Safety and short-term effectiveness of blinatumomab in the treatment of childhood relapsed/refractory acute lymphoblastic leukemia / 中国当代儿科杂志

OBJECTIVES@#To study the safety and short-term effectiveness of blinatumomab in the treatment of childhood relapsed/refractory acute lymphoblastic leukemia (R/R-ALL).@*METHODS@#Six children with R/R-ALL who received blinatumomab treatment from August 2021 to August 2022 were included as subjects, and a retrospective analysis was performed for their clinical data.@*RESULTS@#Among the six children, there were three boys and three girls, with a median age of 10.5 (5.0-13.0) years at the time of inclusion. Of all six children, one had refractory ALL and did not achieve remission after several times of chemotherapy, and 5 relapsed for the first time, with a median time of 30 (9-60) months from diagnosis to relapse. Minimal residual disease (MRD) before treatment was 15.50% (0.08%-78.30%). Three children achieved complete remission after treatment, among whom two had negative conversion of MRD. Five children had cytokine release syndrome (CRS), among whom 3 had grade 1 CRS and 2 had grade 2 CRS. Four children were bridged to allogeneic hematopoietic stem cell transplantation, with a median interval of 50 (40-70) days from blinatumomab treatment to transplantation. The six children were followed up for a median time of 170 days, and the results showed an overall survival rate of 41.7% (95%CI: 5.6%-76.7%) and a median survival time of 126 (95%CI: 53-199) days.@*CONCLUSIONS@#Blinatumomab has good short-term safety and effectiveness in the treatment of childhood R/R-ALL, and its long-term effectiveness needs to be confirmed by studies with a larger sample size.

Association of Anti-β 1 and Anti-M2 Antibodies with Autonomic Nervous System Modulation in Patients with Chronic Chagas Cardiomyopathy

Abstract Background: Different immune mechanisms of myocardial damage involved in the pathophysiology of Chagas disease coexist with high titers of autoantibodies induced by T. cruzi . There are few studies in the literature about the adaptive role of anti-β1 and anti-M2 antibodies in chronic Chagas cardiomyopathy (CCC). Objectives: To evaluate the association between anti-β1 and anti-M2 antibodies with heart rate variability (HRV) parameters on 24h Holter monitoring and the rate-pressure product (RPP) on cardiopulmonary exercise testing (CPET). Methods: Anti-β1 and anti-M2 antibody titers were measured by enzyme-linked immunosorbent assay (ELISA) in 64 patients affected by CCC. Analysis of HRV was performed through the time-domain indices NNs, mean NN, SDNN, SDANN, SDNN index, NNNs, RMSSD, and pNN50. Spearman's correlation coefficient was used to assess the association between antibody titers and numerical variables. The Mann-Whitney test was used for comparison between two groups. Multiple linear regression was used to identify independent variables capable of explaining anti-β1 and anti-M2 antibody titers at the 5% significance level. Results: On 24h Holter, during the period of greatest parasympathetic activation (2:00-6:00 a.m.), an inverse association was found between anti-β1 titers and SDNN (rs=-0.13, p =0.041, n=43), as well as a direct association between anti-M2 titers and SDANN ( r s=0.317, p =0.039, n=43). Regarding CPET variables, anti-β1 titers were directly associated with RPP (rs=0.371, p =0.005, n=56). The subgroup of patients with a normal chronotropic response showed higher anti-β1 titers than the subgroup with an impaired response (p=0.023). RPP was an independent explanatory variable for anti-β1 titers, although with a low coefficient of determination (R2=0.147). Conclusion: The findings of this study suggest that, in patients with CCC, anti-β1 and anti-M2 antibodies may affect HRV parameters. RPP was directly associated with higher anti-β1 titers.

Blinatumomabe para leucemia linfoblástica aguda (LLA) B derivada pediátrica em primeira recidiva medular de alto risco / Blinatumomab for pediatric B-derived acute lymphoblastic leukemia (ALL) in first high-risk spinal cord relapse

INTRODUÇÃO: A leucemia linfoblástica aguda (LLA) pediátrica é uma neoplasia maligna agressiva e heterogênea caracterizada pela proliferação clonal e acúmulo de linfoblastos na medula óssea e sangue periférico. Entre os pacientes pediátricos, mais de 95% atingem remissão completa após o primeiro tratamento e 75% a 85% permanecem livre de doença por cinco anos após o diagnóstico. Porcentagens de 15% a 20% sofrem recidiva que são classificadas em risco padrão (RP) ou alto risco (AR). Em crianças com primeira recidiva medular de alto risco a sobrevida global é de 20%. A recidiva após o tratamento inicial é a segunda maior causa de mortalidade relacionada ao câncer em crianças. Crianças que apresentam recidiva de alto risco ao tratamento inicial são candidatas ao transplante de células hematopoiéticas após atingirem uma segunda remissão completa, entretanto, as chances de remissão diminuem significativamente entre a primeira, segunda e terceiras recidivas. Nessa população, a presença de doença residual

Estudio de costo-efectividad de profilaxis con emicizumab versus agentes hemostáticos alternativos en pacientes con hemofilia A grave en Perú / Cost-effectiveness study of prophylaxis with emicizumab versus bypassing agents in patients with severe hemophilia A in Peru

Contexto La hemofilia es un trastorno hemorrágico de la coagulación que ocurre en uno de cada 5000 nacimientos masculinos. Los pacientes con hemofilia A grave no tratados tienen complicaciones hemorrágicas, incluyendo sangrados articulares y menor sobrevida. El emicizumab es un anticuerpo monoclonal aprobado por los Estados Unidos para la profilaxis rutinaria de pacientes pediátricos y adultos con hemofilia A grave con inhibidores del factor VIII de coagulación. Objetivos Realizar un estudio de costo-efectividad de la profilaxis con emicizumab para niños y adultos con hemofilia A grave, en comparación con el actual manejo de esos pacientes en el Ministerio de Salud y el Seguro Social de Salud de Perú. Metodología Se modeló la transición del paciente entre estados médicos con la metodología de Markov y se estimó a lo largo de su vida costos y efectos incrementales de emicizumab comparados con el actual manejo. Se estimó el impacto presupuestario de emicizumab proyectando costos netos anuales y su valor presente a cinco años. Resultados Emicizumab generaría ahorros en el Ministerio de Salud entre 14,6 y 16,0 por niño y 11,8 por adulto, en US$ millones actuales, y en el Seguro Social de Salud de 12,8 a 14,9 por niño y 40,1 por adulto. Además, se generan ganancias en efectividad, medidas en años de vida ajustados por calidad, de 0,36 por niño y 0,56 por adulto y de 0,25 por niño y 0,36 por adulto en esas respectivas instituciones. El impacto presupuestario sería un ahorro anual neto, en US$ millones, de 12,8 y 15,0 en esas entidades. Conclusión El actual manejo de la enfermedad es muy costoso y con resultados de salud inferiores a los posibles con emicizumab. Este fármaco produciría grandes ahorros y mejor salud. Ambas entidades debieran implementar protocolos para la profilaxis y tratamiento de la hemofilia y financiarla con presupuesto propio.

Settings Hemophilia is a coagulation disorder that occurs in one in 5000 male births. Patients with untreated severe hemophilia A have hemorrhagic complications, including joint bleeds and decreased survival. Emicizumab is a monoclonal antibody approved by the United States for routine prophylaxis of pediatric and adult patients with severe hemophilia A with factor VIII inhibitors. Objectives To perform a cost-effectiveness study of emicizumab prophylaxis for children and adults with severe hemophilia A compared with the current disease management in the Peruvian Ministry of Health and Social Security Health Insurance. Methods The patient transition between medical states was modeled with Markov methodology, and the lifetime costs and incremental effects of emicizumab compared to current management were estimated. The budgetary impact of emicizumab was estimated by projecting annual net costs and its five-year present value. Results In the Ministry of Health, emicizumab would generate savings between 14.6 and 16.0 per child and 11.8 per adult, in current US$ million. Social Security Health Insurance savings would be 12.8 to 14.9 per child and 40.1 per adult. In addition, this strategy would generate effectiveness gains, measured in quality-adjusted life-years, of 0.36 per child and 0.56 per adult and 0.25 per child, and 0.36 per adult in those respective institutions. The budgetary impact would be a net annual saving of 12.8 and 15.0 US$ million in those entities. Conclusions The current management of hemophilia A is very costly and has health outcomes inferior to those possible with emicizumab. This drug would produce significant savings and better patient health. The Ministry of Health and Social Health Insurance should implement hemophilia prophylaxis and treatment protocols and finance this drug.

Analysis of the Effcacy and Safety of Amivantamab in Non-small Cell Lung Cancer Patients with EGFR/MET Gene Abnormalities: A Single Center's Experience / 中国肺癌杂志

BACKGROUND@#Epidermal growth factor receptor (EGFR) and cellular-mesenchymal to epithelial transition factor (c-Met) are widely expressed on cancer cells. There is a synergistic effect of EGFR and HGF/c-Met pathways on proliferation, downstream activation of signal transduction and an additive effect. Studies show that combination of both signaling pathways could potentially be targeted in a synergistic fashion. Amivantamab, a bispecific monoclonal antibody targeting EGFR and c-Met, yielded robust and durable responses in a variety of clinicals trials. However, few researches have reported its efficacy in Chinese non-small cell lung cancer (NSCLC) patients. This study was conducted to evaluate the effectiveness and tolerance of Amivantamab in NSCLC patients with EGFR/MET gene abnormalities at Peking University Cancer Hospital.@*METHODS@#The study enrolled NSCLC patients who received Amivantamab in our hospital between August 2020 and December 2021, and analyzed the response, survival, and treatment-related adverse events.@*RESULTS@#Fifteen patients were enrolled in this research, and six of them received Amivantamab treatment and the other nine patients received Amivantamab plus Lazertinib treatment. The rates of partial response (PR), stable disease (SD), and progressive disease (PD) were 46.7% (7/15), 46.7% (7/15) and 6.7% (1/15), respectively. The overall response rate (ORR) and disease control rate (DCR) were 28.6% (2/7) and 100.0% (7/7) in seven patients with EGFR exon 20 insertion, respectively. The ORR and DCR were 40.0% (2/5) and 100.0% (5/5) in five post-osimertinib EGFR-mutant patients, respectively. After a median follow-up of 8.7 months, the median progression-free survival and overall survival were not reached. The most common treatment-related adverse events were rash (86.7%), paronychia (80.0%), and infusion-related reactions (60.0%), and most of them were graded as 1 to 2. Grade 3 to 4 adverse events included rash (33.3%), alanine aminotransferase elevation (13.3%), gamma-glutamyl transpeptidase elevation (13.3%), peripheral edema (6.7%), thromboembolism (6.7%), interstitial lung disease (6.7%), and thrombocytopenia (6.7%).@*CONCLUSIONS@#Amivantamab was effective in Chinese NSCLC patients with EGFR exon 20 insertion and post-Osimertinib EGFR-mutant patients, similar to the results of clinical trials conducted in western countries. Amivantamab was well tolerated and emphases should be put on adverse events such as rash, paronychia, and infusion-related reactions.

Advances in Treatment of Non-small Cell Lung Cancer Harboring EGFR Exon 20 Insertion Mutations / 中国肺癌杂志

Epidermal growth factor receptor (EGFR) exon 20 insertion mutations are the third most prevalent activating EGFR mutation in non-small cell lung cancer (NSCLC), accounting for 5%-12% of all EGFR mutations in NSCLC cases. Patients harboring EGFR exon 20 insertion mutations exhibit similar clinical characteristics except for worse prognosis as compared to those with 'classic' EGFR mutations. EGFR exon 20 insertion mutations are considered as a heterogeneous class of alterations that cause different conformational changes in EGFR. The majority of mutations (almost 90% of cases) is positioned in the loop that immediately follows the C-terminal of the C-helix, and the most widely reported subtype of insertion mutations is D770_N771>ASVDN(A767_V769dupASV) with frequency of 21%-28%. NSCLC patients with EGFR exon 20 insertion mutations show primary drug resistance to previously approved EGFR tyrosine kinase inhibitors and are generally insensitive to conventional chemotherapy and immunotherapy. The recently approved targeted drugs Amivantamab and Mobocertinib shift the treatment paradigm for NSCLC patients harboring EGFR exon 20 insertion mutations. There are also several new compounds targeting NSCLC EGFR exon 20 insertion mutations are in development. In this article, we provide a through overview on the treatment development in EGFR exon 20 insertion mutant NSCLC.
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Emerging immunological strategies: recent advances and future directions / 医学前沿

Immunotherapy plays a compelling role in cancer treatment and has already made remarkable progress. However, many patients receiving immune checkpoint inhibitors fail to achieve clinical benefits, and the response rates vary among tumor types. New approaches that promote anti-tumor immunity have recently been developed, such as small molecules, bispecific antibodies, chimeric antigen receptor T cell products, and cancer vaccines. Small molecule drugs include agonists and inhibitors that can reach the intracellular or extracellular targets of immune cells participating in innate or adaptive immune pathways. Bispecific antibodies, which bind two different antigens or one antigen with two different epitopes, are of great interest. Chimeric antigen receptor T cell products and cancer vaccines have also been investigated. This review explores the recent progress and challenges of different forms of immunotherapy agents and provides an insight into future immunotherapeutic strategies.

Bispecific antibodies in clinical tumor therapy / 生物工程学报

Bispecific antibody (BsAb) has two different antigen-binding sites, divided into the "IgG-like" format and the "non-IgG-like" format. Different formats have different characteristics and applications. BsAb has higher sensitivity and specificity than conventional antibodies, with special functions such as recruitment of immune cells and blocking of dual signaling pathways, playing an important role in immune-diagnosis and therapy. With the deterioration of the global environment and the irregular living habits of people, the incidence of tumor is becoming higher and higher. Tumor becomes the most serious fatal disease threatening human health after cardiovascular disease. There are 12 million estimated new tumor cases each year worldwide. The major clinical treatments of tumor are surgical resection, chemoradiotherapy, target therapy. Tumor immunotherapy is a novel approach for tumor treatment in recent years, and activates human immune system to control and kill tumor cells. Although the traditional monoclonal antibodies have already acquired some therapeutic effects in tumor targeted therapy and immunotherapy, they induce drug resistance resulted from the heterogeneity and plasticity of tumors. Binding to two target antigens at the same time, BsAb has been used in the clinical treatment of tumors and obtained promising outcomes. This review elaborates the research progress and applications of bispecific antibody in clinical tumor therapy.

Primera experiencia de tratamiento con emicizumab en un paciente con hemofilia A severa e inhibidor de alto título en Uruguay / First report of emicizumab use in a patient with severe haemophilia A and high-titer inhibitor in Uruguay / Primeira experiência de tratamento com emicizumab em paciente com hemofilia A grave e inibidor de alto título no Uruguai

La hemofilia A es una coagulopatía congénita causada por la deficiencia o el mal funcionamiento del factor VIII de la coagulación. Una de las complicaciones más graves del tratamiento de la hemofilia A es el desarrollo de inhibidores que hacen que la terapia de reemplazo con FVIII sea ineficaz, dificultando la prevención y el control de los sangrados. El emicizumab es un anticuerpo monoclonal humanizado biespecífico dirigido contra los factores FIXa y FX, que imita la función de cofactor del FVIII. El tratamiento profiláctico con emicizumab es seguro y eficaz para prevenir hemorragias en los pacientes con hemofilia A con y sin inhibidores. Se presenta el caso del primer paciente tratado con emicizumab en Uruguay.

Haemophilia A is a congenital coagulopathy caused by a deficiency or malfunction of coagulation factor VIII. One of the most serious complications of haemophilia A treatment is the development of inhibitors that render FVIII replacement therapy ineffective, making it difficult to prevent and control bleeding. Emicizumab is a humanized bispecific monoclonal antibody directed against factors FIXa and FX, which mimics the cofactor function of FVIII. Emicizumab has been shown to be safe and effective as prophylaxis to prevent bleeding in haemophilia A patients with or without inhibitors to FVIII. We report the first patient treated with emicizumab in Uruguay.

A hemofilia A é uma coagulopatia congênita que se caracteriza pela ausência ou mau funcionamento do factor VIII da coagulação. Uma das complicações mais sérias do tratamento da hemofilia A é o desenvolvimento de inibidores que tornam a terapia de reposição do FVIII ineficaz, dificultando a prevenção e o controle do sangramento. O emicizumab é um anticorpo monoclonal biespecífico humanizado dirigido contra os fatores FIXa e FX, que imita a função de cofator do FVIII. O tratamento profilático com emicizumab é seguro e eficaz na prevenção de sangramento em pacientes com hemofilia A com e sem inibidores. É apresentado o caso do primeiro paciente tratado com emicizumabe no Uruguai.

Advances in research of bispecific antibodies for antivirus therapy / 生物工程学报

With the rapid development of antibody genetic engineering, bispecific antibody technology has been advanced. They are capable of binding two or more different epitopes simultaneously, thus offering specific advantages over natural monoclonal antibodies in immunotherapy. Bispecific antibodies have been successfully used in cancer therapy (e.g. melanoma, Hodgkin's lymphoma, liver cancer, and stomach cancer) and inflammation therapy (e.g. rheumatoid arthritis, psoriasis and Crohn's disease), but are still in their early stage for viral immunotherapy. In this study, we reviewed the research progress of bispecific antibodies for immunotherapy of virus infections, especially those with good effects in vivo and in vitro, to provide references for the research and development of bispecific antibodies for antivirus treatment.

Potent and conditional redirected T cell killing of tumor cells using Half DVD-Ig

Novel biologics that redirect cytotoxic T lymphocytes (CTLs) to kill tumor cells bearing a tumor associated antigen hold great promise in the clinic. However, the ability to safely and potently target CD3 on CTL toward tumor associated antigens (TAA) expressed on tumor cells remains a challenge of both technology and biology. Herein we describe the use of a Half DVD-Ig format that can redirect CTL to kill tumor cells. Notably, Half DVD-Ig molecules that are monovalent for each specificity demonstrated reduced non-specific CTL activation and conditional CTL activation upon binding to TAA compared to intact tetravalent DVD-Ig molecules that are bivalent for each specificity, while maintaining good drug like properties and appropriate PK properties.

Current progress in innovative engineered antibodies

As of May 1, 2017, 74 antibody-based molecules have been approved by a regulatory authority in a major market. Additionally, there are 70 and 575 antibody-based molecules in phase III and phase I/II clinical trials, respectively. These total 719 antibody-based clinical stage molecules include 493 naked IgGs, 87 antibody-drug conjugates, 61 bispecific antibodies, 37 total Fc fusion proteins, 17 radioimmunoglobulins, 13 antibody fragments, and 11 immunocytokines. New uses for these antibodies are being discovered each year. For oncology, many of the exciting new approaches involve antibody modulation of T-cells. There are over 80 antibodies in clinical trials targeting T cell checkpoints, 26 T-cell-redirected bispecific antibodies, and 145 chimeric antigen receptor (CAR) cell-based candidates (all currently in phase I or II clinical trials), totaling more than 250 T cell interacting clinical stage antibody-based candidates. Finally, significant progress has been made recently on routes of delivery, including delivery of proteins across the blood-brain barrier, oral delivery to the gut, delivery to the cellular cytosol, and gene- and viral-based delivery of antibodies. Thus, there are currently at least 864 antibody-based clinical stage molecules or cells, with incredible diversity in how they are constructed and what activities they impart. These are followed by a next wave of novel molecules, approaches, and new methods and routes of delivery, demonstrating that the field of antibody-based biologics is very innovative and diverse in its approaches to fulfill their promise to treat unmet medical needs.

Progress in the study of Her2-targeted cancer therapeutic antibodies / 药学学报

Tumor surface antigen human epidermal growth factor receptor 2 (Her2) is a type I receptor tyrosine kinase, which belongs to human epidermal growth factor receptor family. Her2-overexpression is associated with tumorigenesis and metastasis. Due to significant clinical effects, Her2-targeted cancer therapy especially therapeutic antibody has become the hot spot in the field of cancer treatment. Anti-Her2 antibody drugs include monoclonal antibodies, antibody-drug conjugates, bispecific antibodies and emerging "two in one" antibody. Based on structure and function of Her2, this review focuses on recent advances in active mechanisms and clinical researches of these antibodies.

Expression and characterization of a bispecific antibody targeting TNF-α and ED-B containing fibronectin / 生物工程学报

To enhance the specificity of anti-TNF-α single chain Fv antibody (TNF-scFv) to inflamed site, we constructed a bispecific antibody BsDb that targets TNF-α and ED-B-containing fibronectin (B-FN) by covalently linking TNF-scFv and the anti-ED-B scFv L19 at the gene level via a flexible peptide linker deriving from human serum albumin. BsDb was successfully secreted from Pichia pastoris as functional protein, identified by immunoblotting, and purified to homogeneity with affinity chromatography. BsDb retained the immunoreactivity of its original antibodies TNF-scFv and L19, and showed a marked gain in antigen-binding affinity and in TNF-α-neutralizing ability, when compared to TNF-scFv and L19 that were produced in Escherichia coli. In the adjuvant-induced arthritis (AIA) mice model, BsDb showed selective accumulation and retention in the inflamed paws but rapid clearance from blood, resulting in high arthritic paw to blood ratios. These data indicate that BsDb is endowed with high specificity to inflamed site and low toxicity to normal tissues and holds great potential for in vivo application for the targeted therapy of RA and other chronic inflammatory diseases.

Therapeutic efficacy of three bispecific antibodies on rheumatoid arthritis mice models / 药学学报

In order to obtain the lead compound for treatment of rheumatoid arthritis (RA), in this study, therapeutic efficacy of three bispecific antibodies (BsAB-1, BsAB-2 and BsAB-3) against both hIL-1beta and hIL-17 were compared on CIA model mice. First, by ELISA method we compared the binding capacity of the three bispecific antibodies to the two antigens. The results showed that all three antibodies could simultaneously bind both antigens, among these antibodies, BsAB-1 was superior over BsAB-2 and BsAB-3. CIA model was established with chicken type II collagen (CII) and developed RA-like symptoms such as ankle swelling, skin tight, hind foot skin hyperemia. The CIA mice were treated with three antibodies once every two days for total of 29 days. Compared with the CIA model mice, the RA-like symptoms of the antibody treated-mice significantly relieved, while the BsAB-1 treated-mice were almost recovered. CII antibody level in the serum and cytokines (IL-2, IL-1beta, IL-17A and TNF-alpha) expression in the spleen were examined. Compared with the CIA model mice, all three antibodies could significantly reduce CII antibody and cytokine expression levels. BsAB-1 antibody was more potent than BsAB-2 and BsAB-3. In summary, BsAB-1 is superior over BsAB-2 and BsAB-3 in amelioration of RA symptoms and regulation of CII antibody production and pro-inflammatory cytokine expression, therefore, BsAB-1 can be chosen as a lead compound for further development of drug candidate for treatment of RA.

Construction and functional analysis of a bispecific antibody that targets TNF-α and ED-B / 药学学报

In order to enhance the specificity of TNF-α monoclonal antibody to inflamed site, a bispecific antibody BsDb that targets TNF-α and the extra-domain B (ED-B) of fibronectin (FN) was constructed by covalently linking the anti-TNF-α single chain Fv antibody (TNF-scFv) and the anti-ED-B scFv L19 via a flexible peptide linker deriving from human serum albumin (HSA). ED-B is an antigen specifically expressed at the inflamed site. BsDb is expressed in E. coli, identified by immunoblot, and purified with affinity chromatography. This was followed by further examination of its bioactivities and pharmacokinetics. We demonstrated that BsDb retained the immunoreactivity of its original antibodies as it could simultaneously bind to TNF-α and ED-B and neutralize the biological action of TNF-α. In the collagen-induced arthritis mice model, BsDb selectively accumulate in the inflamed joint with a maximal uptake of (12.2 ± 1.50)% ID/g in a single inflamed paw and retain in the inflamed paw for at least 72 h. In contrast, BsDb showed a short serum half-life of (0.50 ± 0.05) h and a rapid clearance from normal tissues. The findings reported herein indicate that BsDb has good specificity to the inflamed site and low toxicity to normal tissues. BsDb is therefore likely to have greater clinical applications in the treatment of rheumatoid arthritis and other autoimmune diseases. This laid a stable basis for its preclinical study.

Simultaneous Inhibition of CXCR4 and VLA-4 Exhibits Combinatorial Effect in Overcoming Stroma-Mediated Chemotherapy Resistance in Mantle Cell Lymphoma Cells

There is growing evidence that crosstalk between mantle cell lymphoma (MCL) cells and stromal microenvironments, such as bone marrow and secondary lymphoid tissues, promotes tumor progression by enhancing survival and growth as well as drug resistance of MCL cells. Recent advances in the understanding of lymphoma microenvironment have led to the identification of crucial factors involved in the crosstalk and subsequent generation of their targeted agents. In the present study, we evaluated the combinatory effect of blocking antibodies (Ab) targeting CXCR4 and VLA-4, both of which were known to play significant roles in the induction of environment-mediated drug resistance (EMDR) in MCL cell line, Jeko-1. Simultaneous treatment with anti-CXCR4 and anti-VLA-4 Ab not only reduced the migration of Jeko-1 cells into the protective stromal cells, but also enhanced sensitivity of Jeko-1 to a chemotherapeutic agent to a greater degree than with either Ab alone. These combinatorial effects were associated with decreased phosphorylation of ERK1/2, AKT and NF-kappaB. Importantly, drug resistance could not be overcome once the adhesion of Jeko-1 to the stromal occurred despite the combined use of Abs, suggesting that the efforts to mitigate migration of MCLs should be attempted as much as possible. Our results provide a basis for a future development of therapeutic strategies targeting both CXCR4 and VLA-4, such as Ab combinations or bispecific antibodies, to improve treatment outcomes of MCL with grave prognosis.

Efficacy of bispecific targeted immunotoxin DTATEGF against NSCLC brain metastatic tumor PC9-BrM3 cells / 中南大学学报(医学版)

OBJECTIVE@#To investigate the in vitro and in vivo anticancer efficacy of the immunotoxin DTATEGF against human NSCLC brain metastatic tumor PC9-BrM3 cell line.@*METHODS@#The effect of the immunotoxin DTATEGF was tested for its ability to inhibit the proliferation of PC9-BrM3 cells in vitro by MTT assay. The cell cycle and the apoptosis of cells with 1 pmol/L DTATEGF were examined by flow cytometry. In vivo, 2 μg of DTATEGF or control Bickel3 was given intratumor to nude mice with established PC9-BrM3 xenografts on their hips, and tumor volumes were measured and tumor samples were investigated by immunchistochemistry SABC method. The microvessel density (MVD) was measured in each group.@*RESULTS@#In vitro, DTATEGF killed PC9-BrM3 cells and showed an IC50 of 1 pmol/L. The apoptotic rate in the 1 pmol/L DTATEGF group was (64.0±0.5)% , significantly higher than that in the control group (1.5±0.4)% (P<0.01). The cell cycle was obviously inhibited by DTATEGF in a dose-dependent manner. The percentage of cells treated with 1 pmol/L DTATEGF in SubG0/G1 phase was (32.0±1.5)%, significantly higher than that in the control group (2.0±0.4)% (P<0.01). In vivo, DTATEGF significantly inhibited the growth of PC9-BrM3 hip tumors (P<0.05). The MVD of the DTATEGF group was (15.6±4.6)/mm2, significantly lower than that of the control group (31.2±5.4)/mm2 (P<0.01).@*CONCLUSION@#DTATEGF inhibits the growth of the PC9-BrM3 cell line and induces its apoptosis. It is highly efficacious against human metastatic NSCLC brain tumor and against neovascularization.

Application of bispecific antibody against antigen and hapten for immunodetection and immunopurification

We present a bispecific antibody that recognizes an antigen and a hapten and can be applied to various biological assays, including immunoblotting and immunoprecipitation. In immunoblot analysis of serum, an anti-C5 x anti-cotinine bispecific tandem single-chain variable fragment (scFv)-Fc fusion protein and cotinine-conjugated horseradish peroxidase (HRP) generated a clean signal without the high background that was observed in a parallel experiment using HRP-conjugated goat anti-rabbit immunoglobulin G (Fc-specific) antibody. In immunoprecipitation analysis of serum, use of the bispecific tandem scFv-Fc fusion protein and cotinine-crosslinked magnetic beads significantly reduced the amount of protein contaminants compared with a parallel experiment done with protein A agarose beads. In subsequent immunoblot analysis, use of cotinine-HRP as the secondary probe instead of HRP-conjugated goat anti-rabbit IgG (Fc-specific) antibody successfully eliminated the band corresponding to the bispecific tandem scFv-Fc fusion protein.

An anti-human ovarian carcinoma and CD3 bispecific single-chain antibody mediates CDR3 spectratype drift of T cell receptor alpha and beta chains / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the drift of T cell receptor (TCR) Vα and Vβ gene family CDR3 spectratype in response to ovarian carcinoma cells mediated by an anti-human ovarian carcinoma/CD3 bispecific single-chain antibody (BHL-1), and explore the mechanism of the bispecific single-chain antibody-mediated T cell immune response.</p><p><b>METHODS</b>Immunoscopic spectratyping technique was used to analyze the TCR repertoire diversity (CDR3 spectratype distribution) of the T cells from 6 healthy donors before and after stimulation of the cells with human ovarian carcinoma in the presence of BHL-1. The predominant usage of TCR α and Vβ chain CDR3 was analyzed after the stimulation, and sequence analysis was performed for the CDR3 region of the monoclonal T cells.</p><p><b>RESULTS</b>The spectratypes of Vα and Vβ gene family TCR CDR3 region showed a Gaussian distribution before stimulation of the T cells from the 6 donors. After stimulation of the T cells, CDR3 spectratype drift occurred in the T cells, and some TCR Vα and Vβ families showed an anomalous and oligoclonal expansion. Different CDR3 sequences of the Vα and Vβ gene family TCR were found in the monoclonal T cells stimulated with BHL-1.</p><p><b>CONCLUSION</b>CDR3 spectratype drift occurs in TCR α and Vβ chains of T cells after stimulation with human ovarian carcinoma cells and BHL-1, indicating that the predominant usage of TCR Vα and Vβ families is associated with the specific T cell immune response mediated by BHL-1.</p>