Potential of Antibody-Dependent Cellular Cytotoxicity in Acute and Recovery Phases of SARS-CoV-2 Infection

Background:Severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)has caused a global pandemic that has resulted in millions of casualties.Although researchers have reported the existence of neutralizing antibodies and viral T cell immunity against SARS-CoV-2,little is known about the presence of antibody-dependent cellular cytotoxicity(ADCC)and its role in combating SARS-CoV-2 infection.Methods:Nineteen acute COVID-19 patients at the First Affiliated Hospital of Guangzhou Medical University from January to February,2020 and 55 recovery COVID-19 patients at the Second Peoples Hospital of Changde City from February,2020 to February,2021 were recruited in this study.Longitudinal plasma samples were collected.A virus-specific ADCC assay was performed to study the COVID-19 plasma samples.The correlations between ADCC and total IgG titer,including anti-RBD,anti-N,and neutralizing antibody titer were analyzed.Results:A high level of ADCC with 0.86%of IFN-g+CD107a+NK cells induced by anti RBD antibodies and with 0.54%of IFN-g+CD107a+NK cells induced by anti N antibodies was observed.This activity peaked at 3 weeks after disease onset with 1.16%and 0.63%of IFN-g+CD107a+NK cells induced by anti RBD and anti N antibodies respectively,declined to 0.32%and 0.32%of IFN-g+CD107a+NK cells respectively after more than 2 months,and persisted for 12 months after disease onset.The ADCC did not aggravate the severity of COVID-19 in terms of sequential organ failure assessment,although ADCC decreased with the age of COVID-19 patients.Interestingly,ADCC response is not correlated with neutralizing antibody titer or total IgG titers against S protein RBD and N protein in acute patients.ADCC in recovered patients showed a significant correlation with anti RBD IgG titer(R2=0.33,P<0.001).Conclusion:Antibodies from COVID-19 patients against the N protein and S protein RBD domains could stimulate high levels of ADCC response.Our results provide evidence that vaccination should not only focus on neutralizing antibodies but also binding antibodies that may facilitate the antiviral function of ADCC,especially in the elderly.

A systematic in vitro investigation on poly-arginine modified nanostructured lipid carrier: Pharmaceutical characteristics, cellular uptake, mechanisms and cytotoxicity

The aim of the present study was to develop a poly-arginine modified nanostructured lipid carrier(R-NLC) by fusion-emulsification method and to test its pharmaceutical characteristics. The influence of R-NLC on A549 cells like cellular uptake and cytotoxicity was also appraised using unmodified NLC as the controlled group. As the results revealed, R-NLC had an average diameter of about 40 nm and a positive zeta potential of about +17 mv, the entrapment efficiency decreased apparently, and no significant difference on the in vitro drug release was found after R8-modification. The cellular uptake and cytotoxicity increased obviously compared with unmodified NLC. The cellular uptake mechanisms of R-NLC involved energy, macropinocytosis, clathrin-mediated endocytosis, and caveolin-mediated endocytosis. The outcomes of the present study strongly support the theory that cell penetrating peptides have the ability of enhancing the cellular uptake of nanocarriers.

Cellular antioxidant activity and cytotoxicity assay of canolol

To better understand canolol as an efficient intracellular antioxidant agent in food related fields, potential cellular antioxidant activity and cytotoxicity were evaluated using multiple assays, including cellular antioxidant activity(CAA), 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide(MTT) and methylene blue assay. CAA assay was used to identify the half maximal effective concentration of canolol and other bioactive components, such as sinapic acid, resveratrol and sesamol in oil crops. Results showed that antioxidant capacity(without PBS wash) varies between different compounds. Capacity variation followed the order: sinapic acid > canolol > resveratrol > sesamol. While with PBS wash, the order changed to sinapic acid > resveratrol > canolol > sesamol. Half maximal inhibitory concentration of canolol measured by MTT was 1887.08±1.22 μmol/L, implying that cytotoxicity of canolol was greatly lower than that of resveratrol, sesamol and sinapic acid. Methylene blue assay showed that cell viability was still up to 90% exposed to canolol at a high concentration of 4444 μmol/L. It suggested that canolol had desired antioxidant activity in organism with low cellular cytotoxicity.

A novel method to assess antibody-dependent cell-mediated cytotoxicity against influenza A virus M2 in immunized murine models

The matrix protein 2 (M2) is a preferred target for developing a universal vaccine against the influenza A virus (IAV). This study aimed to develop a method for assessing antibody-dependent cell-mediated cytotoxicity (ADCC) associated with M2-based immunization in mice. We first established a stable cell line derived from mouse lymphoma cells (YAC-1) expressing M2 of H3N2. This cell line, designated as YAC-1-M2, was generated using a second-generation lentiviral tricistronic plasmid system to transduce the M2 gene into YAC-1 cells. The ADCC effect induced by polyclonal antibodies targeting matrix protein 2 ectodomain (M2e) was demonstrated by YAC-1-M2 cell lysis by natural killer cells (NK) derived from mice, in the presence of anti-M2 antibodies obtained from mice immunized with an mRNA vaccine based on M2e. This ADCC effect was found to be stronger compared to the effect induced by monoclonal antibodies (14C2) against M2. Moreover, the ADCC effect was enhanced as the effector-to-target ratio of NK to YAC-1-M2 cells increased. In conclusion, we established a novel method to detect ADCC of M2 of IAV, which paves the way for the development of an M2-based universal vaccine against IAV and an in-depth analysis of its mechanism of broad-spectrum immune protection in mice.

Cytotoxicity and cellular imaging of quantum dots protected by polyelectrolyte

The nanocomposites of poly-diallyldimethylammonium chloride (PDADMAC) and CdTe quantum dots (QDs) (i.e. QDs-PDADMAC nanocomposites) have been prepared based on electrostatic interaction and their fluorescence stability in aqueous solution has been investigated. MTT method (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide method) was used to study their cytotoxicity and A549 lung cancer cell as a model cell was also used to evaluate their cellular imaging. It was shown that the fluorescence stability of QDsPDADMAC nanocomposites was much better than that of bare QDs both in aqueous solution and cell. Meanwhile, QDs-PDADMAC nanocomposites display very low cytotoxicity in the low concentrations and better staining ability compared with QDs. QDs-PDADMAC nanocomposites will have great advantage on the cell analysis detection and imaging.

Anti-PD-L1 antibody enhances curative effect of cryoablation via antibody-dependent cell-mediated cytotoxicity mediating PD-L1^(high)CD11b^(+)cells elimination in hepatocellular carcinoma

Cryoablation(CRA)and microwave ablation(MWA)are two main local treatments for hepatocellular carcinoma(HCC).However,which one is more curative and suitable for combining with immunotherapy is still controversial.Herein,CRA induced higher tumoral PD-L1 expression and more T cells infiltration,but less PD-L1^(high)CD11b^(+)myeloid cells infiltration than MWA in HCC.Furthermore,CRA had better curative effect than MWA for anti-PD-L1 combination therapy in mouse models.Mechanistically,anti-PD-L1 antibody facilitated infiltration of CD8^(+)T cells by enhancing the secretion of CXCL9 from cDC1 cells after CRA therapy.On the other hand,anti-PD-L1 antibody promoted the infiltration of NK cells to eliminate PD-L1^(high)CD11b^(+)myeloid cells by antibody-dependent cell-mediated cytotoxicity(ADCC)effect after CRA therapy.Both aspects relieved the immunosuppressive microenvironment after CRA therapy.Notably,the wild-type PD-L1 Avelumab(Bavencio),compared to the mutant PD-L1 atezolizumab(Tecentriq),was better at inducing the ADCC effect to target PD-L1^(high)CD11b^(+)myeloid cells.Collectively,our study uncovered the novel insights that CRA showed superior curative effect than MWA in combining with anti-PD-L1 antibody by strengthening CTL/NK cell immune responses,which provided a strong rationale for combining CRA and PD-L1 blockade in the clinical treatment for HCC.

Evaluation of antibody-dependent cell-mediatedcy totoxicity activity and cetuximab response in KRAS wildtype metastatic colorectal cancer patients

AIM:To investigate the prognostic role of invariant natural killer T(iNKT) cells and antibody-dependent cell-mediated cytotoxicity(ADCC) in wild type KRAS metastatic colorectal cancer(mC RC) patients treated with cetuximab.METHODS: Forty-one KRAS wt mC RC patients,treated with cetuximab and irinotecan-based chemotherapy in Ⅱ and Ⅲ lines were analyzed. Genotyping of single nucleotide polymorphism(SNP)s in the FCGR2A,FCGR3A and in the 3' untranslated regions of KRAS and mutational analysis for KRAS,BRAF and NRAS genes was determined either by sequencing or allelic discrimination assays. Enriched NK cells were obtained from lymphoprepperipheral blood mononuclear cell and iN KT cells were defined by co-expression of CD3,TCRVα24,TCRVβ11. ADCC was evaluated as ex vivo NK-dependent activity,measuring lactate dehydrogenase release.RESULTS: At basal,mCRC patients performing ADCC activity above the median level(71%) showed an improved overall survival(OS) compared to patients with ADCC below(median 16 vs 8 mo;P=0.026). We did not find any significant correlation of iN KT cells with OS(P=0.19),albeit we observed a trend to a longer survival after 10 mo in patients with iN KT above median basal level(0.382 cells/microliter). Correlation of OS and progression-free survival(PFS) with interesting SNPs involved in ADCC ability revealed not to be significant. Patients carrying alleles both with A in FCGR2 A and TT in FCGR3A presented a trend of longer PFS(median 9 vs 5 mo;P=0.064). Chemotherapy impacted both iN KT cells and ADCC activity. Their prognostic values get lost when we analysed them after 2 and 4 mo of treatment.CONCLUSION: Our results suggest a link between iN KT cells,basal ADCC activity,genotypes in FCGR2A and FCGR3A,and efficacy of cetuximab in KRAS wt mC RC patients.

雷帕霉素对γδT细胞体外增殖和细胞毒活性的影响

目的探讨雷帕霉素与Torin2对人γδT细胞体外培养增殖和细胞毒活性的影响及相关机制。方法选择10例健康志愿者,其中男性5例,女性5例;平均年龄68.0岁(标准差4.7岁)。选择人慢性淋巴细胞白血病(CLL)肿瘤细胞株MEC-1。从志愿者外周静脉血获得外周血单个核细胞(PBMC),经处理获得γδT细胞。体外增殖培养的人γδT细胞在第10天观察细胞形态特征,流式细胞术检测人γδT细胞百分率。γδT细胞分别用100 nmol/L雷帕霉素(雷帕霉素组)和Troin2处理(Troin2组),同时用RPMI 1640培养液作为空白对照(对照组),分别培养24、48 h,计算活细胞数。采用不同效靶比(1∶1、3∶1、9∶1、18∶1、36∶1),乳酸脱氢酶(LDH)释放法检测人γδT细胞对MEC-1细胞的杀伤作用。流式细胞术检测各组白细胞介素(IL)-17的表达。Western blot检测磷脂酰肌醇3-激酶(PI3K)、丝苏氨酸激酶(AKT)、磷酸化AKT(p-AKT)、哺乳动物雷帕霉素靶蛋白(mTOR)、磷酸化mTOR(p-mTOR)、起始因子4E结合蛋白1(4EBP-1)的表达。结果扩增前人γδT细胞百分含量为4.70%±1.17%,经10 d扩增且纯化后γδT细胞百分含量为94.20%±2.18%。雷帕霉素组24 h扩增倍数为1.45±0.20,48 h扩增倍数为2.71±0.06,与对照组间差异无统计学意义(P>0.05);Torin2组24 h扩增倍数为1.14±0.05,48 h扩增倍数为2.09±0.06,均显著低于雷帕霉素组及对照组(P<0.05)。雷帕霉素组γδT细胞的杀伤活性分别为0.05%±0.01%(1∶1)、10.84%±0.88%(3∶1)、23.02%±0.65%(9∶1)、50.74%±2.96%(18∶1)、77.75%±0.55%(36∶1),均显著高于对照组(P<0.05);Torin2组γδT细胞的杀伤活性分别为0.06%±0.01%(1∶1)、4.06%±0.84%(3∶1)、10.72%±2.97%(9∶1)、18.20%±2.83%(18∶1)、36.18%±2.19%(36∶1),均低于雷帕霉素组及对照组(P<0.05)。雷帕霉素组IL-17表达为(32.7±1.7)%,Troin2组IL-17表达为(12.2±1.4)%,均显著低于对照组(73.1±2.7)%(均P<0.05)。且Troin2组抑制γδT分泌IL-17程度更明显,差异有统计学意义(P<0.05)。Western blot结果显示,与对照组相比,雷帕霉素组、Troin2组mTOR表达水平均下降,差异有统计学意义(t_(雷帕霉素组)=14.23,P<0.05;t_(Troin2组)=11.67,P<0.05);雷帕霉素组、Troin2组p-mTOR表达水平均下降,差异有统计学意义(t_(雷帕霉素组)=16.78,P<0.05;t_(Troin2组)=25.31,P<0.05);雷帕霉素组PI3K表达提高,差异有统计学意义(t=18.77,P<0.05);AKT表达提高,差异有统计学意义(t=22.21,P<0.05);pAKT表达提高,差异有统计学意义(t=19.33,P<0.05);4EBP-1表达提高,差异有统计学意义(t=14.37,P<0.05)。结论雷帕霉素能在不影响体外人γδT细胞增殖的基础上,增强人γδT细胞对MEC-1细胞的肿瘤杀伤活性并抑制其IL-17的水平,其机制可能与mTOR C1/C2位点之间的负反馈机制相关。

Recent progress and future directions of the research on nanoplastic-induced neurotoxicity

Many types of plastic products,including polystyrene,have long been used in commercial and industrial applications.Microplastics and nanoplastics,plastic particles derived from these plastic products,are emerging as environmental pollutants that can pose health risks to a wide variety of living organisms,including humans.However,it is not well understood how microplastics and nanoplastics affect cellular functions and induce stress responses.Humans can be exposed to polystyrene-microplastics and polystyrene-nanoplastics through ingestion,inhalation,or skin contact.Most ingested plastics are excreted from the body,but inhaled plastics may accumulate in the lungs and can even reach the brain via the nose-to-brain route.Small-sized polystyrene-nanoplastics can enter cells by endocytosis,accumulate in the cytoplasm,and cause various cellular stresses,such as inflammation with increased pro-inflammatory cytokine production,oxidative stress with generation of reactive oxygen species,and mitochondrial dysfunction.They induce autophagy activation and autophagosome formation,but autophagic flux may be impaired due to lysosomal dysfunction.Unless permanently exposed to polystyrene-nanoplastics,they can be removed from cells by exocytosis and subsequently restore cellular function.However,neurons are very susceptible to this type of stress,thus even acute exposure can lead to neurodegeneration without recovery.This review focuses specifically on recent advances in research on polystyrene-nanoplastic-induced cytotoxicity and neurotoxicity.Furthermore,in this review,based on mechanistic studies of polystyrene-nanoplastics at the cellular level other than neurons,future directions for overcoming the negative effects of polystyrene-nanoplastics on neurons were suggested.

利妥昔单抗对多发性硬化症复发期患者外周血NK细胞 功能

目的观察利妥昔单抗对多发性硬化症(MS)复发期患者外周血NK细胞活化及ADCC功能的影响及机制。方法选取MS复发期病例(n=28),并将无自身免疫疾病及重大感染疾病的受试者作为健康对照组(n=25),提取两组被检者外周血单个核细胞(PBMCs),检测利妥昔单抗处理前后B细胞、自然杀伤细胞(NK)细胞比例及NK细胞活化水平;建立PBMCs与人慢性髓源白血病细胞系K562细胞直接接触共培养体系,检测利妥昔单抗处理后NK细胞抗体依赖细胞介导细胞毒性作用(ADCC)的效应因子释放。结果利妥昔单抗能诱导MS复发期组和健康对照组外周血中B细胞和NK细胞比例显著下调,且能诱导健康对照组的NK细胞活化及ADCC功能的显著上调,但对MS复发期患者NK细胞的活化及ADCC功无明显影响。结论利妥昔单抗可诱导MS复发期患者B细胞及NK细胞比例下调,但对NK细胞的活化及其ADCC功能无明显影响。

Characterization of cytotoxic compound from marine sediment derived actinomycete Streptomyces avidinii strain SU4

To investigate the cytotoxic activity of actinomycete isolated from marine sediment. Methods: In the present study the DNA was isolated and the ITS region of 16s rRNA was amplified by polymerase chain reaction, using two universal bacterial primers, 1492R (5′-GGTTACCTTGTTAC GACTT-3′) and Eubac27F (5′-AGAGTTTGATCCTGGCTC AG-3′). The amplified products were purified using TIANgel mini purification kit, ligated to MD18-T simple vector (TaKaRa), and transformed into competent cells of Escherichia coli DH5α. 16S rRNA gene fragment was sequenced using forward primer M13F (-47) and reverse primer M13R (-48). Blast search sequence similarity was found against the existing non-redundant nucleotide sequence database thus, identified as Streptomyces sp SU, Streptomyces rubralavandulae strain SU1, Streptomyces cacaoi strain SU2, Streptomyces cavourensis strain SU3, Streptomyces avidinii strain SU4, Streptomyces globisporus strain SU5, Streptomyces variabilis strain SU6, Streptomycescoelicolor strain SU 7. Among the eight identified isolates, one actinomycete Streptomyces avidinii strain SU4 was selected for further study. Results: Crude extract of the actinomycete isolate exhibited IC50 in 64.5 μg against Hep-2 cell line, 250 μg in VERO cell line. This value is very close to the criteria of cytotoxicity activity for the crude extracts, as established by the American National Cancer Institute (NCI) is in IC50 < 30 μg /mL. The GC MS analysis showed that the active principle might be 1,2-benzenedicarboxylic acid, bis(2-methylpropyl) ester (12.17%), isooctyl phthalate (15.29%) with the retention time 15.642 and 21.612, respectively. Conclusions: This study clearly proves that the marine sediment derived actinomycetes with bioactive metabolites can be expected to provide high quality biological material for high throughout biochemical and anticancer screening programs. These results help us to conclude that the potential of using metabolic engineering and post genomic approaches to isolate more bioactive compounds and make their possible commercial application is not far off.

Abnormalities of Cellular Immunoregulation in Patients with Epidemic Hemorrhagic Fever

In this report,a comparative study is made of the function test of spontaneousT suppressor cell（STs）and T Lymphocyte subsets in patients with epidemic hemorrha-gic fever（EHF）.It was found that in the early stages of the disease the activity of STs wasmarkedly lower than that of the controls,while the percentage of CD?+ cells increasedsignificantly,which led to the decrease and reciprocation of CD4/CD8 ratio,and that theactivity of STs was reversely related to the proportion of CD8+ cells on linear regressionanalysis,indicating that the CD8+ cells increased may mainly belong to cytotoxic T cells.It was also shown that the changes of STs function and CD4/CD8 ratio were related tothe abnormalities of serum C3 content and circulating immune complex.The results sug-gest that the disturbance of host cellular immunoregulation may play an important rolein the pathogenesis of EHF.

The Effect of Tremella Fuciformis Spores Polysaccharides (TSP) on Immune Cellular Function of Mice in Vitro

TSP could markedly enhance the proliferative response of the murine splenocyte to LPS and induce the mitogenesis of the spleen cells.Furthermore,it was able to augment the activity of natural killer cell and ADGG;at a dosage of 25-250μg/ml,the ability of splenocytes to produce IL-2 induced by onA had been improved; at the concentration of 250μg／ml or more,TSP could inhibit the proliferative response of the murine lymphocyte to GonA and the ~3-HTdR spontaneous incorporation rate of thymocytes,and the inhibitory action ran in paralell with the increase in concentration of TSP.

Cytotoxic T-cells as imaging probes for detecting glioma

Tumor vaccination using tumor-associated antigenprimed dendritic cells(DCs)is in clinical trials.Investigators are using patients’own immune systems to activate T-cells against recurrent or metastatic tumors.Following vaccination of DCs or attenuated tumor cells,clinical as well as radiological improvements have been noted due to migration and accumulation of cytotoxic T-cells(CTLs).CTLs mediated tumor cell killing resulted in extended survival in clinical trails and in preclinical models.Besides administration of primed DCs or attenuated or killed tumors cells to initiate the generation of CTLs,investigators have started making genetically altered T-cells(CTLs)to target specific tumors and showed in vivo migration and accumulation in the implanted or recurrent tumors using different imaging modalities.Our groups have also showed the utilization of both in vivo and in vitro techniques to make CTLs against glioma and used them as imaging probes to determine the sites of tumors.In this short review,the current status of vaccination therapy against glioma and utilization of CTLs as in vivo imaging probes to determine the sites of tumors and differentiate recurrent glioma from radiation necrosis will be discussed.

壳聚糖基因纳米粒子的细胞摄入和体外毒性研究

用分子量为50kDa和400kDa的壳聚糖分别和[α-32P]dATP标记的质粒DNA,在不同的N/P比下,通过复凝聚方法形成基因纳米粒子。对形成的壳聚糖基因纳米粒子(Chitosan gene nanoparticle,CGN)进行表征,评价CGN体外细胞毒性,研究两种壳聚糖形成的基因纳米粒子被A10和K562细胞摄入的量和速度。结果表明:(1)随着壳聚糖分子量和N/P比的增大,形成的基因纳米粒子更易于进入细胞,同时显示纳米粒子的zeta电位与细胞摄入量之间存在关联性;(2)壳聚糖基因纳米粒子的毒性远远小于商品化的细胞转染试剂Lipofectamine2000。

不同感染量REV对鸡免疫反应和细胞毒性作用的影响

用不同剂量网状内皮增生症病毒(REV)感染肉鸡和SPF鸡后,检测血液中T淋巴细胞对ConA的反应和NK细胞、细胞毒T细胞(CTL)的细胞毒性作用以及NDV抗体生成变化等,观察REV感染对机体非特异性、特异性细胞免疫反应和体液免疫反应的影响。结果表明无论高剂量还是低剂量REV感染均造成体液免疫和非特异性细胞免疫抑制,而且高剂量比低剂量对免疫功能的抑制作用更强,但对NK细胞和细胞毒T细胞的细胞杀伤活性却有升高趋势,在抗肿瘤方面发挥一定的作用。这种结果说明REV感染对机体的免疫抑制是有选择性的,且抑制程度与感染病毒量有关。

壳聚糖修饰对细胞摄入和细胞毒性的影响

目的 研究精氨酸或十六烷基修饰壳聚糖对其细胞摄入和细胞毒性的影响及作用机制。方法 用α-^32P-dATP标记质粒DNA，分别与十六烷基化壳聚糖和精氨酸修饰的壳聚糖通过复凝聚方法形成壳聚糖DNA纳米复合物。采用血管平滑肌A10细胞进行摄入测试，并用β液闪计数仪检测结果。用MTT方法对壳聚糖DNA纳米复合物的细胞毒性进行评价。结果 经^32P标记的DNA与不同修饰的壳聚糖复合所形成的纳米复合物粒径约为55．9—174．9nm，zeta电位约为1．8—10．8mV。细胞摄入实验显示通过精氨酸或十六烷基修饰的壳聚糖与DNA形成的纳米复合物更易于进入细胞。其中十六烷基化壳聚糖DNA纳米复合物（HCNC）在N／P为1：1时细胞摄入量最高，精氨酸修饰的壳聚糖DNA纳米复合物（ACNC）细胞摄人次之，与未经修饰的壳聚糖DNA纳米复合物（UCNC）相比，差异具有显著性（HCNC、ACNC比UCNC高1．3倍，P〈0．05）。细胞毒性实验显示，修饰后的壳聚糖纳米复合物的毒性远远小于商品化的细胞转染试剂Lipofectamine2000。结论 两种修饰对壳聚糖DNA纳米复合物的血管平滑肌细胞摄入有明显促进作用，其作用机制各不相同；同时其细胞毒性远小于商品化的细胞转染试剂Lipofeetamine2000。

恶性实体瘤患者外周血细胞因子诱导的杀伤细胞增殖与杀瘤活性

目的探讨恶性实体瘤患者外周血来源的细胞因子诱导的杀伤细胞的增殖能力、免疫表型及杀瘤活性。方法用rhIFN-γ,rhIL-2,Anti-CD3mAb与恶性实体瘤患者外周血单个核细胞共孵育。分别在培养第4、7、10、13天进行细胞计数,通过流式细胞术检测细胞免疫表型及MTT法检测对K562细胞的杀伤活性。结果恶性实体瘤患者外周血单个核细胞与rhIFN-γ,rhIL-2,Anti-CD3mAb孵育4、7、10、13d,细胞数分别增加(2.5±1.6)、(11.9±3.5)、(22.3±7.8)和(29.5±6.1)倍。CD3+、CD4+、CD8+和CD3+CD16+CD56+细胞在培养第13天分别从(62.8±7.6)%、(31.5±5.8)%、(44.9±8.2)%和(1.3±1.1)%增加到(89.3±9.5)%、(50.1±7.2)%、(57±9.0)%和(37.0±12.7)%。对K562细胞的杀伤效应在第4、7、13天分别为(23.6±8.5)%、(56.4±7.2)%和(80.1±4.5)%。结论rhIFN-γ,rhIL-2和Anti-CD3mAb诱导恶性实体瘤患者外周血单个核细胞活化为以CD3+CD16+CD56+为主的细胞因子诱导的杀伤细胞,细胞增殖力强,并对K562细胞有强大的杀伤活性。

重组鸡白细胞介素18(rChIL-18)对MDV感染SPF鸡细胞免疫的影响

用马立克氏病病毒(MDV)感染5日龄SPF鸡后,取21日龄和35日龄鸡的淋巴细胞,运用3H-TdR掺入法检测T淋巴细胞对ConA和重组鸡白细胞介素18(rChIL-18)的反应,并用MTT法检测NK细胞和CTL对MD肿瘤细胞系CU147的杀伤活性及rChIL-18和IFN-γ对它们的作用。结果显示,SPF鸡感染MDV后淋转水平显著下降,NK细胞、CTL杀伤活性在感染后21日龄时升高,而在35日龄时NK细胞杀伤活性显著下降。rChIL-18对对照组和感染组SPF鸡的淋转水平和杀伤活性均有提高作用,同样IFN-γ也具有提高NK细胞和CTL杀伤活性的作用。

定位表达的新城疫病毒HN蛋白对荷瘤小鼠的抗肿瘤免疫作用

背景与目的新城疫病毒HN蛋白是新城疫病毒产生溶瘤作用的重要免疫原。在前期体外实验基础上,比较定位表达细胞不同部位的HN蛋白体内抗肿瘤免疫作用。方法通过构建荷瘤小鼠,瘤内注射定位表达于细胞不同部位的新城疫病毒HN蛋白,即胞浆型(Cy-HN)、跨膜型(M-HN)、分泌型(Sc-HN)重组真核表达质粒,比较荷瘤小鼠的肿瘤生长速度,脾淋巴细胞增殖反应和细胞毒T细胞活性。结果瘤内注射跨膜型重组真核表达质粒的荷瘤小鼠肿瘤生长缓慢,与瘤内注射胞浆型和分泌型重组真核表达质粒的荷瘤小鼠相比有统计学差异(第18天:P=0.022;第21天:P<0.01),同时,该组荷瘤小鼠的淋巴细胞增殖反应和细胞毒T细胞活性也较高[M-HNvsCy-HN,P=0.019;M-HNvsSc-HN,P=0.043;M-HNvspcDNA3.1(+),P<0.01]。结论定位表达于细胞不同部位的HN蛋白体内抗肿瘤免疫作用存在差异,跨膜型HN蛋白的重组DNA质粒能够提高荷瘤小鼠的特异性细胞免疫应答。