Preparation of Anti-HER2 Monoclonal Antibody-paclitaxel Immunoconjugate and Its Biological Evaluation

Anti-HER2 monoclonal antibody （Sc7301）-paclitaxel （TAX） immunoconjugate was pre- pared and its specific binding to tumor cells was investigated in this study. Sc7301 was conjugated to TAX by the active ester method and then the TAX-Sc7301 immunoconjugate was obtained. After purification and labeling by Cyano-fluorescein isothiocyanate （FITC）, the specific binding of TAX-Sc7301 to HER2-positive tumor cells （SKOV3） and HER2-negative tumor cells （HepG2） was evaluated respectively. TAX-Sc7301 （20 nmol/L） showed distinct specific binding to SKOV3 cells rather than HepG2 cells. And the uptake of the immunoconjugate by SKOV3 cells was increased with the TAX-So7301 concentration （3-48 nmol/L） and the incubation time （P〈0.05）. It was concluded that the TAX-Sc7301 immunoconjugate is ootentially applicable as a targeted agent against HER2-10ositive tumor cells.

Clinical application of SARS-CoV-2 antibody detection and monoclonal antibody therapies against COVID-19

The purpose of this study was to investigate the clinical application of severe acute respiratory distress syndrome coronavirus-2(SARS-CoV-2)specific antibody detection and anti-SARS-CoV-2 specific monoclonal antibodies(mAbs)in the treatment of coronavirus infectious disease 2019(COVID-19).The dynamic changes of SARS-CoV-2 specific antibodies during COVID-19 were studied.Immunoglobulin M(IgM)appeared earlier and lasted for a short time,while immunoglobulin G(IgG)appeared later and lasted longer.IgM tests can be used for early diagnosis of COVID-19,and IgG tests can be used for late diagnosis of COVID-19 and identification of asymptomatic infected persons.The combination of antibody testing and nucleic acid testing,which complement each other,can improve the diagnosis rate of COVID-19.Monoclonal anti-SARS-CoV-2 specific antibodies can be used to treat hospitalized severe and critically ill patients and non-hospitalized mild to moderate COVID-19 patients.COVID-19 convalescent plasma,highly concentrated immunoglobulin,and anti-SARS-CoV-2 specific mAbs are examples of anti-SARS-CoV-2 antibody products.Due to the continuous emergence of mutated strains of the novel coronavirus,especially omicron,its immune escape ability and infectivity are enhanced,making the effects of authorized products reduced or invalid.Therefore,the optimal application of anti-SARS-CoV-2 antibody products(especially anti-SARS-CoV-2 specific mAbs)is more effective in the treatment of COVID-19 and more conducive to patient recovery.

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.

Therapeutic Implications of Monoclonal Antibody

Background: The coronavirus disease 2019 (COVID-19) pandemic is a distinct public health issue that calls for the quick development of novel treatments and viral detection. Due to their high specificity and reliability, monoclonal antibodies (mAbs) have emerged as useful diagnostic and therapeutic tools for a variety of diseases. As a result, several scientists have jumped right into developing Ab-based assays for the identification of SARS-CoV-2 and Ab drugs for use as COVID-19 therapy agents. Since the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein is essential for viral infection and has a known precise structure, it has become a key target for the creation of therapeutic antibodies. The use of Ab cocktails is anticipated to be a key component of an efficient COVID-19 treatment plan since SARS-CoV-2 is an RNA virus with a high mutation rate, particularly when subjected to the selection pressure of aggressively applied preventive vaccinations and neutralizing Abs. Furthermore, SARS-CoV-2 infection could provoke an overzealous immune response, leading to a cytokine storm that accelerates the onset of a severe disease. Abs to counteract cytokine storms are also actively being researched as COVID-19 therapies. Abs are now used in SARS-CoV-2 detection assays, including immunoglobulin and antigen tests, in addition to their use as medicines. In order to stop the spread of COVID-19, such Ab-based detection tests are essential surveillance tools. In this article, we’ll go over several important ideas related to mAb-based COVID-19 pandemic detection tests and treatments. Objective: To understand the role of hybridoma technology in therapeutic implications. 1) To study the basic concepts and options in hybridoma technology;2) To study the applications of hybridoma technology;3) To explore how hybridoma technology is applied in diagnostic histopathology. Method: For this method generally there is use of mouse or mammals are transfect with the Ags to find out the formation of antibody afterwards isolate the antibody which has been formed after injecting the antigens for a number of weeks. Following are the steps for mAbs: Step 1: In this step immunization of mouse is done;Step 2: Spleen is used for the isolation of B cells;Step 3: Cultivation of cancerous cells;Step 4: Merging of B cells with Myeloma cells;Step 5: This step cell lines are separated;Step 6: in the next step screening the suitable cell lines;Step 7: observation of multiplication in vitro as well as in vivo;Step 8: Harvesting. Discussion: Now a day there are many diseases which has been cured easily at the mean time it’s very difficult to diagnose and get the treatment. Due to advancement of monoclonal antibodies are used in the diagnosis and treatments such as COVID-19, SARS and SARS COV-2. Therefore important part of the monoclonal antibodies are its used in the diagnosis as well as in the treatment tools.

Tumoricidal activation of murine resident peritoneal macrophages on pancreatic carcinoma by interleukin-2 and monoclonal antibodies

INTRODUCTIONMacrophages play an important role in tumor lysisand growth inhibition.They can be activated to atumoricidal state by a variety of agents such asIFNr,TNFα or IL2.The killing machanisms ofactivated macrophages have been extensivelyinvestigated.Recently,it has been proved thatantibody dependent cellular cytotoxicity (ADCC) isone of the potent arms to lyse tumor cells

Synthesis and evaluation of monoclonal antibody against Plasmodium falciparum merozoite surface antigen 2

Objective:To assess the quality of expressed MSP-2 and also to confirm the immune response against different domains of these proteins.Methods:Mice were immunized with a schizont extract to stimulate the immune system to make antibodies against different antigens of the late stage parasite including production of antibodies against different domains of Plasmodium falciparum(P.falciparum)MSP-2.B lymphocytes of immunized mice were extracted from the spleen and the fusion was performed using NS-1 myeloma cells and the hybridoma cells were assayed by ELISA either with a schizont extract or different domains of MSP-2 and/or by IFAT with whole schizont preparation.Fusion of NS-1 and spleen cells was performed.The positive hybrids were cloned and ELISA was applied against different dilutions.The positive clones were transferred to a small tissue culture flask and after developing they were assayed against schizont extract and the different MSP-2 domains.The positive clones were expanded to large(75 cm^2)flask and cultured under the same conditions,checking them using both ELISA and IFAT and the positive cells were frozen as soon as possible.Results:A total number of 7 fusions including 26 plates(2496 wells)were performed,of which 1336 hybrids were produced and the overall efficiency(1336/24%×100)was about 53%.ELISA was performed to detect the positive hybrids against crude schizont extract by which the highest frequency to crude schizont extract was found for the supernatant of the hybrids produced in fusion number 3(66 out of 315 hybrids).The supernatant of both B5 and Ft hybridoma cells were more positive against domain 2 of the MSP-2 recombinant protein in Western blotting test.Western blotting results also showed that different domains of the MSP-2 recombinant protein and also the MSP-2 of the P.falciparum parasite were recognized by some of the positive clones and also immune sera.Conclusions:Bringing together all the results of this study it has been confirmed that some clones have recognized both schizont extract and different domains of the MSP-2 recombinant protein and therefore confirming the quality of the MSP-2 domains.

Effect of bovine pellucid zone 3 monoclonal antibodies on B cell lymphoma 2 expressions of granulosa cell and mice (Mus musculus) follicle diameter

Objective:To evaluate the effects of pellucid zone 3 monoclonal antibodies against B-cell lymphoma 2 (BCL-2) expression and mice follicle diameter at various time periods.Methods:The animal model of this study was 36 Balb/c mice (Mus musculus). A true experimental design was used with a post-test only control group approach. BCL-2 expression was observed using immunohistochemistry, while the follicle diameter was observed by haematoxylin-eosin staining. The data was analyzed using nested ANOVA to compare the results of the mean expression of BCL-2 on the 5th and 20th day of observation in the pre-antral and antral follicle between the control and treatment groups.Results:No significant differences were found in BCL-2 gene expression. There were also no significant differences in BCL-2 expression on the 10th day of pre-antral follicle analysis. Moreover, there were no significant differences between the mean follicle diameter on the 5th, 10th, and 20th day of pre-antral and antral follicle development between the control and treatment groups. The addition of bovine pellucid zone 3 (bZP3) monoclonal antibodies on the 5th and 20th day of observation did not decrease the expression of BCL-2 gene in the pre-antral and antral follicle of mice. Administering bZP3 monoclonal antibodies on the 10th day of observation did not affect BCL-2 expression in the pre-antral follicle but did decrease BCL-2 expression in the antral follicle. Supplying bZP3 monoclonal antibodies on the 5th, 10th and 20th day did not affect the diameter of pre-antral and antral follicles of the mice.Conclusion: The monoclonal antibodies bovine zona pelusida 3 has the potential to be developed as a safe immunocontraception preparation.

靶向HER2胞外结构域Ⅳ的单克隆抗体在乳腺癌中的应用进展

人表皮生长因子受体2(HER2)阳性乳腺癌侵袭性强且易转移,抗HER2靶向药物的应用能显著改善HER2阳性乳腺癌患者的预后。在已上市的HER2靶向药物中,靶向HER2胞外结构域Ⅳ的大分子单克隆抗体是治疗HER2阳性乳腺癌的基础靶向药物,主要包括曲妥珠单抗、伊尼妥单抗和马吉妥昔单抗。曲妥珠单抗用于乳腺癌全线治疗,循证医学证据充分,实践经验充足且安全性可控;伊尼妥单抗与曲妥珠单抗在HER2阳性转移性乳腺癌和新辅助/辅助治疗中疗效相似,且安全性可控;马吉妥昔单抗聚焦于携带CD16A-158F等位基因的患者,是晚期乳腺癌后线治疗的选择。临床上需根据患者具体病情选择最适合的药物。

猪圆环病毒2型Cap蛋白的原核表达及其单克隆抗体制备

为了制备猪圆环病毒2型(Porcine circovirus type 2,PCV-2)Cap蛋白单克隆抗体,试验将Cap基因克隆至原核表达载体pET-28a(+)上并转化至大肠杆菌BL21(DE3)感受态细胞中,将获得的重组表达菌pET28a-Cap/BL21(DE3)用IPTG进行诱导后表达重组蛋白,利用His标签对表达的重组蛋白进行纯化;将纯化后的重组蛋白于皮下免疫Balb/c小鼠,免疫结束后测定免疫小鼠血清效价,当小鼠血清抗体效价达到1∶100000时进行细胞融合;采用有限稀释法进行亚克隆,筛选能够稳定分泌抗体且抗体效价高的阳性杂交瘤细胞株,鉴定杂交瘤细胞株抗体亚类,并选择1株抗体效价最高的细胞株再次注射到小鼠腹腔中(5×10^(5)个/只),取腹水采用亲和层析法对单克隆抗体进行纯化;采用间接ELISA方法测定单克隆抗体效价并检测其特异性,分别采用Western-blot和间接免疫荧光试验检测单克隆抗体的反应性。结果表明:PCR扩增得到大小为708 bp的Cap基因,经双酶切与测序验证后,成功构建重组表达质粒pET28a-Cap;重组表达菌pET28a-Cap/BL21(DE3)经诱导后表达的重组蛋白可与His标签抗体发生特异性反应,纯化后的重组蛋白在预期位置(31.7 ku)出现清晰的单一条带;共筛选出8株能够稳定分泌抗体且抗体效价高的阳性单克隆细胞株(1E5、2A9、3C6、4B3、5F7、6D11、7A2、8G1株),抗体亚类鉴定均为IgG1亚类。其中7A2株抗体效价最高,用于单克隆抗体的制备;间接ELISA方法证实7A2株单克隆抗体仅与PCV-2 Cap蛋白发生反应,与猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory syndrome virus,PRRSV)、猪流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)、猪瘟病毒(Classical swine fever virus,CSFV)、猪细小病毒(Porcine parvovirus,PPV)和猪伪狂犬病病毒(Porcine pseudorabies virus,PRV)不发生反应;Western-blot和间接免疫荧光试验均证实PCV-2 Cap蛋白可被7A2株单克隆抗体特异性识别。说明本试验成功制备出具有高纯度、强特异性、良好反应性的PCV-2 Cap蛋白单克隆抗体。

HER2阳性乳腺癌靶向治疗的研究进展

乳腺癌是全球女性发病率较高的恶性肿瘤,其中人类表皮生长因子受体2(HER2)阳性乳腺癌病例占总乳腺癌病例的20%~30%。与其他分子分型的乳腺癌比,HER2阳性乳腺癌预后更差,更易复发和转移。近年来,HER2阳性乳腺癌治疗备受关注,针对抗HER2的靶向药物能显著改善HER2阳性乳腺癌患者的疗效。该文对HER2阳性乳腺癌靶向治疗的研究进展作一综述。

TCbHP在老年HER-2阳性乳腺癌患者新辅助化疗中的应用效果

目的:研究TCbHP在老年HER-2阳性乳腺癌患者新辅助化疗中的应用效果。方法:选取2020年3月—2022年4月苏州大学附属第三医院收治的100例老年HER-2阳性乳腺癌患者,随机将其分为对照组(n=50)和观察组(n=50)。对照组给予THP新辅助化疗,观察组给予TCbHP新辅助化疗。比较两组临床疗效、治疗前后肿瘤标志物及不良反应。结果:观察组客观缓解率高于对照组,差异有统计学意义(P<0.05)。治疗后,两组癌胚抗原与糖类抗原125水平均低于治疗前,观察组癌胚抗原与糖类抗原125水平均低于对照组,差异有统计学意义(P<0.05)。两组血小板减少、肝损伤、脱发、恶心呕吐、手足综合征发生率比较,差异无统计学意义(P>0.05)。结论:相比THP,TCbHP可进一步抑制老年HER-2阳性乳腺癌患者肿瘤标志物表达,有效控制疾病发展,不会加重化疗引起的不良反应。

鲤疱疹病毒Ⅱ型ORF72单克隆抗体的制备及应用

鲤疱疹病毒Ⅱ型是引起鲫造血器官坏死病的重要病原。为建立基于抗原水平的免疫检测方法,通过原核表达方法制备鲤疱疹病毒Ⅱ型核衣壳蛋白ORF72,将纯化的ORF72蛋白免疫BALB/c小鼠,应用杂交瘤技术筛选获得单克隆抗体1B3、4B1、4C2、5F4和5H9。免疫印迹分析显示,上述5株单抗均可特异性识别重组蛋白ORF72;免疫荧光分析显示,仅单抗4C2可与感染鲤疱疹病毒Ⅱ型的鲫脾脏发生阳性反应。利用单抗4C2通过间接免疫荧光技术对鲤疱疹病毒Ⅱ型感染鎏金金鱼鳍条细胞系(RyuF-2)后ORF72蛋白表达情况进行检测,结果显示,感染后36 h可检测到阳性信号,并且随着感染时间的延长,细胞中ORF72的表达量明显增加。本试验制备的单克隆抗体4C2为体外进一步探究鲤疱疹病毒Ⅱ型在细胞内的复制机制及建立病鱼免疫检测手段奠定了基础。

A human monoclonal antibody neutralizes SARS-CoV-2 Omicron variants bytargeting the upstream region of spike protein HR2 motif

The continuous emergence of new severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants meansthere is a need to explore additional strategies to develop broad-spectrum vaccines or therapeutics for individuals remaining at risk of coronavirus disease 2019(COVID-19).Neutralizing monoclonal antibody(mAb)that binds to theconserved S2 subunit of the SARS-CoV-2 spike(S)protein alone,or in combination with mAb that binds to the receptor-binding domain(RBD)of S protein,might be effective in eliciting protection from infection by a variety of SARS-CoV2 variants.Using high-throughput single-cell immunoglobulin sequencing of B cells from COVID-19-convalescent donors,we identified a high-affinity S2-specific mAb-39,that could inhibit original SARS-CoV-2 strain,Omicron BA.1,BA.2.86,BA.4,BA.5,and EG.5.1 S protein-mediated membrane fusion,leading to the neutralization of these pseudoviralinfections.Moreover,mAb-39 could also improve the neutralizing activity of anti-RBD antibody against the highlyneutralization-resistant Omicron variants.Molecular docking and point mutation analyses revealed that mAb-39 recognized epitopes within the conserved upstream region of the heptad repeat 2(HR2)motif of the S2 subunit.Collectively,these findings demonstrate that targeting the conserved upstream region of the HR2 motif(e.g.,using mAbs)provides anovel strategy for preventing the infection of SARS-CoV-2 and its variants.

The preparation of anti-hnRNP A2/B1 polyclonal antibody and its potential application in non-small cell lung cancer

Objective： In order to evaluate potential application for diagnosis and prognosis of non-small cell-lung cancer （NSCLC）, as well as to determine its role in the pathogenesis of the disease, we prepared anti-human hnRNPA2/B1 potyclonal antibody. Methods： Prokaryotic expression vector of pET28a （＋）-hnRNP A2/B1 was constructed and bansformed into E.coli BL21. The recombinant protein induced by IPTG was purified and injected to rabbits for antibody preparation. Expression of hnRN P A2/B1 was examined in 45 tissues of NSCLC and 16 inflammatory pseudotumor tissues of lung by immunohistochemistry with the antibody. The commercial hnRNP A2/B1 monoclonal antibody was used as a controI.Results： （1） Polyclonal an-tibody against hnRNP A2/B1 with high title was obtained. （2） The positive staining in NSCLC tissues was 62.22%, which was substantially higher than that in normal tissues （40%, P = 0.035） or inflammatory pseudotumor tissues （31.25%, P=0.033）. （3） Expression of hnRNP A2/B1 positively correlated with age and the history of smoking, whereas it negatively correlated with differentiation staging of tumors. （4） Follow-up study showed that the survival time of patients with positive staining was significantly shorter than that of patients without hnRNP A2/B1 expression （P=0.048）. Conclusion： It is successful to make the recombinant protein and prepare the polyclonal antibody agonist human hnRNP A2/B1. It may be a valuable marker for the diagnosis and prognosis of NSCLC. Our results provide a basis for further study in clinical application.

Comparison on Infectious Bursal Disease Monoclonal Antibodies Prepared with Two Different Immunogens

[ Objective] To compare the characteristics of monoclonal antibodies against infectious bursal disease virus （IBDV） prepared with two different immunogens, VP2 protein expressed by prokaryotic system and purified IBDV. [Methed] IBDV VP2 gene was amplified by RT-PCR and expressed in a prokaryotic system. The recombinant protein was purified by affinity chromatography. IBDV was pudfied by ultracentrifugation. Balb/c mice were immunized with the purified recombinant protein and IBDV, respectively. The monoclonal antibodies were screened by ELISA. [ Result] Two cell lines secreting antibodies against IBDV VP2 protein were obtained, and their ELISA titers were 1：2 × 10^4. Four cell lines secreting antibodies against I BDV were produced, and their ELISA titers were 1：2× 10^6, 1：6 × 10^4, 1：1× 10^5 and 1：4 × 10^3, respectively. All monoclonal antibodies specifically bound to their own immunogen but did not react with other viruses or proteins. After 10 -20 passages, these cell lines still secreted antibodies stably. [Condusion] The monoclonal antibodies prepared with the recombinant IBDV VP2 protein or purified IBDV can induce immune resoonse in mice. and VP2 soecific monoclonal antibodies can be obtained with VP2 orotein expressed in the Drokarvotic system as immunoQen.

抗HER2单抗注射液(皮下注射)的质量控制

目的 研究并建立针对抗HER2单抗注射液(皮下注射)的关键质量属性质控方法。方法 分别采用胰蛋白酶或Lys-C酶切结合反相高效液相色谱法(reversed-phase high performance liquid chromatography, RP-HPLC)的肽图分析法进行抗HER2单抗的特异性鉴别。采用还原/非还原十二烷基硫酸钠毛细管电泳(capillary electrophoresis-sodium dodecyl sulfonate, CE-SDS)和分子排阻色谱(size-exclusion chromatography, SEC)法进行纯度控制。采用阳离子交换色谱(ion-exchange chromatography, IEC)法进行电荷异质性分析。采用亲水相互作用液相色谱(hydrophilic interaction liquid chromatography, HILIC)法进行寡糖图谱分析。采用酶活力测定法分析透明质酸酶含量。采用BT474细胞增殖抑制法测定生物学活性。采用紫外分光光度法测定蛋白含量。结果 两种肽图检测法均获得特征图谱,对抗HER2单抗发挥很好的特异性鉴别作用。还原CE-SDS的重链和轻链峰面积之和百分比为(98.63±0.14)%,非还原CE-SDS主峰面积百分比为(98.20±0.11)%,前峰面积百分比总和为(1.47±0.04)%。SEC测得的单体峰面积百分比为(99.82±0.05)%。IEC测定的主要活性成分(峰3*+峰3)以及产品相关杂质(峰4)的峰面积百分比分别为(75.01±0.04)%和(6.72±0.03)%。寡糖图谱分析aFuc、G2和Man5的面积百分比分别为(9.20±0.01)%,(6.33±0.02)%和(1.92±0.01)%。透明质酸酶含量为(2 021.02±238.41)U/ml。供试品相对于参比品的生物学活性为(95.87±6.10)%,蛋白含量为(115.60±0.45)mg/ml。结论 针对抗HER2单抗注射液(皮下注射)关键质量属性的质控方法的建立可以有效确保该类产品的安全性和有效性。

ANGPT2单克隆抗体对AML小鼠肿瘤组织血管增生和下游信号蛋白表达的影响

目的 探讨ANGPT2单克隆抗体对急性髓系白血病(AML)小鼠肿瘤组织血管增生、下游信号蛋白表达的影响。方法 建立AML小鼠模型20只,对照组与实验组各10只,采用免疫组织化学方法检测微血管密度及VEGF表达情况,采用Western blot检测下游信号通路蛋白TIE2、SHP2和PI3K的表达水平。结果 ANGPT2单克隆抗体治疗后,AML小鼠肿瘤组织微血管密度及VEGF表达水平显著下降79.29%(P<0.01),下游信号通路蛋白SHP2蛋白表达水平上升59.43%,PI3K蛋白表达水平下降20.37%(P<0.01)。结论 ANGPT2单克隆抗体显著抑制AML小鼠肿瘤组织血管增生。

鸭腺病毒3型Fiber-2蛋白单克隆抗体的制备及初步应用

为进一步研究鸭腺病毒3型(DAdV-3)Fiber-2蛋白,研究通过PCR扩增fiber-2基因,构建p ET32a-DAdV3-fiber2原核质粒,表达并纯化蛋白,以纯化的蛋白为免疫原,免疫6周龄雌性BALB/c小鼠制备抗Fiber-2单克隆抗体杂交瘤细胞,采用间接免疫荧光试验和免疫印迹试验进行鉴定,并用于DAdV-3 Fiber-2杆状病毒表达产物的鉴定。结果显示:原核表达获得1.77 mg/mL Fiber-2蛋白,筛选获得2株阳性单克隆细胞株2E10E4和4F7F10,两株单克隆抗体均为IgG 1型,轻链类型为κ;DAdV-3感染的LMH细胞中存在特异性荧光,免疫印迹试验确认在约59 ku处出现特异性条带;采用制备的单克隆抗体确认了表达Fiber-2蛋白的重组杆状病毒。研究获得了针对DAdV-3 Fiber-2蛋白的单克隆抗体,为深入探究Fiber-2在DAdV-3感染机制中的作用以及为建立DAdV-3抗原免疫测定技术奠定了基础。

PD-L2在头颈部鳞状细胞癌免疫治疗预后评估中的意义

背景与目的:程序性死亡[蛋白]-1(programmed death-1,PD-1)单抗免疫治疗在头颈部鳞状细胞癌(head and neck squamous cell carcinoma,HNSCC)中的作用愈发重要,然而目前具有响应率低、缺乏预测性生物标志物的问题。本研究旨在确定程序性死亡[蛋白]配体-2(programmed death ligand-2,PD-L2)能否作为预测HNSCC中PD-1单抗免疫治疗获益情况的生物标志物。方法:收集50例接受PD-1单克隆抗体免疫治疗的中晚期HNSCC的组织标本及临床数据,采用免疫组织化学染色法分析程序性死亡[蛋白]配体-1(programmed death ligand-1,PD-L1)、PD-L2表达量,采用SPSS 26.0软件根据基本临床特征、PD-L1与PD-L2表达量分组统计并进行Kaplan-Meier生存分析,采用GraphPad Prism软件绘制生存曲线。结果:PD-L2在HNSCC患者中阳性表达率较高,有超过80%的患者肿瘤组织可检出PD-L2表达;PD-L2的表达量显著影响免疫治疗结局,PD-L2高表达的患者平均生存期为18.8(16.0~21.7)个月,而PD-L2低表达的患者平均生存期为11.0(9.1~12.8)个月,差异有统计学意义(P<0.05)。结论:PD-L2可作为评估HNSCC中PD-1单克隆抗体免疫治疗获益的生物标志物。

针对SARS-CoV-2核衣壳蛋白的单克隆抗体的制备和鉴定

目的研制SARS-CoV-2的N蛋白单克隆抗体,并对其特异性识别真核表达N蛋白等特性进行鉴定,为下一步应用奠定材料基础。方法利用大肠杆菌表达并纯化SARS-CoV-2重组N蛋白,制备并筛选分泌N蛋白特异性单克隆抗体的阳性B细胞杂交瘤,制备腹水后利用间接ELISA法测定单抗的效价、亚型和亲和力;通过Western blot、间接免疫荧光试验分析其与原核、真核表达SARS-CoV-2重组N蛋白的特异性结合能力;通过间接ELISA法评价其在不同冠状病毒N蛋白检测中的应用潜力。结果成功地表达和纯化SARS-CoV-2重组N蛋白,筛选获得1株特异性识别重组N蛋白的单克隆抗体并命名为11F4,其亚型为IgG1,腹水效价为2.0×10^(7)以上,亲和力为4.44×10^(8)M^(-1);Western Blot分析表明其能与SARS-CoV-2重组N蛋白特异性反应,间接免疫荧光试验显示其能特异性识别HEK-293T细胞表达的SARS-CoV-2 N蛋白,表明该蛋白免疫反应性良好;间接ELISA法结果表明其可特异性识别真核细胞表达的SARS-CoV-2 N蛋白,而与MERS-CoV和HCoV-229E的N蛋白无交叉反应。结论成功获得可特异性识别细胞表达及体外制备的SARS-CoV-2 N蛋白的单克隆抗体,具备特异性检测SARS-CoV-2的潜能,为下一步研究提供了重要生物材料。