<img height="1" width="1" src="https://www.facebook.com/tr?id=1582471781774081&amp;ev=PageView &amp;noscript=1">
  • Menu
  • crown-logo-symbol-1-400x551

Find it Quickly

Get Started

Select the option that best describes what you are looking for

  • Services
  • Models
  • Scientific Information

Search Here For Services

Click Here to Start Over

Search Here For Models

Click Here to Start Over

Search Here For Scientific Information

Click Here to Start Over

In Vitro

Boost oncology drug discovery with XenoBase®, featuring the largest cell line selection and exclusive 3D organoid models. Benefit from OrganoidXplore™ and OmniScreen™ for rapid, in-depth analysis.

Learn More

In Vivo

Enhance drug development with our validated in vivo models, in vitro/ex vivo assays, and in silico modeling. Tailored solutions to optimize your candidates.

Learn More

Tissue

Experience ISO-certified biobanking quality. Access top biospecimens from a global clinical network, annotated by experts for precise research.

Learn More

Biomarkers and Bioanalysis

Leverage our global labs and 150+ scientists for fast, tailored project execution. Benefit from our expertise, cutting-edge tech, and validated workflows for reliable data outcomes.

Learn More

Data Science and Bioinformatics

Harness your data and discover biomarkers with our top bioinformatics expertise. Maximize data value and gain critical insights to accelerate drug discovery and elevate projects.

Learn More

KRAS

Accelerate innovative cancer treatments with our advanced models and precise drug screening for KRAS mutations, efficiently turning insights into clinical breakthroughs.

Learn More

EGFR

Advance translational pharmacology with our diverse pre-clinical models, robust assays, and data science-driven biomarker analysis, multi-omics, and spatial biology.

Learn More

Drug Resistance

Our suite integrates preclinical solutions, bioanalytical read-outs, and multi-omics to uncover drug resistance markers and expedite discovery with our unique four-step strategy.

Learn More

Patient Tissue

Enhance treatments with our human tumor and mouse models, including xenografts and organoids, for accurate cancer biology representation.

Learn More

Bioinformatics

Apply the most appropriate in silico framework to your pharmacology data or historical datasets to elevate your study design and analysis, and to improve your chances of clinical success.

Learn More

Biomarker Analysis

Integrate advanced statistics into your drug development projects to gain significant biological insight into your therapeutic candidate, with our expert team of bioinformaticians.

Learn More

CRISPR/Cas9

Accelerate your discoveries with our reliable CRISPR solutions. Our global CRISPR licenses cover an integrated drug discovery platform for in vitro and in vivo efficacy studies.

Learn More

Genomics

Rely on our experienced genomics services to deliver high quality, interpretable results using highly sensitive PCR-based, real-time PCR, and NGS technologies and advanced data analytics.

Learn More

In Vitro High Content Imaging

Gain more insights into tumor growth and disease progression by leveraging our 2D and 3D fluorescence optical imaging.

Learn More

Mass Spectrometry-based Proteomics

Next-generation ion mobility mass spectrometry (MS)-based proteomics services available globally to help meet your study needs.

Learn More

Ex Vivo Patient Tissue

Gain better insight into the phenotypic response of your therapeutic candidate in organoids and ex vivo patient tissue.

Learn More

Spatial Multi-Omics Analysis

Certified CRO services with NanoString GeoMx Digital Spatial Profiling.

Learn More

Biomarker Discovery

De-risk your drug development with early identification of candidate biomarkers and utilize our biomarker discovery services to optimize clinical trial design.

Learn More

DMPK Services

Rapidly evaluate your molecule’s pharmaceutical and safety properties with our in vivo drug metabolism and pharmacokinetic (DMPK) services to select the most robust drug formulations.

Learn More

Efficacy Testing

Explore how the novel HuGEMM™ and HuCELL™ platforms can assess the efficacy of your molecule and accelerate your immuno-oncology drug discovery programs.

Learn More

Laboratory Services

Employ cutting-edge multi-omics methods to obtain accurate and comprehensive data for optimal data-based decisions.

Learn More

Pharmacology & Bioanalytical Services

Leverage our suite of structural biology services including, recombinant protein expression and protein crystallography, and target validation services including RNAi.

Learn More

Screens

Find the most appropriate screen to accelerate your drug development: discover in vivo screens with MuScreen™ and in vitro cell line screening with OmniScreen™.

Learn More

Toxicology

Carry out safety pharmacology studies as standalone assessments or embedded within our overall toxicological profiling to assess cardiovascular, metabolic and renal/urinary systems.

Learn More

Our Company

Global CRO in California, USA offering preclinical and translational oncology platforms with high-quality in vivo, in vitro, and ex vivo models.

Learn More

Our Purpose

Learn more about the impact we make through our scientific talent, high-quality standards, and innovation.

Learn More

Our Responsibility

We build a sustainable future by supporting employee growth, fostering leadership, and exceeding customer needs. Our values focus on innovation, social responsibility, and community well-being.

Learn More

Meet Our Leadership Team

We build a sustainable future by fostering leadership, employee growth, and exceeding customer needs with innovation and social responsibility.

Learn More

Scientific Advisory Board

Our Scientific Advisory Board of experts shapes our strategy and ensures top scientific standards in research and development.

Learn More

News & Events

Stay updated with Crown Bioscience's latest news, achievements, and announcements. Check our schedule for upcoming events and plan your visit.

Learn More

Career Opportunities

Join us for a fast-paced career addressing life science needs with innovative technologies. Thrive in a respectful, growth-focused environment.

Learn More

Scientific Publications

Access our latest scientific research and peer-reviewed articles. Discover cutting-edge findings and insights driving innovation and excellence in bioscience.

Learn More

Resources

Discover valuable insights and curated materials to support your R&D efforts. Explore the latest trends, innovations, and expertly curated content in bioscience.

Learn More

Blogs

Explore our blogs for the latest insights, research breakthroughs, and industry trends. Stay educated with expert perspectives and in-depth articles driving innovation in bioscience.

Learn More

  • Platforms
  • Target Solutions
  • Technologies
  • Service Types

Humanized Mouse Models for Immunotherapy Research

hCD34+ HSC humanized mouse model immuno-oncology study design flowchart

hCD34+ HSC humanized mouse model immuno-oncology study design flowchart Humanized mouse models simulate real patient responses for the evaluation of immunotherapeutic drug candidates. This supports more translatable preclinical immuno-oncology research with deeper insight into an agent’s likely performance in clinical trials.

Here we review applications for hCD34+ hematopoietic stem cell (HSC)-engrafted humanized models, including recommendations on model selection, study design, timeline, and comments on common misconceptions.

Humanization: hCD34+ vs PBMC

Humanized mouse models are typically generated by one of two approaches:

  • Stable engraftment of hCD34+ hematopoietic stem cells from fetal cord blood, leading to a full spectrum of progenitor cell development.
  • Transient engraftment with adult peripheral blood mononuclear cells (PBMC) into immunodeficient animals.

The two approaches both have distinct advantages and disadvantages; this post will focus on the generation and use of the more complex hCD34+ HSC humanized models.

Murine Model Selection

There is not one single, perfect humanized model out there for preclinical research. Due to the complexity and variability of the human immune system, you need to select a model appropriate for your study objectives.

Depending on the immune populations of interest and the mechanism of the test article, you can select different models with appropriate immune cell properties. For instance, humanized NSG™ mice (huNSG, from The Jackson Laboratory) or humanized NOG® mice (huNOG, from Taconic) are common baseline transgenic strains for studying T cell response, given their dominating lymphoid lineages.

HuNSG-SGM3 and HuNOG-EXL are similar in their dominant lineages, but also present more abundant functional myeloid lineages.

More advanced models for immuno-oncology research are also now available. The Taconic hIL-6 NOG mouse displays higher macrophage and monocyte populations than the huNOG-EXL mouse, while hIL-15 NOG and hIL-2 NOG mice support NK cell reconstitution. These models are, however, relatively new and less characterized compared to the models above, so further validation and optimization before use may be required.

Selecting Models Based on Lymphoid and Myeloid Reconstitution

For huNSG and huNOG, the number of donors and animals needed per donor affects the lead time to obtain animals for study. Lead time can vary from two weeks (i.e. for three donors with 15 animals per donor), to months (i.e. more than five donors, 25 animals per donor). This timeline can also be prolonged if specific HLA types are needed.

B and T cell engraftment levels can be detected as early as six and 12 weeks post-engraftment and are typically checked around 15 to 17 weeks post-engraftment for huNSG and huNOG. Percentage population instead of absolute cell counts are typically assessed.

Percent hCD45 varies greatly, between 20-80%, and hCD3+ subpopulations vary between 10-50% for huNSG/huNOG. For huNSG-SGM3/huNOG-EXL, hCD33% ranges between 2 to 25% 15-17 weeks post-engraftment.

Animals with human T or myeloid cell populations closer to the median from a single donor are selected for study. It’s recommended to keep the average mean %hCD45 and %hCD3 similar across all donors in a single study. While this is an attempt to reduce variability, so far no data has demonstrated that variability in %hCD45 and %hCD3 has influenced either tumor growth or drug response.

Animals are typically implanted with tumors at approximately 18 weeks post-engraftment. The engraftment level in these models is typically sustained for up to 35 weeks post-engraftment.

Conventional Xenografts vs Patient-Derived Xenografts?

Traditional, cell line derived xenograft models are inherently less variable, and historically more characterized than patient-derived xenografts (PDX). However, large collections of well-characterized clinically-relevant PDX models offer disease indications which may not be available in conventional xenograft panels.

PDX databases collate model data, such as RNA sequencing, to provide transcription levels for a library of genes. These powerful tools allow identification of specific target antigens to screen for drug candidates and support the quick and easy choice of models of interest.

It’s important to keep in mind that growth validation may not have been done for all PDX models in a collection. In that case, it’s recommended to do a quick model validation before the humanized study, which could potentially add more overall time to a drug development program.

Common Humanized Model Misconceptions

Misconception: Humanized animals can be housed and handled like any immunodeficient animal.

Humanized animals are very fragile and require extra care compared to immunodeficient animals without any engraftment. Animals typically have ruffled, rough coats and may sometimes be hunched.

Specifically, huNSG-SGM3 and huNOG-EXL are much more fragile than huNSG or huNOG; therefore, it’s recommended to implant more mice prior to randomization (i.e. a higher overage). Typically, a 15% overage for each donor is recommended.

Misconception: Tumors do not spontaneously regress in humanized animals.

Occasionally, spontaneous tumor regression occurs in humanized models, probably due to graft versus tumor effect (GvT) where donor T cells attack the grafted PDX cells. The effect can be tumor-dependent, since animals engrafted with the same donor may vary in regression occurring.

This effect is probably not down to HLA-matching, as donor-to-PDX HLA-mismatching doesn’t show an impact on PDX growth or take rate. This is why having a sufficient amount of overage is important, especially if GvT has been seen previously in the same model you’re interested in.

Misconception: Human anti-PD1 or anti-PD-L1 serve as positive controls.

As the leading immunotherapies in the clinic, anti-PD-1 agents such as pembrolizumab (Keytruda®, Merck) or nivolumab, (Opidvo®, Brisol-Myer Squibbs) and anti-PD-L1 atezolizumab (Tecentriq® Roche/Genentech) are desirable drugs to combine with test articles for combination therapy.

However, you should not expect anti-PD-1/anti-PD-L1 to function as a positive control.

The efficacy of these drugs is highly dependent on donor-to-donor variability. Tumors that are PD-L1 positive are not guaranteed to respond to anti-PD-1 treatments.

A recent study compiled eight randomized controlled clinical trials in over 4,000 patients with five types of advanced or metastatic solid tumors. The results showed either anti-PD-1 or anti-PD-L1 monotherapy led to increased survival in patients that were PD-1 positive (34%) and PD-L1 negative (20%) compared to conventional therapies.

Other studies have also shown patients with low or no PD-L1 expression respond to anti-PD-1 therapy. This clearly shows anti-PD-1/anti-PD-L1 do not have a 100% response rate, and that while PD-L1 positive tumors are better responders, this alone is not an adequate biomarker in selecting patients for anti-PD-1/PD-L1 therapy.

Emerging studies have shown higher tumor mutational burden is correlated with greater response for anti-PD-1/PD-L1 therapies, and may be a good starting point to select models.

Misconception: Tumor growth inhibition is the only readout to assess test article efficacy.

Tumor microenvironment and tumor infiltrating lymphocytes (TIL) are important benchmarks in addition to efficacy, measured by tumor growth inhibition (TGI). It is worthwhile to anticipate multiple readouts for a more comprehensive evaluation on the pharmacodynamic properties of test articles.

Immune cell population and distribution can be examined by flow cytometry, immunohistochemistry, and cytokine production by flow, ELISA, or ELISPOT for more robust evaluation of drug properties. Baseline immunophenotypes for PDX tumor-bearing huNSG are often supplied using a 14-color TIL panel.

Summary

hCD34+ HSC humanized models are a useful tool in immunotherapy drug development. Through careful model selection and study design, they can provide a wealth of data on novel human agent efficacy and PD effects to progress immuno-oncology research programs.


Related Posts