相比 ,U937/aCD87细胞表面CD87分子表达并无明显降低 ,但其分泌MMP 9的能力显著下降。结论 :逆转录病毒载体介导的反义RNA转移不能有效地下调白血病细胞表面uPAR表达 ,但可能干扰CD87分子与MMP的相互作用。     

CD25+ regulatory T cell inhibition enhances vaccine-induced immunity to neuroblastoma

Evidence that CD4CD25 regulatory T (Treg) cells play a role in the progression of cancer continues to mount. There is a great deal of interest as to whether transient elimination or functional inhibition of these cells can improve the efficacy of immunotherapy for cancer. Our goals in this study were to test whether treatment of mice with anti-CD25 monoclonal antibody (mAb) (PC61) could induce rejection of a murine neuroblastoma, whether anti-CD25 treatment could increase tumor immunity when administered just before cell-based vaccination, and to learn how anti-CD25 treatment influences the vaccine-induced antitumor response. Treatment of mice with anti-CD25 mAb induced rejection of the mouse neuroblastoma, Neuro-2a, as 90% of anti-CD25-treated mice survived challenge with a lethal dose of tumor cells. In vivo anti-CD25 mAb treatment before the first of 2 weekly vaccines significantly improved the survival of tumor-vaccinated/challenged mice (75% vs. 33% survival), whereas antibody treatment before each of the 2 vaccines did not, suggesting that excessive treatment with anti-CD25 mAb interferes with activated antitumor effector cells. A detailed phenotypic analysis of tissues from anti-CD25-treated mice indicated that the antibody partially depletes CD4Foxp3 Treg cells (25% to 40%) in A/J mice, and that the antibody may inhibit the remaining cells by inducing loss of CD25 expression and blocking CD25 molecules, partially confirming recent data from other investigators. Importantly, we found that in vivo anti-CD25 mAb treatment significantly decreased the contribution of asialo GM1 cells in the antitumor response. As we did not see a direct effect of anti-CD25 mAb on in vitro assays of immune cell function in spleen cells from treated animals, this indicates that inhibition of Treg cells amplifies the immune response in vivo in a manner that bypasses the requirement for innate immune activation, potentially mediated by natural killer cells, and allows for protective CD4 and CD8 cells to expand directly in response to cell-based vaccines.     

Gab2对结肠癌细胞细胞外黏附作用的影响

;目的探讨Gab2对结肠癌细胞外黏附作用的影响。方法选取SW620和HCT116两种结肠癌细胞系,建立Gab2表达降低和Gab2表达升高的稳定细胞株。将实验NOD/SCID小鼠分为3组,每组10只。(1)对照组;接种scr/MGC803体结肠癌细胞;(2)Gab2降低组;接种Gab2降低的siGab2/MGC803结肠癌细胞;(3)Gab2升高组;接种Gab2升高的Gab2/MGC803结肠癌细胞。检测细胞迁移能力,测量肿瘤的大小和侵袭范围及细胞凋亡情况。结果处理后3组细胞迁移数计算结果显示,Gab2降低组的细胞迁移数显著低于Gab2升高组和对照组(P<0.05)。各组NOD/SCID小鼠均在接种40 d后处死,比较接种前与接种后小鼠体质量,Gab2降低组显著低于Gab2升高组、对照组,对照组低于Gab2升高组。测量瘤体积,Gab2升高组高于Gab2降低组、对照组。Gab2降低组瘤体积抑制率显著高于对照组(P<0.05)。相关分析发现,MMP-2、MMP-9蛋白的表达与Gab2蛋白表达呈正相关。结论 Gab2可有效调控体外细胞迁移数,显著抑制小鼠结肠癌细胞侵袭及转移,通过调节MMP-2、MMP-9蛋白表达,从而抑制结肠癌生长及转移。     

Requirement for CD4+ cells in resistance to Pneumocystis carinii pneumonia in mice

The importance of CD4+ cells in resistance to Pneumocystis carinii (PC) in PC-susceptible severe combined immunodeficient (SCID) mice that were made resistant to PC by immunocompetent spleen cell transfer, and in conventional PC-resistant mice, was investigated. SCID mice with naturally acquired PC pneumonia (PCP) were given infusions of spleen cells from immunocompetent donors. This reconstitution caused the recipients to resolve their PCP. Treatment of reconstituted SCID mice with anti-CD4 monoclonal antibodies (mAbs) to deplete them of CD4+ cells eliminated their ability to resolve PCP, whereas treating them with anti-CD8 mAb to deplete CD8+ cells had no effect. The findings indicate, therefore, that resistance to PCP in immunologically reconstituted SCID mice is dependent on CD4+ cells. To determine whether CD4+ cells enable conventional mice to resist PCP, B6D2 mice were treated with anti-CD4 mAb to deplete them of CD4+ cells in an attempt to induce PCP. After 10-11 wk of treatment, these mice developed progressive PCP. Taken together, these results indicate that loss of CD4+ cells predisposes mice to PC infection.     

A role for CD9 molecules in T cell activation

Costimulation mediated by the CD28 molecule plays an important role in optimal activation of T cells. However, CD28-deficient mice can mount effective T cell-dependent immune responses, suggesting the existence of other costimulatory systems. In a search for other costimulatory molecules on T cells, we have developed a monoclonal antibody (mAb) that can costimulate T cells in the absence of antigen-presenting cells (APC). The molecule recognized by this mAb, 9D3, was found to be expressed on almost all mature T cells and to be a protein of approximately 24 kD molecular mass. By expression cloning, this molecule was identified as CD9, 9D3 (anti-CD9) synergized with suboptimal doses of anti-CD3 mAb in inducing proliferation by virgin T cells. Costimulation was induced by independent ligation of CD3 and CD9, suggesting that colocalization of these two molecules is not required for T cell activation. The costimulation by anti-CD9 was as potent as that by anti-CD28. Moreover, anti-CD9 costimulated in a CD28- independent way because anti-CD9 equally costimulated T cells from the CD28-deficient as well as wild-type mice. Thus, these results indicate that CD9 serves as a molecule on T cells that can deliver a potent CD28- independent costimulatory signal.     

MMP-9和CD44V6在乳腺癌组织中的表达及其意义

目的探讨基质金属蛋白酶MMP-9和CD44V6在乳腺癌中的表达及其与乳腺癌侵袭,转移的关系。方法采用免疫组化S-P方法对92例乳腺癌(20例导管内癌,72例乳腺浸润癌),20例乳腺增生组织MMP-9,CD44V6进行标记和分析。结果MMP-9和CD44V6在乳腺增生组织中几乎不表达,导管内癌,乳腺浸润癌表达率显著增高,各组间差异有显著性(P<0·05),而且MMP-9与CD44V6过表达与淋巴结转移有关。结论MMP-9和CD44V6的过表达在乳腺癌侵袭和转移中发挥重要,可作为乳腺癌侵袭和转移的重要分子学标志。     

BTLA与HVEM顺式复合物对细胞表面BTLA分子检测的影响

目的探讨BTLA-HVEM顺式复合物的存在对细胞表面BTLA分子检测的影响。方法T细胞和U937细胞存在BTLA和HVEM共表达的现象。采用流式细胞术的方法，用抗不同人BTLA位点的商品化单抗MIH26和该室研制的单抗8H9分别检测U937和T细胞等细胞表面BTLA分子的表达水平。293T／BTLA基因转染细胞上BTLA分子的检测采用8H9单抗。结果商品化单抗MIH26（0．5μg）检NT细胞和U937细胞上BTLA分子的表达量均为90％以上，而8H9单抗（1μg）检测到二者的表达量分别为42．2％、30．8％。采用0．02μg和0．05μg的8H9单抗检测293T／BTLA转基因细胞株，显示BTLA分子的表达量分别为80％和91．4％。结论T细胞和U937细胞上共表达的BTLA和HVEM形成顺式复合物，影响8H9对BTLA的检测，而不影响MIH26的检测。     

A novel surface antigen expressed by a subset of human CD3- CD16+ natural killer cells. Role in cell activation and regulation of cytolytic function

The GL183 mAb was obtained by immunizing BALB/c mice with the E57 clone (CD7+CD2+CD3-CD16+CD56+) derived from human peripheral blood NK cells. In human peripheral blood, GL183-reactive cells ranged between 2 and 12% (mean 6.5%) in 10 different donors. Double fluorescence and FACS analysis showed that GL183+ cells were consistently included in the CD56+ or CD16+ cell populations. Moreover, since only a fraction of CD56+ or CD16+ cells (approximately 40%) coexpressed GL183 surface antigen, reactivity with GL183 mAb appears to define two subsets within the CD3- lymphocyte population expressing NK cell markers. Although, the majority of GL183+ cells were CD3-, approximately 1% expressed CD3 surface antigens. As shown by clonal analysis, these infrequent CD3+GL183+ cells coexpressed CD56 and CD16 antigens. Cloning of CD3-GL183+ or CD3-GL183- cell populations under limiting dilution conditions yielded clonal progenies that maintained their original surface phenotype. Therefore, expression or lack of expression of GL183 surface antigens represents a stable phenotypic property of a subset of human CD3- NK cells. Immunoprecipitation experiments and two-dimensional PAGE analysis indicated that GL183-reactive molecules were represented in different clones either by a single 58-kD chain or, more frequently, by two chains of approximately 55 and approximately 58 kD, respectively. Analysis of GL183+ or GL183- NK clones for their ability to lyse human (IGROV I) or murine (P815) tumor target cells indicated that GL183- clones were, on average, fivefold more efficient in inducing target cell lysis. GL183+ and GL183- clones produced comparable levels of TNF-alpha in response to PHA plus PMA or anti-CD16 mAb plus PMA. Importantly, production of TNF-alpha was also induced by stimulation of GL183+ clones with GL183 mAb plus PMA. These data indicated that GL183 antigen could mediate cell triggering. This concept was confirmed by the analysis of Ca2+ mobilization, as GL183 mAb induced (in GL183+ clones) increments of [Ca2+]i comparable with those induced by PHA. Moreover, GL183 mAb, or its F(ab')2 fragments, strongly enhanced the cytolytic activity of GL183+ clones against a panel of human tumor target cells, including U937, Raji, IGROV I, M14, and A549. In contrast, GL183 mAb, but not the F(ab')2 fragments, sharply inhibited the cytolytic activity of the same clones against P815, M12, and P3U1 murine target cells. In this case, the effect of GL183 mAb (inhibition) was opposite that of PHA or of stimulatory anti-CD2 or anti-CD16 mAbs, which consistently enhanced the target cell lysis.(ABSTRACT TRUNCATED AT 400 WORDS)     

Bypassing tumor-specific and bispecific antibodies: triggering of antitumor immunity by expression of anti-FcgammaR scFv on cancer cell surface

We have developed a novel immunostimulatory molecule against tumor cells, composed of an anti-FcgammaRIII (CD16) scFv fused to the platelet-derived growth factor receptor (PDGFR) transmembrane region. This fusion molecule was stably expressed on the tumor cell surface and retained the ability of the parental antibody to bind soluble CD16. Tumor cells expressing anti-CD16 scFv triggered the release of IL-2 by Jurkat-CD 16/gamma cells and of TNFalpha by monocytes when co-cultured with these cells. Furthermore, NK cells could kill scFv-transfected HLA+ class I H1299 lung carcinoma tumor cells, but not the parental cells, indicating that anti-CD16 scFv tumor expression prevents the killer inhibitory receptor (KIR)-mediated inhibition of NK cell cytotoxicity. This anti-CD16 scFv tumor expression also enhanced tumor phagocytosis by IFNgamma-activated macrophages, a mechanism known to induce a protective long-term adaptative immunity to tumors. In vivo Winn tests performed in SCID mice showed that the expression of anti-CD16 scFv on tumor cells, but not of the negative control anti-phOx scFv, prevented tumor cell growth. Thus, expression of FcR antibodies or other FcR-specific ligands on tumor cells represents a novel and potent antibody-based gene therapy approach, which may have clinical applications in cancer