Antibody-platinum(IV)prodrugs conjugates for targeted treatment of cutaneous squamous cell carcinoma

Antibody-drug conjugates(ADCs)are a new type of targeting antibodies that conjugate with highly toxic anticancer drugs via chemical linkers to exert high specificity and efficient killing of tumor cells,thereby attracting considerable attention in precise oncology therapy.Cetuximab(Cet)is a typical antibody that offers the benefits of good targeting and safety for individuals with advanced and inoperable cutaneous squamous cell carcinoma(cSCC);however,its anti-tumor activity is limited to a single use.Cisplatin(CisPt)shows good curative effects;however,its adverse effects and non-tumor-targeting ability are major drawbacks.In this study,we designed and developed a new ADC based on a new cytotoxic platinum(IV)prodrug(C8Pt(IV))and Cet.The so-called antibody-platinum(IV)prodrugs conjugates,named Cet-C8Pt(IV),showed excellent tumor targeting in cSCC.Specifically,it accurately delivered C8Pt(IV)into tumor cells to exert the combined anti-tumor effect of Cet and CisPt.Herein,metabolomic analysis showed that Cet-C8Pt(IV)promoted cellular apoptosis and increased DNA damage in cSCC cells by affecting the vitamin B6 metabolic pathway in tumor cells,thereby further enhancing the tumor-killing ability and providing a new strategy for clinical cancer treatment using antibody-platinum(IV)prodrugs conjugates.

Allogenic Stem Cell Transplantation and COVID-19 Antibodies: Mechanistic Insights and Recipient Concerns

Collecting umbilical cord stem cells is widely practiced due to its numerous benefits. Over the past decade, umbilical cord stem cells (UCSCs) have shown effectiveness in treating various conditions, such as bone pathologies, neuropsychiatry disorders, hereditary diseases, and metabolic disorders. However, factors like immunization affect the quantity and quality of cord harvesting. Studies suggest that antibodies from the mother pass through the umbilical cord to protect the infant against infections. Cleaning the umbilical cord before stem cell extraction is crucial to maintain sterility and cell integrity. Vaccinating a female donor, including for COVID-19, typically does not directly affect the stem cells. Although vaccines aim to trigger an immunological response, they generally do not affect the donor’s stem cells.

Development of Non-ABO Red Blood Cell Alloantibodies in Patient Undergoing Allogeneic Haematopoietic Stem Cell Transplant

Alloantibodies that are non ABO Alloimmunization to protein antigens happens only after exposure, in contrast to ABO isohaemagglutinins, which are present naturally, even in the absence of prior exposure. It is recognized that while non-ABO RBC antibodies are less common than ABO antibodies, they generate essentially the same issues that lead to unfavorable clinical results. If non-ABO alloantibodies are identified early on, these issues related complications may be avoided This call for an in-depth understanding of the recipient and donor’s ABO-Rh grouping, antibody screening, and the phenotype of certain antigens. Equally important, the temporal association time between transplantation and hemolysis can help identify the underlying mechanism of hemolysis and direct appropriate management. Therefore, for that, it is crucial to identify the etiology of post-HSCT anemia for prevention and therapy, in addition to a thorough grasp of the mechanism of anemia in non-ABO-incompatible HSCT and the temporal link between HSCT and anemia. Finding the cause of post-HSCT anemia is essential for prevention and therapy, in addition to a thorough grasp of the mechanism of anemia in non-ABO-incompatible HSCT and the temporal link between HSCT and anemia. Therefore, for that, it is crucial to identify the etiology of post-HSCT anemia. In this case report review, we would like to highlight the vital role of transfusion medicine services and stem cell clinical teams in paying particular attention to the clinical significance of non-ABO alloantibodies involved to avoid causing overt hemolysis of incompatible donor RBCs or delayed erythropoiesis. Considering the fact that some of the Haematopoietic stem cell transplant centers do not give an attention to the other non-ABO RBC antigens.

Prevalence of Anti-endothelial Cell Antibodies in Patients with Pulmonary Arterial Hypertension Associated with Connective Tissue Diseases

Objective To investigate the prevalence of anti-endothelial cell antibodies (AECAs) in the sera of connective tissue diseases (CTD) patients with pulmonary arterial hypertension (PAH) and its correlation with clinical manifestations. Methods AECAs in sera of 39 CTD patients with PAH,22 CTD patients without PAH,and 10 healthy donors as controls were detected with Western blotting. The prevalence of different AECAs in different groups was compared and its correlation with clinical manifestations was also investigated. Results The prevalence of AECAs was 82.1% in CTD patients with PAH,72.7% in CTD patients without PAH,and 20.0% in healthy donors. Anti-22 kD AECA was only detected in CTD patients with PAH (15.4%). Anti-75 kD AECA was more frequently detected in CTD patients with PAH than in those without PAH (51.3% vs. 22.7%,P<0.05). In CTD patients with PAH,anti-75 kD AECA was more frequently detected in those with Raynaud’s phenomenon or with positive anti-RNP antibody. Conclusion AECAs could be frequently detected in CTD patients with or without PAH,while anti-22 kD and anti-75 kD AECA might be specific in CTD patients with PAH.

Anti-endothelial cell antibody rich sera from rheumatic heart disease patients induces proinflammatory phenotype and methylation alteration in endothelial cells

Rheumatic heart disease(RHD)is a major cause of cardiovascular morbidity and mortality in developing nations like India.RHD commonly affects the mitral valve which is lined by a single layer of endothelial cells(ECs).The role of ECs in mitral valve damage during RHD is not well elucidated.In here,anti-endothelial cell antibody from RHD patients has been used to stimulate the ECs(HUVECs and HMVECs).ECs proinflammatory phenotype with increased expression of TNFa,IL-6,IL-8,IFNg,IL-1b,ICAM1,VCAM1,E-selectin,laminin B,and vimentin was documented in both ECs.The promoter hypomethylation of various key inflammatory cytokines(TNFa,IL-6,and IL-8),integrin(ICAM1)associated with leukocyte transendothelial migration,and extracellular matrix genes(vimentin,and laminin)were also observed.Further,the in-vitro data was in accordance with ex-vivo observations which correlated significantly with the etiological factors such as smoking,socioeconomic status,and housing.Thus,the study sheds light on the role of ECs in RHD which is a step forward in the elucidation of disease pathogenesis.

UV/Vis-based process analytical technology to improve monoclonal antibody and host cell protein separation

Process analytical technology(PAT) is gaining more interest in the biomanufacturing industry because of its potential to improve operational control and compliance through real-time quality assurance.Currently, biopharmaceutical producers mainly monitor chromatographic processes with ultraviolet/visible(UV/Vis) absorbance. However, this measurement has a very limited correlation with purity and quantity. The current study aims to determine the concentration of monoclonal antibody(mAb) and host cell proteins(HCPs) using a build-in UV/Vis monitoring during Protein A affinity chromatography and to optimize the separation conditions for high purity of mAb and minimizing the HCPs content. The eluate was analyzed through in-line UV/Vis at 280 and 410 nm, representing mAb and HCPs concentration,respectively. Each 0.1 column volume(CV) fraction of UV/Vis chromatogram peak area were calculated,and different separation conditions were then compared. The optimum conditions of mAb separation were found as 12 CV loading, elution at pH 3.5, and starting the collection at 0.5 CV point, resulting in high m Ab recovery of 95.92% and additional removal of 49.98% of HCP comparing with whole elution pool. This study concluded that UV/Vis-based in-line monitoring at 280 and 410 nm showed a high potential to optimize and real-time control Protein A affinity chromatography for mAb purification from HCPs.

A SARS-CoV-2 neutralizing antibody discovery by single cell sequencing and molecular modeling

Although vaccines have been developed,mutations of SARS-CoV-2,especially the dominant B.1.617.2(delta)and B.1.529(omicron)strains with more than 30 mutations on their spike protein,have caused a significant decline in prophylaxis,calling for the need for drug improvement.Antibodies are drugs preferentially used in infectious diseases and are easy to get from immunized organisms.The current study combined molecular modeling and single memory B cell sequencing to assess candidate sequences before experiments,providing a strategy for the fabrication of SARS-CoV-2 neutralizing antibodies.A total of 128 sequences were obtained after sequencing 196 memory B cells,and 42 sequences were left after merging extremely similar ones and discarding incomplete ones,followed by homology modeling of the antibody variable region.Thirteen candidate sequences were expressed,of which three were tested positive for receptor binding domain recognition but only one was confirmed as having broad neutralization against several SARS-CoV-2 variants.The current study successfully obtained a SARS-CoV-2 antibody with broad neutralizing abilities and provided a strategy for antibody development in emerging infectious diseases using single memory B cell BCR sequencing and computer assistance in antibody fabrication.

IMpower210:A phase Ⅲ study of second-line atezolizumab vs. docetaxel in East Asian patients with non-small cell lung cancer

Objective: IMpower210(NCT02813785) explored the efficacy and safety of single-agent atezolizumab vs.docetaxel as second-line treatment for advanced non-small cell lung cancer(NSCLC) in East Asian patients.Methods: Key eligibility criteria for this phase Ⅲ, open-label, randomized study included age ≥18 years;histologically documented advanced NSCLC per the Union for International Cancer Control/American Joint Committee on Cancer staging system(7th edition);Eastern Cooperative Oncology Group performance status of 0 or 1;and disease progression following platinum-based chemotherapy for advanced or metastatic NSCLC. Patients were randomized 2:1 to receive either atezolizumab(1,200 mg) or docetaxel(75 mg/m^(2)). The primary study endpoint was overall survival(OS) in the intention-to-treat(ITT) population with wild-type epidermal growth factor receptor expression(ITT EGFR-WT) and in the overall ITT population.Results: Median OS in the ITT EGFR-WT population(n=467) was 12.3 [95% confidence interval(95% CI),10.3-13.8] months in the atezolizumab arm(n=312) and 9.9(95% CI, 7.8-13.9) months in the docetaxel arm[n=155;stratified hazard ratio(HR), 0.82;95% CI, 0.66-1.03]. Median OS in the overall ITT population was 12.5(95% CI, 10.8-13.8) months with atezolizumab treatment and 11.1(95% CI, 8.4-14.2) months(n=377) with docetaxel treatment(n=188;stratified HR, 0.87;95% CI, 0.71-1.08). Grade 3/4 treatment-related adverse events(TRAEs) occurred in 18.4% of patients in the atezolizumab arm and 50.0% of patients in the docetaxel arm.Conclusions: IMpower210 did not meet its primary efficacy endpoint of OS in the ITT EGFR-WT or overall ITT populations. Atezolizumab was comparatively more tolerable than docetaxel, with a lower incidence of grade3/4 TRAEs.

Role of adhesion molecules and dendritic cells in rat hepatic/renal ischemia-reperfusion injury and anti-adhesive intervention with anti-P-selectin lectin-EGF domain monoclonal antibody

AIM: To investigate the role of P-selectin, intercellular adhesion molecule-1 (ICAM-1) and dendritic cells (DCs)in liver/kidney of rats with hepatic/renal ischemiareperfusion injury and the preventive effect of anti-Pselectin lectin-EGF domain monoclonal antibody (anti-PsLEGFmAb) on the injury.METHODS: Rat models of hepatic and renal ischemiareperfusion were established. The rats were then divided into two groups, one group treated with anti-PsL-EGFmAb(n = 20) and control treated with saline (n = 20). Both groups were subdivided into four groups according to reperfusion time (1, 3, 6 and 24 h). The sham-operated group (n = 5) served as a control group. DCs were observed by the microscopic image method, while P-selectin and ICAM-1 were analyzed by immunohistochemistry.RESULTS: P-selectin increased significantly in hepatic sinusoidal endothelial cells and renal tubular epithelial cells 1 h after ischemia-reperfusion, and the expression of ICAM-1 was up-regulated in hepatic sinusoid and renal vessels after 6 h. CD1a+CD80+DCs gradually increased in hepatic sinusoidal endothelium and renal tubules and interstitium 1 h after ischemia-reperfusion, and there was the most number of DCs in 24-h group. The localization of DCs was associated with rat hepatic/renal function.These changes became less significant in rats treated with anti-PsL-EGFmAb.CONCLUSION: DCs play an important role in immune pathogenesis of hepatic/renal ischemia-reperfusion injury.Anti-PsL-EGFmAb may regulate and inhibit local DC immigration and accumulation in liver/kidney.

Induction of Endothelial Cell Apoptosis by Anti-alpha-enolase Antibody

Objective To assess the prevalence of anti-alpha-enolase antibody in systemic autoimmune diseases in Chinese patients and its role in endothelial cell apoptosis.Methods The reactivity of anti-alpha-enolase antibody in a variety of autoimmune disorders in Chinese patients was evaluated by dot blot assay.Endothelial cell apoptosis was investigated by in vitro incubation of endothelial cells with IgG purified from anti-alpha-enolase antibody-positive sera,with or without pre-incubation with recombinant alpha-enolase.Results Anti-alpha-enolase antibody was prevalent in different systemic autoimmune diseases with relatively high reactivity in Chinese patients.In vitro incubation of endothelial cells with IgG containing anti-alpha-enolase antibody induced apoptosis in a time-and dose-dependent manner.Apoptosis was partly inhibited by pre-incubation of the endothelial cells with recombinant alpha-enolase.Conclusions Our data suggest that alpha-enolase is a common auto-antigen recognized by anti-endothelial cell antibodies in connective tissue disease.Interaction between alpha-enolase and its autoantibody plays a role in endothelial cell apoptosis.Changes other than cell killing may contribute to the pathogenesis of endothelial damage and microvascular lesions.

Implications of anti-parietal cell antibodies and anti-Helicobacter pylori antibodies in histological gastritis and patient outcome

AIM： To develop a serum or histological marker for early discovery of gastric atrophy or intestinal metaplasia. METHODS： This study enrolled 44 patients with gastric adenocarcinoma, 52 patients with duodenal ulcer, 14 patients with gastric ulcer and 42 consecutive healthy adults as controls. Each patient received an endoscopy and five biopsy samples were obtained. The degrees of histological parameters of gastritis were categorized following the Updated Sydney System. Anti-parietal cell antibodies （APCA） and anti- Helicobacter pylori （ H pylori） antibodies （AHPA） were analyzed by immunoassays. Hpyloriinfection was diagnosed by rapid unease test and histological examination. RESULTS： Patients with gastric cancer and gastric ulcer are significantly older than healthy subjects, while also displaying higher frequency of APCA than healthy controls. Patients with positive APCA showed higher scores in gastric atrophy and intestinal metaplasia of corpus than patients with negative APCA. Patients with positive AHPA had higher scores in gastric atrophy, intestinal metaplasia, and gastric inflammation of antrum than those patients with negative AHPA. Elderly patients had greater prevalence rates of APCA. Following multivariant logistic regression analysis, the only significant risk factor for antral atrophy is positive AHPA, while that for corpus atrophy is positive APCA. CONCLUSION： The existence of positive APCA correlates with glandular atrophy in corpus and the presence of positive AHPA correlates with glandular atrophy in antrum. The existence of serum APCA and AHPA betokens glandular atrophy and requires further examination for gastric cancer.

Safety and efficacy of anti-EGFR monoclonal antibody (SCT200) as second-line therapy in advanced esophageal squamous cell carcinoma

Objective:The mainstay treatment of esophageal squamous cell carcinoma(ESCC)involves chemotherapy and immunotherapy.However,alternative therapies are required for patients who are refractory or intolerant to existing therapies.Methods:In this single-arm,multicenter,open-label phase Ib study,30 patients received an intravenous infusion of SCT200,an antiepidermal growth factor receptor(EGFR)monoclonal antibody,6.0 mg/kg once a week for 6 weeks,followed by 8.0 mg/kg once every 2 weeks until disease progression or intolerable toxicity.The primary endpoint was the objective response rate(ORR).The secondary endpoints were progression-free survival(PFS),overall survival(OS),and safety.Results:Thirty patients were enrolled between July 2018 and May 2019.The ORR was 16.7%(95%CI:5.6%–34.7%).The median PFS and OS were 3.1 months(95%CI:1.5–4.3)and 6.8 months(95%CI:4.7–10.1),respectively.A numerical difference without any statistical significance in ORR was observed in patients with different EGFR expressions(≥50%:25.0%vs.<50%:0%,P=0.140)or TP53 mutation abundance(<10%:23.8%vs.≥10%:0%,P=0.286).Improved median PFS(3.4 vs.1.4 months,P=0.006)and OS(8.0 vs.4.2 months,P=0.027)were associated with TP53 mutation abundance of<10%.The most common treatment-related adverse events of grade 3 or 4(occurring in≥2 patients)were hypomagnesemia[7(23.3%)]and rash[2(6.7%)].No treatmentrelated death occurred.Conclusions:SCT200 monotherapy as the second-or further-line treatment for advanced ESCC showed favorable efficacy,with an acceptable safety profile.TP53 mutation abundance might serve as a potential predictive biomarker.

A panel of monoclonal antibodies against the prion protein proves that there is no prion protein in human pancreatic ductal epithelial cells

Prion diseases are a group of neurodegenerative diseases that are fatal. The study of these unique diseases in China is hampered by a lack of resources. Amongst the most important resources for biological study are monoclonal antibodies. Here, we characterize a panel of monoclonal antibodies specific for cellular prion protein by enzyme-linked immunosorbent assay(ELISA), immunofluorescent staining, flow cytometry, and western blotting. We identify several antibodies that can be used for specific applications and we demonstrate that there is no prion protein expression in human pancreatic ductal epithelial cells(HPDC).

Detection of lymphocystis disease virus infection to flounder gill cells in vitro by monoclonal antibodies

Flounder gill （FG） cells were used to isolate lymphocystis disease virus （LCDV） and two monoclonal antibodies （Mabs） （1A8 and 3G3） against LCDV were used to trace LCDV infection to FG cells. FG monolayer cells was inoculated with LCDV supernatant, obtained from lymphocystis cells of diseased flounder, Paralichthys olivaceus. LCDV infection was detected with Mabs employing immunocytochemical assay （ICA） and indirect immunofluorescence assay test （IIFAT） technique. Detected by IIFAT, they were specifie for LCDV. The results of experimental infection illustrated that FG cells was sensitive to LCDV, and showed virus-infection positive detected by ICA. Cytopathic effect （CPE） occurred 1-2 days post inoculation （PI）, and half tissue culture infection dosage （TCID50） of vires supematant was 2^2.57 per 40μl. Tracing by IIFAT showed that LCDV positive signal first appeared at the cell membrane immediately PI, and then in cytoplasm at 24h PI, it reached the strongest positive at 48-72 h PI, and began to decrease at 96h PI.

Detection and quantitation of host cell proteins in monoclonal antibody drug products using automated sample preparation and data-independent acquisition LC-MS/MS

Ensuring the removal of host cell proteins(HCPs) during downstream processing of recombinant proteins such as monoclonal antibodies(m Abs) remains a challenge.Since residual HCPs might affect product stability or safety,constant monitoring is required to demonstrate their removal to be below the regulatory accepted level of 100 ng/mg.The current standard analytical approach for this procedure is based on ELISA;however,this approach only measures the overall HCP content.Therefore,the use of orthogonal methods,such as liquid chromatography-mass spectrometry(LC-MS),has been established,as it facilitates the quantitation of total HCPs as well as the identification and quantitation of the individual HCPs present.In the present study,a workflow for HCP detection and quantitation using an automated magnetic bead-based sample preparation,in combination with a data-independent acquisition(DIA) LC-MS analysis,was established.Employing the same instrumental setup commonly used for peptide mapping analysis of m Abs allows for its quick and easy implementation into pre-existing workflows,avoiding the need for dedicated instrumentation or personnel.Thereby,quantitation of HCPs over a broad dynamic range was enabled to allow monitoring of problematic HCPs or to track changes upon altered bioprocessing conditions.

Polyfunctional T Cell and Neutralizing Antibody Responses to ACAM2000TM Smallpox Vaccine Immunization in Primary-Vaccinated Individuals

Smallpox eradication was successful via prophylactic administration of live attenuated vaccinia virus. As a result of the discontinuation of the smallpox immunization program, many individuals are now susceptible to smallpox virus infection should it be used as a biological weapon. Presently, only individuals at high risk for exposure are required to receive smallpox vaccine, such as laboratory personnel that handle variola/vaccinia virus. This study endeavored to investigate a one-year period of vaccinia virus-specific T cell responses using polychromatic flow cytometry and neutralizing (Nt) antibody responses using plaque reduction neutralization test (PRNT) in individuals receiving primary immunization (n = 5) with ACAM2000TM smallpox vaccine. Functional and phenotypic profiles of vaccinia virus-specific T cell responses were characterized. Each single functional measurement {CD107a/b expression, production of interferon g (IFN-g), macrophage inflammatory protein 1b (MIP-1b), interleukin 2 (IL-2), and tumor necrosis factor a (TNF-a)} demonstrated that vaccinia virus-specific CD8+ T cells were functional at least one time point after vaccination (p ≤ 0.05). However, vaccinia virus-specific CD4+ T cells were functional only for MIP-1b production (p ≤ 0.05). Vaccinia virus-specific CD8+ T cells induced in these individuals showed increased polyfunctionality in at least 2 phenotypes relative to pre-vaccination (p ≤ 0.05). Although only three of five individuals (60%) showed positive Nt antibody (titer ≥ 20) at first month after vaccination, all five individuals (100%) demonstrated Nt antibody at 2 months, post-immunization. Interestingly, all vaccinees could retain the Nt antibody for 6 months after primary vaccination. In conclusion, ACAM2000TM smallpox vaccine induced both polyfunctional T cell-and Nt antibody-responses in primary immunized individuals.

Anti-P-selectin lectin-EGF domain monoclonal antibody inhibits the maturation of human immature dendritic cells

Dendritic cells(DCs) are professinal antigen-presenting cells with the ability to initiate primary Tcell responses. While it iswell known that inflammatory stimuli induce the functional maturation of immature DCs, whether adhesion molecule selectins regulate DCmaturation is poorly understood. Using anti-P-selectin lectin-EGF domain monoclonal antibody (PsL-EGFmAb) that blocks the adhesionof P-, E-, and L-selectin, we demonstrate herein that selectins play important role in stimulating functional maturation of immature DCs.Immature DCs are generated from human cord blood CD34+hematopoietic stem/progenitor cells that were cultured in the presence of stemcell factor, Fms-like tyrosine-kinase-3 ligand, granulocyte-macrophage colony stimulating factor, and transform growth factor-β1. Whenstimulated with tumor necrosis factor-alpha(TNF-α), immature DCs differentiated into mature DCs, producing increased levels of costim-ulatory molecules and interleukin (IL)-12 and obtaining the ability to potently activate naive Tcells. Interestingly, in contrast to matureDCs derived from TNF-α-induced immature DC cultures without PsL-EGFmAb, immature DCs treated with PsL-EGFmAb for7 days werecompletely blocked their maturation, as evidenced by decreased expression of costimulatory molecules CD80, CD86, and CD83, inhibi-ted production of IL-12, and inability to activate naive Tcellsin vitro. Thus, blockade of selectins using PsL-EGFmAb will prove to bea valuable tool for the study of the molecuar mechanisms of DC maturation, as well as for the prevention and treatment of DC-mediated au-toimmunity.

Polyclonal antibody production and expression of CREG protein in human vascular smooth muscle cells

Objectives The cellular repressor of E1A-activated genes (CREG), a novel gene, was recently found to play a role in inhibiting cell growth and promoting cell differentiation. The purpose of this study was to obtain antibody against CREG protein and to study the expression of CREG protein in human internal thoracic artery cells (HITASY) which express different patterns of differentiation markers after serum withdrawal. Methods The open reading frame of CREG gene sequence was amplified by PCR and cloned into the pGEX-4T-1 vector. Glutathione-S-transferase (GST)-CREG fusion protein was expressed in E. Coli BL21 and purified from inclusion bodies by Sephacryl S-200 chromatography. Rabbits were immunized with the purified GST-CREG protein. Western blot examined with immunohistochemistry staining and the protein expression level was analyzed by Western blot in HITASY cells after serum removal. Results It was confirmed by using endonuclease digesting and DNA sequencing that the PCR product of CREG was correctly inserted into the vector. The GST-CREG protein was purified with gel filtration chromatography. Polyclonal antibody against GST-CREG was obtained from rabbits. CREG protein immunohistochemistry staining displayed a perinuclear distribution in the cytoplasm of HITASY cells. Results from Western blot suggested that comparing with the untreated cells upregulation of CREG polyclonal antibody against CREG was comfirmed. Using this antibody, the changes of CREG protein expression was observed in the process of phenotypic modulation of HITASY cells. These results provide basic understanding on the relationship of CREG gene with the cell phenotypic conversion.

Establishment of anti-thyrotropin monoclonal antibody hybridoma cell lines with extract of human pituitary gland

To get the hybridoma cell lines secreting anti-thyrotropin monoclonal antibodies with high affinity and specificity. Methods: BALB/c mice were immunized with extract of human pituitaries. The spleen cells of one immunized mouse were fused with mouse myeloma cells in polyethylene glycol and the positive clones were subcloned 3 times. Results: Two hybridoma cell lines which secrete anti-thyrotropin monoclonal antibodies with high affinity and specificity have been collected. The antibodies were of the IgG1 subclass and their maximum binding with thyrotropin was 60% and 45. 1% respectively. Using competitive binding assay,the antibodies were found to direct against different epitopes of human thyrotropin. Conclusion: The extract of human pituitaries could be used to produce monoclonal anti-pituitary hormone antibodies. The two anti-thyrotropin monoclonal antibodies produced in this study could be used in the establishment of a sensitive measurement of human thyrotropin.

A Preliminary Study on the Preparation of Monoclonal Antibody with Umbilical Cord Blood Cell

Objective: We conducted a preliminary study on the feasibility of preparing monoclonal antibody by umbilical cord blood cells systems. Methods: Collected umbilical cord blood cells and stimulated by Rubella virus, then incubated them and collected cell supernatant. By using Caprylic acid- saturated Ammonium sulfate method, monoclonal antibody was purified, and IgG subtype identification was conducted by their subtype classification kit of sigma. In traditional way, the preparation of monoclonal antibody cannot do without BABL/C mice and SP2/0 hybridoma cells. Consider this kinds of monoclonal antibody as a positive control, the reactivity and specificity of monoclonal antibodies were identified by Dot-ELISA. Results: By ELISA, we obtained four strains of positive umbilical cord blood cells. After subculture, cryopreservation and resuscitation in vitro, three of them were confirmed to secrete monoclonal antibody against rubella virus stably. The result of monoclonal antibody subtype classification showed that, both IgG1 and IgG2 types were detected. However, the quantity of monoclonal antibody prepared by umbilical cord blood cells was less than that from traditional method. Conclusions: The method of prepare monoclonal antibody using umbilical cord blood cells is feasible.