• Biomedical Science Letters
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• v.26 no.3
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• pp.136-148
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• 2020

A bispecific antibody (BsAb) is an artificial protein containing two kinds of specific antigen binding sites. BsAb can connect target cells to functional cells or molecules, and thus stimulate a directed immune response. Last several decades a wide variety of bsAb formats and production technologies have been developed. BsAbs are constructed either chemically or biologically, exploiting techniques like cell fusion and recombinant DNA technologies. There are over 100 different formats of bsAb so far developed, but they could be classified into the two main categories such as Fc-based (with a Fc region) bsAbs and fragment-based (without a Fc region) bsAbs. BsAb has a broad application prospect in tumor immunotherapy and drug delivery. Here, we present a brief introduction to the structure of antibody, pharmacological mechanisms of antibodies and the trend in the production technologies of therapeutic antibodies. In addition, we address a review on the current status of various bsAb format development and their production technologies together with global situation in the clinical studies of bsAb.

• YAKHAK HOEJI
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• v.54 no.6
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• pp.500-506
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• 2010

TNF-${\alpha}$ and VCAM-1 play a pivotal role in the pathogenesis of rheumatoid arthritis, and the development of drugs targeting these molecules has extended the therapeutical approaches to rheumatoid arthritis patients. Bispecific antibodies combine the antigen-binding sites of two antibodies within a single molecule and thus they are able to bind to two different epitopes simultaneously. A specific bispecific antibody format termed "Di-diabody" was made for the efficient approach to anti-inflammation. In this study, the DNA vector construct of Di-diabody was built up against two antigens, VCAM-1 and TNF-${\alpha}$. For evaluating this Di-diabody as a bispecific antibody on the efficacy of anti-inflammation, the proteins were analyzed according to each antigen binding affinity and cell based assay related separate molecules. The 7H/Humira Di-diabody produced in this study interacted with its ligands, VCAM-1 and TNF-${\alpha}$, respectively. Also, this antibody exhibited the similar functional activities as compared to 7H-IgG in respect to inhibition of hVCAM-1-induced cell adhesion and Humira-IgG in respect to inhibition of TNF-${\alpha}$ induced cytotoxicity. Further study to elucidate the pharmacological significance of the Di-diabody is warranted using experimental animals.

• IMMUNE NETWORK
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• v.22 no.1
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• pp.4.1-4.22
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• 2022

In the era of immunotherapeutic control of cancers, many advances in biotechnology, especially in Ab engineering, have provided multiple new candidates as therapeutic immuno-oncology modalities. Bispecific Abs (BsAbs) that recognize 2 different antigens in one molecule are promising drug candidates and have inspired an upsurge in research in both academia and the pharmaceutical industry. Among several BsAbs, T cell engaging BsAb (TCEB), a new class of therapeutic agents designed to simultaneously bind to T cells and tumor cells via tumor cell specific antigens in immunotherapy, is the most promising BsAb. Herein, we are providing an overview of the current status of the development of TCEBs. The diverse formats and characteristics of TCEBs, in addition to the functional mechanisms of BsAbs are discussed. Several aspects of a new TCEB-Blinatumomab-are reviewed, including the current clinical data, challenges of patient treatment, drawbacks regarding toxicities, and resistance of TCEB therapy. Development of the next generation of TCEBs is also discussed in addition to the comparison of TCEB with current chimeric antigen receptor-T therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2795-2798
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• 2012

Objective: This study is conducted to evaluate the effects of anti-HER-2${\times}$anti-CD3 bi-specific antibodies(BsAb) on HER-2/neuover-expressing human colorectal carcinoma cells. Methods: Growth was assessed by MTT assays after exposure of HCT-116 cells to Herceptin, anti-CD3 and BsAb antibodies. Immunocytochemistry was applied to test the HER-2 level of HCT-116. In a nude mouse model, HER-2${\times}$CD3 BsAb was combined with effector cells (peripheral blood lymph cells from normal human being) for observations on in Vivo growth of tumors. Results: Compared with the control group, using effector cells combined with anti-CD3 McAb, Herceptin or HER2${\times}$CD3 BsAb, tumor cell growth in vitro and in vivo was significantly inhibited (P<0.05), most remarkably in the HER2${\times}$CD3 BsAb case. The growth of xenografts with HER2${\times}$CD3 BsAb combined with effector cells was also significantly inhibited when compared with the anti-CD3 McAb or Herceptin groups (P<0.05). Conclusion: HER-2/neu might be a useful target for immunotherapy in colorectal carcinoma, anti-HER2${\times}$anti-CD3 BsAb exerting clear anti-tumor effects.

• IMMUNE NETWORK
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• v.14 no.6
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• pp.296-306
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• 2014

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-${\kappa}B$. 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.