- The B-NDG mouse is a perfect tool for immune system humanization and patient derived xenograft transplantation
- The B-NDG mice (NOD-Prkdcscid Il2rgtm1/Bcgen), independently developed by Biocytogen, display a severe immunodeficiency phenotype, with no mature T, B or functional NK cells, and deficient in cytokine signaling. The B-NDG mouse is one of the best models for reconstitution of human immune system using peripheral blood mononuclear cells (PBMC) or hematopoietic stem cells (CD34+).
- Humanized knock-in mouse models for evaluating in vivo efficacy of immune-oncology drugs targeting inhibitory immune checkpoint molecules
- In most cases, a human monoclonal antibody does not have mouse cross-reactivity. Therefore, we generated humanized knock-in mouse to evaluate the in vivo efficacy of human IO antibodies. For example, human PD-1 knock-in (B-hPD-1) mice were generated with a chimeric PD-1 receptor, which is recognizable by human PD-1 antibodies, and can be used to test human PD-1 antibody in vivo efficacy.
- Evaluation of the in vivo efficacy of immune-oncology drugs targeting stimulatory immune checkpoint molecules using humanized knock-in mice
- We generated humanized knock-in mice to evaluate the in vivo efficacy of human IO antibodies. For example, human OX40 knock-in (B-hOX40) mice were generated with a chimeric OX40 receptor, which is recognizable by stimulatory human OX40 antibodies. Additionally, more knock-in mice targeting stimulatory immune checkpoint molecules were developed and validated, such as B-hCD137, B-hGITR, B-hCD27, B-hCD40, B-hCD28, B-hCD3 et al,.
- Balancing the efficacy and toxicity of anti-CD47 antibodies by direct screening in humanized mouse models
- CD47 is a transmembrane protein found on the surface of many cells in the body. Its expression is often up-regulated in many cancer cells. The receptor of CD47 was identified as SIRPa, which is expressed on phagocytic cells. Engagement of SIRPa by CD47 serves as “do not eat me” signal, thus inhibiting the phagocytic activity of macrophages.
- Novel CTLA4 antibodies demonstrate potent anti-tumor activity in a humanized mouse model
- CTLA4 (cytotoxic T-lymphocyte-associated protein 4), is a member of the immunoglobulin superfamily. It is expressed in T cells upon activation and transmits an inhibitor signal to T cells. Also, it is constitutively expressed in regulatory T cells (Tregs) which is associated with their immunosuppressive phenotype. CTLA4 is homologous to the co-stimulatory protein CD28, and both receptor binds to CD80 and CD86.
- Developing novel anti-OX40 antibodies on Biocytogen’s in vivo drug screening platform
- We developed a cohort of OX40 specific antibodies using the classic hybridoma technology. In order to screen their efficacy to stimulate anti-tumor activity in live animals, we managed to rank these antibodies using Biocytogen’s humanized mouse platform of immune checkpoints. Specifically, we utilized humanized OX40 mice (h-OX40) and implanted syngeneic tumors subcutaneously, followed by treating mice with purified testing antibodies.