Anti-Proliferative Effects Induced by Anti-CD4 Human/Murine Chimeric Antibody and Murine Anti-CD4 Monoclonal Antibody

Summary: The effects of chimeric anti CD4 human/murine chimeric antibody and murine anti CD4 monoclonal antibody (McAb) on the proliferation induced by anti CD3 McAb, phytohemagglutinin (PHA), IL 2, and allogeneic cells were studied. The results showed that chimeric anti CD4 antibody and murine anti CD4 McAb could inhibit the proliferation induced by the above inducers and the inhibitory effects were related to the dosage of the antibodies.

Novel monoclonal antibody against beta 1 integrin enhances cisplatin efficacy in human lung adenocarcinoma cells

The use of anti-beta 1 integrin monoclonal antibody in lung cancer treatment has proven beneficial. Here, we developed a novel monoclonal antibody （mAb）, called P5, by immunizing mice with human peripheral blood mononuclear cells （PBMC）. Its anti-tumor effect is now being tested, in a clinical phase Ⅲ trial, in combinato- rial treatments with various chemical drugs. To confirm that P5 indeed binds to beta 1 integrin, cell lysates were immunoprecipitated with commercial anti-beta 1 integrin mAb （TS2/16） and immunoblotted against P5 to reveal a 140 kDa molecular weight band, as expected. Immunoprecipitation with P5 followed by LC/MS protein sequence analysis further verified P5 antigen to be beta 1 integrin. Cisplatin treatment upregulated cell surface expression of beta 1 integrin in A549 cells, while causing inhibition of cell growth. When cells were co-treated with different concentrations of P5 mAb, the cisplatin-mediated inhibitory effect was enhanced in a dose-dependent manner. Our findings show that a combinatorial treatment of P5 mAb and cisplatin in A549 cells resulted in a 30% increase in apoptosis, compared to baseline, and significantly more when compared to either the cisplatin or P5 alone group. The entire peptide sequences in CDR from variable region of Ig heavy and light chain gene for P5 mAb are also disclosed. Together, these results provide evidence of the beneficial effect of P5 mAb in combinatorial treatment of human lung adenocarcinoma.

Identification of A Monoclonal Antibody against Chicken CD8 Alpha Chain

[ Objective] The aim of the study was to obtain monoclonal antibody against chicken CD8 molecule. [ Method] A fragment of chicken CD8 a/pha gene was amplified by PCR with a pair of designed primers. Then two recombinant plasmids containing the amplified fragment were constructed. After prokaryotic expression and purification, the obtained recombinant protein was used to immunize Balb/c mice. Finally, the spleen cells were fused with myeloma cells （SP2/0）, and antibody titer of culture supematant was detected by ELISA. [ Result] A 510-bp gene fragment was amplified by PCR. The recombinant plasmid pET-32a-CD8 alpha was transformed into E. coli, and 39 kDa His-CD8 alpha fusion protein was induced to expression. After subcloning, the culture supernetant was detected by ELISA. A hybridoma cell strain, which could stably excrete antibody against CD8 alpha protein, was obtained and named Cll. The ELISA titer of cell supematant was higher than 1 ： 640. [ Conclusion] A hybridoma cell strain has been established using the CD8 alpha expressed in prokaryoUc system as immunogen.

Analysis of Specific Th1/Th2 Helper Cell Responses and IgG Subtype Antibodies in Anti-CD4 Monoclonal Antibody Treated Mice with Autoimmune Cardiomyopathy

The cytokine repertoire of ADP/ATP carrier-specific humoral immune responses and the cytokine-dependent anti-ADP/ATP carrier antibody IgG subclasses were examined in a cohort of ADP/ATP carrier-immunized BALB/c mice treated with anti-CD4 monoclonal antibody. Eighteen male BALB/c mice （6–8 weeks old） were randomized into 3 groups： dilated cardiomyopathy （DCM） group, DCM-tolerance （Tol） group and control group. The mice in DCM group were immunized with the peptides derived from human ADP/ATP carrier protein for 6 months and mice in the control group were sham-immunized, while the mice in DCM-Tol group were immunized with ADP/ATP carrier protein and anti-CD4 McAb simultaneously. Serum autoantibody against ADP/ATP carrier and IgG subclasses were measured by ELISA, intracellular cytokines IFN-γ and IL-4 of Th cells were moni- tored with flow cytometry, and splenic T cell cytokines IFN-γ, IL-2, IL-4 and IL-6 were detected by using real-time fluorescent quantitative PCR. The results showed that the autoantibody against ADP/ATP carrier was found in all mice in DCM group, and the antibody level, serum IgG1 and IgG2a subclasses, cytokines in T cells and Th cells were all elevated in DCM group, as compared with those in control group （P〈0.01）. On the other hand, in DCM-Tol group, the autoantibody level and contents of all the cytokines were significantly different from those in DCM group （P〈0.01）, and were close to those in control group. And the levels of IgG1, IgG2a, IgG2b and IgG3 were influenced, to varying degrees, by anti-CD4 McAb as compared with those in DCM group. All these four types of IgG subclasses were substantially decreased in DCM-Tol group as compared with DCM group. It is concluded that the treatment with anti-CD4 McAb could prevent the activation of T cells, reverse the abnormal secretion of cytokines and the imbalance between Th1/Th2 cell subsets and abnormal production of autoantibody against ADP/ATP carrier, and eventually avoid myocardial injuries.

A multi-center,open-label,randomized,parallel-controlled phase II study comparing pharmacokinetic,pharmacodynamics and safety of ripertamab(SCT400)to rituximab(Mab Thera?)in patients with CD20-positive B-cell non-Hodgkin lymphoma

Objective:This multi-center,open-label,randomized,parallel-controlled phaseⅡstudy aimed to compare the pharmacokinetics(PK),pharmacodynamics(PD)and safety profile of ripertamab(SCT400),a recombinant antiCD20 monoclonal antibody,to rituximab(MabThera^(■))in patients with CD20-positive B-cell non-Hodgkin lymphoma(NHL).Methods:Patients with CD20-positive B-cell NHL who achieved complete remission or unconfirmed complete remission after standard treatment were randomly assigned at a 1:1 ratio to receive a single dose of ripertamab(375mg/m^(2))or rituximab(MabThera^(■),375 mg/m^(2)).PK was evaluated using area under the concentration-time curve(AUC)from time 0 to d 85(AUC_(0-85d)),AUC from time 0 to week 1(AUC0-1 w),AUC from time 0 to week 2(AUC_(0-2 w)),AUC from time 0 to week 3(AUC_(0-3 w)),AUC from time 0 to week 8(AUC_(0-8 w)),maximum serum concentration(C_(max)),terminal half-life(T_(1/2)),time to maximum serum concentration(T_(max))and clearance(CL).Bioequivalence was confirmed if the 90%confidence interval(90%CI)of the geometric mean ratio of ripertamab/rituximab was within the pre-defined bioequivalence range of 80.0%-125.0%.PD,immunogenicity,and safety were also evaluated.Results:From December 30,2014 to November 24,2015,a total of 84 patients were randomized(ripertamab,n=42;rituximab,n=42)and the PK analysis was performed on 76 patients(ripertamab,n=38;rituximab,n=38).The geometric mean ratios of ripertamab/rituximab for AUC_(0-85d),ATC_(0-inf),and Cmaxwere 96.1%(90%CI:87.6%-105.5%),95.9%(90%CI:86.5%-106.4%)and 97.4%(90%CI:91.6%-103.6%),respectively.All PK parameters met the pre-defined bioequivalence range of 80.0%-125.0%.For PD and safety evaluation,there was no statistical difference in peripheral CD 19-positive B-cell counts and CD20-positive B-cell counts at each visit,and no difference in the incidence of anti-drug antibodies was observed between the two groups.The incidences of treatment-emergent adverse events and treatment-related adverse events were also comparable between the two groups.Conclusions:In this study,the PK,PD,immunogenicity,and safety profile of ripertamab(SCT400)were similar to rituximab(MabThera^(■))in Chinese patients with CD20-positive B-cell NHL.

The Effect of CD3-Specific Monoclonal Antibody on Treating Experimental Autoimmune Myasthenia Gravis

CD3-specific monoclonal antibody was the first one used for clinical practice in field of transplantation. Recently, renewed interests have elicited in its capacity to prevent autoimmune diabetes by inducing immune tolerance. In this study, we tested whether this antibody can also be used to treat another kind of autoimmune disease myasthenia gravis （MG） and explored the possible mechanisms. MG is caused by an autoimmune damage mediated by antibody- and complement-mediated destruction of AChR at the neuromuscular junction. We found that administration of CD3-specific antibody （Fab）2 to an animal model with experimental autoimmune myasthenia gravis （EAMG） （B6 mice received 3 times of AChR/CFA immunization） could not significantly improve the clinical signs and clinical score. When the possible mechanisms were tested, we found that CD3 antibody treatment slightly down-regulated the T-cell response to AChR, modestly up-regulation the muscle strength. And no significant difference in the titers of IgG2b was found between CD3 antibody treated and control groups. These data indicated that CD3-specific antibody was not suitable for treating MG, an antibody- and complementmediated autoimmune disease, after this disease has been established. The role of CD3-specific antibody in treating this kind of disease remains to be determined. Cellular ＆ Molecular Immunology. 2005;2（6）：461-465.

A Novel Anti-Human Syndecan-1 (CD138) Monoclonal Antibody 4B3: Characterization and Application

Syndecan-1 （CD138）, a member of integral membrane heparin sulfate proteoglycans, is an essential matrix receptor for maintaining the normal morphological phenotypes. In this study, we generated a specific mouse anti-human syndecan-1 monoclonal antibody （mAb） 4B3 and identified it by competition assay with the available syndecan-1 mAb （BB4）. Stained by 4B3, the expression of syndecan-1 was detected on tumor cell lines, such as 8226, U266, XG-1, XG-2, Daudi and Jurkat. The expression was also found on neuron stem cells. It was established that 4B3 mAb could inhibit XG-1 and XG-2 proliferation. The data not only determined that 4B3 mAb was a functional anti-human syndecan-1 mAb, but also indicated that syndecan-1 might be a valuable surface antigen and play an important role in regulation of tumor pathology and differentiation of neural stem cells. This novel antibody 4B3 may be value of study of tumor proliferation/survival mechanism and contributes to diagnosis and treatment of diverse diseases. Cellular ＆ Molecular Immunology.

Anti-CD 20 monoclonal antibodies and associated viral hepatitis in hematological diseases

Over the past decade, the administration of anti-CD20 monoclonal antibodies such as rituximab has demonstrated various degrees of effectiveness and has improved patients' outcomes during the treatment of autoimmune hematological disorders and hematological malignancies. However, the depletion of B-cells, the distribution of T-cell populations, and the reconstruction of host immunity resulting from the use of anti-CD20 monoclonal antibodies potentially lead to severe viral infections, such as hepatitis B virus(HBV), hepatitis C virus(HCV), parvovirus B19, and herpes viruses, in patients who are undergoing immune therapy or immunochemotherapy. Of these infections, HBV- and HCV-related hepatitis are a great concern in endemic areas because of the high morbidity and mortality rates in untreated patients. As a result, prophylaxis against HBV infection is becoming a standard of care in these areas. Parvovirus B19, a widespread pathogen that causes red blood cell aplasia in immunocompromised hosts, also causes hepatitis in healthy individuals. Recently, its association with hepatitis was recognized in a patient treated with rituximab. In addition, adenovirus, varicella-zoster virus hepatitis E virus, and rituximab itself have been linked to the occurrence of hepatitis during or after rituximab treatments. The epidemiologies and pathogeneses of these etiologies remain unknown. Because of the increasing use of anti-CD20 monoclonal antibodies for the treatment of hematological malignancies or autoimmune hematological disorders, it is imperative that physicians understand and balance the risks of hepatotropic virusassociated hepatitis against the benefits of using antiCD20 monoclonal antibodies.

Production and characterization of monoclonal antibodies against grass carp CD4-1 and CD4-2

CD4 T helper cells are an important group of cells in the immune system of vertebrates and express CD4 receptor on the cell surface.In mammals,the CD4 receptor is encoded by a single copy gene,whilst in fish,two copies of cd4 genes,namely cd4-1 and cd4-2,are found.In this study,the ectodomains of grass carp(Ctenopharyngodon idella,Ci)CD4-1 and CD4-2 were expressed in the E.coli cells and used to generate monoclonal antibodies in mice.Western blotting,confocal microscopy and flow cytometry were performed to characterize the monoclonal antibodies.It has been shown that the CiCD4-1 and CiCD4-2 monoclonal antibodies had good specificity to react with the recombinant ectodomains of CiCD4-1 and CiCD4-2 expressed in the CHO-S cells and the native CD4 molecules of grass carp.The CiCD4-1 monoclonal antibody did not recognize CiCD4-2 and verse versa.In addition,the CD4-1 and CD4-2 monoclonal antibodies specifically recognized the CD4-1 and CD4-2 receptors expressed in the HEK293 cells and native molecules of fish cells.Further,the percentages of lymphocytes in immune tissues of healthy fish were analyzed by flow cytometry.It was found that 17.6%of lymphocytes were CD4-1^(+)cells and 22.5%were CD4-2^(+)in the head kidney.In the spleen,13.1%of lymphocytes were CD4-1^(+)and 18.6%were CD4-2^(+)while 7.3%of blood lymphocytes were CD4-1^(+)cells and 8.8%were CD4-2^(+)cells.The availability of the CD4-1 and CD4-2 monoclonal antibodies provides antibody-based tools for further elucidation of the functions of CD4 T cells in grass carp.

Clinical significance of the loss of CD20 antigen on tumor cells in patients with relapsed or refractory follicular lymphoma

Aim:Anti-CD20 monoclonal antibody is a cornerstone therapy for follicular lymphoma.Following anti-CD20 therapy,a potential decrease in CD20 antigen,and therefore a loss of the tumor target might be expected.However,the incidence and clinical significance of CD20 loss on tumor cells in patients with relapsed or refractory follicular lymphoma are unknown.This study aims to investigate the incidence and outcome of patients with relapsed or refractory follicular lymphoma patients harboring the loss of the tumor target,CD20.Methods:All consecutive adult patients with relapsed or refractory follicular lymphoma referred to the Early Drug Department at Gustave Roussy were included.The main objectives were to assess the incidence and prognosis of the loss in expression of CD20 antigen on the surface of tumor cells on patient outcome.Results:Over the study period 2013-2018,131 patients were screened for clinical trials with B-cell malignancies in the early drug department of Gustave Roussy in France.Forty-four patients presented with relapsed or refractory follicular lymphoma and 32 had tumor biopsies at the time of relapse that were retained for analysis.The median(range)age was 67.5 years(55.3-75.3)and the median number of prior anti-cancer systemic therapies was 3(2-4).At the time of relapse,CD20 expression was positive in 84%of tumors(n=27)and negative in 16%of tumors(n=5).At a median follow-up of 18.3(0.6-83.3)months,CD20 negativity was associated with a poorer prognosis with a median overall survival of 8.9 months(95%CI:2.4-19.1)in comparison to CD20 positive patients(28.3 months,95%CI:25.1-75.3 months,P=0.019).Conclusion:The loss of the tumor target antigen,CD20,occurred in 16%of patients with relapse or refractory follicular lymphoma.Due to confounding factors in patients who received anti-CD20 immunotherapy,it was not possible to formally establish the prognostic significance of CD20 negativity.However,we suggest that a check for CD20 antigen positivity nevertheless be performed to adapt subsequent therapies for patients with relapsed or refractory follicular lymphoma.

CD20F(ab′)_2抗体的发酵与纯化

转化了质粒PYZcpp3的 16C9大肠杆菌可高水平地分泌表达可溶性CD2 0F(ab′) 2 抗体 ;采用经优化的培养条件 ,在发酵罐上进行高密度培养OD550 值达 14 0 ;每升湿菌菌重 2 0 0g ;抗体的产量每升为 2 4 1mg ,其中F(ab′) 2 片段达 5 0 % ,F(ab′) 2 可以特异性的识别CD2 0 + 细胞并与CD2 0相结合 ;F(ab′) 2 对Raji细胞的IC50 值为 2 2 8μg mL ;而Fab′对Raji细胞的IC50 值为 4 5 9μg mL。

抗CD20单克隆抗体在重症系统性红斑狼疮治疗中的临床价值

目的:探讨抗CD20单克隆抗体治疗重症系统性红斑狼疮(SLE)的疗效,研究其临床治疗价值。方法:将66例重症SLE患者随机分为治疗组(36例)和对照组(30例),在激素冲击疗法基础上,两组分别采用抗CD20单克隆抗体和免疫抑制剂治疗。比较治疗后两组的血沉(ESR)、C反应蛋白(CRP)、免疫球蛋白(Ig G、Ig A、Ig M)、补体(C3、C4)及自身抗体(ANA、ds-DNA)相关指标和总有效率。结果:治疗后2周,治疗组外周血B淋巴细胞数量低于对照组(t=13.167,P<0.05);治疗后12周,治疗组ESR、CRP、免疫球蛋白、ANA、ds-DNA、尿蛋白定量及SLE疾病活动指数(SLEDAI)评分均低于对照组,Ig A、Ig M及补体C4与对照组相比,差异无统计学意义(t=0.955,t=1.769,t=1.070;P>0.05),补体C3水平高于对照组,治疗组总有效率高于对照组(x2=5.390,P<0.05)。结论:CD20单克隆抗体可提高重症SLE患者的临床疗效,安全性好。

Hepatitis B virus reactivation during immunosuppressive therapy: Appropriate risk stratification

Our understanding of hepatitis B virus(HBV) reactivation during immunosuppresive therapy has increased remarkably during recent years. HBV reactivation in hepatitis B surface antigen(HBs Ag)-positive individuals has been well-described in certain immunosuppressive regimens, including therapies containing corticosteroids, anthracyclines, rituximab, antibody to tumor necrosisfactor(anti-TNF) and hematopoietic stem cell transplantation(HSCT). HBV reactivation could also occur in HBs Ag-negative, antibody to hepatitis B core antigen(anti-HBc) positive individuals during therapies containing rituximab, anti-TNF or HSCT.For HBs Ag-positive patients, prophylactic antiviral therapy is proven to the effective in preventing HBV reactivation. Recent evidence also demonstrated entecavir to be more effective than lamivudine in this aspect. For HBs Ag-negative, antiHBc positive individuals, the risk of reactivations differs with the type of immunosuppression. For rituximab, a prospective study demonstrated the 2-year cumulative risk of reactivation to be 41.5%, but prospective data is still lacking for other immunosupressive regimes. The optimal management in preventing HBV reactivation would involve appropriate risk stratification for different immunosuppressive regimes in both HBs Ag-positive and HBs Ag-negative, anti-HBc positive individuals.

Treatment strategies for nodal and gastrointestinal follicular lymphoma:Current status and future development

In recent years,therapies for follicular lymphoma (FL) have steadily improved.A series of phase Ⅲ trials comparing the effect of rituximab with chemotherapy vs chemotherapy alone in treating FL have indicated significant improvements in progression-free survival (PFS) and overall survival.Recent studies have found that prolonged response durations and PFS were obtained with maintenance therapy using rituximab or interferon after completion of first line therapy.For patients with relapsed or refractory FL,phase Ⅱ studies have assessed the effectiveness of combination therapies using a Toll-like receptor-9 agonist (1018ISS),oblimersen sodium (a Bcl-2 antisense oligonucleotide),bendamustine,and rituximab,as well as veltuzumab,a new humanized anti-CD20 antibody,and epratuzumab.In addition,the effectiveness of yttrium-90 ibritumomab tiuxetan and iodine-131 tositumomab as radioimmunotherapies has been reported.Furthermore,three phase Ⅲ studies on an idiotype vaccine are near completion.Unfortunately,these vaccines,which appeared highly effective in phase Ⅰ and Ⅱ trials,do not appear to result in prolonged PFS.This report will summarize the current knowledge on therapies for treatment of FL,and will conclude with a brief discussion of feasiblefuture options for effective treatments.Lastly,we added descriptions of the management of gastrointestinal FL,which is considered to be controversial because it is rare.

Biodistribution and Anti-tumor Activities of the ^(131)I-labeled Rituximab in Nude Mice Bearing Human Burkitt's lymphoma

OBJECTIVE To explore the biodistribution and anti-tumoractivity of ^(131)I labeled rituximab injected intratumorally orintraperitoneally in vivo in nude mice bearing Raji human Burkitt's lymphoma xenografts.METHODS The rituximab and the mouse IgG were labeled withNa^(131)I using the IODO-GEN method.BALB/C nude mice werexenografted with ^(131)I-Rituximab or ^(131)I-IgG and killed on the 1st,3rd,7th,and 15th day after injection.The tumor/non-tumor ratio(T/NT)and the dose injected in each gram of the tissue(%ID/g)from12 organs or tissues of interest,e.g.tumor,blood,were calculated.The long and short axes of each tumor were measured by calipersat 2-3-day intervals after treatment,and the growth inhibition ofthe tumor was calculated using the MIRD formula.RESULTS When comparing intraperitoneal injection(IP)andintratumoral injection(IT)of ^(131)I-IgG,intratumoral injection of^(131)I-rituximab produced a significantly higher tumor/non-tumorratio in all tissues and organs of interest on the 1st,3rd,and 7thday,respectively(P<0.05).The %ID/g of tumor was 1.4-1.7-foldand 1.5-3.7-fold in the IP and IgG IT groups,respectively,but the%ID/g of non-tumors was significantly lower in the IP group andIgG IT group.Similarly,the tumor growth was greatly inhibitedby intratumoral injection of the ^(131)I-rituximab,whereas it wasless inhibited by other forms of the treatment(P<0.05).However^(131)I-rituximab injected intratumorally inhibited tumor growth ina dose-dependent manner.The inhibition rate was less with alow dose(75μCi)and greater with a high dose(150μCi),yet thedifference was not significant(P>0.05).CONCLUSION Tumors can absorb the highest amount of theradiolabelled antibodies,and the tumor/non-tumor ratios in thegroup with intratumoral injection of the ^(131)I-rituximab resulted inthe optimal anti-tumor activity.

嵌合抗CD_(20)抗体Fab片段在大肠杆菌中表达及活性鉴定

目的 :构建抗CD2 0 嵌合抗体Fab片段表达载体 ,并在大肠杆菌中进行高效可溶性分泌表达。方法 :利用PCR方法从抗CD2 0 单链抗体 (ScFv)表达载体上扩增抗CD2 0 抗体轻链可变区基因 (VL)、重链可变区基因 (VH) ,然后将VH、VL 基因重组到Fab表达载体pYZF中 ,构建抗CD2 0 Fab表达载体pYZF1cd2 0 ,并在 2 7C7菌中高效表这。结果 :经Fab表达载体转化的 2 7C7菌株 ,进行表达培养 ,经分离纯化获得具有CD2 0 特异结合活性的Fab片段 ,竞争性免疫荧光抑制实验表明 ,表达产物Fab片段能竞争性抑制鼠源性抗CD2 0 抗体HI47和CD2 0 表达细胞Raji细胞结合。结论 :在大肠杆菌中高效可溶性分泌表达有活性的抗CD2 0 嵌合抗体Fab片段。

流式细胞术检测化疗前后卵巢癌细胞凋亡的临床意义

目的 :探讨化疗前后卵巢癌细胞及外周血淋巴细胞凋亡率及凋亡因子Fas和Apo2 7的含量及其临床意义。方法 :从 75例化疗前后卵巢癌患者的腹水中提取富含癌细胞的悬液 ,用AnnexinV -FITC/PI双染法分辨凋亡细胞及坏死细胞 ,并以两种凋亡因子单克隆抗体Fas和Apo2 7标记上述细胞 ,均用流式细胞仪检测。结果 :化疗后卵巢癌细胞凋亡率显著高于化疗前的临床疗效好 ,反之疗效差 ;被Fas及Apo2 7标记的癌细胞率显著增加者临床疗效好 ,反之疗效差 ;化疗后外周血淋巴细胞凋亡率及凋亡因子有不同程度的增加。结论 :通过对化疗前后卵巢癌细胞凋亡程度的检测 ,有助于判断化疗效果 ,有重要的临床意义。

CD_3AK细胞的诱导及其体外抗肿瘤活性的实验研究

本研究采用抗ＣＤ３单克隆抗体（ＣＤ３ＭｃＡｂ）辅以少量的基因重组人白细胞介素２（γＩＬ—２）和植物血凝素（ＰＨＡ）诱导外周血淋巴细胞，成功地研制出具有抗瘤活性的ＣＤ３ＭｃＡｂ激活的杀伤细胞（ＣＤ３ＡＫ细胞）。结果表明：微量的ＣＤ３ＭｃＡｂ辅以少量的γＩＬ—２和ＰＨＡ就能诱导并大量扩增ＣＤ３ＡＫ细胞。３０ｎｇ／ｍｌ的ＣＤ３ＭｃＡｂ就能一次性激活ＣＤ３ＡＫ细胞，当ＣＤ３ＭｃＡｂ浓度提高到３００ｎｇ／ｍｌ时，ＣＤ３ＡＫ细胞的扩增能力明显高于ＬＡＫ细胞；ＣＤ３ＡＫ细胞是以ＣＤ３＋、ＣＤ８＋和ＣＤ４＋细胞为主的异质性细胞群，ＣＤ３＋和ＣＤ８＋细胞百分率随培养时间延长而增加，培养第４天至第１６天的ＣＤ３ＡＫ细胞均有很强的杀瘤活性，而最佳时期在第７天至第１０天；其体外杀瘤活性明显高于ＬＡＫ细胞（Ｐ＜０．０５）。本实验研究表明：ＣＤ３ＡＫ细胞是继ＬＡＫ、ＴＩＬ后又一更为有效的杀瘤细胞。

抗CD_(20)嵌合抗体Fab’片段在大肠杆菌中高效表达

利用PCR方法从抗CD2 0 ScFv表达载体上扩增重链可变区 (VH)、轻链可变区(VL)基因 ,然后将VH、VL 基因重组到Fab’表达载体中 ,构建成抗CD2 0 嵌合抗体Fab’片段表达载体 pYZFcd2 0 ,用pYZFcd2 0转化大肠杆菌 16C9,在 16C9菌中分泌表达可溶性抗CD2 0 Fab’片段 ,经分离纯化获得具有CD2 0 抗原特异结合活性的Fab’片段 ,竞争性免疫荧光抑制实验表明 ,抗CD2 0 Fab’片段能竞争性抑制亲本鼠源性抗CD2 0 单克隆抗体HI4 7和Daudi细胞CD2 0

抗人CD154单克隆抗体抑制免疫应答的实验研究

目的 :探讨抗人CD1 54单克隆抗体对免疫应答的抑制作用。方法 :①在体外进行混合淋巴细胞反应 ,研究抗人CD1 54单克隆抗体对淋巴细胞增殖反应的影响 ;②在严重免疫联合缺陷 (SCID)鼠体内重建人的免疫功能后 ,研究抗人CD1 54单克隆抗体在SCID小鼠体内对T细胞增殖的影响和对B细胞功能的影响。结果 :①双向混合淋巴细胞反应结果显示 ,抗体的 5个剂量组的 [3H] -TdR的掺入率均显著低于对照组 (均P <0 .0 1 ) ;②在输注人外周血单个核细胞第 6d、第 1 2d、第 2 1d ,实验组SCID鼠体内人T细胞占SCID鼠淋巴细胞的百分率均明显低于对照组(均P <0 .0 5) ;在输注人外周血单个核细胞后的第 1 2d、第 2 1d、第 31d ,实验组SCID鼠体内人IgG的含量明显低于对照组 (均P <0 .0 5)。结论 :抗人CD1 54单克隆抗体能够在体外抑制淋巴细胞的增殖 。