An Anti-HER2 Monoclonal Antibody H 2 Mab-41 Exerts Antitumor Activities in Mouse Xenograft Model Using Dog HER2-Overexpressed Cells

February 15, 2022 0 Comments

Overexpression of human epidermal growth factor receptor 2 (HER2) has been reported in a variety of cancer types, including breast, lung, gastric, pancreatic, and colorectal cancers. Trastuzumab, a humanized anti-HER2 monoclonal antibody (mAb), has been shown to provide significant survival benefits in HER2-overexpressing breast cancer and gastric cancer patients. Previously, an anti-HER2 mAb, H2Mab-41 (IgG2b, kappa), was developed in our laboratory and its antitumor activity was demonstrated in mouse xenograft models of human colon cancer. The present study aimed to investigate the ability of H2Mab-41 to induce antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) in dog HER2 (dHER2)-overexpressed cell lines, and thus exert its antitumor activity against dHER2-overexpressed tumors in vivo.
Flow cytometry results demonstrated the cross-reactivity of H2Mab-41 with dHER2. Further evaluation of interaction between H2Mab-41 and dHER2-overexpressed CHO-K1 (CHO/dHER2) cells indicated moderate binding affinity of H2Mab-41 toward dHER2, with a dissociation constant (KD) of 2.6 × 10-8 M. In vitro analysis revealed that the administration of H2Mab-41 induced high levels of ADCC and CDC in CHO/dHER2 cells. Furthermore, intraperitoneal administration of H2Mab-41 in mouse xenograft models of CHO/dHER2 resulted in significant inhibition of tumor development compared to the control mouse IgG. Thus, the findings of the present study demonstrated the in vivo safety and efficacy of H2Mab-41, highlighting its suitability to be included as a part of a therapeutic regimen for dHER2-expressing canine cancers.

Converting an Anti-Mouse CD4 Monoclonal Antibody into an scFv Positron Emission Tomography Imaging Agent for Longitudinal Monitoring of CD4 + T Cells

Immuno-positron emission tomography (PET), a noninvasive imaging modality, can provide a dynamic approach for longitudinal assessment of cell populations of interest. Transformation of mAbs into single-chain variable fragment (scFv)-based PET imaging agents would allow noninvasive tracking in vivo of a wide range of possible targets. We used sortase-mediated enzymatic labeling in combination with PEGylation to develop an anti-mouse CD4 scFv-based PET imaging agent constructed from an anti-mouse CD4 mAb. This anti-CD4 scFv can monitor the in vivo distribution of CD4+ T cells by immuno-PET.
We tracked CD4+ and CD8+ T cells in wild-type mice, in immunodeficient recipients reconstituted with monoclonal populations of OT-II and OT-I T cells, and in a B16 melanoma model. Anti-CD4 and -CD8 immuno-PET showed that the persistence of both CD4+ and CD8+ T cells transferred into immunodeficient mice improved when recipients were immunized with OVA in CFA. In tumor-bearing animals, infiltration of both CD4+ and CD8+ T cells increased as the tumor grew. The approach described in this study should be readily applicable to convert clinically useful Abs into the corresponding scFv PET imaging agents.

Research progress in the rapid preparation of monoclonal antibodies of mouse hybridoma

Mouse hybridoma monoclonal antibody is the most commonly used antibody in immunology because of its stable source, easy preparation in later stage and high yield. The traditional time-consuming and laborious hybridoma preparation technology could not meet the growing market demand. In this paper, we describe the rapid preparation techniques involved in antigen design and screening, B cell enrichment and screening, transgenic myeloma cells, fusion technology improvement, positive hybridoma cell screening and rapid detection of monoclonal antibody performance, to provide a reference for rapid preparation of mouse hybridoma monoclonal antibody.

Murine Monoclonal Antibodies against the Receptor Binding Domain of SARS-CoV-2 Neutralize Authentic Wild-Type SARS-CoV-2 as Well as B.1.1.7 and B.1.351 Viruses and Protect In Vivo in a Mouse Model in a Neutralization-Dependent Manner

After first emerging in late 2019 in China, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has since caused a pandemic leading to millions of infections and deaths worldwide. Vaccines have been developed and authorized, but the supply of these vaccines is currently limited. With new variants of the virus now emerging and spreading globally, it is essential to develop therapeutics that are broadly protective and bind conserved epitopes in the receptor binding domain (RBD) or the full-length spike protein of SARS-CoV-2.
In this study, we generated mouse monoclonal antibodies (MAbs) against different epitopes on the RBD and assessed binding and neutralization of authentic SARS-CoV-2. We demonstrate that antibodies with neutralizing activity, but not nonneutralizing antibodies, lower viral titers in the lungs when administered in a prophylactic setting in vivo in a mouse challenge model. In addition, most of the MAbs cross-neutralize the B.1.351 as well as the B.1.1.7 variant in vitro.
IMPORTANCE Cross-neutralization of SARS-CoV-2 variants by RBD-targeting antibodies is still not well understood, and very little is known about the potential protective effect of nonneutralizing antibodies in vivo. Using a panel of mouse monoclonal antibodies, we investigate both of these points.

Effects of Mild and Moderate Monoclonal Antibody Dose on Inflammation, Bone Loss, and Activation of the Central Nervous System in a Female Collagen Antibody-induced Arthritis Mouse Model

Induction of severe inflammatory arthritis in the collagen antibody-induced arthritis (CAIA) murine model causes extensive joint damage and pain-like behavior compromising analysis. While mild models are less severe, their reduced, variable penetrance makes assessment of treatment efficacy difficult. This study aimed to compare macroscopic and microscopic changes in the paws, along with central nervous system activation between a mild and moderate CAIA model.
  • Balb/c mice (n=18) were allocated to control, mild, and moderate CAIA groups. Paw inflammation, bone volume (BV), and paw volume (PV) were assessed.
  • Histologically, the front paws were assessed for joint inflammation, cartilage damage, and pre/osteoclast-like cells and the lumbar spinal cord and the periaqueductal gray (PAG) region of the brain for glial reactivity.
  • A moderate CAIA dose induced (1) significantly greater local paw inflammation, inflammatory cell infiltration, and PV; (2) significantly more osteoclast-like cells on the bone surface and within the surrounding soft tissue; and (3) significantly greater glial reactivity within the PAG compared with the mild CAIA model.
  • These findings support the use of a moderate CAIA model (higher dose of monoclonal antibodies with low-dose lipopolysaccharide) to induce more consistent histopathological features, without excessive joint destruction.

Immunological studies on chicken interferon-kappa using an antigen-capture ELISA developed using new mouse monoclonal antibodies

Interferon (IFN)-κ is a type I IFN that plays a central role in anti-viral defense and host immune response. The functions of type I IFNs have not been clearly defined in chickens compared to those of their mammalian counterparts. In this study, we developed an antigen-capture ELISA using newly developed mouse monoclonal antibodies (mAbs) which are specific for chicken IFN-κ (chIFN-κ) and showed that this ELISA can measure native chIFN-κ production during the activation of macrophages by polyinosinic:polycytidylic acid (poly I:C). The recombinant chicken IFN-κ expressed in Escherichia coli was used to immunize mice. Five mAbs that specifically recognized chIFN-κ were selected and characterized based on their specificity and binding activity toward chIFN-κ via indirect ELISA and western blotting.
To develop a capture ELISA for chicken IFN-κ, two sets of the best capture and detection mAbs combinations were identified via pairing assays. To validate the antigen-capture assay, the production of native IFN-κ was induced in chicken HD11 macrophages using poly I:C. Furthermore, qRT-PCR was used to confirm the transcript-level expression of IFN-κ in HD11 cells at 24 and 48 h.
The neutralizing effects of anti-chIFN-κ mAbs were evaluated based on their ability to block the induction of IFN-stimulated genes (ISGs) in DF-1 fibroblast cells stimulated with recombinant chIFN-κ proteins. All five mAbs blocked the mRNA expression of ISGs in a dose-dependent manner. Our results validate the specificity and utility of these newly developed mAbs for the detection of native chicken IFN-κ. This novel antigen-capture ELISA will be a valuable tool for fundamental and applied research involving IFN-κ in the normal and diseased states.

Mouse Monoclonal Antibody

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Mouse Monoclonal Antibody

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Mouse Monoclonal Antibody

28298-100Tests SAB 100 Tests 499 EUR

Mouse Monoclonal Antibody

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PCNA Mouse Monoclonal Antibody

21801-100ul SAB 100ul 252 EUR

PCNA Mouse Monoclonal Antibody

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PCNA Mouse Monoclonal Antibody

37978-100ul SAB 100ul 252 EUR

PCNA Mouse Monoclonal Antibody

37978-50ul SAB 50ul 187 EUR

EGFR Mouse Monoclonal Antibody

37996-100ul SAB 100ul 252 EUR

EGFR Mouse Monoclonal Antibody

37996-50ul SAB 50ul 187 EUR

CD20 Mouse Monoclonal Antibody

38003-100ul SAB 100ul 252 EUR

CD20 Mouse Monoclonal Antibody

38003-50ul SAB 50ul 187 EUR

CD23 Mouse Monoclonal Antibody

38004-100ul SAB 100ul 252 EUR

CD23 Mouse Monoclonal Antibody

38004-50ul SAB 50ul 187 EUR

CD68 Mouse Monoclonal Antibody

38005-100ul SAB 100ul 252 EUR

CD68 Mouse Monoclonal Antibody

38005-50ul SAB 50ul 187 EUR

CK19 Mouse Monoclonal Antibody

38006-100ul SAB 100ul 252 EUR

CK19 Mouse Monoclonal Antibody

38006-50ul SAB 50ul 187 EUR

p53 Mouse Monoclonal Antibody

38007-100ul SAB 100ul 252 EUR

p53 Mouse Monoclonal Antibody

38007-50ul SAB 50ul 187 EUR

CK7 Mouse Monoclonal Antibody

38009-100ul SAB 100ul 252 EUR

CK7 Mouse Monoclonal Antibody

38009-50ul SAB 50ul 187 EUR

CK8 Mouse Monoclonal Antibody

38010-100ul SAB 100ul 252 EUR

CK8 Mouse Monoclonal Antibody

38010-50ul SAB 50ul 187 EUR

CK16 Mouse Monoclonal Antibody

38011-100ul SAB 100ul 252 EUR

CK16 Mouse Monoclonal Antibody

38011-50ul SAB 50ul 187 EUR

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